Watermelon is one of the main economic crops in Zhejiang Province. In recent years, due to the application of greenhouses and the promotion of grafting and seedling technology, the watermelon planting area in the province has been stable at more than 1 million mu. However, since 2011, there has been a disease called “cucumber green mottle mosaic virus†in watermelon production in Zhejiang Province. Because of its high pathogenicity and rapid spread, it has brought about watermelon production in the province. Threat. It is reported that cucumber green mottle mosaic virus disease is a devastating plant disease and is the national phytosanitary object. Once the cucumber, watermelon and other cucurbit crops are infected, it is difficult to eradicate, generally resulting in a reduction of more than 20%, serious or even no harvest.
According to relevant experts, cucumber green mottle mosaic virus disease can occur in watermelon production, seedling and adult stage. The watermelon plants infected by this virus in the early stage grew slowly, with irregular fading or yellowish flower leaves. The green part protruded from the surface, the leaf surface was uneven, the leaf edge curled up, and then the green plaque appeared, followed by aging symptoms of the leaves. Reduced; diseased vines grow stagnant and wilting, when the whole plant turns yellow, can not grow normally and die; brown necrotic streaks often appear in the fruit stems, the surface of the fruit has inconspicuous thick green spots, sometimes growing not very obvious deep Green tumor blister. Compared with the fruit, the disease is elastic, and the sound is blunt when slap. The flesh around the flesh is yellow water-stained, with blocky yellow fiber inside. The flesh is fibrotic, and the flesh around the seed turns purple or dark red water stain. The ripe fruit flesh turns into dark red, and there are a lot of voids inside. Loofah scorpion, commonly known as "blood flesh", can not be eaten bitter, lose economic value.
Cucumber green mottle mosaic virus disease is mainly transmitted by seed infection and contact infection. Grafting, field operation, soil continuous poisoning, etc. can be transmitted, and the virus can survive for more than one year in the soil. According to the investigation and analysis, the seeds of the poisoned watermelon rootstock were purchased as the source of infection of the disease in Zhejiang Province, and then spread through intensive grafting and breeding, and the sale of poisoned watermelon grafted seedlings, and the seedlings and grafting of some old watermelon producing areas. The farming operations such as pruning and the soil poisoning in the continuous crops have intensified the spread of the disease.
How to effectively control cucumber green mottle mosaic virus disease in watermelon production?
One must control the source to curb the spread. The seeds should be sold and purchased to avoid the use of poisonous seeds and diseased seedlings. Seeds with dry heat-treated labels should be purchased; seeds that are of unknown origin should not be provided and tested, and the test plots should be isolated as much as possible.
Second, we must pay attention to the rotation. The diseased field is carried out with non-host crops such as solanaceous fruits and beans for more than three years of rotation or water and drought rotation. It is indeed necessary to continuously use the field for soil treatment with 100-150 kg of quicklime or 30-40 kg of lime nitrogen per acre.
Third, we must cultivate disease-free and strong seedlings. Seed disinfection before sowing (washing with 10% trisodium phosphate for 10-20 minutes). Grafting tools should be completely disinfected (steam fumigation, or disinfected with 40% formalin 100 times solution) to avoid contact with infection. The diseased seedlings were found to be promptly sent for inspection, and they were destroyed after confirmation. The unqualified seedlings did not leave, and the poisonous seedlings were prevented from entering the production field.
Fourth, we must strengthen cultivation management. Through reasonable fertilizer and water management, creating suitable temperature and humidity environmental conditions for watermelon growth, such as cultivation and management measures, phosphorus and potassium fertilizers, micro-fertilizers, and spraying of zinc sulfate on the foliar surface to enhance plant resistance. It is found that the diseased plants are removed in time, concentrated and destroyed, and the agricultural products such as pruning and fruit-harvesting should be sprayed in time to prevent artificial cross-infection and spread of viral diseases.
Fifth, we must use medicines scientifically. Anti-viral agents are sprayed for prevention and treatment after colonization or early onset. In the early stage of the disease, spray 5% bactericidal WP WP 300 times solution, 7.5% bactericidal morpholine water-repellent agent 700-800 times solution or 30% morpholinium hydrochloride copper WP 500 times solution.
Digital Door Viewer,Door Eye Viewer,Door Peehole Viewer, brass door viewer,peehole for home
Leader Hardware Manufacturer Limited , https://www.leaderhardwarecn.com