绿手指
首页
动态
文章
百科
花园
设置
简体中文
已关注
+
关注
花园 (6)
动态 (3585)
Dummer. ゛☀
2017年09月15日
Dummer. ゛☀
A soil-borne fungal disease that affects seeds and new seedlings, damping off usually refers to the rotting of stem and root tissues at and below the soil surface. In most cases, infected plants will germinate and come up fine, but within a few days they become water-soaked and mushy, fall over at the base and die.
Several fungi can cause decay of seeds and seedlings including species of rhizoctonia, fusarium and phytophthora. However, species of the soil fungus pythium are most often the culprit. Damping off typically occurs when old seed is planted in cold, wet soil and is further increased by poor soil drainage. High humidity levels, rich potting soils and planting too deeply will also encourage its growth. Fungal spores live in the soil and are primarily a problem in seed beds. They can be transported on garden tools and in garden soils taken into the house or greenhouse. Note: Older plants are rarely killed by damping off primarily because the production of secondary stem tissue forms a protective barrier and limits fungal penetration.
Treatment There is no cure for plants that already have damping off. However, you can easily prevent the problem by providing good air circulation. A small fan or simply cracking the lid of the germination tray will suffice. The biological fungicide Mycostop may also be used as a seed treatment to prevent seed or soil-borne diseases. Other steps for preventing damping off include the following: When starting seeds indoors, use good organic potting soil or sterilize your own potting soil in an oven. Make sure your seed starter mix is light and fast-draining. Plant seedlings so that the soil surface is near the top of the container to insure proper air circulation. Sow seeds thinly to prevent over crowding which can lead to humid, moist conditions.
Seedling trays that provide water from below are preferable to overhead watering. Never water past noon so that the soil surface and the plants are dry by evening. Avoid overwatering tender seedlings. Organocide® Plant Doctor is an earth-friendly systemic fungicide that works its way through the entire plant to combat a large number of disease problems. Apply as a soil drench or foliar spray (3-4 tsp/ gallon of water) to prevent and attack many fungal problems, including pythium, fusarium and root rot.
0
0
文章
Dummer. ゛☀
2017年09月15日
Dummer. ゛☀
Crown gall is a common plant disease caused by the soil-borne bacterium Agrobacterium tumefaciens. It is found throughout the world and occurs on woody shrubs and herbaceous plants including grapes, raspberries, blackberries and roses.
Crown gall symptoms include round, wart-like growths — 2 inches or larger in diameter — that appear at or just above the soil line, or on lower branches and stems. Plants with several galls may be unable to move water and nutrients up the trunk and become weakened, stunted and unproductive. Young plants can be killed by developing gall tissue.
The bacteria responsible for crown gall can persist in the soil for many years and are released when galls become saturated with moisture or as older galls decompose. Susceptible plants are infected through fresh wounds or abrasions, many of which are a result of pruning, freeze injury, soil insects, cultivation and other factors that may damage plants. Nursery stock is often infected through grafting and budding scars.
Treatment Select resistant cultivars when possible and purchase plants from a reputable nursery. Do not buy plants that shows signs of swelling or galling. When caring for susceptible plants, avoid injury or pruning wounds that may come in contact with the soil. Use Tree Wrap to protect against string trimmer damage and keep your garden tools clean.
Provide winter protection with natural burlap so bark does not crack. In many cases, existing galls can be removed with a sharp pruning knife. Destroy the infected plant tissue and treat the wound with pruning sealer. If the plant does not recover, remove and destroy it.
0
0
文章
Dummer. ゛☀
2017年09月15日
Dummer. ゛☀
Frequently found in backyard gardens and small farms, corn smut is caused by the fungus Ustilago zeae and can appear in the stalks, leaves, tassels or ears. Symptoms are most commonly noticed when the ears produce mushroom-like tumors or galls. These “swellings” begin as small, whitish-gray irregularities which expand and turn black as they fill with spores. Ear galls can grow to 4- to 5-inches in diameter and release thousands of spores as they rupture. These fungal spores are blown by the wind for considerable distances to infect new plants. Galls on leaves remain small and eventually become hard and dry.
Corn smut overwinters on garden debris and in the soil. It is carried by wind, rain and irrigation and does best in hot, dry weather. Spores may remain viable for 5- to 7-years. Wounds from various injuries, including cultivation and abrasion from blowing soil, provide points for the fungus to enter the plant. Treatment Choose the best resistant varieties, such as silver king, fantasia, brilliant and seneca sensation, when available.
In backyard gardens, collecting and destroying galls before the dark fungal spores are released is suggested. This will limit the number of available fungal spores and help break the disease-cycle. Reduce infection points by avoiding injury of roots, stalks and leaves during cultivation. Prevent damage from insects, such as corn borers, with Monterey® Garden Insect Spray or other organic insecticide. Fungicides are NOT an effective control option since the disease is so widespread and can persist in the soil for years.
High nitrogen fertilizers may increase the severity of the disease — use a balanced organic fertilizer in the vegetable garden. Remove and destroy all garden debris after harvest and practice crop rotation the following year. Bag or burn infected plant parts — do NOT compost.
0
0
文章
Dummer. ゛☀
2017年09月15日
Dummer. ゛☀
Affecting most brassica crops (cabbage, broccoli, cauliflower, etc.), club root is a serious plant disease in North American home gardens. It is caused by the soil-borne fungus Plasmodiophora brassicae which infects susceptible plants through root hairs. Diseased roots become swollen, misshapen and deformed (clubbed) often cracking and rotting. As a result, plants have difficulty absorbing water and nutrients properly.
Plants often grow poorly and wilt during the heat of the day; plants often revive during cool nights. Outer leaves may turn yellow, purple or brown. Club root will reduce yields and can cause total crop failure. Fungal spores can be spread by wind, water and garden tools. Disease development can occur over a wide range of conditions, but is favored by excessive moisture, low soil pH and soil temperatures between 64 and 77˚F. Spores can survive in the soil for as many as 10 years.
Treatment Fungicides will NOT treat this soil-dwelling micro-organism. Choose resistant cultivars when possible. Try to prevent the occurrence of this disease by keeping a clean garden and rotating crops. Keep in mind that the disease spores can persist in the soil for up to 20 years. If club root is present you may want to solarize the soil.* Control susceptible weeds — mustard, radish, shepherd’s purse — that may be infected to reduce potential buildup of the disease. Carefully remove infected plants and sterilize garden tools (one part bleach to 4 parts water) after use.
Raise your soil’s pH to a more alkaline 7.2 by mixing oyster shell or dolomite lime into your garden in the fall. Simple and affordable soil test kits are available to check pH often. * To solarize your soil, you must leave a clear plastic tarp on the soil surface for 4-6 weeks during the hottest part of the year. Soil solarization will reduce or eliminate many soil inhabiting pests including nematodes, fungi, insects, weeds and weed seeds.
0
0
文章
Dummer. ゛☀
2017年09月15日
Dummer. ゛☀
Cedar apple rust (Gymnosporangium juniperi-virginianae) is a fungal disease that requires juniper plants to complete its complicated two year life-cycle. Spores overwinter as a reddish-brown gall on young twigs of various juniper species. In early spring, during wet weather, these galls swell and bright orange masses of spores are blown by the wind where they infect susceptible apple and crab-apple trees. The spores that develop on these trees will only infect junipers the following year. From year to year, the disease must pass from junipers to apples to junipers again; it cannot spread between apple trees.
On apple and crab-apple trees, look for pale yellow pinhead sized spots on the upper surface of the leaves shortly after bloom. These gradually enlarge to bright orange-yellow spots which make the disease easy to identify. Orange spots may develop on the fruit as well. Heavily infected leaves may drop prematurely. Treatment Choose resistant cultivars when available. Rake up and dispose of fallen leaves and other debris from under trees. Remove galls from infected junipers. In some cases, juniper plants should be removed entirely.
Apply preventative, disease-fighting fungicides labeled for use on apples weekly, starting with bud break, to protect trees from spores being released by the juniper host. This occurs only once per year, so additional applications after this springtime spread are not necessary. On juniper, rust can be controlled by spraying plants with a copper solution (0.5 to 2.0 oz/ gallon of water) at least four times between late August and late October. Safely treat most fungal and bacterial diseases with SERENADE Garden. This broad spectrum bio-fungicide uses a patented strain of Bacillus subtilis that is registered for organic use. Best of all, SERENADE is completely non-toxic to honey bees and beneficial insects.
Containing sulfur and pyrethrins, Bonide® Orchard Spray is a safe, one-hit concentrate for insect attacks and fungal problems. For best results, apply as a protective spray (2.5 oz/ gallon) early in the season. If disease, insects or wet weather are present, mix 5 oz in one gallon of water. Thoroughly spray all parts of the plant, especially new shoots. Contact your local Agricultural Extension office for other possible solutions in your area.
0
0
文章
Dummer. ゛☀
2017年09月15日
Dummer. ゛☀
The most common fungal disease affecting the blossoms and fruit of almonds, apricots, cherries, peaches and plums. Brown rot (Monilinia fructicola) overwinters in mummified fruit (on the tree and on the ground) and infected twigs.
The disease first infects blossoms in spring and grows back into the small branches to cause cankers that can kill stems. Large numbers of flower-bearing stems are killed when the disease is severe. Dead flowers often remain attached into the summer. Developing or mature fruits show circular or brown spots that spread rapidly over the surface and light gray masses of spores are produced on the rotted areas. Rotted tissue remains relatively firm and dry.
Brown rot spores are carried by wind, rain and insects to the open or unopened blossoms and young shoots. If water is present — either from rain, dew or watering — on the flower surface the spores can germinate and penetrate the plant. Disease development takes place over a wide temperature range and flowers can be infected from the time buds open until petals fall. Under favorable conditions, brown rot spreads quickly and an entire crop can be completely destroyed on the tree.
Treatment Choose resistant varieties whenever possible. Prompt removal and destruction of infected plant parts helps breaks the life cycle of the disease in individual trees and small orchards, and may be sufficient to keep brown rot below damaging levels. It is important to rake up and remove any fallen fruit or debris from under trees. Prune trees occasionally to improve air circulation. Also, water from below to keep from wetting blossoms, foliage and fruit. Use Tanglefoot® Pruning Sealer to seal all cuts and wounds and protect against insects and disease organisms.
Ready to use copper fungicides or sulfur powders should be applied weekly to infected trees starting when the blossoms are just beginning to open and continuing throughout the growing season. If at all possible, time applications so that 12 hours of dry weather follows application. Organocide® Plant Doctor is an earth-friendly systemic fungicide that works its way through the entire plant to combat a large number of diseases on ornamentals, turf, fruit and more. Apply as a foliar spray (1 tsp/ gallon of water) to combat this destructive stone fruit problem.
Containing sulfur and pyrethrins, Bonide® Orchard Spray is a safe, one-hit concentrate for insect attacks and fungal problems. For best results, apply as a protective spray (2.5 oz/ gallon) early in the season. If disease, insects or wet weather are present, mix 5 oz in one gallon of water. Thoroughly spray all parts of the plant, especially new shoots.
0
0
文章
Dummer. ゛☀
2017年09月15日
Dummer. ゛☀
A serious disorder of tomato, pepper, cucumber and eggplant, blossom end rot is an environmental problem (not fungal) most often caused by uneven watering or by calcium deficiency. (These can be related; uneven watering can interfere with the uptake of calcium.) This common garden “disease” is often brought on by rapid growth from too much fertilizer, high salt levels or drought.
Blossom end rot symptoms occur on both green and ripe fruits and is identified by water-soaked areas that gradually widen and mature into sunken, brown, leathery spots on the bottom end. In many cases, secondary pathogens, which appear as a black, fuzzy-like growth, attack the affected area and cause complete rotting of the fruit. Blossom end rot will not spread from plant to plant.
Treatment Since this plant problem is physiological in nature, fungicides will not work as a control measure. We recommend the following: Choose resistant vegetable varieties whenever possible. Prevent problems by keeping soil evenly moist and by foliar spraying plants with a kelp or calcium solution. Adding high levels of calcium — bone meal, oyster shell or gypsum — to the soil at planting time usually prevents this problem from developing. A layer of mulch (straw, compost, grass ) will help conserve soil moisture during the hot, dry days of July and August. Foliar applications of Liquid Calcium 5% (1-2 Tbsp/ gallon of water) can be used to correct or prevent deficiencies of this essential nutrient. For best results, combine with a natural surfactant to increase adhesion and spray leaves to the point of run-off.
Mulching plants will help conserve moisture and provide a more uniform water supply. Avoid using high nitrogen fertilizers which accelerate vegetative growth and reduce the uptake of calcium by plants. A large selection of balanced organic fertilizers are available at Planet Natural.
0
0
文章
Dummer. ゛☀
2017年09月14日
Dummer. ゛☀
Widely distributed throughout the United States, bacterial canker is most common on cherries and plums, but may also affect apricots, peaches and many other kinds of stone fruits. Suspect this plant disease if sunken, water-soaked or “gummy” lesions form on the trunk or twigs. When trees begin active growth in the spring, a sour smelling sap may ooze from these wounded areas. The cankers become darker than the surrounding healthy bark, and the underlying tissue is reddish-brown to black and moist.
Note: If cankers girdle the branches or trunk, the leaves above the diseased area curl and turn yellow. Growth stops and the branch or tree will eventually die. The bacterium that causes canker, Pseudomonas syringae, enters trees through injured bark or an existing wound, such as a pruning cut on a twig or branch. Frost damage in the spring may promote additional infections. Bacterial canker infections occur during fall, winter and early spring (during cool, wet weather) and are spread by rain or water, and pruning tools. The bacteria overwinter in active cankers, in infected buds and on the surface of infected and healthy trees and weeds.
Treatment Prune flowering trees during blooming when wounds heal fastest. Remove wilted or dead limbs well below infected areas. Avoid pruning in early spring and fall when bacteria are most active. Treat all pruning cuts immediately with Tanglefoot® Tree Pruning Sealer and make sure to disinfect your pruning equipment — one part bleach to 4 parts water — after each cut. If using string trimmers around the base of trees avoid damaging bark with breathable Tree Wrap to prevent infection. Brush bark with white latex paint diluted with water to reduce bark-damaging temperature fluctuations. Research has shown that copper fungicides have some success against this stone fruit problem. However, results are inconsistent. We recommend using it as one part of a total management program.
Remove weeds and grass from around the base of young trees to improve air circulation and keep the trunk and crown dry. Organocide® Plant Doctor is an earth-friendly systemic fungicide that works its way through the entire plant to combat a large number of diseases on ornamentals, turf, fruit and more. Mix 1/3 to 3/4 oz per gallon of water and paint or spray over pruning wounds and surrounding areas.
0
0
文章
Dummer. ゛☀
2017年09月14日
Dummer. ゛☀
A serious disease of apples and ornamental crabapples, apple scab (Venturia inaequalis) attacks both leaves and fruit. The fungal disease forms pale yellow or olive-green spots on the upper surface of leaves. Dark, velvety spots may appear on the lower surface. Severely infected leaves become twisted and puckered and may drop early in the summer.
Symptoms on fruit are similar to those found on leaves. Scabby spots are sunken and tan and may have velvety spores in the center. As these spots mature, they become larger and turn brown and corky. Infected fruit becomes distorted and may crack allowing entry of secondary organisms. Severely affected fruit may drop, especially when young. Apple scab overwinters primarily in fallen leaves and in the soil. Disease development is favored by wet, cool weather that generally occurs in spring and early summer. Fungal spores are carried by wind, rain or splashing water from the ground to flowers, leaves or fruit. During damp or rainy periods, newly opening apple leaves are extremely susceptible to infection. The longer the leaves remain wet, the more severe the infection will be. Apple scab spreads rapidly between 55-75 degrees F.
Treatment Choose resistant varieties when possible. Rake under trees and destroy infected leaves to reduce the number of fungal spores available to start the disease cycle over again next spring. Water in the evening or early morning hours (avoid overhead irrigation) to give the leaves time to dry out before infection can occur. Spread a 3- to 6-inch layer of compost under trees, keeping it away from the trunk, to cover soil and prevent splash dispersal of the fungal spores. For best control, spray liquid copper soap early, two weeks before symptoms normally appear. Alternatively, begin applications when disease first appears, and repeat at 7 to 10 day intervals up to blossom drop.
Bonide® Sulfur Plant Fungicide, a finely ground wettable powder, is used in pre-blossom applications and must go on before rainy or spore discharge periods. Apply from pre-pink through cover (2 Tbsp/ gallon of water), or use in cover sprays up to the day of harvest. Organocide® Plant Doctor is an earth-friendly systemic fungicide that works its way through the entire plant to combat a large number of diseases on ornamentals, turf, fruit and more. Apply as a soil drench or foliar spray (3-4 tsp/ gallon of water) to prevent and attack fungal problems.
Containing sulfur and pyrethrins, Bonide® Orchard Spray is a safe, one-hit concentrate for insect attacks and fungal problems. For best results, apply as a protective spray (2.5 oz/ gallon) early in the season. If disease, insects or wet weather are present, mix 5 oz in one gallon of water. Thoroughly spray all parts of the plant, especially new shoots.
0
0
文章
Dummer. ゛☀
2017年09月14日
Dummer. ゛☀
Generally found in the eastern part of the United States, anthracnose is caused by fungi in the genus Colletotrichum, a common group of plant pathogens that are responsible for diseases on many plant species. Infected plants develop dark, water soaked lesions on stems, leaves or fruit. The centers of these lesions often become covered with pink, gelatinous masses of spores especially during moist, warm weather. Anthracnose can reduce a beautiful harvest into rotted waste in just a few days.
The fungal disease overwinters in and on seeds, soil and garden debris. Cool wet weather promotes its development, and the optimum temperature for continued growth of the spores is between 75-85˚F. Moisture is required for development and germination of the fungus as well as for infection of the plant. It is spread by wind, rain, insects and garden tools.
Treatment Choose resistant plant varieties when possible and use western grown seeds which have not been exposed to the disease. If this fungal problem is common, do NOT save your own seed from plantings. To avoid spreading the disease, keep out of gardens when plants are wet and make sure to disinfect all garden tools (one part bleach to 4 parts water) after use. Do not compost infected leaves, fruit or stems and thoroughly clean up garden areas in the fall, after harvest, to reduce over wintering sites for the fungal spores.
Safely treat most fungal and bacterial diseases with SERENADE Garden. This broad spectrum bio-fungicide uses a patented strain of Bacillus subtilis that is registered for organic use. Best of all, SERENADE is completely non-toxic to honey bees and beneficial insects. Liquid copper sprays and sulfur powders should be applied weekly, starting when foliage begins to develop in the early spring and continuing throughout the growing season. Spray early in the day, and avoid applications during hot weather. Seeds may also be treated prior to planting. Neem oil spray is an organic, multi-purpose fungicide/insecticide/miticide that kills eggs, larvae and adult stages of insects as well as prevents fungal attack on plants. Apply early, at the first sign of spring budding, every 7-14 days as a preventative measure or on a 7-day schedule until existing problems are eliminated.
0
0
文章
110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125
相关用户
茉莉花
茉莉花
来自： Faye
朝阳
绿萝
绿萝
来自： 采元气少女✨
长沙
茉莉花
茉莉花
来自： 小松树快乐
长沙
绿萝
绿萝
来自： 水中月
赣州市
茉莉花
茉莉花
来自： 艺源
广安市
芦荟
芦荟
来自： 采元气少女✨
长沙
茉莉花
茉莉花
来自： 阿罗
南昌
芦荟
芦荟
来自： Bailu_Yuan
北京
白掌
白掌
来自： 韩凯
武汉
绿萝
绿萝
来自： 阿罗
南昌
举报 反馈

您有什么意见或建议，欢迎给我们留言。

请输入内容
提交
取消
设置
VIP
退出登录
关闭
分享

分享好文，绿手指（GFinger）养花助手见证你的成长。

关闭
请前往电脑端操作

请前往电脑端操作

关闭
转发
插入话题
提醒好友
发布
/
提交成功 提交失败 最大图片质量 成功 警告 啊哦！ 出了点小问题 转发成功 举报 转发 显示更多 _zh 文章 求助 动态 刚刚 回复 邀你一起尬聊！ 表情 添加图片 评论 仅支持 .JPG .JPEG .PNG .GIF 图片尺寸不得小于300*300px 最少上传一张图片 请输入内容