Methods for controlling rice pests and diseases after heavy rain

Since mid-June, Hunan, Guangxi and other places have experienced continuous heavy rainfall, with torrential rain in some areas, and the floods and waterlogging have affected crops such as rice to varying degrees. On July 1, the Hunan Academy of Agricultural Sciences and the Hunan Provincial Agricultural Society jointly held a special consultation meeting of experts on disaster relief and loss reduction for crops, and put forward technical measures and suggestions. Experts said that due to the effects of prolonged cloudy and rainy weather and waterlogging, the growth and development of rice will be slower and weaker, and it will be more susceptible to pests and diseases. Therefore, first, attention should be paid to timely prevention and control of pest and disease damage; second, depending on the growth of the seedlings, appropriately apply fertilizer to promote seedling growth or spray foliar fertilizer, etc., to promote their growth and development.

Fang Baohua, deputy director and associate researcher of the Hunan Rice Research Institute, suggested that targeted disaster relief and loss reduction measures should be adopted for rice at different growth stages such as early rice and late rice.

Early rice at the dough stage:

When the flood gradually recedes, promptly wash the leaves, preferably with a sprayer, focusing on washing the top, that is, the panicles and the top 3 leaves. After washing the rice leaves, immediately spray with 125 ml of 25% Yekuling or 20% thiasen copper, diluted with 60 kg of water. After the flood recedes, if it is cloudy, drain the accumulated water all at once; if it is sunny, a shallow water layer should still be kept in the field, and draining should be done after the plants recover for 1 to 2 days. Do not manually straighten seedlings that have fallen at an angle due to flood washing; let them adjust automatically. At the same time, when washing seedlings with clean water, be careful to avoid spraying toward the stems. For severely lodged rice, tie it into bundles and straighten it promptly, wash the leaves, reduce losses, and harvest at the appropriate time.

Single-season rice at the early stage of young panicle differentiation:

When the flood recedes, splash water to wash the rice leaves so as to restore photosynthesis in the rice leaves. After washing the rice leaves, immediately spray pesticides to prevent and control diseases. After timely drainage, check the leaf tips and base in the morning. If there is dew on the leaf tips and the base is firm, it indicates that the rice has regained vitality; you can carry out light drying of the field for 2 to 3 days, then irrigate with shallow water and supplement with urea and potassium fertilizer at 4 to 5 kg per mu each, choosing to broadcast after the dew has dried on a cloudy day or after 4 p.m. on a sunny day. If the base of the rice stems is soft and mushy and wilting appears, promptly plow and replant with medium-maturing early rice varieties, and direct-seed before July 25.

At the late rice seedling stage:

Adopt the method of washing while the water recedes. After washing the leaves, apply pesticides as soon as possible to prevent and control pests and diseases, and try to apply pesticides on a cloudy day or after 4 p.m. on a sunny day. If leaf rolling is found, promptly set up a shade net to prevent bacterial wilt and dead seedlings.