文章
Dummer. ゛☀
2017年09月17日
Scale insects are small, piercing-sucking insects that often go unnoticed on indoor plants. The adult forms can be attached to leaves, petioles, and stems. They suck plant juices and can cause plants to lose vigor.
Symptoms and Diagnosis
Since the insects are often overlooked, the first signs may be yellowing or wilting leaves that may eventually drop. Leaves may also be covered with a clear sticky substance called honeydew. Honeydew is the insects’ excrement consisting of partially digested sap and may coat the floor and other objects beneath the plant as it spatters down from above. A sticky floor beneath a susceptible plant is a telltale sign that infestation is underway. Under humid conditions, a black mold, called sooty mold, may grow on the honeydew making the leaves look dirty. Closer inspection will reveal small cottony or dome-shaped shells attached to stems and leaves. When pried off with a knifepoint, they may be hollow underneath or house adults and/or eggs. Scale can be differentiated from parts of the plant by scraping. If the structure is green when scraped or cannot be pried off, it is more than likely part of the plant.
Life Cycle
Scale insects have a simple life cycle of egg, nymph (crawler), and adult. Indoors, eggs can be laid any time under the protective shell. The eggs hatch and the crawlers seek out new feeding sites. This crawler stage is when scale is easiest to control. When the crawlers settle, they insert their mouth parts into the plant and begin feeding on the plant's sap. The protective shell develops soon after feeding begins and the insect loses use of its legs. Indoor scales can go through many generations a year.
Integrated Pest Management Strategies
1. Remove insects by hand. If caught early, scale insects can be rubbed off by hand, with a discarded toothbrush, or with a cotton swab soaked in isopropyl alcohol. Prune out heavily infested portions of the plant.
2. Use insecticidal soap. Monitor plants frequently. When crawlers are noticed, use insecticidal soaps that are formulated to kill insects and not damage plants. Frequent sprays may be needed until the problem is under control.
3. Use superior horticultural oil sprays. Highly refined oils sold as superior or ultra-refined horticultural oils are effective in controlling both adults and scale crawlers. The oil suffocates the insects. Unlike dormant oils, these oils are highly refined and under proper conditions, can be applied to plants in foliage without damage. Follow label directions to avoid damage to certain plants that may be sensitive. Superior oils are also considered nontoxic and are less likely to harm beneficial insects. When spraying indoors, protect surfaces that may be damaged by an oil residue.
4. Use chemical insecticides. Many insecticides registered for use indoors are available. Sprays containing pyrethrins, a plant-derived insecticide, are effective and more benign than other chemical pesticides. Follow label directions and, if possible, spray out-of-doors or in a garage, weather permitting.
5. To limit future problems, inspect plants regularly. With regular inspection, pest problems can be caught when just beginning and control is easier. It is also recommended to isolate newly acquired plants for 2–3 weeks to limit introducing pests indoors. Bringing plants indoors in the fall is another way of introducing insects indoors. Infested houseplants summered outdoors frequently benefit from the many natural enemies of scale. Be sure to check plants thoroughly before bringing them indoors in fall to be sure they are pest-free.
Symptoms and Diagnosis
Since the insects are often overlooked, the first signs may be yellowing or wilting leaves that may eventually drop. Leaves may also be covered with a clear sticky substance called honeydew. Honeydew is the insects’ excrement consisting of partially digested sap and may coat the floor and other objects beneath the plant as it spatters down from above. A sticky floor beneath a susceptible plant is a telltale sign that infestation is underway. Under humid conditions, a black mold, called sooty mold, may grow on the honeydew making the leaves look dirty. Closer inspection will reveal small cottony or dome-shaped shells attached to stems and leaves. When pried off with a knifepoint, they may be hollow underneath or house adults and/or eggs. Scale can be differentiated from parts of the plant by scraping. If the structure is green when scraped or cannot be pried off, it is more than likely part of the plant.
Life Cycle
Scale insects have a simple life cycle of egg, nymph (crawler), and adult. Indoors, eggs can be laid any time under the protective shell. The eggs hatch and the crawlers seek out new feeding sites. This crawler stage is when scale is easiest to control. When the crawlers settle, they insert their mouth parts into the plant and begin feeding on the plant's sap. The protective shell develops soon after feeding begins and the insect loses use of its legs. Indoor scales can go through many generations a year.
Integrated Pest Management Strategies
1. Remove insects by hand. If caught early, scale insects can be rubbed off by hand, with a discarded toothbrush, or with a cotton swab soaked in isopropyl alcohol. Prune out heavily infested portions of the plant.
2. Use insecticidal soap. Monitor plants frequently. When crawlers are noticed, use insecticidal soaps that are formulated to kill insects and not damage plants. Frequent sprays may be needed until the problem is under control.
3. Use superior horticultural oil sprays. Highly refined oils sold as superior or ultra-refined horticultural oils are effective in controlling both adults and scale crawlers. The oil suffocates the insects. Unlike dormant oils, these oils are highly refined and under proper conditions, can be applied to plants in foliage without damage. Follow label directions to avoid damage to certain plants that may be sensitive. Superior oils are also considered nontoxic and are less likely to harm beneficial insects. When spraying indoors, protect surfaces that may be damaged by an oil residue.
4. Use chemical insecticides. Many insecticides registered for use indoors are available. Sprays containing pyrethrins, a plant-derived insecticide, are effective and more benign than other chemical pesticides. Follow label directions and, if possible, spray out-of-doors or in a garage, weather permitting.
5. To limit future problems, inspect plants regularly. With regular inspection, pest problems can be caught when just beginning and control is easier. It is also recommended to isolate newly acquired plants for 2–3 weeks to limit introducing pests indoors. Bringing plants indoors in the fall is another way of introducing insects indoors. Infested houseplants summered outdoors frequently benefit from the many natural enemies of scale. Be sure to check plants thoroughly before bringing them indoors in fall to be sure they are pest-free.
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文章
Dummer. ゛☀
2017年09月17日
Black rot, caused by the fungus Guignardia bidwellii, is a serious disease of cultivated and wild grapes. The disease is most destructive in warm, wet seasons. It attacks all green parts of the vine – leaves, shoots, leaf and fruit stems, tendrils, and fruit. The most damaging effect is to the fruit. Note: Guignardia bidwellii forma parthenocissi causes a leaf spot on Boston ivy and Virginia creeper. Control is as for black rot of grapes.
Warm, muggy weather in the spring and summer, along with unsprayed fruit of susceptible varieties, may cause fruit to become almost completely rotted by harvest time. Black rot is not difficult to control if good cultural practices are followed along with the use of protective fungicide sprays.
Symptoms and Diagnosis
Leaves: Reddish brown and circular to angular spots appear on the upper surface of the leaves starting in late spring. As spots merge, they form irregular, reddish brown blotches. The number of spots or lesions per leaf varies from 2 to more than 100 depending on the severity of the disease. The center of the leaf spot turns tannish brown and is surrounded by a black margin. Black, speck-sized fruiting bodies (pycnidia) are arranged in a definite ring just inside the margin of the lesion. Only young, rapidly growing leaves are affected.
Fruit: Shortly after the flower petals fall, fruit infection can occur. Most infections start when the fruit is half to almost full size. A small spot will appear that becomes circular and whitish tan, often surrounded by a brown ring. This happens while the berry is still green. The spots grow rapidly and may cover half of the berry within 48 hours. Within a few days the entire berry becomes coal black, hard, and mummified. The surface of the withered fruit is soon covered with minute, black, pimple-like, sporeproducing pycnidia that are arranged in circular zones.
Life Cycle
The black rot fungus overwinters in canes, tendrils, and leaves on the grape vine and on the ground. Mummified berries on the ground or those that are still clinging to the vines become the major infection source the following spring. During rain, microscopic spores (ascospores) are shot out of numerous, black fruiting bodies (perithecia) and are carried by air currents to young, expanding leaves. In the presence of moisture, these spores germinate in 36 to 48 hours and eventually penetrate the leaves and fruit stems. The infection becomes visible after 8 to 25 days. When the weather is wet, spores can be released the entire spring and summer providing continuous infection. Cool weather slows growth of the fungus. It requires warm weather for optimal growth and a period of 2 to 3 days of rain, drizzle, or fog.
New black rot infections continue into late spring and summer during prolonged periods of warm, rainy weather. During August, the pycnidia are transformed into the overwintering stage (pycnosclerotia) that gives rise to perithecia within which the spring ascospores are produced, completing the disease cycle.
Integrated Pest Management Strategies
1. Planting. Space vines properly and choose a planting site where the vines will be exposed to full sun and good air circulation. Keep the vines off the ground and insure they are properly tied, limiting the amount of time the vines remain wet thus reducing infection.
2. Sanitation. Keep the fruit planting and surrounding areas free of weeds and tall grass. This practice will promote lower relative humidity and rapid drying of vines and thereby limit fungal infection.
3. Pruning. Prune the vines in early winter during dormancy. Select only a few strong, healthy canes from the previous year’s growth to produce the following season’s crop. Remove these prunings from the vineyard and burn or destroy.
4. Cultivation. Cultivate the vineyard before budbreak to bury the mummified berries. Diseased berries covered with soil do not produce spores that will reach the developing vines. For homegrown grapes, use 2–3 inches of leaf mulch or fine bark to cover infected debris.
5. Fungicides. Use protective fungicide sprays. Pesticides registered to protect the developing new growth include copper, captan, ferbam, mancozeb, maneb, triadimefon, and ziram. Important spraying times are as new shoots are 2 to 4 inches long, and again when they are 10 to 15 inches long, just before bloom, just after bloom, and when the fruit has set.
6. Cultivars. Cultivars with large, juicy berries are the most susceptible. In general, grapes that ripen late in the season are affected the least. Most commercial cultivars are sufficiently resistant if adequately protected with a fungicide spray program.
Warm, muggy weather in the spring and summer, along with unsprayed fruit of susceptible varieties, may cause fruit to become almost completely rotted by harvest time. Black rot is not difficult to control if good cultural practices are followed along with the use of protective fungicide sprays.
Symptoms and Diagnosis
Leaves: Reddish brown and circular to angular spots appear on the upper surface of the leaves starting in late spring. As spots merge, they form irregular, reddish brown blotches. The number of spots or lesions per leaf varies from 2 to more than 100 depending on the severity of the disease. The center of the leaf spot turns tannish brown and is surrounded by a black margin. Black, speck-sized fruiting bodies (pycnidia) are arranged in a definite ring just inside the margin of the lesion. Only young, rapidly growing leaves are affected.
Fruit: Shortly after the flower petals fall, fruit infection can occur. Most infections start when the fruit is half to almost full size. A small spot will appear that becomes circular and whitish tan, often surrounded by a brown ring. This happens while the berry is still green. The spots grow rapidly and may cover half of the berry within 48 hours. Within a few days the entire berry becomes coal black, hard, and mummified. The surface of the withered fruit is soon covered with minute, black, pimple-like, sporeproducing pycnidia that are arranged in circular zones.
Life Cycle
The black rot fungus overwinters in canes, tendrils, and leaves on the grape vine and on the ground. Mummified berries on the ground or those that are still clinging to the vines become the major infection source the following spring. During rain, microscopic spores (ascospores) are shot out of numerous, black fruiting bodies (perithecia) and are carried by air currents to young, expanding leaves. In the presence of moisture, these spores germinate in 36 to 48 hours and eventually penetrate the leaves and fruit stems. The infection becomes visible after 8 to 25 days. When the weather is wet, spores can be released the entire spring and summer providing continuous infection. Cool weather slows growth of the fungus. It requires warm weather for optimal growth and a period of 2 to 3 days of rain, drizzle, or fog.
New black rot infections continue into late spring and summer during prolonged periods of warm, rainy weather. During August, the pycnidia are transformed into the overwintering stage (pycnosclerotia) that gives rise to perithecia within which the spring ascospores are produced, completing the disease cycle.
Integrated Pest Management Strategies
1. Planting. Space vines properly and choose a planting site where the vines will be exposed to full sun and good air circulation. Keep the vines off the ground and insure they are properly tied, limiting the amount of time the vines remain wet thus reducing infection.
2. Sanitation. Keep the fruit planting and surrounding areas free of weeds and tall grass. This practice will promote lower relative humidity and rapid drying of vines and thereby limit fungal infection.
3. Pruning. Prune the vines in early winter during dormancy. Select only a few strong, healthy canes from the previous year’s growth to produce the following season’s crop. Remove these prunings from the vineyard and burn or destroy.
4. Cultivation. Cultivate the vineyard before budbreak to bury the mummified berries. Diseased berries covered with soil do not produce spores that will reach the developing vines. For homegrown grapes, use 2–3 inches of leaf mulch or fine bark to cover infected debris.
5. Fungicides. Use protective fungicide sprays. Pesticides registered to protect the developing new growth include copper, captan, ferbam, mancozeb, maneb, triadimefon, and ziram. Important spraying times are as new shoots are 2 to 4 inches long, and again when they are 10 to 15 inches long, just before bloom, just after bloom, and when the fruit has set.
6. Cultivars. Cultivars with large, juicy berries are the most susceptible. In general, grapes that ripen late in the season are affected the least. Most commercial cultivars are sufficiently resistant if adequately protected with a fungicide spray program.
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文章
Dummer. ゛☀
2017年09月17日
Black knot is a name used to describe a disease of woody stems with black, knotty, outgrowths. It is most widespread on plum and cherry trees, but also infects apricots and peaches. Infection occurs in the spring, but symptoms of the disease may not be obvious until the following spring or even in later seasons.
Symptoms and Diagnosis
Initially the bark of infected twigs and medium-sized branches will begin to crack in the springtime. A light yellow discoloration and cork-like swelling occurs on infected areas. Knotted areas later turn an olive-green color and finally turn black and harden during the summer. The swelling weakens branches and may stunt or kill smaller branches due to decreased water and nutrient flow.
Life Cycle
Dibotryon morbosum is the fungus responsible for causing black knot disease on cherries and plums. Spores overwinter in the blackened "knots" of infected branches. Disease spores are spread to new hosts by wind during warm spring weather when temperatures are between 55–75 degrees F and there is rain or high humidity. Trees are weakened because the knots disrupt the normal flow of water and nutrients throughout the branches. Twig dieback is common.
Integrated Pest Management Strategies
1. Plant resistant varieties. Plums such as ‘President’, ‘Santa Rosa’, or ‘Fellinberg’.
2. Prune and destroy all knotted branches in the winter or before March 1. Prune 3–4 inches below the knot to remove all fungal material. Dip tools in a solution of 1–part bleach and 9–parts water between cuts.
3. Remove any wild cherry and plum trees surrounding your property. These trees may be harboring black knot and it spreads easily to cultivated varieties. Pruned material should be disposed of or burned.
4. Apply a fungicide cover spray at bud break. Pesticides registered for use include copper, chlorothalonil (Daconil), mancozeb, and thiophanate methyl (Cleary 3336).
Symptoms and Diagnosis
Initially the bark of infected twigs and medium-sized branches will begin to crack in the springtime. A light yellow discoloration and cork-like swelling occurs on infected areas. Knotted areas later turn an olive-green color and finally turn black and harden during the summer. The swelling weakens branches and may stunt or kill smaller branches due to decreased water and nutrient flow.
Life Cycle
Dibotryon morbosum is the fungus responsible for causing black knot disease on cherries and plums. Spores overwinter in the blackened "knots" of infected branches. Disease spores are spread to new hosts by wind during warm spring weather when temperatures are between 55–75 degrees F and there is rain or high humidity. Trees are weakened because the knots disrupt the normal flow of water and nutrients throughout the branches. Twig dieback is common.
Integrated Pest Management Strategies
1. Plant resistant varieties. Plums such as ‘President’, ‘Santa Rosa’, or ‘Fellinberg’.
2. Prune and destroy all knotted branches in the winter or before March 1. Prune 3–4 inches below the knot to remove all fungal material. Dip tools in a solution of 1–part bleach and 9–parts water between cuts.
3. Remove any wild cherry and plum trees surrounding your property. These trees may be harboring black knot and it spreads easily to cultivated varieties. Pruned material should be disposed of or burned.
4. Apply a fungicide cover spray at bud break. Pesticides registered for use include copper, chlorothalonil (Daconil), mancozeb, and thiophanate methyl (Cleary 3336).
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文章
Dummer. ゛☀
2017年09月17日
The large milkweed bug, Oncopeltus fasciatus, is colored orange-red and black. It has a long proboscis and is a piercing sucking insect. It feeds on the seeds, leaves and stems of milkweed (Asclepias). It is found in small groups on milkweed often on the stems, leaves and on the seed pods. The bodies of milkweed bugs contain toxic compounds derived from the sap which they suck from milkweed. Milkweed bugs are true bugs (Hemiptera) . They are used as research insects because they are easy to use in the laboratory, have a short life cycle and are easy to manipulate.
Symptoms and Diagnosis
Milkweed bugs are more of a nuisance than a threat to milkweed plants. They feed on the seeds by piercing the seed pod and can be found in all stages of growth on the plants in mid to late summer.
Life Cycle
The milkweed bug undergoes incomplete metamorphosis. The nymphs look like adults but do not have full wings and their color pattern is different. They have five instars before they reach adulthood. Black wing pads appear early in their development. Eggs are a light lemon yellow changing to a reddish color. Incubation period is about four to five days. Each molt lasts five to six days. An adult will live for about one month. The insect overwinters as an adult.
Integrated Pest Management Strategies
1. Live with the damage. Milkweed bugs do little damage and are only present for a short period of time. Just living with the insects may be the most prudent thing to do.
2. Sanitation. Remove leaf litter and spent stalks in the fall to eliminate overwintering sites.
3. Use insecticidal soap. For quick control of an infestation insecticidal soaps are very effective and safe. Good coverage of the insects with the spray is necessary for it to be effective.
4. Use chemical insecticides. If necessary use chemical insecticides such as malathion or carbaryl.
Symptoms and Diagnosis
Milkweed bugs are more of a nuisance than a threat to milkweed plants. They feed on the seeds by piercing the seed pod and can be found in all stages of growth on the plants in mid to late summer.
Life Cycle
The milkweed bug undergoes incomplete metamorphosis. The nymphs look like adults but do not have full wings and their color pattern is different. They have five instars before they reach adulthood. Black wing pads appear early in their development. Eggs are a light lemon yellow changing to a reddish color. Incubation period is about four to five days. Each molt lasts five to six days. An adult will live for about one month. The insect overwinters as an adult.
Integrated Pest Management Strategies
1. Live with the damage. Milkweed bugs do little damage and are only present for a short period of time. Just living with the insects may be the most prudent thing to do.
2. Sanitation. Remove leaf litter and spent stalks in the fall to eliminate overwintering sites.
3. Use insecticidal soap. For quick control of an infestation insecticidal soaps are very effective and safe. Good coverage of the insects with the spray is necessary for it to be effective.
4. Use chemical insecticides. If necessary use chemical insecticides such as malathion or carbaryl.
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文章
Dummer. ゛☀
2017年09月16日
Rust, Puccinia heterospora, is a fungal disease that infects leaves and stems of hollyhock. Lower leaves show the condition first, and the disease progresses upward during the growing season. The extent and severity depend on weather conditions.
Symptoms and Diagnosis
First symptoms appear on the leaves as individual, yellow, circular spots about one-eighth inch in size that enlarge to one-quarter inch or more in diameter. On the underside of the leaves, swellings or blisters soon emerge within these spots. At this stage, the symptoms resemble insect or mite galls found on many other plants; however, such galls are rare on hollyhock. The swellings continue to develop and in a few more days, they release masses of reddishbrown spores, covering the entire undersurface of the leaf.
You can easily identify the disease in the field by the round pustules that are covered by loosely attached red spores. Leaves that are heavily infected eventually turn gray or tan and die. Rust spots may also occur on the stems and leaf petioles and occasionally on green flower parts.
Life Cycle
The reddish spores are easily spread by splashing water, rain, and wind. The fungus overwinters in plant debris and possibly in overwintering, living plant tissue. Symptoms will appear very early the following spring when weather conditions are favorable.
Hollyhock rust is not extremely common throughout the state. Fortunately, we can usually enjoy colorful hollyhocks in spite of the disease, though the foliage may become unattractive in wet years.
Integrated Pest Management Strategies
1. Use disease-free plants.Start plants from seeds and place them some distance from infected stock.
2. Improve air circulation. Space plants out in a dry sunny location so that moisture is quickly evaporated from the foliage.
3. Keep plants healthy. Maintain the plants in a vigorous growing condition through a good fertility program. Irrigate during dry periods but keep the foliage dry, if possible.
4.Remove infested material. Remove old plant material and bury, burn, or compost it at the end of the flowering season. Picking off the first infected leaves as they appear may also be helpful. However, this practice alone often is not successful in controlling rust.
5. Control weeds. Destroy common mallow weeds in the vicinity as they may be hosts to the rust disease and a source of hollyhock infection.
6. Use fungicides if necessary. Consider using fungicides to supplement cultural control methods. Direct the applications primarily at the lower surface of the leaves and treat at approximately 7 to 10 day intervals. Reapply if rainfall exceeds 1/2 inch during the period. Pesticides registered for use include chlorothalonil (Daconil), sulfur, mancozeb, and maneb. All are protective fungicides and prevent rather than eradicate the fungus. Start using a fungicide prior to the first sign of disease development.
Symptoms and Diagnosis
First symptoms appear on the leaves as individual, yellow, circular spots about one-eighth inch in size that enlarge to one-quarter inch or more in diameter. On the underside of the leaves, swellings or blisters soon emerge within these spots. At this stage, the symptoms resemble insect or mite galls found on many other plants; however, such galls are rare on hollyhock. The swellings continue to develop and in a few more days, they release masses of reddishbrown spores, covering the entire undersurface of the leaf.
You can easily identify the disease in the field by the round pustules that are covered by loosely attached red spores. Leaves that are heavily infected eventually turn gray or tan and die. Rust spots may also occur on the stems and leaf petioles and occasionally on green flower parts.
Life Cycle
The reddish spores are easily spread by splashing water, rain, and wind. The fungus overwinters in plant debris and possibly in overwintering, living plant tissue. Symptoms will appear very early the following spring when weather conditions are favorable.
Hollyhock rust is not extremely common throughout the state. Fortunately, we can usually enjoy colorful hollyhocks in spite of the disease, though the foliage may become unattractive in wet years.
Integrated Pest Management Strategies
1. Use disease-free plants.Start plants from seeds and place them some distance from infected stock.
2. Improve air circulation. Space plants out in a dry sunny location so that moisture is quickly evaporated from the foliage.
3. Keep plants healthy. Maintain the plants in a vigorous growing condition through a good fertility program. Irrigate during dry periods but keep the foliage dry, if possible.
4.Remove infested material. Remove old plant material and bury, burn, or compost it at the end of the flowering season. Picking off the first infected leaves as they appear may also be helpful. However, this practice alone often is not successful in controlling rust.
5. Control weeds. Destroy common mallow weeds in the vicinity as they may be hosts to the rust disease and a source of hollyhock infection.
6. Use fungicides if necessary. Consider using fungicides to supplement cultural control methods. Direct the applications primarily at the lower surface of the leaves and treat at approximately 7 to 10 day intervals. Reapply if rainfall exceeds 1/2 inch during the period. Pesticides registered for use include chlorothalonil (Daconil), sulfur, mancozeb, and maneb. All are protective fungicides and prevent rather than eradicate the fungus. Start using a fungicide prior to the first sign of disease development.
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文章
Dummer. ゛☀
2017年09月15日
Wilting plant leaves, sagging stems, and aborting flowers and fruits. Dry soil, especially where new plants have not had a chance to put down deep roots. Dry compost in pots and hanging baskets, and pots blowing over.
Plants affected
All plants are affected.
About Wilting through lack of water
Plants have a vascular system which enables water and nutrients to be taken from the environment through a complex root system.
The continual flow of water and nutrients ensures that the vascular system remains firm, and that the plant continues to grow in a healthy way.
Lack of water results in a loss of firmness which causes the symptoms of wilting.
Plants respond to lack of water by closing down areas of the vascular system, which consequently results in leaf, flower and fruit loss.
Plants can usually recover from short periods of lack of water, but sustained periods of drought often result in death.
Treatment
Chemical
Products containing the following chemical ingredients are all effective on Wilting through lack of water
There is no chemical control available for this problem.
Note: It is important to read manufacturer's instructions for use and the associated safety data information before applying chemical treatments.
Organic
Water wilted plants as soon as possible.
Plunge pots with very wilted plants into a bucket of water for an hour or so.
After plunging or watering, place pots with wilted plants in the shade to recover, and consider moving them to a shady spot permanently.
Move wilted plants out of windy spots, and avoid putting them back in the same place.
If the problem is affecting plants in the greenhouse, after watering them, damp down the floor with a hose or watering can.
Prevention
Regularly monitor plants for wilting symptoms.
Design a watering schedule for plants based on their individual needs. As a general guide, pots need watering once a day, hanging baskets twice a day, new plants in the border need careful monitoring in their first year and will probably need watering two or three times a week. Established border plants will have deeper roots and will benefit most from one long drink each week rather than a daily dose.
For potted and hanging basket plants, water-retaining gel granules can be used in the compost.
The base of the pot or basket can also be lined with a plastic bag to help retain water. If lining a pot, make a few small holes in the bag with a kitchen fork so the compost does not get waterlogged.
Avoid planting delicate plants in locations of intense sunlight, or strong winds.
During summer use shading to protect greenhouse crops.
Incorporating mulch and organic material into the soil improves its water retention.
Plants affected
All plants are affected.
About Wilting through lack of water
Plants have a vascular system which enables water and nutrients to be taken from the environment through a complex root system.
The continual flow of water and nutrients ensures that the vascular system remains firm, and that the plant continues to grow in a healthy way.
Lack of water results in a loss of firmness which causes the symptoms of wilting.
Plants respond to lack of water by closing down areas of the vascular system, which consequently results in leaf, flower and fruit loss.
Plants can usually recover from short periods of lack of water, but sustained periods of drought often result in death.
Treatment
Chemical
Products containing the following chemical ingredients are all effective on Wilting through lack of water
There is no chemical control available for this problem.
Note: It is important to read manufacturer's instructions for use and the associated safety data information before applying chemical treatments.
Organic
Water wilted plants as soon as possible.
Plunge pots with very wilted plants into a bucket of water for an hour or so.
After plunging or watering, place pots with wilted plants in the shade to recover, and consider moving them to a shady spot permanently.
Move wilted plants out of windy spots, and avoid putting them back in the same place.
If the problem is affecting plants in the greenhouse, after watering them, damp down the floor with a hose or watering can.
Prevention
Regularly monitor plants for wilting symptoms.
Design a watering schedule for plants based on their individual needs. As a general guide, pots need watering once a day, hanging baskets twice a day, new plants in the border need careful monitoring in their first year and will probably need watering two or three times a week. Established border plants will have deeper roots and will benefit most from one long drink each week rather than a daily dose.
For potted and hanging basket plants, water-retaining gel granules can be used in the compost.
The base of the pot or basket can also be lined with a plastic bag to help retain water. If lining a pot, make a few small holes in the bag with a kitchen fork so the compost does not get waterlogged.
Avoid planting delicate plants in locations of intense sunlight, or strong winds.
During summer use shading to protect greenhouse crops.
Incorporating mulch and organic material into the soil improves its water retention.
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文章
Dummer. ゛☀
2017年09月15日
These bright red beetles are very distinctive and therefore quite easy to spot on affected plants. Also, look for holes in leaves, stems and flowers, left by the small slimy black larvae.
Plants affected
They're highly destructive to lilies (Lilium), and fritillaries (Fritillaria).
About Scarlet lily beetle
These bright red beetles, with distinctive black legs and antennae, are an invasive species which was first recorded in the UK during the 1940s.
They're also known as red lily beetles and are now commonly found across the south-east of England, and have recently been reported in parts of Scotland, Wales and Ireland.
When disturbed, adults emit a high pitch squeak, perhaps as a warning to other beetles.
Adults overwinter in the soil and emerge in late-March to early April.
Adults will continue to mate and feed from spring until autumn.
After mating, females will lay small groups of bright orange eggs on the underside of leaves.
Larvae hatch a few days later as red or orange-coloured grubs with black heads and three pairs of legs on their upper body.
As they feed, the larvae cover themselves in their own sticky black excrement.
Lily beetle larvae are usually found on the underside of leaves where they feed from the tip and work back to the stem.
Any larvae which survive to become adults will drop to the soil in late autumn to overwinter, and emerge again the next spring.
Treatment
Chemical
Products containing the following chemical ingredients are all effective on Scarlet lily beetle
Pyrethrum
Natural fatty acids
Surfactant-based products
Note: It is important to read manufacturer's instructions for use and the associated safety data information before applying chemical treatments.
Organic
Inspect plants carefully in early spring and remove any adults and larvae by hand to prevent infestations becoming established.
Use netting and fleece to contain the pests and stop adults moving between plants.
Replant pot-grown lilies and fritillarias using fresh compost in early spring before the overwintering adult beetles emerge from the soil.
There are no biological controls commercially available, although a range of native parasites and predators will feed on both adult and larval stages. So encourage these by establishing a natural balance of wildlife in your garden and avoid using chemicals.
Prevention
Check plants regularly for signs of infestation and deal with them as soon as they appear.
Encourage insect-eating birds by putting up feeders in winter and provide nesting boxes in spring.
Plants affected
They're highly destructive to lilies (Lilium), and fritillaries (Fritillaria).
About Scarlet lily beetle
These bright red beetles, with distinctive black legs and antennae, are an invasive species which was first recorded in the UK during the 1940s.
They're also known as red lily beetles and are now commonly found across the south-east of England, and have recently been reported in parts of Scotland, Wales and Ireland.
When disturbed, adults emit a high pitch squeak, perhaps as a warning to other beetles.
Adults overwinter in the soil and emerge in late-March to early April.
Adults will continue to mate and feed from spring until autumn.
After mating, females will lay small groups of bright orange eggs on the underside of leaves.
Larvae hatch a few days later as red or orange-coloured grubs with black heads and three pairs of legs on their upper body.
As they feed, the larvae cover themselves in their own sticky black excrement.
Lily beetle larvae are usually found on the underside of leaves where they feed from the tip and work back to the stem.
Any larvae which survive to become adults will drop to the soil in late autumn to overwinter, and emerge again the next spring.
Treatment
Chemical
Products containing the following chemical ingredients are all effective on Scarlet lily beetle
Pyrethrum
Natural fatty acids
Surfactant-based products
Note: It is important to read manufacturer's instructions for use and the associated safety data information before applying chemical treatments.
Organic
Inspect plants carefully in early spring and remove any adults and larvae by hand to prevent infestations becoming established.
Use netting and fleece to contain the pests and stop adults moving between plants.
Replant pot-grown lilies and fritillarias using fresh compost in early spring before the overwintering adult beetles emerge from the soil.
There are no biological controls commercially available, although a range of native parasites and predators will feed on both adult and larval stages. So encourage these by establishing a natural balance of wildlife in your garden and avoid using chemicals.
Prevention
Check plants regularly for signs of infestation and deal with them as soon as they appear.
Encourage insect-eating birds by putting up feeders in winter and provide nesting boxes in spring.
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Dummer. ゛☀
2017年09月15日
Leaves, stems, flowers and buds will blacken, shrivel, wilt and possibly die. Fruits can become discoloured, and plants may be covered in a white, shiny frost. Stem and trunk bark may split, and develop cankers as a result of the damage.
Plants affected
Potentially all non-hardy plants.
About
Frost damage can occur anytime between late September to mid May.
Regular freezing and thawing of plants weakens cell walls.
Ice crystals form inside the plant removing water from the cells, or causing them swell and rupture.
Younger, tender plants are generally more susceptible, although hardier plants can be damaged during severe frosts.
Gardens sometimes have areas where cold air collects, commonly called “frost pockets”.
Plants infected with viral diseases are often more susceptible to frost damage.
When soil freezes, young plants may be squeezed out from beneath the surface.
The length of exposure to cold temperatures is often as important and the actual temperature.
Preventing further damage
Covering plants with horticultural fleece will reduce exposure to frost.
Removing any affected plant material will reduce the spread of disease from the damaged areas.
Avoid planting seeds in “frost pockets” in your garden.
Choose hardy plant varieties to grow.
A south facing wall will provide a warmer micro-climate for tender plants.
Plants affected
Potentially all non-hardy plants.
About
Frost damage can occur anytime between late September to mid May.
Regular freezing and thawing of plants weakens cell walls.
Ice crystals form inside the plant removing water from the cells, or causing them swell and rupture.
Younger, tender plants are generally more susceptible, although hardier plants can be damaged during severe frosts.
Gardens sometimes have areas where cold air collects, commonly called “frost pockets”.
Plants infected with viral diseases are often more susceptible to frost damage.
When soil freezes, young plants may be squeezed out from beneath the surface.
The length of exposure to cold temperatures is often as important and the actual temperature.
Preventing further damage
Covering plants with horticultural fleece will reduce exposure to frost.
Removing any affected plant material will reduce the spread of disease from the damaged areas.
Avoid planting seeds in “frost pockets” in your garden.
Choose hardy plant varieties to grow.
A south facing wall will provide a warmer micro-climate for tender plants.
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Dummer. ゛☀
2017年09月15日
Stems will be damaged at the base and may be completely severed. Plants will wilt and may die. There may also be damage to leaves, roots and tubers.
Plants affected
Many garden fruit, vegetable, and ornamental plants are affected.
About Cutworms
Cutworms are the larvae of certain species of nocturnal moths.
They are widespread throughout the UK.
In June and July the moths lay eggs in batches of 30-50 on leaves and stems. The eggs hatch two weeks later.
Larvae range from dull grey or brown in colour to green or white. They can reach 2-4cm in length when fully grown.
Larvae can be found feeding at night on the soil surface.
They cause severe damage by chewing the base of stems, roots, leaves and tubers.
After one to two months of feeding they pupate in the soil.
A second generation hatches in August and September.
Second generation larvae will over-winter in the soil, coming to the surface to feed when environmental conditions are favourable.
Treatment
Chemical
Products containing the following chemical ingredients are all effective on Cutworms
There are no approved insecticides currently available to amateur gardeners.
Note: It is important to read manufacturer's instructions for use and the associated safety data information before applying chemical treatments.
Organic
Regularly cultivate soil in winter to expose over-wintering larvae to predators.
Encourage insectivorous birds by hanging bird boxes and feeders.
In greenhouses drench potted plants to bring larvae to the surface, then pick them off by hand.
Prevention
Use pheromone traps to monitor the presence of moths during June and July.
Avoid planting in known areas of infestation.
Keep gardens free from weeds and plant debris as they can be used for egg laying.
Plants affected
Many garden fruit, vegetable, and ornamental plants are affected.
About Cutworms
Cutworms are the larvae of certain species of nocturnal moths.
They are widespread throughout the UK.
In June and July the moths lay eggs in batches of 30-50 on leaves and stems. The eggs hatch two weeks later.
Larvae range from dull grey or brown in colour to green or white. They can reach 2-4cm in length when fully grown.
Larvae can be found feeding at night on the soil surface.
They cause severe damage by chewing the base of stems, roots, leaves and tubers.
After one to two months of feeding they pupate in the soil.
A second generation hatches in August and September.
Second generation larvae will over-winter in the soil, coming to the surface to feed when environmental conditions are favourable.
Treatment
Chemical
Products containing the following chemical ingredients are all effective on Cutworms
There are no approved insecticides currently available to amateur gardeners.
Note: It is important to read manufacturer's instructions for use and the associated safety data information before applying chemical treatments.
Organic
Regularly cultivate soil in winter to expose over-wintering larvae to predators.
Encourage insectivorous birds by hanging bird boxes and feeders.
In greenhouses drench potted plants to bring larvae to the surface, then pick them off by hand.
Prevention
Use pheromone traps to monitor the presence of moths during June and July.
Avoid planting in known areas of infestation.
Keep gardens free from weeds and plant debris as they can be used for egg laying.
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Dummer. ゛☀
2017年09月15日
Distorted, yellowing or slowed growth on plants can often be a sign of scale insects. These look like tiny brown or orange blobs and can often be found on the undersides of the leaves near the veins, on the stems or in the leaf joints. They produce sticky honeydew as they feed which can cause the foliage on infested plants to become sticky and covered with dark sooty mould.
Plants affected
Scales are usually pests of ornamental plants and can be especially troublesome in greenhouses. Over 300 species of ornamental plants are known hosts.
About Scale insects
Scale insects are small sap-sucking insects, so called because they produce an umbrella-like waxy coating or 'scale' over their soft bodies.
They're often difficult to detect on plants, although leaf yellowing or sticky honeydew deposits can be the first signs of infestation.
Scale insects may appear as small, flattened white, yellow or brown 'discs' or 'blobs', on stems or on the underside of leaves near the veins.
Scale insects are divided into two families - soft scale (Coccidae) and hard scale (Diaspididae).
Soft scales can breed all year round on protected crops and produce large amounts of sugary honeydew when they feed on the plant's sap. This honeydew attracts sooty moulds that grow on the leaves.
Hard scales lay eggs under their scales which hatch into nymphs or 'crawlers' after the female dies in early summer.
The nymphs can move short distances on a plant, but disperse long distances on the wind or on animals.
Hard scale don't produce large amounts of honeydew.
Female scale insect nymphs become immobile once they find a suitable feeding site and become adults.
Males are rarely seen but are often winged and midge-like in appearance.
The 'scale' produced by these insects can remain on a plant for a long time after they're dead.
Treatment
Chemical
Products containing the following chemical ingredients are all effective on Scale insects
Pyrethrum
Natural fatty acids
Rape seed oil
Tar oil wash (for use on deciduous trees and roses in December)
Thiacloprid (for use with outdoor fruit crops)
Note: It is important to read manufacturer's instructions for use and the associated safety data information before applying chemical treatments.
Organic
Check bought plants thoroughly. If an infestation is in the early stages, the scales can be cleaned off using a brush and water, or just a thumbnail.
Biological control is available in the form of a tiny wasp which parasitises soft scales, Metaphycus helvolus. This can be purchased for release into the greenhouse but requires good light and temperatures of at least 22°C (72°F) to be effective.
The small predatory ladybird Chilocorus nigritus can also be purchased, that feeds on hard scale species. Lacewing larvae also control scale.
Prevention
Check plants regularly for signs of scale infestation and deal with them as soon as they appear.
Keep the environment clear of weeds because these often harbour the pest.
Monitor plants for signs of scale, such as leaf drop, honeydew or sooty mould.
Look out for ants running up and down the plants, 'milking' the honeydew.
Avoid using broad spectrum insecticides which will kill beneficial insects as well as scale.
Destroy any leaves that have been removed from an infested plant because these can harbour many mobile juvenile scales.
Plants affected
Scales are usually pests of ornamental plants and can be especially troublesome in greenhouses. Over 300 species of ornamental plants are known hosts.
About Scale insects
Scale insects are small sap-sucking insects, so called because they produce an umbrella-like waxy coating or 'scale' over their soft bodies.
They're often difficult to detect on plants, although leaf yellowing or sticky honeydew deposits can be the first signs of infestation.
Scale insects may appear as small, flattened white, yellow or brown 'discs' or 'blobs', on stems or on the underside of leaves near the veins.
Scale insects are divided into two families - soft scale (Coccidae) and hard scale (Diaspididae).
Soft scales can breed all year round on protected crops and produce large amounts of sugary honeydew when they feed on the plant's sap. This honeydew attracts sooty moulds that grow on the leaves.
Hard scales lay eggs under their scales which hatch into nymphs or 'crawlers' after the female dies in early summer.
The nymphs can move short distances on a plant, but disperse long distances on the wind or on animals.
Hard scale don't produce large amounts of honeydew.
Female scale insect nymphs become immobile once they find a suitable feeding site and become adults.
Males are rarely seen but are often winged and midge-like in appearance.
The 'scale' produced by these insects can remain on a plant for a long time after they're dead.
Treatment
Chemical
Products containing the following chemical ingredients are all effective on Scale insects
Pyrethrum
Natural fatty acids
Rape seed oil
Tar oil wash (for use on deciduous trees and roses in December)
Thiacloprid (for use with outdoor fruit crops)
Note: It is important to read manufacturer's instructions for use and the associated safety data information before applying chemical treatments.
Organic
Check bought plants thoroughly. If an infestation is in the early stages, the scales can be cleaned off using a brush and water, or just a thumbnail.
Biological control is available in the form of a tiny wasp which parasitises soft scales, Metaphycus helvolus. This can be purchased for release into the greenhouse but requires good light and temperatures of at least 22°C (72°F) to be effective.
The small predatory ladybird Chilocorus nigritus can also be purchased, that feeds on hard scale species. Lacewing larvae also control scale.
Prevention
Check plants regularly for signs of scale infestation and deal with them as soon as they appear.
Keep the environment clear of weeds because these often harbour the pest.
Monitor plants for signs of scale, such as leaf drop, honeydew or sooty mould.
Look out for ants running up and down the plants, 'milking' the honeydew.
Avoid using broad spectrum insecticides which will kill beneficial insects as well as scale.
Destroy any leaves that have been removed from an infested plant because these can harbour many mobile juvenile scales.
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Dummer. ゛☀
2017年09月15日
Botrytis infects plant material above ground which is usually dead or dying. Depending on the species of the plant and the fungus there may be different symptoms at different times of year. A common sign of botrytis is a grey mould on leaves, stems, fruits, flowers and buds. Before the mould appears symptoms include dead brown patches on leaves, stems and buds, white or pale brown spots on petals and fruit, and rotting on unplanted bulbs.
Plants affected
Most fruit and vegetables, some houseplants, ornamentals, shrubs and trees.
About Grey mould
There are many species of botrytis with different infection methods. They cause a range of symptoms before the fuzzy grey mould appears including dead brown patches on leaves, stems and buds, white or pale brown spots on petals and fruit, and rotting on unplanted bulbs.
The spores will attack weak or dying plants in preference to healthy ones.
Conditions must be cool and humid for plants to be infected.
The fungal phase can only survive a narrow range of temperatures.
Botrytis overwinters as small, dark, hard structures, called sclerotia, on plant debris and other surfaces.
When spring weather conditions are favourable they produce spores. These are dispersed by wind, air movement, water splash and pesticide sprays.
Once a plant is infected, botrytis may spread to all parts depending on its species and variety.
Treatment
Chemical
Products containing the following chemical ingredients are all effective on Grey mould
Myclobutanil
Penconazole
Note: It is important to read manufacturer's instructions for use and the associated safety data information before applying chemical treatments.
Organic
Regular observation is essential to prevent infections establishing.
Remove all dead and injured plant material before it can become infected.
Remove infected leaves, fruits and buds by cutting right back into healthy growth. Bin or burn the infected material to help reduce the spread of infection.
Isolate infected plants to reduce infection spread.
Place fleece between plants to reduce the movement of spores.
Prevention
Regularly check plants for signs of infection and deal with them as soon as they appear.
Ensure greenhouses are always well ventilated.
Space plants out to reduce the humidity around them and prevent infections establishing.
Reduce the humidity in greenhouses and around houseplants to prevent infections establishing.
Plants affected
Most fruit and vegetables, some houseplants, ornamentals, shrubs and trees.
About Grey mould
There are many species of botrytis with different infection methods. They cause a range of symptoms before the fuzzy grey mould appears including dead brown patches on leaves, stems and buds, white or pale brown spots on petals and fruit, and rotting on unplanted bulbs.
The spores will attack weak or dying plants in preference to healthy ones.
Conditions must be cool and humid for plants to be infected.
The fungal phase can only survive a narrow range of temperatures.
Botrytis overwinters as small, dark, hard structures, called sclerotia, on plant debris and other surfaces.
When spring weather conditions are favourable they produce spores. These are dispersed by wind, air movement, water splash and pesticide sprays.
Once a plant is infected, botrytis may spread to all parts depending on its species and variety.
Treatment
Chemical
Products containing the following chemical ingredients are all effective on Grey mould
Myclobutanil
Penconazole
Note: It is important to read manufacturer's instructions for use and the associated safety data information before applying chemical treatments.
Organic
Regular observation is essential to prevent infections establishing.
Remove all dead and injured plant material before it can become infected.
Remove infected leaves, fruits and buds by cutting right back into healthy growth. Bin or burn the infected material to help reduce the spread of infection.
Isolate infected plants to reduce infection spread.
Place fleece between plants to reduce the movement of spores.
Prevention
Regularly check plants for signs of infection and deal with them as soon as they appear.
Ensure greenhouses are always well ventilated.
Space plants out to reduce the humidity around them and prevent infections establishing.
Reduce the humidity in greenhouses and around houseplants to prevent infections establishing.
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Dummer. ゛☀
2017年09月15日
Dark brown or black patches surrounded by paler areas on wilted and curled leaves. As the plant weakens, stems can also be affected showing brown discolouration and decomposition of the whole plant soon follows. Underground potato tubers suffer from an all over reddish brown rot that destroys the vegetable and has a foul odour. The fruits on a tomato will soon start rotting after the leaves become infected.
Plants affected
Potatoes, tomatoes and other members of the Solanaceae family.
About
Potato blight and tomato blight are both caused by the same fungal disease.
Once the fungus takes hold it rapidly spreads rapidly by wind-borne spores.
Tomatoes grown under glass will be less likely to succumb as the blight spores do not easily get inside greenhouses.
The fungus spreads easiest when weather conditions are above 10 degrees centigrade and when there is high humidity in the air.
Tubers carrying the disease which are not incinerated can become ‘Primary Infectors’ if they are replanted and conditions are ideal for the fungus.
Periods of hot dry weather can subdue and delay potato blight symptoms.
Blight cannot survive in soil or fully composted plant material. It over-winters in living plant material and is spread on the wind the following year.
The most common way to allow blight to remain in your garden is through ‘volunteer potatoes’. These are tiny potato tubers which survive over the winter in the soil or the compost heap and shoot up again in the following spring.
Treatment
Chemical
There are a number of copper based fungicides, including Bordeaux mixture which will have some effect. They mainly work in a preventative way so waiting until the first symptoms appear may be too late.
Note: It is important to read manufacturer's instructions for use and the associated safety data information before applying chemical treatments.
Organic
Regularly observe crops to check for damage and remove all affected plants immediately and incinerate.
Keep weeds under control that could be alternative host plants e.g. Deadly Night Shade.
Avoid growing at times of year when weather conditions are favourable for the fungus.
At the first sign of infection, cut down all the tops of potato plants (known as the haulms) and burn or fully compost them. Then leave the tubers in the ground for a few days before lifting them to allow any blight spores on the soil surface to die off.
Do not compost infected or unused tubers.
Tomatoes should be harvested as soon as blight becomes apparent even if they’re still green (make chutney!)
Preventing Further Infection
Grow resistant varieties such as: Potatoes ‘Axona’ or ‘Mira’ and Tomato ‘Ferline’.
Plants affected
Potatoes, tomatoes and other members of the Solanaceae family.
About
Potato blight and tomato blight are both caused by the same fungal disease.
Once the fungus takes hold it rapidly spreads rapidly by wind-borne spores.
Tomatoes grown under glass will be less likely to succumb as the blight spores do not easily get inside greenhouses.
The fungus spreads easiest when weather conditions are above 10 degrees centigrade and when there is high humidity in the air.
Tubers carrying the disease which are not incinerated can become ‘Primary Infectors’ if they are replanted and conditions are ideal for the fungus.
Periods of hot dry weather can subdue and delay potato blight symptoms.
Blight cannot survive in soil or fully composted plant material. It over-winters in living plant material and is spread on the wind the following year.
The most common way to allow blight to remain in your garden is through ‘volunteer potatoes’. These are tiny potato tubers which survive over the winter in the soil or the compost heap and shoot up again in the following spring.
Treatment
Chemical
There are a number of copper based fungicides, including Bordeaux mixture which will have some effect. They mainly work in a preventative way so waiting until the first symptoms appear may be too late.
Note: It is important to read manufacturer's instructions for use and the associated safety data information before applying chemical treatments.
Organic
Regularly observe crops to check for damage and remove all affected plants immediately and incinerate.
Keep weeds under control that could be alternative host plants e.g. Deadly Night Shade.
Avoid growing at times of year when weather conditions are favourable for the fungus.
At the first sign of infection, cut down all the tops of potato plants (known as the haulms) and burn or fully compost them. Then leave the tubers in the ground for a few days before lifting them to allow any blight spores on the soil surface to die off.
Do not compost infected or unused tubers.
Tomatoes should be harvested as soon as blight becomes apparent even if they’re still green (make chutney!)
Preventing Further Infection
Grow resistant varieties such as: Potatoes ‘Axona’ or ‘Mira’ and Tomato ‘Ferline’.
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Dummer. ゛☀
2017年09月15日
Large black or dark purple spots on the surface of the leaves or stems are the main signs of black spot. As the problem gets worse the foliage gradually turns yellow and drops prematurely, weakening the plant.
Plants affected
Rose black spot is an extremely common and widespread fungal disease of both cultivated and wild rose varieties.
About Rose black spot
Rose black spot is specific to roses and all types are susceptible.
The disease causes dark spots or irregular brown or black blotches on both leaf surfaces. Leaves then turn yellow and drop prematurely, resulting in weakened plants.
The disease is worse in warm, wet weather.
The black spot fungus produces spores which are released under wet conditions and usually spread by rain-splash.
The disease can also be passed from plant to plant on hands, clothing or tools.
Spores overwinter mostly on the shoots, but can survive on fallen leaves and within the soil.
Recently, rose black spot has become more common in town and city gardens due to less sulphur dioxide within atmospheric pollution. Sulphur is known to reduce fungal problems.
Treatment
Chemical
Products containing the following chemical ingredients are all effective on Rose black spot
Penconazole
Myclobutanil - alternating any of these with the protectant Mancozeb to prevent the fungus developing resistance to the fungicides.
Note: It is important to read manufacturer's instructions for use and the associated safety data information before applying chemical treatments.
Organic
Remove infected, fallen leaves promptly and burn.
Hard prune shoots in spring and burn the prunings.
Treat infections with powdered sulphur, which is deemed organically acceptable.
Some cultivars are partially resistant to black spot but in a bad year all varieties may succumb. Generally, many of the older cultivars and more yellow than red or pink cultivars are susceptible to the disease. So checking catalogues and choosing resistant varieties, such as 'Bonita', 'Royal William' or 'New Dawn', and growing a mixed planting should help. Rose varieties less than five years old should be relatively disease resistant.
Prevention
Prevention of rose black spot is very difficult and many strains of the fungi are resistant. However, regular raking around the plant with a hoe and pruning and burning of infected material will certainly help along with the advised treatments.
Choosing resistant varieties also helps, but don't rely too heavily on resistance because there are many species of fungus and even new varieties can quickly succumb.
Adopt a regular, fortnightly spraying regime to protect your plants before the problem begins. It's a good idea to alternate the chemical that you use to prevent resistance occurring.
Dig in plenty of organic matter at planting time and keep plants well fed throughout the growing season. Strong healthy plants will generally resist attack better those that are weak.
Surround plants with a fresh layer of mulch each spring. This will smother any spores that have fallen around your plants and stop them from being splashed on to roses by rain.
Plants affected
Rose black spot is an extremely common and widespread fungal disease of both cultivated and wild rose varieties.
About Rose black spot
Rose black spot is specific to roses and all types are susceptible.
The disease causes dark spots or irregular brown or black blotches on both leaf surfaces. Leaves then turn yellow and drop prematurely, resulting in weakened plants.
The disease is worse in warm, wet weather.
The black spot fungus produces spores which are released under wet conditions and usually spread by rain-splash.
The disease can also be passed from plant to plant on hands, clothing or tools.
Spores overwinter mostly on the shoots, but can survive on fallen leaves and within the soil.
Recently, rose black spot has become more common in town and city gardens due to less sulphur dioxide within atmospheric pollution. Sulphur is known to reduce fungal problems.
Treatment
Chemical
Products containing the following chemical ingredients are all effective on Rose black spot
Penconazole
Myclobutanil - alternating any of these with the protectant Mancozeb to prevent the fungus developing resistance to the fungicides.
Note: It is important to read manufacturer's instructions for use and the associated safety data information before applying chemical treatments.
Organic
Remove infected, fallen leaves promptly and burn.
Hard prune shoots in spring and burn the prunings.
Treat infections with powdered sulphur, which is deemed organically acceptable.
Some cultivars are partially resistant to black spot but in a bad year all varieties may succumb. Generally, many of the older cultivars and more yellow than red or pink cultivars are susceptible to the disease. So checking catalogues and choosing resistant varieties, such as 'Bonita', 'Royal William' or 'New Dawn', and growing a mixed planting should help. Rose varieties less than five years old should be relatively disease resistant.
Prevention
Prevention of rose black spot is very difficult and many strains of the fungi are resistant. However, regular raking around the plant with a hoe and pruning and burning of infected material will certainly help along with the advised treatments.
Choosing resistant varieties also helps, but don't rely too heavily on resistance because there are many species of fungus and even new varieties can quickly succumb.
Adopt a regular, fortnightly spraying regime to protect your plants before the problem begins. It's a good idea to alternate the chemical that you use to prevent resistance occurring.
Dig in plenty of organic matter at planting time and keep plants well fed throughout the growing season. Strong healthy plants will generally resist attack better those that are weak.
Surround plants with a fresh layer of mulch each spring. This will smother any spores that have fallen around your plants and stop them from being splashed on to roses by rain.
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文章
Dummer. ゛☀
2017年09月15日
Colonies of aphids can be found in clusters on soft new growth of a wide variety of plants. Buds, tips of stems and the undersides of leaves are all good places to look. Aphids come in many different colours from common greenfly and blackfly to yellows, browns and whites. Many species are specific to one group of plants but they all need to be dealt with in a similar way.
Plants affected
From time to time, aphids may attack almost any garden plant.
About
Adult aphids are rarely more than 3mm long and are elliptical in shape.
Large colonies can cover areas on the youngest sections of stems, and the undersides of leaves and sometimes on flower-buds.
During the warmer months aphids give birth to as many as five live young a day, so large colonies can develop very quickly.
When the colonies become over-populated, they move to different locations by producing winged aphids.
During the cooler months, aphids mate and produce eggs which over-winter.
Aphids feed on plant sap and excrete plant sugars as honeydew.
Honeydew often covers the leaves of a plant and then becomes infested with black sooty moulds.
Treatment
Chemical
Lambda-cyhalothrin and deltamethrin are both contact insecticides which are effective only when sprayed directly onto the aphids. A suitable systemic insecticide is thiacloprid which is taken in through the leaves and is taken up by the feeding aphids. Naturally occurring insecticides such as pyrethrum and fatty acids can also be used.
Note: It is important to read manufacturer's instructions for use and the associated safety data information before applying chemical treatments.
Organic
Encourage natural predators such as ladybirds and lacewings and insectivorous birds.
Have patience – when aphid populations peak, predatory insects will soon move in. Often this is when people lose their nerve and turn to sprays and, in doing so, kill all the natural predators too.
Don’t over-feed plants. Too much fertilizer will lead to lots of soft, sappy growth which will encourage aphid attacks.
Consider planting a sacrificial crop near to vegetables. For example, nasturtiums which attract black-fly away from brassicas.
Infestations in greenhouses or conservatories can be effectively treated with a biological control such as ladybird larvae.
Plants affected
From time to time, aphids may attack almost any garden plant.
About
Adult aphids are rarely more than 3mm long and are elliptical in shape.
Large colonies can cover areas on the youngest sections of stems, and the undersides of leaves and sometimes on flower-buds.
During the warmer months aphids give birth to as many as five live young a day, so large colonies can develop very quickly.
When the colonies become over-populated, they move to different locations by producing winged aphids.
During the cooler months, aphids mate and produce eggs which over-winter.
Aphids feed on plant sap and excrete plant sugars as honeydew.
Honeydew often covers the leaves of a plant and then becomes infested with black sooty moulds.
Treatment
Chemical
Lambda-cyhalothrin and deltamethrin are both contact insecticides which are effective only when sprayed directly onto the aphids. A suitable systemic insecticide is thiacloprid which is taken in through the leaves and is taken up by the feeding aphids. Naturally occurring insecticides such as pyrethrum and fatty acids can also be used.
Note: It is important to read manufacturer's instructions for use and the associated safety data information before applying chemical treatments.
Organic
Encourage natural predators such as ladybirds and lacewings and insectivorous birds.
Have patience – when aphid populations peak, predatory insects will soon move in. Often this is when people lose their nerve and turn to sprays and, in doing so, kill all the natural predators too.
Don’t over-feed plants. Too much fertilizer will lead to lots of soft, sappy growth which will encourage aphid attacks.
Consider planting a sacrificial crop near to vegetables. For example, nasturtiums which attract black-fly away from brassicas.
Infestations in greenhouses or conservatories can be effectively treated with a biological control such as ladybird larvae.
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文章
Dummer. ゛☀
2017年09月15日
Found in warmer growing climates, mealybugs are soft-bodied, wingless insects that often appear as white cottony masses on the leaves, stems and fruit of plants. They feed by inserting long sucking mouthparts, called stylets, into plants and drawing sap out of the tissue. Damage is not often significant at low pest levels. However, at higher numbers they can cause leaf yellowing and curling as the plant weakens. Feeding is usually accompanied by honeydew, which makes the plant sticky and encourages the growth of sooty moulds. Mealybugs are a common greenhouse pest that affect ornamentals, houseplants, avocados and fruits.
Adults (1/10 — 1/4 inch long) are soft, oval distinctly segmented insects that are usually covered with a white or gray mealy wax. Small nymphs, called crawlers, are light yellow and free of wax. They are active early on, but move little once a suitable feeding site is found.
Note: There are approximately 275 species of mealybugs known to occur throughout the United States.
Life Cycle
Adult females deposit 300-600 eggs within an excreted, compact, waxy cottony-appearing mass mostly found on the underside of leaves (these egg cases can be confused with downy mildew). Egg laying is continues for about 2 weeks with the female dying shortly after all eggs are laid. Hatching occurs within 1-3 weeks and the small active yellow nymphs begin migrating over the plant in search of feeding sites on which to settle. As they feed, they secrete honeydew and a waxy coating begins to form over their bodies. Female nymphs pass through three stages (instars) with a generation taking as little as one month, depending on temperature. Male nymphs pass through five instars. They do not feed after the first two instars and exist solely to fertilize the females. In the greenhouse, continuous and overlapping generations occur throughout the year. There is little winter survival outside of greenhouses in the North.
Mealybug Control
Prune out light infestations or dab insects with a Q-tip dipped in rubbing alcohol.
Do not over water or overfertilize — mealybugs are attracted to plants with high nitrogen levels and soft growth.
Commercially available beneficial insects, such as ladybugs, lacewing and the Mealybug Destroyer (Cryptolaemus montrouzieri), are important natural predators of this pest.
Use the Bug Blaster to hose off plants with a strong stream of water and reduce pest numbers. Washing foliage regularly with a leaf shine — made from neem oil — will help discourage future infestations.
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.
Neem oil disrupts the 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. Mix 1 oz/ gallon of water and spray every 7-14 days, as needed.
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.
Washing foliage regularly with a leaf shine will help discourage future infestations.
Adults (1/10 — 1/4 inch long) are soft, oval distinctly segmented insects that are usually covered with a white or gray mealy wax. Small nymphs, called crawlers, are light yellow and free of wax. They are active early on, but move little once a suitable feeding site is found.
Note: There are approximately 275 species of mealybugs known to occur throughout the United States.
Life Cycle
Adult females deposit 300-600 eggs within an excreted, compact, waxy cottony-appearing mass mostly found on the underside of leaves (these egg cases can be confused with downy mildew). Egg laying is continues for about 2 weeks with the female dying shortly after all eggs are laid. Hatching occurs within 1-3 weeks and the small active yellow nymphs begin migrating over the plant in search of feeding sites on which to settle. As they feed, they secrete honeydew and a waxy coating begins to form over their bodies. Female nymphs pass through three stages (instars) with a generation taking as little as one month, depending on temperature. Male nymphs pass through five instars. They do not feed after the first two instars and exist solely to fertilize the females. In the greenhouse, continuous and overlapping generations occur throughout the year. There is little winter survival outside of greenhouses in the North.
Mealybug Control
Prune out light infestations or dab insects with a Q-tip dipped in rubbing alcohol.
Do not over water or overfertilize — mealybugs are attracted to plants with high nitrogen levels and soft growth.
Commercially available beneficial insects, such as ladybugs, lacewing and the Mealybug Destroyer (Cryptolaemus montrouzieri), are important natural predators of this pest.
Use the Bug Blaster to hose off plants with a strong stream of water and reduce pest numbers. Washing foliage regularly with a leaf shine — made from neem oil — will help discourage future infestations.
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.
Neem oil disrupts the 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. Mix 1 oz/ gallon of water and spray every 7-14 days, as needed.
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.
Washing foliage regularly with a leaf shine will help discourage future infestations.
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