What fungicide works well for controlling brown patch disease?
Brown patch disease is a fungal disease caused by Rhizoctonia solani, widely distributed around the world, and can infect all turfgrasses, with cool-season turfgrasses suffering the most severe damage, causing turf plants to die and forming large areas of bare patches in the lawn, greatly destroying the lawn landscape. Let's take a look below at what fungicide is used to control brown patch disease!
Turf brown patch disease
[Symptoms] When the disease first appears on the lawn, nearly circular patches of dead grass of varying sizes often appear. When conditions are suitable, the disease develops quickly, and the diameter of the dead grass patches can expand from a few centimeters to one or two meters. Because the diseased plants in the center of the patch can recover, the dead grass patches mostly take on a “frog-eye” appearance, that is, green in the center with a withered-yellow ring band at the edge.
[Control] Before or during periods of high temperature and high humidity, apply little or no nitrogen fertilizer, maintain a certain amount of phosphorus and potassium fertilizer, avoid continuous flooding irrigation and flood irrigation, and especially avoid watering in the evening. When dead patches appear on the lawn, guttation (or dew) should be removed as early as possible in the morning, which helps reduce the severity of the disease. Do not mow too low in summer (generally 5-6 cm); excessively dense lawns should be properly aerated and verticut, and dead grass and clippings after mowing should be removed promptly. Disease-resistant (tolerant) varieties should be planted, and timely and effective chemical control should be carried out.
Poinsettia brown patch disease
[Symptoms] It damages leaves, initially as small yellow-brown spots, sometimes with dozens of disease spots on a single leaf. The small spots gradually expand into lesions 1-2 cm in diameter, with a light brown interior and edges that are slightly angular with concentric rings of varying shades. In severe cases, the lesions can reach 2-3 cm in diameter. In the dark gray part where diseased and healthy tissue meet, grayish-white cottony mold develops.
[Control] Thoroughly remove diseased plant debris to reduce the initial infection source. Manage temperature and humidity well in the greenhouse, pay attention to ventilation and moisture removal, and improve air circulation.
Tulip brown patch disease
[Symptoms] Infected leaf buds develop poorly and become deformed and curled; leaves that grow from damaged young buds become curled. If the environment is humid, large amounts of gray mold-like conidia are produced on the diseased tissue, affecting nearby healthy plants and causing leaf infection, so bulb growth is greatly affected. After flowers are infected, white or light yellow-brown lesions first appear, then rapidly expand and the flowers wither and drop, or turn brown and dry up. Ring bands may also appear on the flower stalk, sometimes with conidial layers forming on them.
[Control] Remove diseased bulbs before planting and practice crop rotation. Once buds or flower buds showing symptoms of this disease are found, remove them immediately to control disease development. Before planting, soak the bulbs in 2% formalin solution for 30 minutes, then dry them before planting to reduce residual pathogens. During the growing period, spray 50% iprodione 1000-fold solution or 50% procymidone 2000-fold solution or 50% dimethirimol 1000-fold solution.