After suffering from root rot, rhododendrons grew weak, and the leaves were wilting and dry. Water-stained brown fields appeared on the root surface. Severe soft rot was gradually rotted and peeled, and the xylem became black. The disease is most likely to occur under conditions of high temperature and high humidity. The prevention and control method is to sterilize the earth before dumping and keep the soil loose and moist to make it have good permeability and prevent water accumulation. If the plant is found to be sick, the diseased plants and potted soil should be treated in time. For treatment, use 0.1% potassium permanganate solution or 2% ferrous sulfate solution Wash the diseased plants, rinse with fresh water, and re-wash basins. With 70% thiophanate WP plus 1000. times the water made solution spray basin soil, can be cured. Brown spot is a major disease of azaleas. At the time of disease initiation, brown spots appeared on the leaves and gradually developed into irregular spots. Many black or gray-brown spots were generated on the lesions, causing the affected leaves to turn yellow and fall off, affecting flowering and bud development in the following year. . This disease often occurs when humidity is high during the rainy season. The treatment method is to pay attention to the ventilation and light transmission of the plants, not to make the humidity too high, and to increase the application of organic fertilizer and NPK mixed fertilizer to enhance the plant's ability to resist infection and growth. If diseased leaves are found, they must be promptly removed and burned. At the beginning of the disease, spray 0.5% Bordeaux mixture or 0.4 Baume degree lime sulfur, and add 4% flour to increase adhesion. Leaf spot and black spot can also be treated in the same way. Iron deficiency yellowing often occurs in areas where the soil is alkaline. When the disease is mild, only the phenomenon of late-greenness occurs; when it is severe, the leaf tissue can turn yellow and the edges of the leaves are dry. At the time of onset, the leaves on the tips of the plants showed the most obvious, usually caused by internal iron deficiency. The prevention method is to change the iron deficiency properties in the soil and reduce the alkalinity of the soil. Increase organic fertilizers to modify the clay soil. For iron-deficient plants, 0.2%-0.3% ferrous sulfate solution can be directly sprayed. It is also possible to poke holes in the soil around the plant with holes of about 15 cm in depth, and slowly inject it with a 1:30 aqueous ferrous sulfate solution to fill the holes to increase the acidity of the soil and reduce the alkalinity. The incidence and environmental conditions of black spot disease in azaleas are similar to that of brown spot disease. Similar methods can be used for prevention and control. Greenhouse Film Manual Roll Up The Greenhouse Film Electric Roll-Up Unit replacing traditional manual roll-up unit to reach high speed automation in revolving & releasing films and greenhouse environment, it is the new generation of greenhouse ventilation and temperature regulation facilities. Portability, output torque, output lock, wide range and precise adjustment, waterproof, dew-proof and power-saving are the key characteristics for Electric Roll-Up Unit, which is the best choice for modern daylight greenhouse applied in different climates. Greenhouse Film Manual Roll Up,Greenhouse Manual Winch,Greenhouse Side Film Roll Up JIANGSU SKYPLAN GREENHOUSE TECHNOLOGY CO.,LTD , https://www.greenhousehydroponic.com
Azalea Disease Prevention and Control
The diseases of azaleas mainly include root rot, brown spot, black spot, leaf blight, and iron deficiency yellowing.