Control of Tomato Early Blight in Sheds
Dried Tomato,Semi Dried Tomatoes,Sun Dried Tomatoes,Dehydrating Tomatoes Ningxia Lihe Food Co., Ltd. , http://www.lihedried.com
Tomato early blight is also known as rosy rot. Tomatoes grown in greenhouses and in greenhouses can occur throughout the year. Losses of 20% to 30% are common year-on-year, and up to 50% can be severe and even shed. 1. Symptoms of diseased leaves initially appear as water-stained, dark-green lesions. They appear to be enlarged, rounded, or irregularly shaped, with concentric ring patterns on them, and lesions grow out of black mold under moist conditions. Most of the disease began to develop gradually from the lower leaves of the plants, and the lower leaves died when severe. Petioles, stems, and fruits onset, initially dark brown oval lesions, slightly dilated after expansion, with black mold and concentric pattern. Green disease spots arise from the vicinity of the calyx, the severely diseased fruit is cracked, and the diseased part is hard. 2. Cause of the disease The disease is caused by the infection of the fungus Alternaria spp. The pathogens overwinter with the diseased body in the soil or overwinter on the seeds and spread by wind, water, and insects. High temperature and high humidity make it easy to develop. Tomato early blight occurs at a temperature of about 15 degrees Celsius and a relative humidity of more than 80%. At 20-25 degrees, when the indoor humidity is high, the condition develops rapidly. Most of the disease began to occur in the early stages of the results, resulting in more severe onset of the disease. The old leaves are usually first diseased, and the young leaves are lightly diseased. Long time dew condensation in the greenhouse, insufficient base fertilizer, low waterlogging, extensive management, and weak plant growth all contribute to the outbreak of early blight. 3. Control methods (1) Selection of disease-resistant varieties, such as strong-rich, full silk, hair powder 802, strong rice, Chinese vegetable No. 6, Jiafen No. 2, Jiafen No. 10, Shenfen No. 1 and Daqiang, etc. Anti-early blight, all parts can be selected according to adaptability. (2) Seed disinfection is soaked in 52-degree warm water for 30 minutes, removed and spread, and then germinated. (3) Selection of seedling-free seedlings for the two consecutive years No seedlings of the nightshade seedlings were used as seedbeds or seedbeds for new soil. Conditional rotation with non-solanum crops for more than 3 years (4) Planting, disease prevention and low-lying cultivation with high sorghum, pay attention to clean drainage after rain, reduce groundwater. Proper close planting, planting around 4,000 per acre, improve the line Interval permeability, to strengthen the greenhouse temperature and humidity control, after planting to control water cultivation, watering before flowering, until the formation of the second ear fruit and then pouring enough water in time to promote fruit growth. Watering sunny first 10 o'clock in the morning, Ventilate immediately after watering to avoid condensation on the leaves in the morning. Strengthen the cultivator in the cultivator, remove the old diseased leaves in time and bring them out of the shed. Sparse flowers, harvest fruit, to keep 3 ear fruit is appropriate. Potassium fertilizer can be topdressed in the later stage. Foliage sprayed with 0.1% sucrose plus 0.2% potassium dihydrogen phosphate plus 0.3% urea during fruit setting can enhance the resistance of the plant. (5) The drug can be used to control the seedling stage. 70% mancozeb can be used. Wettable powder 500 times spray control, so that with drug colonization. The early incubation period is short and the lesions should be prevented and treated. Available 75% chlorothalonil WP 600 times, 50% carbendazim WP 500 times, 40% DF WP 500 times, 64% MIC M8 WP 400 times, also Available 1:1: 200-240 times Bordeaux mixture or copper ammonia 400 times solution spray, can also use 45% chlorothalonil smoke smoke control, 250 grams per acre.