文章
Dummer. ゛☀
2017年09月16日
Caterpillars are the larvae of moths and butterflies, and like their winged metamorphoses, they come in all shapes and sizes. While all species share a common appetite for plant foliage, the good news is that the methods for controlling them are basically the same. Before deciding upon a control method, take the time to identify which caterpillars might eventually become the gorgeous butterflies and lovely nocturnal moths we usually welcome to our gardens. These larvae should be protected, and fortunately, most are colorful and harmless.
Caterpillars inflict damage by eating the foliage and stems of just about any plant in your flower or vegetable garden, as well as your fruit and shade trees. Furthermore, they are voracious eaters, and can defoliate a plant in a short period of time. Telltale symptoms of a caterpillar infestation are holes in leaves and chewed leaf edges, as well as leaves that are rolled up or fastened with silk.
If you are able to catch the infestation early on, the best strategy for controlling caterpillars is to handpick them, then crush them or drop them in a pail of soapy water. Make sure you also remove rolled or folded leaves that shelter the caterpillars. (Make sure you wear gloves before handling saddleback caterpillars, as their sting is severe.) To prevent inadvertently killing desirable butterflies- and moths-to-be, use a good field guide such as Peterson First Guide to Caterpillars and pick only those caterpillars which become drab adults.
Cleanup and disposal of garden debris throughout the growing season, followed by a thorough end-of-season cleanup, will help reduce the size of future generations of caterpillars. Furthermore, many insects--such as fireflies, ground beetles, soldier beetles, stink bugs, and tachinid flies-- prey upon or parasitize caterpillars, and will gladly assist you in your quest to keep caterpillar numbers under control.
Specific recommendations for flowers. An effective but less selective control for caterpillars is to dust or spray all parts of the leaves on which they are feeding (especially the undersides) with BT (Bacillus thuringiensis). Apply at 3-5 day intervals, reapplying after rain, until caterpillars cease to be a problem. For an infestation that is out of control, spray all sides of the leaves with pyrethrum; usually two applications spaced 3-4 days apart will solve the problem.
Specific recommendations for vegetables. There are some species of caterpillars that are particularly troublesome in the vegetable garden. Cabbage loopers, as their name suggests, are very fond of cabbage (including the Chinese variety), and will also feed on lima and snap beans, broccoli, brussel sprouts, cauliflower, lettuce, parsley, radishes, rutabagas and turnips. They damage crops by chewing small to large ragged holes in the foliage, and by boring into developing heads of cabbage family crops. The best control strategy is to spray plants with BT (Bacillus thuringiensis) every 2 weeks until pests are under control, or until heads begin to form in the case of cabbage family members. Other effective controls are handpicking; spraying plants with liquefied and strained cabbage loopers, or hot pepper spray; and planting trap crops such as celery or amaranth. For serious infestations, spray leaves with pyrethrum.
Another caterpillar that shares the cabbage looper's taste in plants is the imported cabbage worm. Symptoms of infestation include ragged holes in the leaves and bits of green excrement; you will also notice white butterflies skipping about from plant to plant. Like cabbage loopers, imported cabbage worms eventually bore into the developing heads of cabbage family plants, turning them into mush in the process. The most effective strategy for controlling this pest is to use an agricultural fleece or net barrier and a preventive BT (Bacillus thuringiensis) spray early in the season, then to use more BT for later infestations. A thorough fall cleanup is essential to prevent recurring infestations, since these pests overwinter in the soil or on garden litter. After harvesting crops, promptly remove all old plants and overgrown weeds, leaving the soil completely bare, then cultivate soil to a depth of 6-8 inches. Make sure old plants are actively composted or destroyed.
European corn borers are most notorious for boring holes into the stalks and ears of the corn plant, but also damage chard, peppers, potatoes and tomatoes. Squash vine borers affect crops such as cucumbers, muskmelons, pumpkins, squash (summer and winter), and watermelons by burrowing into their vines and causing them to wilt. For more information on these pests, see Caterpillars - Borers and Miners: Specific recommendations for vegetables.
Parsleyworms are 2 inches long, and are a brightly colored green with yellow-dotted black bands across each body segment. They give off an odor and project orange horns when they are upset. They will someday become lovely, black swallowtail butterflies, so carefully weigh their aesthetic value against the damage inflicted on your carrots, celery, dill, fennel, parsley and parsnip plants before deciding to destroy them. If you decide the parsleyworms are eating excessively into your harvest, reduce their numbers by handpicking them, or try attracting birds such as northern orioles, barn swallows, bluebirds, chickadees, flycatchers and kinglets into your garden.
The tomato hornworm is a large (3 to 5 inches long), green caterpillar with a horn projecting from its rear; it will eventually become a moth whose diurnal feeding habits and ability to hover have earned it the name of "hummingbird moth." The hornworm chews holes in the leaves of dill, eggplant, pepper, potato and tomato plants, and will sometimes also damage the fruits of the latter three. Check damaged plants for dark colored droppings, and spray them with water; this should cause the hornworms to thrash about and enable you to handpick them more easily. If you notice papery cocoons on their backs, remove but don't destroy the caterpillars: they are already doomed by natural parasites, which should be allowed to reproduce. You can also control hornworms with a Bacillus thuringiensis (BT) spray, or a pyrethrum spray if the infestation gets out of hand.
Specific recommendations for trees. This section will address three pests that primarily affect trees: codling moths, gypsy moths, and tent caterpillars. The larvae of codling moths primarily damage apple, apricot and pear crops, both when they are immature and again when they have ripened. Symptoms of infestation include holes in the fruit skin, tunnels through the fruit, and fecal waste in the core; check also for mounds of excrement around the tunnel entrances and for cocoons in the bark crevices. To control this pest, use a preventive spray of Bacillus thuringiensis (BT) early in the season and light horticultural oil later in the season to get the newly hatched larvae before they bore into the fruit. In addition, set out sticky traps to snare the moths during their emergence times (check with orchard growers in your area).
Gypsy moths are imported pests that primarily affect the eastern United States, and their populations fluctuate between sheer nuisance to plague proportions. Their larvae damage host trees by devouring their leaves, often leaving them (and sometimes entire forests) completely defoliated. When the larvae are young, they chew only around leaf edges; by the time they are an inch long, large holes begin to appear in leaves. In July, the mature caterpillars encase themselves in brown shells to pupate. To control this voracious pest, particularly when its population is waxing, spray trees with Bacillus thuringiensis (BT) every 10 to 14 days from late April to mid-June. In June, wrap trunks of vulnerable trees with a piece of burlap a foot wide, hung about chest high; tie it at the center with heavy twine, letting the top fold over to form a skirt. When caterpillars descend from the tree each morning, they will hide under the fold. In the late afternoon, put on garden gloves and sweep the caterpillars off into a container of detergent and water. To prevent future gypsy moth problems, check for egg clusters on lawn furniture before putting it away in the fall, and stone walls, woodpiles, fences, garages and outbuildings throughout the winter. Destroy egg masses by scraping them into a can of kerosene, gasoline or water, or by burning them. Reduce debris on the ground that can serve as protection for egg masses, larvae and pupae.
Tent caterpillars form large, tent-like, silken nests in the forks of tree branches, and can defoliate their woody hosts if given the chance. Remove the nests and destroy the caterpillars by hand. Spray the tree with Bacillus thuringiensis (BT) as soon as you see the nests begin to reappear, and repeat every 5 to 7 days until the pest is gone.
Caterpillars inflict damage by eating the foliage and stems of just about any plant in your flower or vegetable garden, as well as your fruit and shade trees. Furthermore, they are voracious eaters, and can defoliate a plant in a short period of time. Telltale symptoms of a caterpillar infestation are holes in leaves and chewed leaf edges, as well as leaves that are rolled up or fastened with silk.
If you are able to catch the infestation early on, the best strategy for controlling caterpillars is to handpick them, then crush them or drop them in a pail of soapy water. Make sure you also remove rolled or folded leaves that shelter the caterpillars. (Make sure you wear gloves before handling saddleback caterpillars, as their sting is severe.) To prevent inadvertently killing desirable butterflies- and moths-to-be, use a good field guide such as Peterson First Guide to Caterpillars and pick only those caterpillars which become drab adults.
Cleanup and disposal of garden debris throughout the growing season, followed by a thorough end-of-season cleanup, will help reduce the size of future generations of caterpillars. Furthermore, many insects--such as fireflies, ground beetles, soldier beetles, stink bugs, and tachinid flies-- prey upon or parasitize caterpillars, and will gladly assist you in your quest to keep caterpillar numbers under control.
Specific recommendations for flowers. An effective but less selective control for caterpillars is to dust or spray all parts of the leaves on which they are feeding (especially the undersides) with BT (Bacillus thuringiensis). Apply at 3-5 day intervals, reapplying after rain, until caterpillars cease to be a problem. For an infestation that is out of control, spray all sides of the leaves with pyrethrum; usually two applications spaced 3-4 days apart will solve the problem.
Specific recommendations for vegetables. There are some species of caterpillars that are particularly troublesome in the vegetable garden. Cabbage loopers, as their name suggests, are very fond of cabbage (including the Chinese variety), and will also feed on lima and snap beans, broccoli, brussel sprouts, cauliflower, lettuce, parsley, radishes, rutabagas and turnips. They damage crops by chewing small to large ragged holes in the foliage, and by boring into developing heads of cabbage family crops. The best control strategy is to spray plants with BT (Bacillus thuringiensis) every 2 weeks until pests are under control, or until heads begin to form in the case of cabbage family members. Other effective controls are handpicking; spraying plants with liquefied and strained cabbage loopers, or hot pepper spray; and planting trap crops such as celery or amaranth. For serious infestations, spray leaves with pyrethrum.
Another caterpillar that shares the cabbage looper's taste in plants is the imported cabbage worm. Symptoms of infestation include ragged holes in the leaves and bits of green excrement; you will also notice white butterflies skipping about from plant to plant. Like cabbage loopers, imported cabbage worms eventually bore into the developing heads of cabbage family plants, turning them into mush in the process. The most effective strategy for controlling this pest is to use an agricultural fleece or net barrier and a preventive BT (Bacillus thuringiensis) spray early in the season, then to use more BT for later infestations. A thorough fall cleanup is essential to prevent recurring infestations, since these pests overwinter in the soil or on garden litter. After harvesting crops, promptly remove all old plants and overgrown weeds, leaving the soil completely bare, then cultivate soil to a depth of 6-8 inches. Make sure old plants are actively composted or destroyed.
European corn borers are most notorious for boring holes into the stalks and ears of the corn plant, but also damage chard, peppers, potatoes and tomatoes. Squash vine borers affect crops such as cucumbers, muskmelons, pumpkins, squash (summer and winter), and watermelons by burrowing into their vines and causing them to wilt. For more information on these pests, see Caterpillars - Borers and Miners: Specific recommendations for vegetables.
Parsleyworms are 2 inches long, and are a brightly colored green with yellow-dotted black bands across each body segment. They give off an odor and project orange horns when they are upset. They will someday become lovely, black swallowtail butterflies, so carefully weigh their aesthetic value against the damage inflicted on your carrots, celery, dill, fennel, parsley and parsnip plants before deciding to destroy them. If you decide the parsleyworms are eating excessively into your harvest, reduce their numbers by handpicking them, or try attracting birds such as northern orioles, barn swallows, bluebirds, chickadees, flycatchers and kinglets into your garden.
The tomato hornworm is a large (3 to 5 inches long), green caterpillar with a horn projecting from its rear; it will eventually become a moth whose diurnal feeding habits and ability to hover have earned it the name of "hummingbird moth." The hornworm chews holes in the leaves of dill, eggplant, pepper, potato and tomato plants, and will sometimes also damage the fruits of the latter three. Check damaged plants for dark colored droppings, and spray them with water; this should cause the hornworms to thrash about and enable you to handpick them more easily. If you notice papery cocoons on their backs, remove but don't destroy the caterpillars: they are already doomed by natural parasites, which should be allowed to reproduce. You can also control hornworms with a Bacillus thuringiensis (BT) spray, or a pyrethrum spray if the infestation gets out of hand.
Specific recommendations for trees. This section will address three pests that primarily affect trees: codling moths, gypsy moths, and tent caterpillars. The larvae of codling moths primarily damage apple, apricot and pear crops, both when they are immature and again when they have ripened. Symptoms of infestation include holes in the fruit skin, tunnels through the fruit, and fecal waste in the core; check also for mounds of excrement around the tunnel entrances and for cocoons in the bark crevices. To control this pest, use a preventive spray of Bacillus thuringiensis (BT) early in the season and light horticultural oil later in the season to get the newly hatched larvae before they bore into the fruit. In addition, set out sticky traps to snare the moths during their emergence times (check with orchard growers in your area).
Gypsy moths are imported pests that primarily affect the eastern United States, and their populations fluctuate between sheer nuisance to plague proportions. Their larvae damage host trees by devouring their leaves, often leaving them (and sometimes entire forests) completely defoliated. When the larvae are young, they chew only around leaf edges; by the time they are an inch long, large holes begin to appear in leaves. In July, the mature caterpillars encase themselves in brown shells to pupate. To control this voracious pest, particularly when its population is waxing, spray trees with Bacillus thuringiensis (BT) every 10 to 14 days from late April to mid-June. In June, wrap trunks of vulnerable trees with a piece of burlap a foot wide, hung about chest high; tie it at the center with heavy twine, letting the top fold over to form a skirt. When caterpillars descend from the tree each morning, they will hide under the fold. In the late afternoon, put on garden gloves and sweep the caterpillars off into a container of detergent and water. To prevent future gypsy moth problems, check for egg clusters on lawn furniture before putting it away in the fall, and stone walls, woodpiles, fences, garages and outbuildings throughout the winter. Destroy egg masses by scraping them into a can of kerosene, gasoline or water, or by burning them. Reduce debris on the ground that can serve as protection for egg masses, larvae and pupae.
Tent caterpillars form large, tent-like, silken nests in the forks of tree branches, and can defoliate their woody hosts if given the chance. Remove the nests and destroy the caterpillars by hand. Spray the tree with Bacillus thuringiensis (BT) as soon as you see the nests begin to reappear, and repeat every 5 to 7 days until the pest is gone.
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文章
Dummer. ゛☀
2017年09月16日
Leaf blight, Volutella pachysandrae, on Japanese pachysandra can be very detrimental to the plant. Two other leaf spots, Phyllosticta and Gloeosporium, cause leaf spots on foliage but are not as destructive as Volutella.
Ground covers, such as pachysandra, are sometimes used where grass or other plants will not grow due to low light. Consequently, the environmental stress factors, including prolonged leaf wetness or dry soils, can favor certain infectious diseases in the sites.
Symptoms and Diagnosis
Volutella blight begins as small, brown to tan spots on the leaves that enlarge to form blotches. These blotches can then spread and coalesce to form a blight where young growing tissue, especially leaves and twigs, are killed. Concentric line patterns form within the brown spots as leaves yellow and fall. Infected stems become brown to black in color and die.
Circular, spreading areas on diseased plants will be noticeable in the planting. The disease will be especially severe when plants are crowded and wet conditions prevail.
Life Cycle
Many spore masses cause the spread of the disease, which is especially rapid among plants that have been weakened by the attack of scale insects or by winter injury. The sexual stage of this fungus is Pseudonectria pachysandricola. Under moist conditions, salmon- to pink-colored masses of fungal spores form on the surface of dead stems in spring. Initial infections may lead to large patches of plants killed.
Integrated Pest Management Strategies
1. Maintain plant vigor. Purchase healthy plants and maintain this condition by watering during drought. Water early in the day so that drying occurs before evening. Avoid splashing of water. Fertilize as needed or as indicated by soil testing.
2. Select planting area carefully. Plants should be planted in a well-draining soil. If the site is persistently wet, amend the soil or raise the bed before planting.
3. Removal. Lift out and destroy severely diseased plants. Bury or remove from the site. Do not place in the compost pile.
4. Use fungicides. It is difficult to thoroughly apply fungicides unless using a forceful sprayer. Fungicides can be applied beginning in spring and at 7 to 14 day intervals through early summer. Once temperatures rise above 90 degrees F, discontinue application. Pesticides registered for use include chlorothalonil (Daconil), copper, mancozeb, maneb, and thiophanate methyl (Cleary 3336).
5. Mulch. Mulch with leaf mold in the spring to cover up fallen debris containing inoculum.
6. Thinning. Thin plants in fall, during dry weather, to remove dense growth.
7. Pests. Scale is a harmful pest on pachysandra and may make it more susceptible to disease. The female insects are dark brown and shaped like oyster shells. The males are smaller and narrower, pure white, and are very prominent on the leaves and stems. Heavy infestations of scale can be brought under control by applying summer oil spray before the new growth starts in spring. Follow this with several applications of a scale insecticide like malathion or Sevin at 2-week intervals or several applications of a scale insecticide or summer oil every 10 days to 2 weeks starting in mid-May.
Ground covers, such as pachysandra, are sometimes used where grass or other plants will not grow due to low light. Consequently, the environmental stress factors, including prolonged leaf wetness or dry soils, can favor certain infectious diseases in the sites.
Symptoms and Diagnosis
Volutella blight begins as small, brown to tan spots on the leaves that enlarge to form blotches. These blotches can then spread and coalesce to form a blight where young growing tissue, especially leaves and twigs, are killed. Concentric line patterns form within the brown spots as leaves yellow and fall. Infected stems become brown to black in color and die.
Circular, spreading areas on diseased plants will be noticeable in the planting. The disease will be especially severe when plants are crowded and wet conditions prevail.
Life Cycle
Many spore masses cause the spread of the disease, which is especially rapid among plants that have been weakened by the attack of scale insects or by winter injury. The sexual stage of this fungus is Pseudonectria pachysandricola. Under moist conditions, salmon- to pink-colored masses of fungal spores form on the surface of dead stems in spring. Initial infections may lead to large patches of plants killed.
Integrated Pest Management Strategies
1. Maintain plant vigor. Purchase healthy plants and maintain this condition by watering during drought. Water early in the day so that drying occurs before evening. Avoid splashing of water. Fertilize as needed or as indicated by soil testing.
2. Select planting area carefully. Plants should be planted in a well-draining soil. If the site is persistently wet, amend the soil or raise the bed before planting.
3. Removal. Lift out and destroy severely diseased plants. Bury or remove from the site. Do not place in the compost pile.
4. Use fungicides. It is difficult to thoroughly apply fungicides unless using a forceful sprayer. Fungicides can be applied beginning in spring and at 7 to 14 day intervals through early summer. Once temperatures rise above 90 degrees F, discontinue application. Pesticides registered for use include chlorothalonil (Daconil), copper, mancozeb, maneb, and thiophanate methyl (Cleary 3336).
5. Mulch. Mulch with leaf mold in the spring to cover up fallen debris containing inoculum.
6. Thinning. Thin plants in fall, during dry weather, to remove dense growth.
7. Pests. Scale is a harmful pest on pachysandra and may make it more susceptible to disease. The female insects are dark brown and shaped like oyster shells. The males are smaller and narrower, pure white, and are very prominent on the leaves and stems. Heavy infestations of scale can be brought under control by applying summer oil spray before the new growth starts in spring. Follow this with several applications of a scale insecticide like malathion or Sevin at 2-week intervals or several applications of a scale insecticide or summer oil every 10 days to 2 weeks starting in mid-May.
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文章
Dummer. ゛☀
2017年09月16日
This creeping juniper (Juniperus) died from overwatering
Overwatering is one of the more common causes of plant problem. Heavy and poorly drained soils are susceptible to becoming waterlogged. Roots growing in waterlogged soil may die because they cannot absorb the oxygen needed to function normally. The longer the air is cut off, the greater the root damage. The dying roots decay and cannot supply the plants with nutrients and water. Damage caused by over watering is frequently misdiagnosed as pest damage. However, pest damage rarely causes roots to concentrate near the surface of the soil. Plants stressed or injured by waterlogging can become abnormally susceptible to certain fungal pathogens. Phytophthora spp. for example, cause root rot most often in soils that are periodically waterlogged.
Symptoms and Diagnosis
Plants growing in soil that is too wet suffer from a lack of oxygen which leads to the death of roots and a loss of vigor in the plant. Stunted slow growth with yellowing leaves is a symptom of over watering. Plants may suffer from leaf scorch or leaf burn. Water soaked spots and blisters (Oedema) may appear on stems and leaves. The crown of the plant may rot. Damaged roots have little defense against the entrance of rot causing soil organisms. And so the plant dies of root rot.
Integrated Pest Management Strategies
1. Deep watering encourages roots to go deep down in the soil to where it is moist and a lot cooler. Water less frequently but for longer periods, so water reaches deep into soil. Good thorough watering promotes healthier plants.
2. Investigate using water conserving drip emitters or soaker hoses on a timer. Adjust watering frequency and amounts based on season, temperature and amount of rainfall. Overhead watering uses more water and can promote fungal disease. Also make sure you don't have leaking irrigation pipes or downspouts that are keeping the soil too wet in a location.
3. Add mulch to individual plants or beds. Add organic matter such as compost or rotted manure to plantings ---organic matter can improve drainage in heavy clay soils. Take care to keep mulch away from stems.
4. Use appropriate plants. Evaluate your site for new plantings. Choose plants with the appropriate water and cultural needs that will thrive on your site. Use water loving plants for moist poorly drained soils. Also consider native plants, which generally adapt better, have lower water demands and fewer pest problems.
5. Water only when necessary. Most plants will normally wilt in hot sun and may recover on their own later in the day as the sun moves. Make sure soil is not too wet based on the needs of particular plants before watering; you may end up by over watering.
6. A dry surface is not always a sign of water need. The surface generally dries out first and is not a true indicator of what is going on down deep near the plant root. Make use of a hand trowel or soil probe to check for moisture. Check for overwatering by digging into root zone or knocking a small potted plant out of its container. Soil that has been too long without oxygen usually smells sour or rotten.
7. Give priority to watering newly planted trees and shrubs. Young plants have not had sufficient time to establish deep root systems, and depend on surface water for survival. Do not let the root balls of newly planted trees and shrubs dry out completely or become too saturated. Before watering use a soil probe or a hand trowel. Remember that when plants are fully established, they will require less water.
Overwatering is one of the more common causes of plant problem. Heavy and poorly drained soils are susceptible to becoming waterlogged. Roots growing in waterlogged soil may die because they cannot absorb the oxygen needed to function normally. The longer the air is cut off, the greater the root damage. The dying roots decay and cannot supply the plants with nutrients and water. Damage caused by over watering is frequently misdiagnosed as pest damage. However, pest damage rarely causes roots to concentrate near the surface of the soil. Plants stressed or injured by waterlogging can become abnormally susceptible to certain fungal pathogens. Phytophthora spp. for example, cause root rot most often in soils that are periodically waterlogged.
Symptoms and Diagnosis
Plants growing in soil that is too wet suffer from a lack of oxygen which leads to the death of roots and a loss of vigor in the plant. Stunted slow growth with yellowing leaves is a symptom of over watering. Plants may suffer from leaf scorch or leaf burn. Water soaked spots and blisters (Oedema) may appear on stems and leaves. The crown of the plant may rot. Damaged roots have little defense against the entrance of rot causing soil organisms. And so the plant dies of root rot.
Integrated Pest Management Strategies
1. Deep watering encourages roots to go deep down in the soil to where it is moist and a lot cooler. Water less frequently but for longer periods, so water reaches deep into soil. Good thorough watering promotes healthier plants.
2. Investigate using water conserving drip emitters or soaker hoses on a timer. Adjust watering frequency and amounts based on season, temperature and amount of rainfall. Overhead watering uses more water and can promote fungal disease. Also make sure you don't have leaking irrigation pipes or downspouts that are keeping the soil too wet in a location.
3. Add mulch to individual plants or beds. Add organic matter such as compost or rotted manure to plantings ---organic matter can improve drainage in heavy clay soils. Take care to keep mulch away from stems.
4. Use appropriate plants. Evaluate your site for new plantings. Choose plants with the appropriate water and cultural needs that will thrive on your site. Use water loving plants for moist poorly drained soils. Also consider native plants, which generally adapt better, have lower water demands and fewer pest problems.
5. Water only when necessary. Most plants will normally wilt in hot sun and may recover on their own later in the day as the sun moves. Make sure soil is not too wet based on the needs of particular plants before watering; you may end up by over watering.
6. A dry surface is not always a sign of water need. The surface generally dries out first and is not a true indicator of what is going on down deep near the plant root. Make use of a hand trowel or soil probe to check for moisture. Check for overwatering by digging into root zone or knocking a small potted plant out of its container. Soil that has been too long without oxygen usually smells sour or rotten.
7. Give priority to watering newly planted trees and shrubs. Young plants have not had sufficient time to establish deep root systems, and depend on surface water for survival. Do not let the root balls of newly planted trees and shrubs dry out completely or become too saturated. Before watering use a soil probe or a hand trowel. Remember that when plants are fully established, they will require less water.
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文章
Dummer. ゛☀
2017年09月16日
Angular leaf spot is a common bacterial disease of Goldsturm coneflower (Rudbeckia fulgida var. sullivantii 'Goldsturm')
Two common leaf spots affect rudbeckia in the St. Louis area. Both rarely endanger the survival of the plant but both can cause depreciation of the foliage. One is caused by a fungus and the other by a bacterium.
Symptoms and Diagnosis
Septoria leaf spot is caused by the fungus Septoria rudbeckiae and causes small 1/8 - 1/4 inch spots on the leaves. Small, black, pinpoint size fruiting bodies (pycnidia) form in the center of the spots. Lower leaves are affected first. The disease then moves up the plant by splashing water. Angular leaf spot of rudbeckia is most common on the cultivar 'Goldsturm'. It begins as small, brown, angular spots on lower leaves, which may appear water-soaked but can quickly expand to affect the whole leaf. It begins at the base of the plant and moves up. Angular leaf spot is caused by a bacterium. The absence of fungal pycnidia and the presence of bacterial streaming under microscopic examination can be used to differentiate angular leaf spot from septoria leaf spot.
Life Cycle
Both organisms overwinter in infected debris in the garden. Initial infection occurs in late spring or early summer on the lower leaves and then spread up the plant. Plants are rarely killed, but plants can look unsightly by early fall.
Integrated Pest Management Strategies
1. Clean up old foliage each fall and then live with the disease. Sanitation can go a long way to helping control both diseases. Collect and dispose of old foliage in the fall or by late winter to help prevent early infection.
2. Provide good air circulation and avoid overhead watering. Keeping the leaves dry and help prevent movement of the fungi or bacteria by not watering overhead. If irrigation is necessary, use soaker hoses or at least water early in the day so the foliage can dry before nightfall.
3. Apply chemical protectants. Septoria leaf spot can be controlled with fungicides containing chlorothalonil or copper. Angular leaf spot can be controlled by applying a copper-based fungicide such as Bordeaux mixture as needed started in early spring. Kocide is also effective. Apply at the first signs of disease to protect healthy yet unaffected foliage.
Two common leaf spots affect rudbeckia in the St. Louis area. Both rarely endanger the survival of the plant but both can cause depreciation of the foliage. One is caused by a fungus and the other by a bacterium.
Symptoms and Diagnosis
Septoria leaf spot is caused by the fungus Septoria rudbeckiae and causes small 1/8 - 1/4 inch spots on the leaves. Small, black, pinpoint size fruiting bodies (pycnidia) form in the center of the spots. Lower leaves are affected first. The disease then moves up the plant by splashing water. Angular leaf spot of rudbeckia is most common on the cultivar 'Goldsturm'. It begins as small, brown, angular spots on lower leaves, which may appear water-soaked but can quickly expand to affect the whole leaf. It begins at the base of the plant and moves up. Angular leaf spot is caused by a bacterium. The absence of fungal pycnidia and the presence of bacterial streaming under microscopic examination can be used to differentiate angular leaf spot from septoria leaf spot.
Life Cycle
Both organisms overwinter in infected debris in the garden. Initial infection occurs in late spring or early summer on the lower leaves and then spread up the plant. Plants are rarely killed, but plants can look unsightly by early fall.
Integrated Pest Management Strategies
1. Clean up old foliage each fall and then live with the disease. Sanitation can go a long way to helping control both diseases. Collect and dispose of old foliage in the fall or by late winter to help prevent early infection.
2. Provide good air circulation and avoid overhead watering. Keeping the leaves dry and help prevent movement of the fungi or bacteria by not watering overhead. If irrigation is necessary, use soaker hoses or at least water early in the day so the foliage can dry before nightfall.
3. Apply chemical protectants. Septoria leaf spot can be controlled with fungicides containing chlorothalonil or copper. Angular leaf spot can be controlled by applying a copper-based fungicide such as Bordeaux mixture as needed started in early spring. Kocide is also effective. Apply at the first signs of disease to protect healthy yet unaffected foliage.
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文章
Dummer. ゛☀
2017年09月16日
Herbicide damage can be hard to diagnose. A trained individual can generally tell when damage from an herbicide is a possible cause, but validation requires a laboratory test of the plant tissue and/or the soil while the chemical is still present. Such tests can cost between $65 and $150 per sample or more. Individual tests need to be made for each suspected herbicide. Testing may not be available for some herbicides. More commonly, a circumstantial case is made after a thorough examination of the damaged plant(s), surrounding plants, the pattern of damage, the likelihood of damage occurring given the suspected point of herbicide application, and the history of the symptoms.
Symptoms and Diagnosis
General symptoms can include one or more of the following symptoms: curling or cupped leaves, stunted growth, discolored leaves, or leaves with dead spots. The same herbicide may cause different symptoms on different plant species.
Since herbicides do not leave a "calling card" like mites, insects, and diseases (but the damage they cause can be mistaken for herbicide damage), it is advised to rule these out first. Other disorders that produce symptoms that can resemble herbicide damage include virus diseases, adverse weather, salt damage, drought, soil compaction, misapplied fertilizers, root stress, and nutrient deficiencies. Excluding these as causes requires close examination of the site and attention to patterns. Is the pattern of damaged plants consistent with drifting spray? Is more than just one kind of plant affected? Did the symptoms appear within one or two days (in most cases) of the suspected application of an herbicide? Were any lawn weed control products used in the area, including weed and feed products containing an herbicide? The answer to these and other questions can help make a circumstantial case of herbicide damage.
Recovery Prognosis
Recovery of plants damaged by herbicides is dependent upon many factors including amount of initial damage incurred as well as what herbicide caused the damage. Trees and shrubs that receive minor damage from a broadleaf herbicide such as 2,4-D are likely to recover or have only minor damage. Trees and shrubs that have been damaged by dicamba which was applied to a lawn area and then was washed down into the root system of trees and shrubs can show damage for several years as they gradually recover. Plants damaged by soil sterilant herbicides are the least likely to recover.
Plants that show signs of growing out of the problem will likely recover. Plants that appear to lose vigor may not. The survival of damaged plants can be increased by reducing other stresses. Water during dry periods, fertilize according to a soil test report to increase vigor, and watch for and control any insect or disease problems.
Symptoms and Diagnosis
General symptoms can include one or more of the following symptoms: curling or cupped leaves, stunted growth, discolored leaves, or leaves with dead spots. The same herbicide may cause different symptoms on different plant species.
Since herbicides do not leave a "calling card" like mites, insects, and diseases (but the damage they cause can be mistaken for herbicide damage), it is advised to rule these out first. Other disorders that produce symptoms that can resemble herbicide damage include virus diseases, adverse weather, salt damage, drought, soil compaction, misapplied fertilizers, root stress, and nutrient deficiencies. Excluding these as causes requires close examination of the site and attention to patterns. Is the pattern of damaged plants consistent with drifting spray? Is more than just one kind of plant affected? Did the symptoms appear within one or two days (in most cases) of the suspected application of an herbicide? Were any lawn weed control products used in the area, including weed and feed products containing an herbicide? The answer to these and other questions can help make a circumstantial case of herbicide damage.
Recovery Prognosis
Recovery of plants damaged by herbicides is dependent upon many factors including amount of initial damage incurred as well as what herbicide caused the damage. Trees and shrubs that receive minor damage from a broadleaf herbicide such as 2,4-D are likely to recover or have only minor damage. Trees and shrubs that have been damaged by dicamba which was applied to a lawn area and then was washed down into the root system of trees and shrubs can show damage for several years as they gradually recover. Plants damaged by soil sterilant herbicides are the least likely to recover.
Plants that show signs of growing out of the problem will likely recover. Plants that appear to lose vigor may not. The survival of damaged plants can be increased by reducing other stresses. Water during dry periods, fertilize according to a soil test report to increase vigor, and watch for and control any insect or disease problems.
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文章
Dummer. ゛☀
2017年09月16日
Foliar nematodes, Aphelenchoides spp., are considered disease-causing organisms that attack plant parts above the ground in over 200 host plants. They are an emerging problem for gardeners because of this broad host range, ability to spread quickly and lack of symptom recognition. Additionally, there are few products registered for use in the home landscape that can limit their infection and spread. Some of the most common hosts include anemone, strawberry, hosta, phlox, verbena, zinnia, carnation, impatiens, begonia, fern and African violet.
Symptoms and Diagnosis
The two most prominent foliar nematodes are A. ritzemabosi called the chrysanthemum foliar nematode and A. fragariae called the strawberry crimp or fern nematode. Both are serious pathogens of ornamental plants both in the greenhouse and outside in the garden. However, their host ranges rarely overlap except on African violet, begonia, gloxinia, Siberian bugloss, violet and verbena. The most prominent symptoms occur in the leaves of infected plants. Two interveinal symptom types are commonly found. The first is a development of linear lesions between the leaf veins causing the leaf to become striped in appearance. Plants that have parallel venation like hosta are likely to display this leaf pattern. The second leaf symptom which is more common is the development of angular, water-soaked lesions occurring between the veins of netted-veined plants. These lesions will become brown and eventually turn black and perhaps drop out of the leaf leaving a ragged, wind-tattered appearance. Other symptoms may appear as stunting, leaf proliferation or bunching of leaves around the crown, multicolored leaves, lack of flowering and plant death. It is not uncommon to find new leaves emerging without symptoms while older leaves turn brown and collapse or fall. This occurs because the spread of nematodes requires free moisture. Lack of water on the leaves causes them to become localized so that they cannot move to new plant parts. Thus, under dry conditions, new leaves may appear unaffected.
Life Cycle
Unique to this group of pathogens, foliar nematodes live in and feed upon the aerial portion of the plant, mostly leaves, and are rarely associated with the soil unless it is within infested plant debris. A common over wintering site is within the crown of the plant where new leaves will emerge in spring. They commonly spread from plant to plant by splashing water and leaf contact. Nematodes can swim in a thin film of water to move upward towards leaves where they enter stomata. Another way they spread is by vegetative cuttings of leaves, stems and crowns. Gardeners who are active in propagation are likely to move the pathogen with every division. Nematodes remain active, feeding on leaf tissue and repeating their life cycle multiple times in the growing season. Once it becomes cooler, they will migrate towards the plant crown, live in dormant buds or leaf debris.
Integrated Pest Management Strategies
1. Sanitation: remove all infested debris from the plant and ground. This should be buried or burned. Floors and benches of propagation areas should be thoroughly cleaned of debris. Tools and containers should be heat treated in an oven or steamed for 30 minutes at 180 F.
2. Destroy infested plants: it is almost impossible to rid the plant of foliar nematodes. Therefore, it is best to destroy infested plants. Plants that are suspected of being infected should be isolated from healthy plants.
3. Select disease-free plants: Only healthy, nematode-free plants should be purchased and used for propagation stock. Contact between plants and extended periods of free moisture from overhead irrigation should be avoided. Dormant plant material can be treated with warm water (120 F) for 15 minutes to eliminate the nematode infestation on valuable planting stock.
4. Resistance: Some resistant cultivars of chrysanthemum are available. At this time, no resistant varieties are known for other garden plants.
5. Pesticides: Commercial growers who are certified for using nematicides can control foliar nematodes on greenhouse and nursery crops. There are no nematicides labeled for residential users.
Symptoms and Diagnosis
The two most prominent foliar nematodes are A. ritzemabosi called the chrysanthemum foliar nematode and A. fragariae called the strawberry crimp or fern nematode. Both are serious pathogens of ornamental plants both in the greenhouse and outside in the garden. However, their host ranges rarely overlap except on African violet, begonia, gloxinia, Siberian bugloss, violet and verbena. The most prominent symptoms occur in the leaves of infected plants. Two interveinal symptom types are commonly found. The first is a development of linear lesions between the leaf veins causing the leaf to become striped in appearance. Plants that have parallel venation like hosta are likely to display this leaf pattern. The second leaf symptom which is more common is the development of angular, water-soaked lesions occurring between the veins of netted-veined plants. These lesions will become brown and eventually turn black and perhaps drop out of the leaf leaving a ragged, wind-tattered appearance. Other symptoms may appear as stunting, leaf proliferation or bunching of leaves around the crown, multicolored leaves, lack of flowering and plant death. It is not uncommon to find new leaves emerging without symptoms while older leaves turn brown and collapse or fall. This occurs because the spread of nematodes requires free moisture. Lack of water on the leaves causes them to become localized so that they cannot move to new plant parts. Thus, under dry conditions, new leaves may appear unaffected.
Life Cycle
Unique to this group of pathogens, foliar nematodes live in and feed upon the aerial portion of the plant, mostly leaves, and are rarely associated with the soil unless it is within infested plant debris. A common over wintering site is within the crown of the plant where new leaves will emerge in spring. They commonly spread from plant to plant by splashing water and leaf contact. Nematodes can swim in a thin film of water to move upward towards leaves where they enter stomata. Another way they spread is by vegetative cuttings of leaves, stems and crowns. Gardeners who are active in propagation are likely to move the pathogen with every division. Nematodes remain active, feeding on leaf tissue and repeating their life cycle multiple times in the growing season. Once it becomes cooler, they will migrate towards the plant crown, live in dormant buds or leaf debris.
Integrated Pest Management Strategies
1. Sanitation: remove all infested debris from the plant and ground. This should be buried or burned. Floors and benches of propagation areas should be thoroughly cleaned of debris. Tools and containers should be heat treated in an oven or steamed for 30 minutes at 180 F.
2. Destroy infested plants: it is almost impossible to rid the plant of foliar nematodes. Therefore, it is best to destroy infested plants. Plants that are suspected of being infected should be isolated from healthy plants.
3. Select disease-free plants: Only healthy, nematode-free plants should be purchased and used for propagation stock. Contact between plants and extended periods of free moisture from overhead irrigation should be avoided. Dormant plant material can be treated with warm water (120 F) for 15 minutes to eliminate the nematode infestation on valuable planting stock.
4. Resistance: Some resistant cultivars of chrysanthemum are available. At this time, no resistant varieties are known for other garden plants.
5. Pesticides: Commercial growers who are certified for using nematicides can control foliar nematodes on greenhouse and nursery crops. There are no nematicides labeled for residential users.
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文章
Dummer. ゛☀
2017年09月16日
The water needs of different plants vary greatly. Some factors to consider include the species and age of the plant, the type of soil in which it is planted, and its exposure. The symptoms of drought stress may be similar to the symptoms of over watering or even to some pest and disease problems. It is important to identify the causes of the problem in order to take corrective steps.
Symptoms and Diagnosis
With mild water deficiency, plants are usually slow growing and stunted. Some plant leaves turn from shiny to dull at first signs of stress. Grasses, which are the first to show the loss of water in the landscape, will show signs of wilt. Footprints in wilted grass persist instead of disappearing as grass blades spring upright.
Under long term water stress, plants might permanently wilt or stop growing; they may have diminished crops and discolored leaves, flower buds and flowers. Plants may eventually die. Bare spots will appear in ground covers. Water-stressed plantings may show the effects of weeds, insect pests, and diseases.
Drought symptoms can be very confusing, and can vary with different types of plants. Woody plants under drought stress can have many symptoms including yellowing, wilting leaves that develop early fall color and burning or scorching on edges of leaves. Plants may drop some or all of their leaves and appear dead.
Most established woody plants recover when watered. Plants that appear to be dead, having dropped all or most of their leaves, might recover when watered. Scrape the outer layer of a twig or the bark to see if a green layer exists indicating it is still alive. Do not remove this plant the first season. Wait until the following year to see if it recovers.
Integrated Pest Management Strategies
1. Water well. Deep watering encourages roots to go deep down in the soil to where it is moist and a lot cooler. Water less frequently but for longer periods, so water reaches deep into soil. Good thorough watering promotes healthier plants.
2. Investigate using water conserving drip emitters or soaker hoses on a timer. Adjust watering frequency and amounts based on season, temperature and amount of rainfall. Overhead watering uses more water and can promote fungal disease.
3. Add mulch to individual plants or beds. Add organic matter such as compost or rotted manure to plantings ---drought becomes less of a problem as soils with high humus levels hold more moisture. Take care to keep mulch away from stems.
4. Plant selection. Use appropriate plants, which catalogs and plant tags often marked as drought tolerant or resistant. Also consider native plants, which generally adapt better, have lower water demands and fewer pest problems.
5. Water only when necessary, based on condition of the plant. Most plants will normally wilt in hot sun, and then recover when watered. Also, a dry surface is not always a sign of water need. The surface generally dries out first and is not a true indicator of what is going on down deep near the plant root. Make use of a hand trowel or soil probe to check for moisture.
6. Give priority to watering newly planted trees and shrubs during periods of drought. Young plants have not had sufficient time to establish deep root systems, and depend on surface water for survival. Do not let the root balls of newly planted trees and shrubs dry out completely or become too saturated. Before watering use a soil probe or a hand trowel. Inspect plants several times a week during drought conditions.
Symptoms and Diagnosis
With mild water deficiency, plants are usually slow growing and stunted. Some plant leaves turn from shiny to dull at first signs of stress. Grasses, which are the first to show the loss of water in the landscape, will show signs of wilt. Footprints in wilted grass persist instead of disappearing as grass blades spring upright.
Under long term water stress, plants might permanently wilt or stop growing; they may have diminished crops and discolored leaves, flower buds and flowers. Plants may eventually die. Bare spots will appear in ground covers. Water-stressed plantings may show the effects of weeds, insect pests, and diseases.
Drought symptoms can be very confusing, and can vary with different types of plants. Woody plants under drought stress can have many symptoms including yellowing, wilting leaves that develop early fall color and burning or scorching on edges of leaves. Plants may drop some or all of their leaves and appear dead.
Most established woody plants recover when watered. Plants that appear to be dead, having dropped all or most of their leaves, might recover when watered. Scrape the outer layer of a twig or the bark to see if a green layer exists indicating it is still alive. Do not remove this plant the first season. Wait until the following year to see if it recovers.
Integrated Pest Management Strategies
1. Water well. Deep watering encourages roots to go deep down in the soil to where it is moist and a lot cooler. Water less frequently but for longer periods, so water reaches deep into soil. Good thorough watering promotes healthier plants.
2. Investigate using water conserving drip emitters or soaker hoses on a timer. Adjust watering frequency and amounts based on season, temperature and amount of rainfall. Overhead watering uses more water and can promote fungal disease.
3. Add mulch to individual plants or beds. Add organic matter such as compost or rotted manure to plantings ---drought becomes less of a problem as soils with high humus levels hold more moisture. Take care to keep mulch away from stems.
4. Plant selection. Use appropriate plants, which catalogs and plant tags often marked as drought tolerant or resistant. Also consider native plants, which generally adapt better, have lower water demands and fewer pest problems.
5. Water only when necessary, based on condition of the plant. Most plants will normally wilt in hot sun, and then recover when watered. Also, a dry surface is not always a sign of water need. The surface generally dries out first and is not a true indicator of what is going on down deep near the plant root. Make use of a hand trowel or soil probe to check for moisture.
6. Give priority to watering newly planted trees and shrubs during periods of drought. Young plants have not had sufficient time to establish deep root systems, and depend on surface water for survival. Do not let the root balls of newly planted trees and shrubs dry out completely or become too saturated. Before watering use a soil probe or a hand trowel. Inspect plants several times a week during drought conditions.
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成长记
meriunkat
2017年09月16日
Its kind small but i forgot to post this plant is no longer mine, i gave it to my mother in law as a gift. Official goodbye to this little guy.
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求助
Katrina
2017年09月16日
My Senecio Vitalis (Blue Chalk Fingers) plant keeps having limbs shrivel and die! Please help! I keep it out of direct sunlight and only water it every 3 to 4 days depending on need. I just separated the roots of the two plants and repoted a week ago.
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sunnyzou：maybe you hurt the roots when you repotting. no direct sunlight until they recovered growth.
Ueca：I know this sounds somewhat counter-intuitive, but try giving it a bit more sunlight.
成长记
Ueca
2017年09月16日
It's now been a full year since this plant first appeared as a speck on a fallen leaf from my local department store.
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文章
Miss Chen
2017年09月16日
La cola de caballo, Equisetum arvense L, es un arbusto perenne perteneciente a la familia Equisetaceae. Ha sido uno de los remedios naturales que utilizaban culturas antiguas debido a sus propiedades medicinales. Para fines medicinales se utiliza la planta entera.
Propiedades medicinales de la cola de caballo, Equisetum arvense L
Contiene ácido silícico, taninos, flavonoides, sapónidos, entre otros compuestos. Tiene acción astringente, diurética, antiinflamatoria, antiséptica, antifúngica, tónica, antihemorrágica, antioxidante.
Beneficios y usos de la cola de caballo
Mejora las dolencias de las articulaciones
Tiene propiedades diuréticas
Depura la sangre
Se usa para la conjuntivitis
Combate la retención de líquidos
Fortalece las uñas y el cabello
Se usa para los cálculos de riñón y vejiga
Mejora las infecciones urinarias (uretritis, cistitis)
Elimina la caspa
Cuida la glándula prostática y evita la prostatitis
Ayuda a cicatrizar las heridas
Fortalece los capilares sanguíneos
Frena las hemorragias
Es utilizada para la incontinencia urinaria
Favorece la pérdida de peso
Protege los tendones
Es efectiva para la diarrea
Combate la inflamación
Se utiliza para la gingivitis
Fortalece los huesos combatiendo la osteoporosis
Remedios caseros con cola de caballo
* Elaborando compresas con la infusión de la planta podemos tratar las afecciones cutáneas, quemaduras, eccemas, dermatitis, los picores, llagas o fístulas.
* Para eliminar o reducir las hemorroides preparamos emplastos
* Haciendo gárgaras con la infusión mejoraremos las anginas. Además combatiremos el sangrado de encías y la gingivitis.
* Para mantener un cabello fuerte y sano masajea el cuero cabelludo con la infusión de la planta.
* Si tienes huerto o jardín con la cola de caballo puedes combatir el mildiu, oídio, roya o botritis, gracias a su acción antifúngica. Sólo tienes que dejar la planta cortada macerando en agua durante 48 horas.
Propiedades medicinales de la cola de caballo, Equisetum arvense L
Contiene ácido silícico, taninos, flavonoides, sapónidos, entre otros compuestos. Tiene acción astringente, diurética, antiinflamatoria, antiséptica, antifúngica, tónica, antihemorrágica, antioxidante.
Beneficios y usos de la cola de caballo
Mejora las dolencias de las articulaciones
Tiene propiedades diuréticas
Depura la sangre
Se usa para la conjuntivitis
Combate la retención de líquidos
Fortalece las uñas y el cabello
Se usa para los cálculos de riñón y vejiga
Mejora las infecciones urinarias (uretritis, cistitis)
Elimina la caspa
Cuida la glándula prostática y evita la prostatitis
Ayuda a cicatrizar las heridas
Fortalece los capilares sanguíneos
Frena las hemorragias
Es utilizada para la incontinencia urinaria
Favorece la pérdida de peso
Protege los tendones
Es efectiva para la diarrea
Combate la inflamación
Se utiliza para la gingivitis
Fortalece los huesos combatiendo la osteoporosis
Remedios caseros con cola de caballo
* Elaborando compresas con la infusión de la planta podemos tratar las afecciones cutáneas, quemaduras, eccemas, dermatitis, los picores, llagas o fístulas.
* Para eliminar o reducir las hemorroides preparamos emplastos
* Haciendo gárgaras con la infusión mejoraremos las anginas. Además combatiremos el sangrado de encías y la gingivitis.
* Para mantener un cabello fuerte y sano masajea el cuero cabelludo con la infusión de la planta.
* Si tienes huerto o jardín con la cola de caballo puedes combatir el mildiu, oídio, roya o botritis, gracias a su acción antifúngica. Sólo tienes que dejar la planta cortada macerando en agua durante 48 horas.
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成长记
WHdeckgardener
2017年09月16日
I've never had a pitcher plant bloom!
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WHdeckgardener：@fekorod yes, the flower stalk comes out of the leaf.
fekorod：The first picture... is that a leaf?
文章
Dummer. ゛☀
2017年09月15日
Concerns about the presence of the Oak Pinhole Borer (Platypus cylindrus) in oak logs imported from the continent have been raised with the Plant Health Service.
This beetle used to be regarded as rare in this country but populations grew in the south and south-east as a result of the gales in 1987 when it took advantage of the sudden glut of suitable breeding material. A similar situation now exists on the continent following the severe gales in the winter of 1999 and buyers are reporting damage to oak logs bought in from mainland Europe. Adults emerge from June to September from larvae that may have been present for up to two years.
The beetle is the only borer which, in the absence of fungal decay, will bore into the heartwood of oak thus reducing its value. However, it is not on the quarantine list as it is already present in this country and is not a pest of standing healthy trees. There are, therefore, no quarantine controls against it and there are no treatments available that will provide protection.
We strongly recommend that anyone intending to purchase oak logs from areas where the beetle is known to occur specifies wood that is free from signs of wood borer damage.
This beetle used to be regarded as rare in this country but populations grew in the south and south-east as a result of the gales in 1987 when it took advantage of the sudden glut of suitable breeding material. A similar situation now exists on the continent following the severe gales in the winter of 1999 and buyers are reporting damage to oak logs bought in from mainland Europe. Adults emerge from June to September from larvae that may have been present for up to two years.
The beetle is the only borer which, in the absence of fungal decay, will bore into the heartwood of oak thus reducing its value. However, it is not on the quarantine list as it is already present in this country and is not a pest of standing healthy trees. There are, therefore, no quarantine controls against it and there are no treatments available that will provide protection.
We strongly recommend that anyone intending to purchase oak logs from areas where the beetle is known to occur specifies wood that is free from signs of wood borer damage.
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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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