Hazardous characteristics: bacterial bacterial leaf spot disease, also known as bacterial leaf spot disease, it mainly harms leaves, stems, flowers, petiole and fruit. The leaves are susceptible, producing dark brown to black irregular spots, 2-4 cm in diameter with or without yellow halos around the spots. Petioles and stalks have similar symptoms, producing black spots but no yellow halos around the lesions. Lesions are easily linked to plaques, and when severe, a section of the stem becomes dark. The flower buds are affected and many black spots are formed on the sepals. When they are contiguous, the sepals are dried and cannot normally bloom. The small spots in the early stage of the young fruit swell slightly, and the lesion often remains green for a long time around the fruit. Flesh near the lesion sunken, black spots around the lesion, the middle light and slight depression.
Occurrence pattern: The pathogen of tomato bacterial spot disease is Pseudomonas syringae pv tomato. Germs can overwinter on tomato plants, seeds, diseased bodies, soils, and weeds. They can survive on dried seeds for 20 years and can be spread over long distances with seeds. Seeding of seed with bacteria can cause disease, seedlings spread into the field after the onset of disease, and spread through rain, insects, and agricultural operations, resulting in an epidemic; as long as 10% of the initial plant disease occurs in the field, it can be transmitted to the entire plot, temperature Conditions below 25°C and relative humidity above 80% are conducive to disease occurrence.
Control methods First, agricultural control. Strengthen quarantine to prevent the introduction of infected seeds into the non-epidemic area; select disease-resistant and disease-resistant varieties; establish disease-free seed fields, adopt disease-free seedlings; implement rotation for more than three years with non-sweet-end vegetables; pruning, snoring, and harvesting Other agricultural operations should pay attention to avoid the spread of diseases; drip irrigation or furrow irrigation should be used in drought areas to avoid sprinkler irrigation as much as possible. Second, seed processing. Soaking in warm water at 55°C for 30 minutes, or soaking in 0.6% acetic acid solution for 24 hours, or soaking in 5% hydrochloric acid for 5-10 hours, or soaking in 1.05% sodium hypochlorite for 20-40 minutes. After soaking, rinse the liquid with water and let it dry before germination. Third, chemical control. In the early stage of disease, 77% of the WP can be used to kill 400-500 times, or 53.8% can be used to kill 2000 times of the 2000 dry suspension agent, or 20% of Thiabendazole (Longket) suspension 500 times. Or 14% complex ammonia copper water agent 300 times, or 0.3% -0.5% copper hydroxide solution to control, spray once every 10 days or so, even spray 3-4 times.
Stainless Steel Sink,Hospital Operating Room Sink,Medical Wash Basin,Hospital Steel Sink
Taizhou Gaogang District Dixin Medical Equipment Co., Ltd. , https://www.dixinmedical.com