Occurrence and Control of Dwarf Disease in Japonica Rice

I. harmful symptoms

The rice plant is dwarfed, the tiller increases, the leaf is dark green, and there are transparent yellow-white dotted stripes on the young leaf and leaf sheath. After booting, yellow-white stripes appeared only on the inverted leaf or other leaf sheaths, and those with late onset often had necked panicles, small panicles, more empty grains and low seed setting rate.

II. Preventive measures

Once dwarf disease occurs in japonica rice, it is difficult to cure, so comprehensive preventive measures should be taken actively.

1. Disease-resistant and disease-tolerant varieties were selected. Breeding varieties with relatively mild disease according to local conditions to reduce the incidence of disease.

two。 Improve cultivation techniques. The sowing date of rice should be adjusted reasonably so that the growth period of japonica rice with high susceptibility can avoid the migration peak of virus-transmitting insects. Appropriately increase the planting density, strengthen the management of fertilizer and water, promote the early development and middle stage of seedlings, enhance the disease resistance and reduce the harm.

3. Do a good job in field sanitation. Remove weeds on the edge of the field in time and reduce the place where leafhoppers live.

4. Strengthen the management of fertilizer and water. Apply sufficient base fertilizer, early topdressing, not blind partial application of nitrogen fertilizer, prevent greedy green late ripening, reduce the amount of insects, and improve the ability of disease resistance. Transplanting seedlings in thin water and shallow water irrigation to reduce the natural parasitism rate of black-tailed cicada eggs.

5. Pay close attention to disease and pest control. Catch the two migration peak periods of the black-tailed leafhopper for control, use 3% carbofuran granules 1.5 kg 2.0 kg, mix dry fine soil 20 kg, spread on the seedling board after sowing rice; after the seedlings are green, mix 100 ml of Wei EC and 20% of Cicada EC with 50% for every 667 square meters (1 mu), 40 kg of water and 50 kg of water, spray evenly, control once every 5 days and spray twice. In the field seedling stage should often go deep into the field, constantly check the number of black-tailed leafhoppers in rice fields, timely and appropriate amount of drug control, every 667 square meters with 25% aphids 20 grams, 40 kg 50 kg of water, evenly sprayed, the effect is remarkable. During the growth of japonica rice, we should always pay attention to the occurrence of black-tailed leafhopper and kill the virus-carrying mediators in time to prevent the occurrence of diseases.