文章
Dummer. ゛☀
2017年09月14日
A common pest found in greenhouses and indoor/ outdoor gardens, thrips damage plants by sucking their juices and scraping at fruits, flowers and leaves. Plant leaves may turn pale, splotchy, and silvery, then die. Injured plants are twisted, discolored and scarred.
Adults are very small (less than 1/25 inch) straw-colored or black slender insects with two pairs of feathery wings. Without the use of a hand lens, they resemble tiny dark threads.
Damage
Extremely active, thrips feed in large groups. They leap or fly away when disturbed. Host plants include onions, beans, carrots, squash and many other garden vegetables, and many flowers, especially gladioli and roses. Both adults and the wingless larvae are attracted to white, yellow and other light colored blossoms and are responsible for spreading tomato spotted wilt virus and impatiens necrotic spot virus.
Life Cycle
Adults and pupae overwinter in garden soil. In spring, newly emerged females insert eggs into the tissues of flowers, leaves or stems. (They do not need to mate for reproduction.) Each female can produce up to 80 eggs, which hatch within days in warm weather or weeks to months in colder weather. They become wingless larvae (nymphs), which feed on plant sap. After two or more nymphal stages, many thrips drop to the soil to pupate. Emerging adults fly to the plant and repeat the cycle. There may be 12-15 generations per year with the entire cycle from egg to adult requiring less than 16 days in warm weather.
Control
Thrip management is a matter of garden maintenance — reducing the places where thrips may breed — and requires removing plant debris while it’s still on the ground and green. Thrips lay their eggs in slits they cut in live plant stems. Vigilance — spotting problems early and responding to them — is also required. Check your plants for damage and clusters of the pests at the place where leaves are attached to stems. Don’t wait to take action. Take the measures listed below. And be sure to use the safest, most proven products.
To get rid of thrips remove weeds and grass from around garden areas to eliminate alternate hosts. Clean up crop debris in the garden, especially onion leaves after harvest. (Dry mulch will not attract thrips. Green mulch will.)
Inspect all plants you import into the garden for signs of thrips or their damage. Discard any infested plants by securely bagging and putting in the trash.
Blue sticky traps are helpful for monitoring adult populations.
If found, use the Bug Blaster to hose off plants with a strong, encompassing spray of water to reduce pest numbers.
Release commercially available beneficial insects, such as minute pirate bugs, the effective thrips predator (feeds on eggs and larvae before they can become adults), ladybugs, and lacewing, (especially effective in green houses) to attack and destroy all stages of this pest. For best results, make releases after first knocking down severe infestations with water spray or other method.
Severe populations may require a least-toxic, short-lived botanical insecticide (pyrethrin) to reduce pest numbers. Follow-up with predatory insects to maintain control.
Safe, smothering insecticidal soaps made from naturally occurring plant oils and fats, are also effective for knocking down heavy infestations (and won’t harm most naturally occurring beneficial insects). Spinosad and neem oil can be used to spot treat heavily infested areas.
Adults are very small (less than 1/25 inch) straw-colored or black slender insects with two pairs of feathery wings. Without the use of a hand lens, they resemble tiny dark threads.
Damage
Extremely active, thrips feed in large groups. They leap or fly away when disturbed. Host plants include onions, beans, carrots, squash and many other garden vegetables, and many flowers, especially gladioli and roses. Both adults and the wingless larvae are attracted to white, yellow and other light colored blossoms and are responsible for spreading tomato spotted wilt virus and impatiens necrotic spot virus.
Life Cycle
Adults and pupae overwinter in garden soil. In spring, newly emerged females insert eggs into the tissues of flowers, leaves or stems. (They do not need to mate for reproduction.) Each female can produce up to 80 eggs, which hatch within days in warm weather or weeks to months in colder weather. They become wingless larvae (nymphs), which feed on plant sap. After two or more nymphal stages, many thrips drop to the soil to pupate. Emerging adults fly to the plant and repeat the cycle. There may be 12-15 generations per year with the entire cycle from egg to adult requiring less than 16 days in warm weather.
Control
Thrip management is a matter of garden maintenance — reducing the places where thrips may breed — and requires removing plant debris while it’s still on the ground and green. Thrips lay their eggs in slits they cut in live plant stems. Vigilance — spotting problems early and responding to them — is also required. Check your plants for damage and clusters of the pests at the place where leaves are attached to stems. Don’t wait to take action. Take the measures listed below. And be sure to use the safest, most proven products.
To get rid of thrips remove weeds and grass from around garden areas to eliminate alternate hosts. Clean up crop debris in the garden, especially onion leaves after harvest. (Dry mulch will not attract thrips. Green mulch will.)
Inspect all plants you import into the garden for signs of thrips or their damage. Discard any infested plants by securely bagging and putting in the trash.
Blue sticky traps are helpful for monitoring adult populations.
If found, use the Bug Blaster to hose off plants with a strong, encompassing spray of water to reduce pest numbers.
Release commercially available beneficial insects, such as minute pirate bugs, the effective thrips predator (feeds on eggs and larvae before they can become adults), ladybugs, and lacewing, (especially effective in green houses) to attack and destroy all stages of this pest. For best results, make releases after first knocking down severe infestations with water spray or other method.
Severe populations may require a least-toxic, short-lived botanical insecticide (pyrethrin) to reduce pest numbers. Follow-up with predatory insects to maintain control.
Safe, smothering insecticidal soaps made from naturally occurring plant oils and fats, are also effective for knocking down heavy infestations (and won’t harm most naturally occurring beneficial insects). Spinosad and neem oil can be used to spot treat heavily infested areas.
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文章
Dummer. ゛☀
2017年09月14日
Many species of the spider mite (family: Tetranychidae), so common in North America, attack both indoor and outdoor plants. They can be especially destructive in greenhouses.
Spider mites are not true insects, but are classed as a type of arachnid, relatives of spiders, ticks and scorpions. Adults are reddish brown or pale in color, oval-shaped and very small (1/50 inch long) – about the size of the period at the end of this sentence. Immature stages resemble the adults except only smaller.
Mites live in colonies, mostly on the underside of leaves, and feed by piercing leaf tissue and sucking up the plant fluids. Feeding marks show up as light dots on the leaves. As feeding continues, the leaves turn yellow and may dry up and drop off.
Spider mites are most common in hot, dry conditions, especially where their natural enemies have been killed off by insecticide use. Some of the many species common in North America are predators of the plant-feeding mites, which make up the vast majority. They are also very prolific, which is why heavy infestations often build up unnoticed before plants begin to show damage.
Large populations are often accompanied by fine webbing. Host plants are many and include strawberries, melons, beans, tomatoes, eggplant, ornamental flowers, trees and most houseplants.
Life Cycle
Most mite species overwinter as eggs on the leaves and bark of host plants. In early spring, as temperatures warm, tiny six-legged larvae begin hatching and feed for a few days before seeking shelter where they molt into the first nymphal stage. Nymphs have eight-legs and pass through two more molts before becoming mature adults.
After mating, females continuously produce as many as 300 eggs over a couple of weeks. Hot, dry weather favors rapid development of these pests. During such conditions the time it takes to pass from egg to adult may occur in as little as 5 days. There are several overlapping generations per year.
Note: Spider mites are wind surfers. They disperse over wide areas riding their webbing on the breezes. Careful containment and disposal of infested plants is crucial.
Damage
Spider mites, almost too small to be seen, pass into our gardens without notice. No matter how few, each survives by sucking material from plant cells. Large infestations cause visible damage. Leaves first show patterns of tiny spots or stipplings. They may change color, curl and fall off. The mites activity is visible in the tight webs that are formed under leaves and along stems.
The University of California Agricultural and Natural Resources division’s Integrated Pest Management website says the following about the damage mites cause:
On annual vegetable crops — such as squash, melons and watermelons — loss of leaves can have a significant impact on yield and lead to sunburning.
On crops such as sugar peas and beans, where pods are attacked, spider mites can cause direct damage.
On ornamentals, mites are primarily an aesthetic concern, but they can kill plants if populations become very high on annual plants. Spider mites are also important pests of field-grown roses.
Control
Chemical pesticide use actually encourages the spread of spider mites by killing the beneficial insects that prey on them. Mites are also known to develop quick resistance to various pesticides. For these reasons, it’s important to control mites with effective natural and organic methods.
Prune leaves, stems and other infested parts of plants well past any webbing and discard in trash (and not in compost piles). Don’t be hesitant to pull entire plants to prevent the mites spreading to its neighbors.
Use the Bug Blaster to wash plants with a strong stream of water and reduce pest numbers.
Commercially available beneficial insects, such as ladybugs, lacewing and predatory mites are important natural enemies. For best results, make releases when pest levels are low to medium.
Nuke Em, a relatively new organic insecticide containing food-grade ingredients, works fast and kills most indoor gardening pests at the egg, larvae or adult stage. Best of all, it does this without leaving a residue on the leaves that can impact flavor.
If populations are high, use a least-toxic, short-lived pesticide (Take Down Spray, Doktor Doom Foggers) to reduce infestations, then release predatory mites to maintain control.
Insecticidal soap, neem oil or botanical insecticides can be used to spot treat heavily infested areas.
On fruit trees, horticultural oil should be applied early in the season or late in the fall to destroy overwintering eggs.
Dust on leaves, branches and fruit encourages mites. A mid-season hosing (or two!) to remove dust from trees is a worthwhile preventative.
Water stress makes both trees and garden plants more susceptible to mite infestations. Make sure your plants are properly watered.
Spider mites are not true insects, but are classed as a type of arachnid, relatives of spiders, ticks and scorpions. Adults are reddish brown or pale in color, oval-shaped and very small (1/50 inch long) – about the size of the period at the end of this sentence. Immature stages resemble the adults except only smaller.
Mites live in colonies, mostly on the underside of leaves, and feed by piercing leaf tissue and sucking up the plant fluids. Feeding marks show up as light dots on the leaves. As feeding continues, the leaves turn yellow and may dry up and drop off.
Spider mites are most common in hot, dry conditions, especially where their natural enemies have been killed off by insecticide use. Some of the many species common in North America are predators of the plant-feeding mites, which make up the vast majority. They are also very prolific, which is why heavy infestations often build up unnoticed before plants begin to show damage.
Large populations are often accompanied by fine webbing. Host plants are many and include strawberries, melons, beans, tomatoes, eggplant, ornamental flowers, trees and most houseplants.
Life Cycle
Most mite species overwinter as eggs on the leaves and bark of host plants. In early spring, as temperatures warm, tiny six-legged larvae begin hatching and feed for a few days before seeking shelter where they molt into the first nymphal stage. Nymphs have eight-legs and pass through two more molts before becoming mature adults.
After mating, females continuously produce as many as 300 eggs over a couple of weeks. Hot, dry weather favors rapid development of these pests. During such conditions the time it takes to pass from egg to adult may occur in as little as 5 days. There are several overlapping generations per year.
Note: Spider mites are wind surfers. They disperse over wide areas riding their webbing on the breezes. Careful containment and disposal of infested plants is crucial.
Damage
Spider mites, almost too small to be seen, pass into our gardens without notice. No matter how few, each survives by sucking material from plant cells. Large infestations cause visible damage. Leaves first show patterns of tiny spots or stipplings. They may change color, curl and fall off. The mites activity is visible in the tight webs that are formed under leaves and along stems.
The University of California Agricultural and Natural Resources division’s Integrated Pest Management website says the following about the damage mites cause:
On annual vegetable crops — such as squash, melons and watermelons — loss of leaves can have a significant impact on yield and lead to sunburning.
On crops such as sugar peas and beans, where pods are attacked, spider mites can cause direct damage.
On ornamentals, mites are primarily an aesthetic concern, but they can kill plants if populations become very high on annual plants. Spider mites are also important pests of field-grown roses.
Control
Chemical pesticide use actually encourages the spread of spider mites by killing the beneficial insects that prey on them. Mites are also known to develop quick resistance to various pesticides. For these reasons, it’s important to control mites with effective natural and organic methods.
Prune leaves, stems and other infested parts of plants well past any webbing and discard in trash (and not in compost piles). Don’t be hesitant to pull entire plants to prevent the mites spreading to its neighbors.
Use the Bug Blaster to wash plants with a strong stream of water and reduce pest numbers.
Commercially available beneficial insects, such as ladybugs, lacewing and predatory mites are important natural enemies. For best results, make releases when pest levels are low to medium.
Nuke Em, a relatively new organic insecticide containing food-grade ingredients, works fast and kills most indoor gardening pests at the egg, larvae or adult stage. Best of all, it does this without leaving a residue on the leaves that can impact flavor.
If populations are high, use a least-toxic, short-lived pesticide (Take Down Spray, Doktor Doom Foggers) to reduce infestations, then release predatory mites to maintain control.
Insecticidal soap, neem oil or botanical insecticides can be used to spot treat heavily infested areas.
On fruit trees, horticultural oil should be applied early in the season or late in the fall to destroy overwintering eggs.
Dust on leaves, branches and fruit encourages mites. A mid-season hosing (or two!) to remove dust from trees is a worthwhile preventative.
Water stress makes both trees and garden plants more susceptible to mite infestations. Make sure your plants are properly watered.
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文章
Dummer. ゛☀
2017年09月14日
Sometimes called jumping plant lice, psyllids feed on a variety of plants including most fruit trees and small fruits as well as tomato and potato. Both adults and nymphs feed by piercing the leaf surface and extracting cell sap. This causes foliage (especially the upper leaves) to turn yellow, curl and eventually die. Honeydew secreted by the psyllids encourages the growth of dark sooty molds. Many species transmit disease-carrying viruses.
Adults (1/10 inch long) are reddish brown in color with transparent wings and strong jumping legs. They are very active and will hop or fly away when disturbed. Nymphs are flat and elliptical in shape, almost scale-like. They are less active than adults and are most numerous on the undersides of leaves. Newly hatched nymphs are yellowish in color but turn green as they mature.
Note: Psyllids are monophagous which means that they are host specific (each species feeds on only one plant type).
Life Cycle
Adults overwinter in crevices on tree trunks. In early spring they mate and females begin depositing orange-yellow eggs in the crevices about the buds, and after the foliage is out, on the leaves. Hatching occurs in 4-15 days. Yellow to green nymphs pass through five in instars in 2-3 weeks before reaching the adult stage. There are one to five generations per year depending on species.
Psyllid Control
To get rid of psyllids spray horticultural oil in early spring to destroy overwintering adults and eggs.
Beneficial insects, such as ladybugs and lacewing, are important natural predators of this pest. For best results, make releases when pest levels are low to medium.
If populations are high, use a least-toxic, short-lived natural pesticide to establish control, then release predatory insects to maintain control.
Diatomaceous earth contains no toxic poisons and works quickly on contact. Dust lightly and evenly over vegetable crops wherever adults are found.
Safer® Insecticidal Soap will work fast on heavy infestations. A short-lived natural pesticide, it works by damaging the outer layer of soft-bodied insect pests, causing dehydration and death within hours. Apply 2.5 oz/ gallon of water when insects are present, repeat every 7-10 day as needed.
Surround WP (kaolin clay) forms a protective barrier film, which acts as a broad spectrum crop protectant for preventing damage from insect pests.
70% Neem Oil is approved for organic use and can be sprayed on vegetables, fruit trees and flowers to kill eggs, larvae and adult insects. Mix 1 oz/ gallon of water and spray all leaf surfaces (including the undersides of leaves) until completely wet.
If pest levels become intolerable, spot treat with insecticides approved for organic use every 5-7 days. Thorough coverage of both upper and lower infested leaves is necessary for effective control.
Adults (1/10 inch long) are reddish brown in color with transparent wings and strong jumping legs. They are very active and will hop or fly away when disturbed. Nymphs are flat and elliptical in shape, almost scale-like. They are less active than adults and are most numerous on the undersides of leaves. Newly hatched nymphs are yellowish in color but turn green as they mature.
Note: Psyllids are monophagous which means that they are host specific (each species feeds on only one plant type).
Life Cycle
Adults overwinter in crevices on tree trunks. In early spring they mate and females begin depositing orange-yellow eggs in the crevices about the buds, and after the foliage is out, on the leaves. Hatching occurs in 4-15 days. Yellow to green nymphs pass through five in instars in 2-3 weeks before reaching the adult stage. There are one to five generations per year depending on species.
Psyllid Control
To get rid of psyllids spray horticultural oil in early spring to destroy overwintering adults and eggs.
Beneficial insects, such as ladybugs and lacewing, are important natural predators of this pest. For best results, make releases when pest levels are low to medium.
If populations are high, use a least-toxic, short-lived natural pesticide to establish control, then release predatory insects to maintain control.
Diatomaceous earth contains no toxic poisons and works quickly on contact. Dust lightly and evenly over vegetable crops wherever adults are found.
Safer® Insecticidal Soap will work fast on heavy infestations. A short-lived natural pesticide, it works by damaging the outer layer of soft-bodied insect pests, causing dehydration and death within hours. Apply 2.5 oz/ gallon of water when insects are present, repeat every 7-10 day as needed.
Surround WP (kaolin clay) forms a protective barrier film, which acts as a broad spectrum crop protectant for preventing damage from insect pests.
70% Neem Oil is approved for organic use and can be sprayed on vegetables, fruit trees and flowers to kill eggs, larvae and adult insects. Mix 1 oz/ gallon of water and spray all leaf surfaces (including the undersides of leaves) until completely wet.
If pest levels become intolerable, spot treat with insecticides approved for organic use every 5-7 days. Thorough coverage of both upper and lower infested leaves is necessary for effective control.
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文章
Dummer. ゛☀
2017年09月14日
Found in greenhouses, home gardens and landscaped areas across the country, leafminers are the larval (maggot) stage of an insect family that feeds between the upper and lower surfaces of leaves. On heavily infested plants it is not uncommon to find 6 or more maggots per leaf. Although damage can restrict plant growth, resulting in reduced yields and loss of vigor, healthy plants can tolerate considerable injury. Host plants include beans, blackberries, cabbage, lettuce, peppers, and a variety of ornamental flowers, trees and shrubs.
Adults (1/10 inch long) are often black to gray flies with yellow stripes and clear wings. They are similar in appearance to small, hunched-back house flies and lay their eggs on the undersides of leaves. Larvae are worm-like maggots (1/3 inch) which are often pale yellow or green in color. They create winding tunnels that are clear, except for the trail of black fecal material (frass) left behind as they feed.
Note: In some cases, pathogenic fungi and bacteria may enter old mines left from eradicated insects. This can cause leaves to turn yellow and drop.
Life Cycle
Mature larvae overwinter in the soil under host plants. As temperatures warm in the spring larvae pass to the pupal stage and appear as young adults in late April. Mated females use their needle-like ovipositor to lay up to 250 eggs just under the surface of the leaf epidermis. Deposited eggs may appear as small raised spots on the leaf. Within 10 days hatching larvae tunnel through the mid-leaf tissue, feeding as they go and leaving tell-tale wavy lines that are visible on the surface. Larvae mature in 2-3 weeks, and when ready to pupate, leave the leaf and drop to the soil. Once on the ground, they dig 1-2 inches into the soil and pupate. Adults emerge within 15 days as adult flies. There are several generations per year.
Damage
Various types of leafminers attack various kinds of plants. They’re found on broadleaf trees, including elm, aspen, hawthorn, and poplar as well as shrubs and bushes, including lilacs. Damage can be limited in initial stages of infestations but increase as leafminer numbers multiply, and even minor infestations, while not killing a plant, will cripple its hardiness. Leafminers are a major cause of poor harvest numbers in home gardens as they weaken individual vegetable plants. They’re especially fond of spinach leaves and their tunneling severely decreases the attractiveness and value of the crop.
Leafminer Control
Natural, and organic control methods work best when fighting leafminer problems. That’s because they don’t harm the naturally occurring beneficial insect populations that largely keep the leafminer and other harmful pests under control. While pesticide use can encourage leafminer outbreaks, natural controls and beneficial insects prevent as well as cure these pest problems. Don’t wait until you spot leafminer tunnels in your plants’ leaves, especially if you’ve had problems with them in the past. Be prepared with the products you’ll need to prevent and destroy infestations. Then stay vigilant.
Monitor plant leaves closely. At the first sign of tunneling, squeeze the leaf at the tunnel between two fingers to crush any larvae. Done soon enough, this killing larvae can allow plants to survive minor outbreaks. Pick off and destroy badly infested leaves in small gardens.
The more healthy the plant, the less chance that leafminers will hurt it. Maintain plant health with organic fertilizers and proper watering to allow plants to outgrow and tolerate pest damage. Keep your soil alive by using compost and other soil amendments.
Use floating row covers (Harvest-Guard) to prevent fly stage from laying eggs on leaves.
The parasitic wasp Diglyphus isaea is a commercially available beneficial insect that will kill leafminer larva in the mine. The wasp is especially beneficial to indoor growers of ornamentals and vegetables.
Use yellow or blue sticky traps to catch egg laying adults. Cover soil under infested plants with plastic mulches to prevent larvae from reaching the ground and pupating.
Azatrol EC contains azadirachtin, the key insecticidal ingredient found in neem oil. This concentrated spray disrupts growth and development of pest insects and has repellent and anti-feedant properties. Best of all, it’s non-toxic to honey bees and many other beneficial insects.
Fast-acting botanical insecticides should be used as a last resort. Derived from plants which have insecticidal properties, these natural pesticides have fewer harmful side effects than synthetic chemicals and break down more quickly in the environment.
Adults (1/10 inch long) are often black to gray flies with yellow stripes and clear wings. They are similar in appearance to small, hunched-back house flies and lay their eggs on the undersides of leaves. Larvae are worm-like maggots (1/3 inch) which are often pale yellow or green in color. They create winding tunnels that are clear, except for the trail of black fecal material (frass) left behind as they feed.
Note: In some cases, pathogenic fungi and bacteria may enter old mines left from eradicated insects. This can cause leaves to turn yellow and drop.
Life Cycle
Mature larvae overwinter in the soil under host plants. As temperatures warm in the spring larvae pass to the pupal stage and appear as young adults in late April. Mated females use their needle-like ovipositor to lay up to 250 eggs just under the surface of the leaf epidermis. Deposited eggs may appear as small raised spots on the leaf. Within 10 days hatching larvae tunnel through the mid-leaf tissue, feeding as they go and leaving tell-tale wavy lines that are visible on the surface. Larvae mature in 2-3 weeks, and when ready to pupate, leave the leaf and drop to the soil. Once on the ground, they dig 1-2 inches into the soil and pupate. Adults emerge within 15 days as adult flies. There are several generations per year.
Damage
Various types of leafminers attack various kinds of plants. They’re found on broadleaf trees, including elm, aspen, hawthorn, and poplar as well as shrubs and bushes, including lilacs. Damage can be limited in initial stages of infestations but increase as leafminer numbers multiply, and even minor infestations, while not killing a plant, will cripple its hardiness. Leafminers are a major cause of poor harvest numbers in home gardens as they weaken individual vegetable plants. They’re especially fond of spinach leaves and their tunneling severely decreases the attractiveness and value of the crop.
Leafminer Control
Natural, and organic control methods work best when fighting leafminer problems. That’s because they don’t harm the naturally occurring beneficial insect populations that largely keep the leafminer and other harmful pests under control. While pesticide use can encourage leafminer outbreaks, natural controls and beneficial insects prevent as well as cure these pest problems. Don’t wait until you spot leafminer tunnels in your plants’ leaves, especially if you’ve had problems with them in the past. Be prepared with the products you’ll need to prevent and destroy infestations. Then stay vigilant.
Monitor plant leaves closely. At the first sign of tunneling, squeeze the leaf at the tunnel between two fingers to crush any larvae. Done soon enough, this killing larvae can allow plants to survive minor outbreaks. Pick off and destroy badly infested leaves in small gardens.
The more healthy the plant, the less chance that leafminers will hurt it. Maintain plant health with organic fertilizers and proper watering to allow plants to outgrow and tolerate pest damage. Keep your soil alive by using compost and other soil amendments.
Use floating row covers (Harvest-Guard) to prevent fly stage from laying eggs on leaves.
The parasitic wasp Diglyphus isaea is a commercially available beneficial insect that will kill leafminer larva in the mine. The wasp is especially beneficial to indoor growers of ornamentals and vegetables.
Use yellow or blue sticky traps to catch egg laying adults. Cover soil under infested plants with plastic mulches to prevent larvae from reaching the ground and pupating.
Azatrol EC contains azadirachtin, the key insecticidal ingredient found in neem oil. This concentrated spray disrupts growth and development of pest insects and has repellent and anti-feedant properties. Best of all, it’s non-toxic to honey bees and many other beneficial insects.
Fast-acting botanical insecticides should be used as a last resort. Derived from plants which have insecticidal properties, these natural pesticides have fewer harmful side effects than synthetic chemicals and break down more quickly in the environment.
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文章
Dummer. ゛☀
2017年09月14日
Look for
Seedlings germinate and begin to grow well until whole trays rapidly collapse and die. Damping off can also cause trays of seeds to fail to germinate.
Plants affected
Young seedlings of annual bedding and vegetables are the most commonly affected, but damping off can be a problem on a wide range of plants.
About
Damping off is caused by a variety of different soil borne fungi including Pythium, Rhizoctonia and Phytophthora.
Once plants have been affected, Botrytis (Grey mould) often also attacks.
Plants are more likely to succumb if they are under stress.
Stress can be caused by high temperature, high humidity and waterlogging.
Treatment
Good hygiene is important in combating damping off. Wash and disinfect pots and trays after use and use fresh compost.
Dispose of pots, trays and compost where damping off has been a problem.
High humidity around plants can increase the likelihood of damping off. Keep greenhouses well ventilated and sow seeds thinly to avoid overcrowding.
The fungi can infect plants through their water. Make sure all rainwater-butts have sealed lids to prevent leaves and debris entering them and introducing fungi to the water.
Seedlings germinate and begin to grow well until whole trays rapidly collapse and die. Damping off can also cause trays of seeds to fail to germinate.
Plants affected
Young seedlings of annual bedding and vegetables are the most commonly affected, but damping off can be a problem on a wide range of plants.
About
Damping off is caused by a variety of different soil borne fungi including Pythium, Rhizoctonia and Phytophthora.
Once plants have been affected, Botrytis (Grey mould) often also attacks.
Plants are more likely to succumb if they are under stress.
Stress can be caused by high temperature, high humidity and waterlogging.
Treatment
Good hygiene is important in combating damping off. Wash and disinfect pots and trays after use and use fresh compost.
Dispose of pots, trays and compost where damping off has been a problem.
High humidity around plants can increase the likelihood of damping off. Keep greenhouses well ventilated and sow seeds thinly to avoid overcrowding.
The fungi can infect plants through their water. Make sure all rainwater-butts have sealed lids to prevent leaves and debris entering them and introducing fungi to the water.
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文章
Dummer. ゛☀
2017年09月14日
Grasshoppers are voracious feeders, consuming approximately one-half of their body weight per day. Both adults and nymphs cause damage by chewing on the leaves and stems of plants, and if infestations are severe, may defoliate entire fields. It is estimated that grasshoppers consume up to 25 percent of the available forage in the western United States annually.
Adults (1-2 inch long) are brown to reddish yellow or green in color with prominent jaws, fully developed wings and short antennae. They have enlarged hind legs and can jump great distances. Immature stages — nymphs — are similar in appearance to adults, but are smaller and have wing buds instead of wings.
Note: Ten adults per square yard are economically damaging to rangeland, according to the USDA. Smaller numbers can damage cropland or gardens, depending on crop type and age. A classic study showed that 6-7 adults per square yard on 10 acres of pasture ate as much as a cow.
Life Cycle
The injurious species of grasshoppers are all alike in their cycle of development. Eggs are deposited in late summer in elongated masses or pods inserted in the soil. These pass through the winter, and on hatching in the spring, the young seek food in the immediate area. As they increase in size and food becomes scarce, migration to other food sources takes place. After molting 5 or 6 times, during a period of 40-60 days, the adults appear and continue feeding until cold weather kills them. One generation per year in most areas.
Control
Roto-till or cultivate crops in the spring to destroy overwintering eggs.
Harvest-Guard row covers can be used to cover and protect small garden areas.
For long-term grasshopper protection, apply organic Semaspore Bait (Nosema locustae) to hatching beds – field margins and other undisturbed grassy areas – when grasshoppers are young. Heavy infestations may require multiple applications.
Azamax contains azadirachtin, the key insecticidal ingredient found in neem oil. This concentrated spray is approved for organic use and offers multiple modes of action, making it virtually impossible for pest resistance to develop. Best of all, it’s non-toxic to honey bees and many other beneficial insects.
Spread EcoBran Bait or apply botanical insecticides, such as organic pyrethrins, to areas where you are experiencing heavy grasshopper damage and require a quick-kill.
Read our pamphlet on How to Control Grasshoppers with Modern Baits here.
Tip: Mow a “clean” strip between grassy fields and your garden area to help slow grasshopper migration. Pests are reluctant to enter the strip because it has no food, and they are very exposed to predators. A wider strip is better, especially if the adjacent area is large.
Adults (1-2 inch long) are brown to reddish yellow or green in color with prominent jaws, fully developed wings and short antennae. They have enlarged hind legs and can jump great distances. Immature stages — nymphs — are similar in appearance to adults, but are smaller and have wing buds instead of wings.
Note: Ten adults per square yard are economically damaging to rangeland, according to the USDA. Smaller numbers can damage cropland or gardens, depending on crop type and age. A classic study showed that 6-7 adults per square yard on 10 acres of pasture ate as much as a cow.
Life Cycle
The injurious species of grasshoppers are all alike in their cycle of development. Eggs are deposited in late summer in elongated masses or pods inserted in the soil. These pass through the winter, and on hatching in the spring, the young seek food in the immediate area. As they increase in size and food becomes scarce, migration to other food sources takes place. After molting 5 or 6 times, during a period of 40-60 days, the adults appear and continue feeding until cold weather kills them. One generation per year in most areas.
Control
Roto-till or cultivate crops in the spring to destroy overwintering eggs.
Harvest-Guard row covers can be used to cover and protect small garden areas.
For long-term grasshopper protection, apply organic Semaspore Bait (Nosema locustae) to hatching beds – field margins and other undisturbed grassy areas – when grasshoppers are young. Heavy infestations may require multiple applications.
Azamax contains azadirachtin, the key insecticidal ingredient found in neem oil. This concentrated spray is approved for organic use and offers multiple modes of action, making it virtually impossible for pest resistance to develop. Best of all, it’s non-toxic to honey bees and many other beneficial insects.
Spread EcoBran Bait or apply botanical insecticides, such as organic pyrethrins, to areas where you are experiencing heavy grasshopper damage and require a quick-kill.
Read our pamphlet on How to Control Grasshoppers with Modern Baits here.
Tip: Mow a “clean” strip between grassy fields and your garden area to help slow grasshopper migration. Pests are reluctant to enter the strip because it has no food, and they are very exposed to predators. A wider strip is better, especially if the adjacent area is large.
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Dummer. ゛☀
2017年09月14日
Many species of flea beetles are found throughout the United States. They are small jumping insects (similar in appearance to fleas) commonly found in home gardens early in the growing season. A voracious pest, they will damage plants by chewing numerous small holes in the leaves, which make them look as if they have been peppered by fine buckshot. When populations are high, flea beetles can quickly defoliate and kill entire plants. They feed most on hot sunny days and attack a wide variety of plants including beans, cabbage, corn, eggplant, potatoes, peppers, tomatoes, lettuce and most seedlings.
Adults are small (1/10 inch long), shiny, dark brown or black beetles with large hind legs that allow them to jump when disturbed. Some species may have white or yellow stripes on their wing cases. Larvae are small, cream-colored worms (1/8 – 1/3 inch long). They live underground and feed on the roots and tubers of young plants as well as on germinating seeds.
Note: Flea beetles transmit viral and bacterial diseases.
Life Cycle
Adults overwinter in the soil or garden debris and become active in the spring, feeding on host plants as new growth appears. Tiny white eggs are laid on or in soil cracks around the base of plants. These hatch in about one week, and the slender white larvae feed on plant roots for approximately 2-3 weeks. Pupae usually remain in the soil for 7-9 days until adults emerge and the cycle is completed. There are one to four generations per year, depending on species and climate.
Flea Beetle Control
Remove garden trash and plow or roto-till under weeds to reduce overwintering sites.
Floating row covers are extremely effective when placed on seedlings and left in place until plants are old enough to tolerate beetle damage.
Place yellow sticky traps throughout garden rows every 15 to 30 feet to capture adults.
Beneficial nematodes applied to the soil will destroy the larval stage, reducing root feeding and helping to prevent the next generation of adults from emerging.
Apply food-grade Diatomaceous Earth for long-lasting protection. Made up of tiny fossilized aquatic organisms, that look like broken glass under the microscope, DE kills by scoring an insect’s outer layer as it crawls over the fine powder. Contains NO toxic poisons!
Surround WP (kaolin clay) forms a protective barrier film, which acts as a broad spectrum crop protectant for preventing damage from insect pests.
Azatrol EC contains azadirachtin, the key insecticidal ingredient found in neem oil. This concentrated product is approved for organic use and offers multiple modes of action, making it virtually impossible for insect resistance to develop. Best of all, it’s non-toxic to honey bees and many other beneficial insects.
Least-toxic botanical insecticides should be used as a last resort. Derived from plants which have insecticidal properties, these natural pesticides have fewer harmful side effects than synthetic chemicals and break down more quickly in the environment.
Adults are small (1/10 inch long), shiny, dark brown or black beetles with large hind legs that allow them to jump when disturbed. Some species may have white or yellow stripes on their wing cases. Larvae are small, cream-colored worms (1/8 – 1/3 inch long). They live underground and feed on the roots and tubers of young plants as well as on germinating seeds.
Note: Flea beetles transmit viral and bacterial diseases.
Life Cycle
Adults overwinter in the soil or garden debris and become active in the spring, feeding on host plants as new growth appears. Tiny white eggs are laid on or in soil cracks around the base of plants. These hatch in about one week, and the slender white larvae feed on plant roots for approximately 2-3 weeks. Pupae usually remain in the soil for 7-9 days until adults emerge and the cycle is completed. There are one to four generations per year, depending on species and climate.
Flea Beetle Control
Remove garden trash and plow or roto-till under weeds to reduce overwintering sites.
Floating row covers are extremely effective when placed on seedlings and left in place until plants are old enough to tolerate beetle damage.
Place yellow sticky traps throughout garden rows every 15 to 30 feet to capture adults.
Beneficial nematodes applied to the soil will destroy the larval stage, reducing root feeding and helping to prevent the next generation of adults from emerging.
Apply food-grade Diatomaceous Earth for long-lasting protection. Made up of tiny fossilized aquatic organisms, that look like broken glass under the microscope, DE kills by scoring an insect’s outer layer as it crawls over the fine powder. Contains NO toxic poisons!
Surround WP (kaolin clay) forms a protective barrier film, which acts as a broad spectrum crop protectant for preventing damage from insect pests.
Azatrol EC contains azadirachtin, the key insecticidal ingredient found in neem oil. This concentrated product is approved for organic use and offers multiple modes of action, making it virtually impossible for insect resistance to develop. Best of all, it’s non-toxic to honey bees and many other beneficial insects.
Least-toxic botanical insecticides should be used as a last resort. Derived from plants which have insecticidal properties, these natural pesticides have fewer harmful side effects than synthetic chemicals and break down more quickly in the environment.
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Dummer. ゛☀
2017年09月14日
A major pest of corn, the European corn borer (Ostrinia nubilalis) will also feed on over 300 different garden plants including peppers, snap beans, potatoes, tomatoes, apples and gladiolus. Damage to corn is caused by the young larvae which chew leaves and tassels. Later they tunnel all parts of the stalks and ears, resulting in reduced plant vigor, broken stalks, poor ear development and dropped ears. Other crops are damaged primarily by the tunneling of the stalks, pods or stems by the larvae.
Fully grown corn borer larvae (3/4 – 1 inch long) are extremely destructive flesh-colored caterpillars with a reddish or dark brown head and several distinct spots on the top of each abdominal ring or segment. The adult borer is a night-flying yellowish-brown colored moth (1 inch wingspan) with dark wavy bands across its wings.
Note : The European corn borer most likely arrived in the United States during the early 1900’s in imported corn which was used to make brooms.
Life Cycle
Fully grown larvae pass the winter concealed in corn stubble or other plant parts on which they have been feeding. Pupation takes place in late spring with the adult moths appearing in May and June. When mature, the females begin laying clumps of white eggs on the undersides of the lower leaves of host plants. (Adult females may lay up to 500 eggs over their short lifetime.) Under ideal conditions, these first generation eggs hatch within 3-7 days. Tiny caterpillars begin feeding on host plants and complete their development in 3-4 weeks. Pupation occurs deep inside the corn stalks and second generation moths emerge and begin laying eggs in early summer. Produces 1-3 generations per year depending upon the climate.
Note: Second generation borers are considered to be the most damaging to corn.
Corn Borer Control
Shred and plow under cornstalks in or near fields where borers overwinter. This should be done in fall or early spring before the adults emerge.
Use pheromone traps to determine main flight period for moths, then release trichogramma wasps to destroy eggs.
Beneficial insects, such as ladybugs and lacewing larvae, will consume a large number of borer eggs.
Treat silk frequently with Garden Dust (Bt-kurstaki) or Monterey Garden Insect Spray (spinosad) to kill young larvae. Repeat applications every 4-5 days until tassels turn brown.
Use organic insecticides only as a last resort.
Note: Ladybugs will consume almost 60 borer eggs a day. Stink bugs, damsel bugs, spiders and hover fly larvae feed on young caterpillars.
Fully grown corn borer larvae (3/4 – 1 inch long) are extremely destructive flesh-colored caterpillars with a reddish or dark brown head and several distinct spots on the top of each abdominal ring or segment. The adult borer is a night-flying yellowish-brown colored moth (1 inch wingspan) with dark wavy bands across its wings.
Note : The European corn borer most likely arrived in the United States during the early 1900’s in imported corn which was used to make brooms.
Life Cycle
Fully grown larvae pass the winter concealed in corn stubble or other plant parts on which they have been feeding. Pupation takes place in late spring with the adult moths appearing in May and June. When mature, the females begin laying clumps of white eggs on the undersides of the lower leaves of host plants. (Adult females may lay up to 500 eggs over their short lifetime.) Under ideal conditions, these first generation eggs hatch within 3-7 days. Tiny caterpillars begin feeding on host plants and complete their development in 3-4 weeks. Pupation occurs deep inside the corn stalks and second generation moths emerge and begin laying eggs in early summer. Produces 1-3 generations per year depending upon the climate.
Note: Second generation borers are considered to be the most damaging to corn.
Corn Borer Control
Shred and plow under cornstalks in or near fields where borers overwinter. This should be done in fall or early spring before the adults emerge.
Use pheromone traps to determine main flight period for moths, then release trichogramma wasps to destroy eggs.
Beneficial insects, such as ladybugs and lacewing larvae, will consume a large number of borer eggs.
Treat silk frequently with Garden Dust (Bt-kurstaki) or Monterey Garden Insect Spray (spinosad) to kill young larvae. Repeat applications every 4-5 days until tassels turn brown.
Use organic insecticides only as a last resort.
Note: Ladybugs will consume almost 60 borer eggs a day. Stink bugs, damsel bugs, spiders and hover fly larvae feed on young caterpillars.
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文章
Dummer. ゛☀
2017年09月14日
Many species of cutworms from the night-flying moth family Noctuidae are found in home gardens across the United States. The larvae commonly feed on plant stems at or below ground, eventually cutting them down. Cutworms attack a wide variety of plants including beets, cabbage, broccoli, kale and cauliflower.
Cutworm caterpillars (larvae) are stout, soft-bodied, gray or dull brown caterpillars (1-2 inch long) that curl up when at rest or disturbed. They feed at night and burrow into the soil during the day. Adults are dark gray or brown, night-flying moths (1-1/2 inch wingspan) with ragged blotches or stripes on their wings. They do not damage plants.
Note: Pest populations vary greatly from year to year. When numerous, cutworms can destroy up to 75% of a crop.
Life Cycle
Most species pass the winter in soil or under garden waste as young larvae. In the spring, as temperatures warm, they become active and begin feeding on plants at night remaining hidden during the day. The larvae molt several times and when fully grown pupate in the soil (late spring). Within one week moths emerge and begin laying hundreds of eggs mostly on stems and leaves. One to five generations per year, depending upon the species.
Note: Overwintering larvae and the first generation in the spring are the most damaging. A few species pass the winter as pupae or hibernating moths.
Damage
Damage occurs at night when caterpillars feed by clipping off seedling stems and young plants near or just below the soil surface. Often, an entire row of newly planted garden vegetables will be cut off during the night.
Different cutworm species will climb plants doing damage to foliage, buds and shoots. Cutworms are also known to gouge potato tubers. Late season cutworms will tunnel in fruit.
Cut worms, like their close cousins armyworms, will also frequently attack turf grass. The damage they inflict on grass — cutting off blades at the crown — is usually more dispersed than damage from army worms. Cutworms favor golf courses where they cause “ballmark” pockets of dead and missing turf both on fairways and putting greens.
Cutworm Control
Losing precious transplants once to cutworms is all most people require to implement preventive measures as part of an Integrated Pest Management plan. There’s little more heart-breaking than coming out to the garden one morning to find the seedlings you started months ago indoors have been severed at the root.
Tempted to spray chemicals after losing young plants to the slow-moving eating machines? Despite the fact that it will endanger your pets, your children and the environment, pesticide use against cutworm, reports Michigan State University Extension, is “often unsuccessful.”
Preventive Measures
Before planting a new garden remove weeds and plant debris that might feed and shelter developing larvae.
Turn the soil after fall clean up then give birds and other predators a chance to pick off the expose larvae and pupae.
Mow as closely as possible to the edge of your garden to give cutworms less to feed on and less shelter near your plants.
A three-foot wide (or more) bare-soil strip between your lawn and your garden plants makes it harder for larvae to reach your plants. It also gives you more of a chance to spot them.
Wait as late as possible before setting out starts. Cutworms go on the move early in the growing season. Give them a chance to starve before you put out dinner.
Place cardboard collars (or milk containers with the bottom cut out) around transplant stems at planting time. Be sure to work the collar into the soil at least an inch or two.
Plant sunflowers along the edge of your garden. Sunflowers are a favorite target of cutworms. The plants will attract the larvae giving you a chance to pick them from the ground before they head to your corn.
Dealing with Infestations
The presence of many birds feeding in the yard may indicate cutworms in your turf.
Handpick caterpillars after dark. This is often most productive following a rain or thorough watering.
Slow the progress of worms, who don’t like navigating dry soil, by watering in the morning then cultivating your garden’s walkways lightly to a depth of an inch or so. This cultivated soil will dry quickly while trapping moisture beneath it. Do not use mulch which gives the worms shelter.
Beneficial nematodes released in moist, spring soil will attack and destroy cutworms living underground. They’re especially beneficial to apply the season after cutworms have been a problem.
At the first sign of moths, release trichogramma wasps weekly for three consecutive weeks to parasitize cutworm eggs.
Spreading a line of diatomaceous earth around the base of plants sets up a barrier to larvae. Diatomaceous earth, the fossilized, abrasive remains of prehistoric sea life, literally lets you draw a line in the dirt that’s deadly to any larvae that pass over.
Scatter bran or corn meal mixed with Monterey Bt (Bt-kurstaki) and molasses on the soil surface to attract and kill caterpillars. Eco-Bran will also kill caterpillars that feed on it.
Cutworm caterpillars (larvae) are stout, soft-bodied, gray or dull brown caterpillars (1-2 inch long) that curl up when at rest or disturbed. They feed at night and burrow into the soil during the day. Adults are dark gray or brown, night-flying moths (1-1/2 inch wingspan) with ragged blotches or stripes on their wings. They do not damage plants.
Note: Pest populations vary greatly from year to year. When numerous, cutworms can destroy up to 75% of a crop.
Life Cycle
Most species pass the winter in soil or under garden waste as young larvae. In the spring, as temperatures warm, they become active and begin feeding on plants at night remaining hidden during the day. The larvae molt several times and when fully grown pupate in the soil (late spring). Within one week moths emerge and begin laying hundreds of eggs mostly on stems and leaves. One to five generations per year, depending upon the species.
Note: Overwintering larvae and the first generation in the spring are the most damaging. A few species pass the winter as pupae or hibernating moths.
Damage
Damage occurs at night when caterpillars feed by clipping off seedling stems and young plants near or just below the soil surface. Often, an entire row of newly planted garden vegetables will be cut off during the night.
Different cutworm species will climb plants doing damage to foliage, buds and shoots. Cutworms are also known to gouge potato tubers. Late season cutworms will tunnel in fruit.
Cut worms, like their close cousins armyworms, will also frequently attack turf grass. The damage they inflict on grass — cutting off blades at the crown — is usually more dispersed than damage from army worms. Cutworms favor golf courses where they cause “ballmark” pockets of dead and missing turf both on fairways and putting greens.
Cutworm Control
Losing precious transplants once to cutworms is all most people require to implement preventive measures as part of an Integrated Pest Management plan. There’s little more heart-breaking than coming out to the garden one morning to find the seedlings you started months ago indoors have been severed at the root.
Tempted to spray chemicals after losing young plants to the slow-moving eating machines? Despite the fact that it will endanger your pets, your children and the environment, pesticide use against cutworm, reports Michigan State University Extension, is “often unsuccessful.”
Preventive Measures
Before planting a new garden remove weeds and plant debris that might feed and shelter developing larvae.
Turn the soil after fall clean up then give birds and other predators a chance to pick off the expose larvae and pupae.
Mow as closely as possible to the edge of your garden to give cutworms less to feed on and less shelter near your plants.
A three-foot wide (or more) bare-soil strip between your lawn and your garden plants makes it harder for larvae to reach your plants. It also gives you more of a chance to spot them.
Wait as late as possible before setting out starts. Cutworms go on the move early in the growing season. Give them a chance to starve before you put out dinner.
Place cardboard collars (or milk containers with the bottom cut out) around transplant stems at planting time. Be sure to work the collar into the soil at least an inch or two.
Plant sunflowers along the edge of your garden. Sunflowers are a favorite target of cutworms. The plants will attract the larvae giving you a chance to pick them from the ground before they head to your corn.
Dealing with Infestations
The presence of many birds feeding in the yard may indicate cutworms in your turf.
Handpick caterpillars after dark. This is often most productive following a rain or thorough watering.
Slow the progress of worms, who don’t like navigating dry soil, by watering in the morning then cultivating your garden’s walkways lightly to a depth of an inch or so. This cultivated soil will dry quickly while trapping moisture beneath it. Do not use mulch which gives the worms shelter.
Beneficial nematodes released in moist, spring soil will attack and destroy cutworms living underground. They’re especially beneficial to apply the season after cutworms have been a problem.
At the first sign of moths, release trichogramma wasps weekly for three consecutive weeks to parasitize cutworm eggs.
Spreading a line of diatomaceous earth around the base of plants sets up a barrier to larvae. Diatomaceous earth, the fossilized, abrasive remains of prehistoric sea life, literally lets you draw a line in the dirt that’s deadly to any larvae that pass over.
Scatter bran or corn meal mixed with Monterey Bt (Bt-kurstaki) and molasses on the soil surface to attract and kill caterpillars. Eco-Bran will also kill caterpillars that feed on it.
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文章
Dummer. ゛☀
2017年09月14日
A pest throughout most of the United States, black vine weevils (Otiorhynchus sulcatus) attack over 100 different kinds of ornamental plants including rhododendrons, azaleas, yews and hemlocks. When weevils enter greenhouses or indoor gardens they are damaging to begonias, ferns and other common container plants. They are particularly damaging to cyclamens and are often called the “cyclamen grub.”
Adult black vine weevils (3/4 inch long) are large slate-gray to black insects that cannot fly. They have short, broad snouts, bent or “elbowed” antennae and patches of short hairs on their wings. Adults feed at night, damaging plants as they chew small notches in the edges of leaves. During the day, they hide in soil cracks, garden debris and mulch.
Larvae cause the greatest level of injury to plants. They are small (1/2 inch long), white, C-shaped grubs that tunnel through roots as they feed. Leaves will often wilt (even when properly watered) and plants may be stunted or die. Larvae may also girdle the main stem just below the soil line.
Life Cycle
Black vine weevils overwinter as nearly grown larvae in the soil around the roots of host plants. In spring they change to pupae and begin emerging as adults. In two or more weeks (depending on temperature) they begin depositing eggs near the crowns of the host plants. Hatching occurs in about 10 days, and the tiny larvae burrow into the soil and begin feeding. One generation per year.
Vine Weevil Control
Remove mulch and other hiding places from around plants and water only when necessary (larvae and adults prefer moist soil).
As non-flying insects, weevils travel from plant to plant by walking. It stands to reason then, that Tanglefoot Sticky Barrier should form the first line of defense.
Apply food-grade Diatomaceous Earth for long-lasting pest protection. Made up of tiny fossilized aquatic organisms, DE kills by scoring an insect’s outer layer as it crawls over the fine powder. Contains NO toxic poisons!
Immature stages of the black vine weevil are particularly vulnerable to attack by beneficial nematodes, especially in potted plants.
Fast-acting crack and crevice sprays, like Don’t Bug Me, can be used around windows, doors and vents to prevent adult weevils from entering structures.
Least-toxic botanical insecticides should be used as a last resort. Derived from plants which have insecticidal properties, these natural pesticides have fewer harmful side effects than synthetic chemicals and break down more quickly in the environment.
Tip: Place burlap fabric at the bases of trees and shrubs to trap weevils that hide under it during the day.
Adult black vine weevils (3/4 inch long) are large slate-gray to black insects that cannot fly. They have short, broad snouts, bent or “elbowed” antennae and patches of short hairs on their wings. Adults feed at night, damaging plants as they chew small notches in the edges of leaves. During the day, they hide in soil cracks, garden debris and mulch.
Larvae cause the greatest level of injury to plants. They are small (1/2 inch long), white, C-shaped grubs that tunnel through roots as they feed. Leaves will often wilt (even when properly watered) and plants may be stunted or die. Larvae may also girdle the main stem just below the soil line.
Life Cycle
Black vine weevils overwinter as nearly grown larvae in the soil around the roots of host plants. In spring they change to pupae and begin emerging as adults. In two or more weeks (depending on temperature) they begin depositing eggs near the crowns of the host plants. Hatching occurs in about 10 days, and the tiny larvae burrow into the soil and begin feeding. One generation per year.
Vine Weevil Control
Remove mulch and other hiding places from around plants and water only when necessary (larvae and adults prefer moist soil).
As non-flying insects, weevils travel from plant to plant by walking. It stands to reason then, that Tanglefoot Sticky Barrier should form the first line of defense.
Apply food-grade Diatomaceous Earth for long-lasting pest protection. Made up of tiny fossilized aquatic organisms, DE kills by scoring an insect’s outer layer as it crawls over the fine powder. Contains NO toxic poisons!
Immature stages of the black vine weevil are particularly vulnerable to attack by beneficial nematodes, especially in potted plants.
Fast-acting crack and crevice sprays, like Don’t Bug Me, can be used around windows, doors and vents to prevent adult weevils from entering structures.
Least-toxic botanical insecticides should be used as a last resort. Derived from plants which have insecticidal properties, these natural pesticides have fewer harmful side effects than synthetic chemicals and break down more quickly in the environment.
Tip: Place burlap fabric at the bases of trees and shrubs to trap weevils that hide under it during the day.
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文章
Dummer. ゛☀
2017年09月14日
There are approximately 4,000 aphid species found throughout the world. Low to moderate numbers are usually not harmful to plants and rarely require aphid control. However, heavy infestations will cause leaves to curl, wilt or yellow and stunted plant growth. A general decline in overall plant vigor will also be noticed. Several species can transmit plant diseases, particularly viruses which they pass on during feeding.
Aphids are small (1/8 inch long), soft bodied, pear-shaped insects that may be green, yellow, brown, red or black in color depending on species and food source. Generally adults are wingless, but some can grow wings, especially if populations are high. They have two whip-like antennae at the tip of the head and a pair of tube-like structures, called cornicles, projecting backward out of their hind end.
Note: As they feed, aphids secrete large amounts of a sticky fluid known as honeydew. This sweet goo drips onto plants, attracting ants and promoting a black sooty mold growth on leaves. Cars and lawn furniture that are under infested trees will also be covered with this sticky fluid.
Life Cycle
In spring wingless female aphids hatch from overwintering eggs and soon give birth to many nymphs (males are not present). Young nymphs increase gradually in size and within a week give birth to many more nymphs. This process is repeated several times and results in huge population explosions. As the colony grows, a few of the females develop wings and fly off to other host plants to start new colonies. In late summer and early fall sexual forms (males and females) develop which mate and lay overwintering eggs. There are many overlapping generations per year.
Note: Most aphids, except for the sexual forms, do not have to mate in order to reproduce, and they produce live young, rather than eggs.
Control
Pinch or prune off heavily infested leaves or other plant parts.
Use the Bug Blaster to hose off plants with a strong stream of water and reduce pest numbers.
Commercially available beneficial insects, such as ladybugs and lacewing are important natural predators. For best results, make releases when pest levels are low to medium. If populations are high, use a least-toxic, short-lived natural pesticide to establish control, then release predatory insects to maintain control.
Apply food-grade Diatomaceous Earth for long-lasting protection. Made up of tiny fossilized aquatic organisms, that look like broken glass under the microscope, DE kills by scoring an insect’s outer layer as it crawls over the fine powder. Contains NO toxic poisons!
Safer® Soap will work fast on heavy infestations. A short-lived natural pesticide, it works by damaging the outer layer of soft-bodied insect pests, causing dehydration and death within hours. Apply 2.5 oz/ gallon of water when insects are present, repeat every 7-10 day as needed.
Horticultural oils should be applied early in the season or late in the fall to destroy overwintering eggs.
Fast-acting botanical insecticides should be used as a last resort. Derived from plants which have insecticidal properties, these natural pesticides have fewer harmful side effects than synthetic chemicals and break down more quickly in the environment.
Do not over water or over fertilize – aphids like plants with high nitrogen levels and soft new growth. Use organic fertilizers which release nutrients slowly.
Tip: Ants feed on the honeydew that sucking insects produce and will protect these pests from their natural enemies. An application of Tanglefoot Pest Barrier to the stalks of roses and other woody plants will help keep ants away.
Aphids are small (1/8 inch long), soft bodied, pear-shaped insects that may be green, yellow, brown, red or black in color depending on species and food source. Generally adults are wingless, but some can grow wings, especially if populations are high. They have two whip-like antennae at the tip of the head and a pair of tube-like structures, called cornicles, projecting backward out of their hind end.
Note: As they feed, aphids secrete large amounts of a sticky fluid known as honeydew. This sweet goo drips onto plants, attracting ants and promoting a black sooty mold growth on leaves. Cars and lawn furniture that are under infested trees will also be covered with this sticky fluid.
Life Cycle
In spring wingless female aphids hatch from overwintering eggs and soon give birth to many nymphs (males are not present). Young nymphs increase gradually in size and within a week give birth to many more nymphs. This process is repeated several times and results in huge population explosions. As the colony grows, a few of the females develop wings and fly off to other host plants to start new colonies. In late summer and early fall sexual forms (males and females) develop which mate and lay overwintering eggs. There are many overlapping generations per year.
Note: Most aphids, except for the sexual forms, do not have to mate in order to reproduce, and they produce live young, rather than eggs.
Control
Pinch or prune off heavily infested leaves or other plant parts.
Use the Bug Blaster to hose off plants with a strong stream of water and reduce pest numbers.
Commercially available beneficial insects, such as ladybugs and lacewing are important natural predators. For best results, make releases when pest levels are low to medium. If populations are high, use a least-toxic, short-lived natural pesticide to establish control, then release predatory insects to maintain control.
Apply food-grade Diatomaceous Earth for long-lasting protection. Made up of tiny fossilized aquatic organisms, that look like broken glass under the microscope, DE kills by scoring an insect’s outer layer as it crawls over the fine powder. Contains NO toxic poisons!
Safer® Soap will work fast on heavy infestations. A short-lived natural pesticide, it works by damaging the outer layer of soft-bodied insect pests, causing dehydration and death within hours. Apply 2.5 oz/ gallon of water when insects are present, repeat every 7-10 day as needed.
Horticultural oils should be applied early in the season or late in the fall to destroy overwintering eggs.
Fast-acting botanical insecticides should be used as a last resort. Derived from plants which have insecticidal properties, these natural pesticides have fewer harmful side effects than synthetic chemicals and break down more quickly in the environment.
Do not over water or over fertilize – aphids like plants with high nitrogen levels and soft new growth. Use organic fertilizers which release nutrients slowly.
Tip: Ants feed on the honeydew that sucking insects produce and will protect these pests from their natural enemies. An application of Tanglefoot Pest Barrier to the stalks of roses and other woody plants will help keep ants away.
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文章
Dummer. ゛☀
2017年09月14日
Parasitic nematodes seek out insects harmful to garden plants, shrubs and trees in their soil-borne stages and destroy them from the inside out. Present in soils throughout the world, these microscopic, non-segmented worms destroy over 200 types of insects that mature in the ground including weevils, Japanese beetles, fleas, borers and fungus gnats, before they reach adult stages.
Shop our large selection of biological controls, including beneficial nematodes, at Planet Natural. One pint — 10 million active units — treats up to 550 square feet and costs $29.95 with FedEx 2-Day shipping included!
When released into the soil, nematodes seek out the larvae and pupae of susceptible pests by sensing the heat and carbon dioxide they generate. They enter pests through various orifices or directly through the “skin.” Once inside the host, they release a bacterium that kills it within a day or two. They will continue to feed on the remains, multiplying as they do, before exhausting it and leaving to seek another food source.
Nematodes do not prey on lady bugs, earthworms or most other beneficial insects. They are harmless to plants and humans as is the bacterium they produce. Evidence of the nematodes effectiveness, other than reduced pest populations, is difficult to spot as these microscopic creatures consume their hosts in the soil, leaving little trace behind. They’re appropriate for use on lawns, in gardens and around trees and shrubs. They need generally moist condition to facilitate their movement.
HOW TO RELEASE:
Simply scatter over the infested area, then water. Optimally, nematodes should be applied at sunset to protect them against sunlight.
To control boring insects, prepare a water suspension, then inject or spray the solution into the burrows.
Repeat weekly for a minimum of three weeks.
Note: Scanmask®, a product based on a selected strain of Steinernema feltiae, will provide insect control in an area from 250 to 550 square feet. This refers to the area actually at risk or already infested by insects. Since infestations are rarely uniform, nematodes should be used as a “directed control measure” on areas already or at risk of being infested.
Shop our large selection of biological controls, including beneficial nematodes, at Planet Natural. One pint — 10 million active units — treats up to 550 square feet and costs $29.95 with FedEx 2-Day shipping included!
When released into the soil, nematodes seek out the larvae and pupae of susceptible pests by sensing the heat and carbon dioxide they generate. They enter pests through various orifices or directly through the “skin.” Once inside the host, they release a bacterium that kills it within a day or two. They will continue to feed on the remains, multiplying as they do, before exhausting it and leaving to seek another food source.
Nematodes do not prey on lady bugs, earthworms or most other beneficial insects. They are harmless to plants and humans as is the bacterium they produce. Evidence of the nematodes effectiveness, other than reduced pest populations, is difficult to spot as these microscopic creatures consume their hosts in the soil, leaving little trace behind. They’re appropriate for use on lawns, in gardens and around trees and shrubs. They need generally moist condition to facilitate their movement.
HOW TO RELEASE:
Simply scatter over the infested area, then water. Optimally, nematodes should be applied at sunset to protect them against sunlight.
To control boring insects, prepare a water suspension, then inject or spray the solution into the burrows.
Repeat weekly for a minimum of three weeks.
Note: Scanmask®, a product based on a selected strain of Steinernema feltiae, will provide insect control in an area from 250 to 550 square feet. This refers to the area actually at risk or already infested by insects. Since infestations are rarely uniform, nematodes should be used as a “directed control measure” on areas already or at risk of being infested.
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文章
Dummer. ゛☀
2017年09月14日
Effective biological control for aphids! This tiny parasitic wasp (Aphidius colemani ) hones in on its prey by sensing the distress signals of infested plants as well as detecting the aphid’s honeydew secretions. Once there, it injects an egg into the aphid. When the egg hatches, the larvae begin to consume the pest from inside. The resulting wasp then emerges from the rear of the dead aphid to seek out other prey. Surviving aphids react by emitting an “alarm” pheromone which causes the colony to flee, often falling to the ground where they die.
Shop our large selection of beneficial insects, including aphid parasites, at Planet Natural. One bottle — 1,000 parasitic wasps — treats up to 7,000 square feet and costs $94.95 with UPS Express shipping included!
Appropriate for garden and greenhouse use, aphid parasites can be used both as a preventive measure and to combat infestations. Adult wasps live two to three weeks and will lay eggs in as many as 300 aphids over the period of their lives, increasing the numbers of wasps as they do. Proof they’re at work can be found by searching for the brown, mummified shells left of dead aphids.
HOW TO RELEASE:
Spread the material evenly over soil or rockwool slabs.
Efficacy is reduced at high temperatures, greater than 80˚F.
Repeat weekly for 2-3 weeks, as needed.
Shop our large selection of beneficial insects, including aphid parasites, at Planet Natural. One bottle — 1,000 parasitic wasps — treats up to 7,000 square feet and costs $94.95 with UPS Express shipping included!
Appropriate for garden and greenhouse use, aphid parasites can be used both as a preventive measure and to combat infestations. Adult wasps live two to three weeks and will lay eggs in as many as 300 aphids over the period of their lives, increasing the numbers of wasps as they do. Proof they’re at work can be found by searching for the brown, mummified shells left of dead aphids.
HOW TO RELEASE:
Spread the material evenly over soil or rockwool slabs.
Efficacy is reduced at high temperatures, greater than 80˚F.
Repeat weekly for 2-3 weeks, as needed.
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文章
Dummer. ゛☀
2017年09月14日
Downy Mildew on Impatiens
There's been an increase in downy mildew affecting Impatiens plants recently. The particular mildew affecting impatiens is Plasmopara abducens. It spreads rapidly, under the right conditions, and once infected, there is no cure. However, there are some preventative measures you can take. But first, here's some background to help you understand the disease.
What is Downy Mildew?
Downy mildew diseases are caused by oomycetes or water molds. They are fungus-like, but more closely related to algae.
There are 2 types of downy mildew spores. One type, zoospores, can be splashed up by water or spread by the wind. The other type, oospores, reside inside the plant tissue and can spread rapidly and over-winter. At this point, there is no evidence that this particular mildew affecting impatiens is doing that, but why take chances.
Downy mildew is more prevalent in the spring and fall when the cool, wet or humid weather provides ideal conditions.
Which Impatiens Varieties are Affected?
According to an e-Grow Alert by Nora Catlin, Floriculture Specialist, Cornell Cooperative Extension of Suffolk County, the following types of Impatiens are susceptible to downy mildew.
All Impatiens waller IANA, including the double and mini types. These are the most common bedding impatiens sold in garden centers. (I. waller IANA hybrids, like the Fusion® series, are less prone, but still susceptible)
Balsam Impatiens / Garden Balsam (I. balsam in a) These are taller plants than common Impatiens, with elongated, pointed leaves.
Jewel Weed (I. capers is) and Yellow Jewel Weed (I. pallidum). Generally considered weeds, but if they are in the area, they can spread the disease to your landscape Impatiens.
Impatiens Not Affected
Himalayan balsam / policeman’s helmet (Impatiens glanduliferous), a wild and sometimes invasive species that can reach heights of 6 - 10 ft. (2 - 3 m), is tolerant of the disease but can act as a host.
New Guinea impatiens (Impatiens hawkers) and its hybrids, like SunPatiens®, have so far shown resistance.
There may be more plants affected or that act as hosts, but this is the information so far.
Symptoms of Downy Mildew on Impatiens
Early symptoms can be hard to spot and might be mistaken for a nutrient problem.
Leaves stippled or chlorotic (yellowing) and looking like they need fertilizer.
Floppy or downward curling leaves.
Sometimes white fuzzy spots will form on the undersides of the leaves. These are spores and usually appear in cool, damp weather. (See photo on page 2.)
As the disease progresses the plants may stop growing and look stunted, drop their leaves or completely collapse.
What to Do about Downy Mildew on Impatiens
Although there is no cure for Impatiens already infected with downy mildew, there are some steps you can take keep it from spreading.
Prevention
Avoiding downy mildew entirely can be very difficult, because so much is weather dependent. High humidity and cool, damp weather cannot always be avoided. But there are a few growing conditions you can provide, so as not to make matters worse.
Provide good air circulation. Don't overcrowd your plants.
Water from below, trying not to wet the leaves when watering and water early in the day.
Remove any suspect plants immediately.
Cultural management is your best bet. Once a plant is infected, there is no cure. If you want to try controlling the spread of the disease with a preventative fungicide, neem and copper sprays are recommended for homeowners.
Will it Over-Winter and Re-infect Plants?
So far, there is no sign that it infects seed, although other mildews do - so there is a chance. Some mildews can also over-winter in plant tissues. Although that does not seem to be happening with this downy mildew, don't take a chance by composting affected plants.
If downy mildew becomes a major problem in your garden, you should consider not planting them for a year or two. Shade plant alternatives to impatiens include New Guinea impatiens, begonias, and coleus.
Additional resources:
Downy Mildew of Impatiens – Some (But Not All) Questions Answered
Cornell Cooperative Extension of Suffolk County
There's been an increase in downy mildew affecting Impatiens plants recently. The particular mildew affecting impatiens is Plasmopara abducens. It spreads rapidly, under the right conditions, and once infected, there is no cure. However, there are some preventative measures you can take. But first, here's some background to help you understand the disease.
What is Downy Mildew?
Downy mildew diseases are caused by oomycetes or water molds. They are fungus-like, but more closely related to algae.
There are 2 types of downy mildew spores. One type, zoospores, can be splashed up by water or spread by the wind. The other type, oospores, reside inside the plant tissue and can spread rapidly and over-winter. At this point, there is no evidence that this particular mildew affecting impatiens is doing that, but why take chances.
Downy mildew is more prevalent in the spring and fall when the cool, wet or humid weather provides ideal conditions.
Which Impatiens Varieties are Affected?
According to an e-Grow Alert by Nora Catlin, Floriculture Specialist, Cornell Cooperative Extension of Suffolk County, the following types of Impatiens are susceptible to downy mildew.
All Impatiens waller IANA, including the double and mini types. These are the most common bedding impatiens sold in garden centers. (I. waller IANA hybrids, like the Fusion® series, are less prone, but still susceptible)
Balsam Impatiens / Garden Balsam (I. balsam in a) These are taller plants than common Impatiens, with elongated, pointed leaves.
Jewel Weed (I. capers is) and Yellow Jewel Weed (I. pallidum). Generally considered weeds, but if they are in the area, they can spread the disease to your landscape Impatiens.
Impatiens Not Affected
Himalayan balsam / policeman’s helmet (Impatiens glanduliferous), a wild and sometimes invasive species that can reach heights of 6 - 10 ft. (2 - 3 m), is tolerant of the disease but can act as a host.
New Guinea impatiens (Impatiens hawkers) and its hybrids, like SunPatiens®, have so far shown resistance.
There may be more plants affected or that act as hosts, but this is the information so far.
Symptoms of Downy Mildew on Impatiens
Early symptoms can be hard to spot and might be mistaken for a nutrient problem.
Leaves stippled or chlorotic (yellowing) and looking like they need fertilizer.
Floppy or downward curling leaves.
Sometimes white fuzzy spots will form on the undersides of the leaves. These are spores and usually appear in cool, damp weather. (See photo on page 2.)
As the disease progresses the plants may stop growing and look stunted, drop their leaves or completely collapse.
What to Do about Downy Mildew on Impatiens
Although there is no cure for Impatiens already infected with downy mildew, there are some steps you can take keep it from spreading.
Prevention
Avoiding downy mildew entirely can be very difficult, because so much is weather dependent. High humidity and cool, damp weather cannot always be avoided. But there are a few growing conditions you can provide, so as not to make matters worse.
Provide good air circulation. Don't overcrowd your plants.
Water from below, trying not to wet the leaves when watering and water early in the day.
Remove any suspect plants immediately.
Cultural management is your best bet. Once a plant is infected, there is no cure. If you want to try controlling the spread of the disease with a preventative fungicide, neem and copper sprays are recommended for homeowners.
Will it Over-Winter and Re-infect Plants?
So far, there is no sign that it infects seed, although other mildews do - so there is a chance. Some mildews can also over-winter in plant tissues. Although that does not seem to be happening with this downy mildew, don't take a chance by composting affected plants.
If downy mildew becomes a major problem in your garden, you should consider not planting them for a year or two. Shade plant alternatives to impatiens include New Guinea impatiens, begonias, and coleus.
Additional resources:
Downy Mildew of Impatiens – Some (But Not All) Questions Answered
Cornell Cooperative Extension of Suffolk County
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文章
Dummer. ゛☀
2017年09月14日
Botrytis blight is a cruel disease for flower gardeners, because it frequently strikes garden plants in their prime, destroying blossoms just as they are ready to open. Botrytis, also called grey mold, is a fungal disease, and gardeners can recognize it when they see these symptoms in plants:
Spotting or discoloration on leaves
Wilting or decaying leaves and shoots
Leaf drop
Fuzzy grayish brown growth on flowers and foliage
Flower buds that fail to open
Rotting flower buds
Damping off disease of seedlings
Botrytis thrives in high humidity and cool weather, so gardeners will see signs of grey mold most often on spring flowers.
Flowers Affected by Botrytis
In the outdoor flower garden, marigolds, impatiens, peonies and roses are the most likely plants to show signs of botrytis. In the greenhouse, several flowers are susceptible to this fungus, especially cyclamen, geraniums, and poinsettia. Seedlings that often succumb to damping off disease caused by botrytis fungi include pansies, petunias, and snapdragons.
Organic Sprays for Botrytis
Sulfur powders and sprays are effective at controlling fungal diseases like botrytis in the flower garden. Apply sprays early in the morning or evening to avoid harming bees or beneficial insects.
A less common, but very effective organic treatment against foliage diseases in the flower garden is the bacterium Bacillus subtilis, sold under the trade name Serenade.
Many gardeners report that the fragrance of this spray is less offensive compared to other organic or conventional fungicide sprays.
Cultural Control of Botrytis
When you notice the first signs of botrytis in the flower garden, get out the clippers. Remove all affected foliage and flowers, and destroy the plant matter.
Sanitize clippers with an alcohol wipe after pruning diseased plants to prevent spreading the fungi to healthy plants. It’s also important to keep the ground around plants free of decaying leaves, which act like a nursery for fungal spores.
Although you can’t do anything about humid conditions in your area, you can help plants cope with excessive moisture. Use drip irrigation, which delivers water to the root zone where it's needed and keeps leaves dry. Avoid overhead watering, which can splash disease-carrying soil onto leaves. Water in the morning to allow the sun's rays to quickly evaporate any moisture on leaves. Follow proper plant spacing guidelines, to enhance air circulation. Prune the interior of dense plants to increase air movement that carries away disease spores.
Greenhouse Botrytis Management
The principles of botrytis management in the greenhouse are similar to those in the garden, but greenhouse gardeners can control the greenhouse environment more than the outdoors. Use fans of adequate size and number for the greenhouse size. You should aim for a relative humidity below 80%, and completely changing the air three one to three times an hour should help to achieve this.
Your greenhouse retailer can help you calculate fans needed according to the cubic feet of your greenhouse.
Raise the temperature of the greenhouse at sunset to dry condensation on leaves. This is especially important in the winter.
Isolate plants showing signs of botrytis from the greenhouse population. Destroy the plants on inexpensive specimens that you can easily replace; this prevents widespread, more costly outbreaks.
Conventional Control of Botrytis
Severe botrytis outbreaks may require fungicide applications to achieve control of the disease. Botrytis can become resistant to chemicals, so switching it up occasionally may achieve better control. Gardeners should look for fungicides that contain one of these active ingredients:
Chlorothalonil
Fenhexamid
Fludioxonil
Myclobutanil
Botrytis Resistant Flowers to Grow
Unfortunately, horticulturists haven’t developed any completely botrytis-resistant flower species.
'Fantasy Blue' petunias and 'Tidal Wave Pink' petunias are two varieties that are more resistant to flower blight than older petunia varieties. Peony lovers may have more luck with tree peonies and intersectional hybrids than with P. lactiflora garden peonies. Gardeners must continue to battle this tenacious fungal flower disease by practicing good garden and greenhouse hygiene and cultural practices.
Spotting or discoloration on leaves
Wilting or decaying leaves and shoots
Leaf drop
Fuzzy grayish brown growth on flowers and foliage
Flower buds that fail to open
Rotting flower buds
Damping off disease of seedlings
Botrytis thrives in high humidity and cool weather, so gardeners will see signs of grey mold most often on spring flowers.
Flowers Affected by Botrytis
In the outdoor flower garden, marigolds, impatiens, peonies and roses are the most likely plants to show signs of botrytis. In the greenhouse, several flowers are susceptible to this fungus, especially cyclamen, geraniums, and poinsettia. Seedlings that often succumb to damping off disease caused by botrytis fungi include pansies, petunias, and snapdragons.
Organic Sprays for Botrytis
Sulfur powders and sprays are effective at controlling fungal diseases like botrytis in the flower garden. Apply sprays early in the morning or evening to avoid harming bees or beneficial insects.
A less common, but very effective organic treatment against foliage diseases in the flower garden is the bacterium Bacillus subtilis, sold under the trade name Serenade.
Many gardeners report that the fragrance of this spray is less offensive compared to other organic or conventional fungicide sprays.
Cultural Control of Botrytis
When you notice the first signs of botrytis in the flower garden, get out the clippers. Remove all affected foliage and flowers, and destroy the plant matter.
Sanitize clippers with an alcohol wipe after pruning diseased plants to prevent spreading the fungi to healthy plants. It’s also important to keep the ground around plants free of decaying leaves, which act like a nursery for fungal spores.
Although you can’t do anything about humid conditions in your area, you can help plants cope with excessive moisture. Use drip irrigation, which delivers water to the root zone where it's needed and keeps leaves dry. Avoid overhead watering, which can splash disease-carrying soil onto leaves. Water in the morning to allow the sun's rays to quickly evaporate any moisture on leaves. Follow proper plant spacing guidelines, to enhance air circulation. Prune the interior of dense plants to increase air movement that carries away disease spores.
Greenhouse Botrytis Management
The principles of botrytis management in the greenhouse are similar to those in the garden, but greenhouse gardeners can control the greenhouse environment more than the outdoors. Use fans of adequate size and number for the greenhouse size. You should aim for a relative humidity below 80%, and completely changing the air three one to three times an hour should help to achieve this.
Your greenhouse retailer can help you calculate fans needed according to the cubic feet of your greenhouse.
Raise the temperature of the greenhouse at sunset to dry condensation on leaves. This is especially important in the winter.
Isolate plants showing signs of botrytis from the greenhouse population. Destroy the plants on inexpensive specimens that you can easily replace; this prevents widespread, more costly outbreaks.
Conventional Control of Botrytis
Severe botrytis outbreaks may require fungicide applications to achieve control of the disease. Botrytis can become resistant to chemicals, so switching it up occasionally may achieve better control. Gardeners should look for fungicides that contain one of these active ingredients:
Chlorothalonil
Fenhexamid
Fludioxonil
Myclobutanil
Botrytis Resistant Flowers to Grow
Unfortunately, horticulturists haven’t developed any completely botrytis-resistant flower species.
'Fantasy Blue' petunias and 'Tidal Wave Pink' petunias are two varieties that are more resistant to flower blight than older petunia varieties. Peony lovers may have more luck with tree peonies and intersectional hybrids than with P. lactiflora garden peonies. Gardeners must continue to battle this tenacious fungal flower disease by practicing good garden and greenhouse hygiene and cultural practices.
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