Common on tomato and potato plants, early blight is caused by the fungus Alternaria solani and occurs throughout the United States. Symptoms first appear on the lower, older leaves as small brown spots with concentric rings that form a “bull’s eye” pattern. As the disease matures, it spreads outward on the leaf surface causing it to turn yellow, wither and die. Eventually the stem, fruit and upper portion of the plant will become infected. Crops can be severely damaged.[图片]Early blight overwinters on infected plant tissue and is spread by splashing rain, irrigation, insects and garden tools. The disease is also carried on tomato seeds and in potato tubers. In spite of its name, early blight can occur any time throughout the growing season. High temperatures (80-85˚F.) and wet, humid conditions promote its rapid spread. In many cases, poorly nourished or stressed plants are attacked.[图片]Treatment Prune or stake plants to improve air circulation and reduce fungal problems. Make sure to disinfect your pruning shears (one part bleach to 4 parts water) after each cut. Keep the soil under plants clean and free of garden debris. Add a layer of organic compost to prevent the spores from splashing back up onto vegetation. Drip irrigation and soaker hoses can be used to help keep the foliage dry.[图片]For best control, apply copper-based fungicides early, two weeks before disease normally appears or when weather forecasts predict a long period of wet weather. Alternatively, begin treatment when disease first appears, and repeat every 7-10 days for as long as needed. Containing copper and pyrethrins, Bonide® Garden Dust is a safe, one-step control for many insect attacks and fungal problems. For best results, cover both the tops and undersides of leaves with a thin uniform film or dust. Depending on foliage density, 10 oz will cover 625 sq ft. Repeat applications every 7-10 days, as needed.[图片]SERENADE Garden is a broad spectrum, preventative bio-fungicide recommended for the control or suppression of many important plant diseases. For best results, treat prior to foliar disease development or at the first sign of infection. Repeat at 7-day intervals or as needed. Remove and destroy all garden debris after harvest and practice crop rotation the following year. Burn or bag infected plant parts. Do NOT compost.

...显示更多

Downy mildew (Plasmopara viticola) affects many plants and appears as yellow to white patches on the upper surfaces of older leaves. On the undersides, these areas are covered with white to grayish, cotton-like fungi. These “downy” masses are most often noticed after rain or heavy dew and disappear soon after sunny weather resumes. As the disease progresses leaves may eventually turn crisp and brown and fall off even though the plant has ample water.[图片]Downy mildew occurs in cool, moist weather usually in early spring or late fall. Spore production is favored by temperatures cooler than 65˚F. and by relative humidities approaching 100%. This disease overwinters on plant debris and in the soil. Fungal spores can be carried by insects, wind, rain or garden tools. Treatment The best way to prevent downy mildew is to avoid the environmental conditions that favor the disease.[图片]Prune or stake plants and remove any weeds to improve air circulation. Water in the early morning hours, or use a soaker hose, to give the plants time to dry out during the day. Keep the ground under infected plants clean during the fall and winter to prevent the disease from spreading. Remove and destroy any plants with serious infection (see Fall Garden Cleanup). Choose resistant varieties whenever possible. Downy mildew is comparatively easy to control on most plants when the foliage and fruit are kept protected by a copper spray. Begin treatments two weeks before disease normally appears or when weather forecasts predict a long period of wet weather. Alternatively, begin treatment when disease first appears, and repeat at 7-10 day intervals for as long as needed.[图片]The systemic action of Organocide® Plant Doctor moves throughout the entire plant to treat common disease problems. Mix 3/4 tsp per gallon of water and apply to foliage. Spray to run-off, as required for disease control.

...显示更多

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.[图片]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.[图片]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.[图片]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.

...显示更多

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.[图片]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.[图片]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.[图片]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.[图片]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.

...显示更多

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.[图片]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.[图片]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.[图片]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.

...显示更多

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.[图片]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.[图片]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.[图片]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.

...显示更多

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.[图片]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.[图片]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.[图片]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.

...显示更多

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.[图片]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.[图片]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.[图片]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.[图片]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.[图片]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.

...显示更多

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.[图片]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.[图片]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.[图片]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.

...显示更多

#海棠花 在中国可以说是最受大众喜欢的花之一了，因而有许多的人都在家里养了海棠花，其中尤以四季海棠为最，具有株型圆整、花多而密集、极易与其它花坛植物配植、四季开花观赏期长等优点，因而越来越受到欢迎;其开花时分单瓣和重瓣两种。四季海棠喜温暖湿润的环境，性畏寒、怕早、酷热、忌涝，因而在半阴湿温暖环境中生长最佳。 [图片]四季海棠的养殖方法 第一、盆土，四季海棠盆土以河沙、腐叶土和蛇木屑混合调制最为理想。四季海棠畏酷热，夏季应放在凉爽的地方养护。 第二、浇水，四季海棠喜欢温润的条件，所以在生长期间，应该根据植株生长情况和气温变化情况浇水。萌芽期少浇水，保持盆土略干燥，如果过湿会导致烂根。生长期每两天浇水1次，并经常向植株周围喷水，以增加空气湿度。另外要注意的是，浇水时不要将自叶及茎顶浇下，要沿着花盆的边沿浇，否则茎叶容易积水腐烂。 第三、施肥，四季海棠在生育期间应根据植株叶色及叶的生长悄况施加肥料，不能施肥过多，否则会导致叶片徒长，影响开花。花前要施加适量的磷肥和钾肥，以提高开花品质。 第四、在冬季来临时，要掘起球根悬挂贮藏于干燥通风处或将盆花置于室内温暖处越冬。 第五、防病，四季海棠在高温干燥期间，容易发生根腐病和茎腐病。发现初期应及时控制浇水，并喷洒多菌灵防治。连续使用一段时间可见疗效。 第六、冬夏管理，四季海棠冬、夏因受温度的影响，生长比较缓慢，需加强肥、水的管理。 第七、阳光，在盛夏高温时节，千万要避免四季海棠受到强光的直射，这样的话会晒伤四季海棠。 第八、四季海棠在花谢后一定要记得及时摘除心，除去残花，这样的话它就能生长的更加茂盛。 [图片]第九、虫害，四季海棠常见的病害虫是卷叶蛾，此虫以幼虫食害嫩叶和花，直接影响四季海棠的生长和开发，对于这种情况，如果不是特别的严重，可以人工捉，对于严重的要用乐果稀释液喷洒。 第十、四季海棠的花盆，平时应该放在阳台或庭院的半阴养护，切不可让阳光直射进来，并且要注意通风，四季海棠栽植半个月后可施一个腐熟的肥水，以后生长期，每隔20-30天施一次清淡的肥水，冬季要移入室内置于阳光充足地，而且最低温度不得低于10度。 [图片]注意事项 ①肥。春秋四海棠生长期需掌握薄肥勤施的原则，主要施腐熟无异味的有机薄肥水或无机肥浸泡液。在幼苗发棵期多施氮肥，促长枝叶;在现蕾开花期阶段多施磷肥，促使多孕育花蕾，花多又鲜艳，如果缺肥，四季海棠植株会枯萎，甚至死亡。 ②水。春秋四海棠生长旺盛期土壤需要含有较多的水分，浇水要及时，保持湿润。 ③度夏越冬管理。夏、冬因受温度的影响，生长缓慢，需加强肥、水的管理。在盛夏高温季节，要采取避强直射光和降温措施，创造一个30℃以下小环境养护，保持盆土干湿相宜，过湿易烂根，过干叶片会萎蔫，只要略湿润便可;这时期若施肥过多，会引起茎叶发嫩或发生腐烂病。冬季气温只要保持在10℃以上就能安全越冬。在夏冬管理中，温度如能控制在30℃以下，10℃以上，浇水干湿适宜，施肥适量，植株必定健壮，便可达到四季开花不断。