Maize dwarf mosaic virus disease _ Hongzhou agronomic

Symptoms of my 1966 in Henan Huixian first found, Shaanxi, Gansu, Hebei, Shandong, Shanxi, Inner Mongolia, Liaoning, Beijing, has occurred. Corn entire growth period can be infected. Seedling disease heart leaves basal cells appear oval faded green dot, intermittent flow into bar point mosaic-like, and developed into yellow green and white stripes late disease symptoms, tip of the leaf margin to red to purple and dry. The onset of the leaves turned yellow, brittle, easy to fold. Diseases of the ear leaf sheath, also has leaf bud mosaic-like. Early onset, dwarfing the diseased plant. Disease occurrence area wide and heavy damage. Pathogen Maize dwarf short MDMV, called mosaicvirus maize dwarf mosaic virus, in the case of potato virus Y. The virus particle size in linear, 750 × 12-15 (nm), in electron microscopic observation of tissue sections under the windy rotavirus contains body. In vitro-virus for a period of 24 hours, lethal temperature of 55-60 ° c, dilution limit point 1000-2000 times. The spatial organization of viruses in ultra-low temperature refrigerator save 5 years remain infected. Transmission and disease conditions the virus mainly in bromus, hemarthria, wintering on the host, is an important source of primary infection of the disease, the poison seed sprouting back can also be an attack Center. Download virus spread by aphids. Upload a virus aphid Myzus persicae, maize, cotton aphid, APHIS cereal cable pipe, schizaphis, avenae, 23 species of aphids, are non-persistent ways upload virus, which is mainly transmitted maidis virus aphid, drug toxicity after passing, but the loss of vitality is also faster; disease juice can also be transmitted free of friction; infected corn seeds also has certain upload virus rate, generally 0.05% up or down. In addition to infecting corn, infection of Digitaria, Tiger tail grass, imperata, eragrostis, bristlegrass, Barnyard, bromus, hemarthria, Sudan grass, etc. Maize dwarf mosaic virus with A, B, C, D and O strains, where a, B two strains of the most important. A line of major infection of corn and Johnson grass, B strains infected corn only. We have identified the B strains, O strains. Virus invasion by aphids, corn plant after the latent period is shortened with the temperature rising. The disease occurs and the close relationship of aphids. Production of large-area planted on susceptible corn varieties and aphids activities favorable climatic conditions, 5-7, cool, rainfall, aphids they swarmed into corn field pass drug addiction, a large number of reproductive damage, after whom easily cause disease epidemic. In recent years, China's maize dwarf mosaic North area. One is the main push maize varieties and inbred lines are not poisonous nature resistance, sources, climate suitable for mediator breeding, migration, etc. The second is the high rate of seed poison, primary infection source base. Tested 81515, M017, mentor 107 seed poison respectively 0.1, 0.13, 0.16%, 8112-l.04 per cent, the seeds of 7942 poison rate 12.6 percent, as early as 4, 478 does not detect the poison seed. The rate of increase in seed of poison, the field source base increase primary infection, disease-resistant varieties are still lacking in the case of corn seedlings climate suitable, mediator aphids multiply, virus diseases that spread rapidly. Control methods (1) the local conditions, disease-resistant hybrids or reasonable choice of varieties such as Feng-l,, no. 2, in a single nongda3138, agro-5, 7, the new single, Zheng-l,, no. 2, no. 4, yellow early, start as early as 4; ludan 31, no. 6, Dan-Yu, Shanxi-9, no. 1, Feng three, long, single, single, 1 day, 1, Wu Dongquan 105, 11, 12, 13, single-hand 25l, 5 numbers in jade, JI-29, etc. (2) in the field of early identification and removal of the diseased plant this is one of the key measures for disease prevention and control. (3) optimum seeding and timely weeding hoe, reduces upload virus host, reduce morbidity. (4) in transfer virus aphid moved to the start of the cornfield and the flourishing period, the timely spraying 50% omethoate EC 800 times the liquid or 50 per cent of pirimicarb wettable powder 3000 times more liquid, 10 per cent of imidacloprid wettable powder 2000 times more liquid. Control methods (1) the local conditions, disease-resistant hybrids or reasonable choice of varieties such as Feng-l,, no. 2, in a single nongda3138, agro-5, 7, the new single, Zheng-l,, no. 2, no. 4, yellow early, start as early as 4; ludan 31, no. 6, Dan-Yu, Shanxi-9, no. 1, Feng three, long, single, single, 1 day, 1, Wu Dongquan 105, 11, 12, 13, single-hand 25l, 5 numbers in jade, JI-29, etc. (2) in the field of early identification and removal of the diseased plant this is one of the key measures for disease prevention and control. (3) optimum seeding and timely weeding hoe, reduces upload virus host, reduce morbidity. (4) in transfer virus aphid moved to the start of the cornfield and the flourishing period, the timely spraying 50% omethoate EC 800 times the liquid or 50 per cent of pirimicarb wettable powder 3000 times more liquid, 10 per cent of imidacloprid wettable powder 2000 times more liquid.