Relationship between heading and fruiting Rice yield Management method of heading and fruiting stage of Rice

Rice heading and fruiting stage refers to the period from heading to maturity, including heading, flowering, filling and maturity. Generally, it takes about 35-45 days, during which vegetative growth basically stops, and the growth center shifts to the formation and filling of rice grains, which is the key period to determine the seed setting rate and the size of 1000-grain weight. The main measures of field management are scientific management of water, proper application of seed fertilizer, prevention and control of diseases and insect pests.

heading and seed setting stage of rice

1. Scientific management of water. Water management principle: heading with water, wet filling, timely water cut. Water heading: rice heading and flowering period, rice field such as drought, pollen and stigma easy to dry, can not pollinate, even heading difficult, so heading and flowering period generally to maintain a certain water layer in the field, it is best to irrigate fresh water once every 2-3 days to avoid dehydration and drought. Moist filling: After flowering and pollination, rice grains are fully developed through filling, and both water and water are needed during filling period. Because of the decline of aeration tissue in late rice stage, the air transmission condition from leaves to roots is poor, the soil water is more oxygen-deficient, and the roots are easy to premature senescence, moist irrigation is adopted. The water management based on "dry, wet and wet" not only meets the demand for water and fertilizer during filling period, but also achieves the purpose of increasing air to promote roots to nourish leaves and strengthen seeds by leaves. Timely water cut: rice yellow ripening, physiological water demand decline, should be timely water cut, but can not be premature water cut. Cutting off water too early will reduce dry matter accumulation and grain weight. Water cut time depends on rice field, general field can be cut off about a week before harvest, deep mud field in about half a month, sand field 3-5 days, so as not to "dry forced ripening" affect grain weight and beneficial harvest.

2. Apply seed fertilizer appropriately. Rice heading period or before and after the application of topdressing called grain fertilizer, also known as "strong seed fertilizer." Grain fertilizer is mainly applied to rice fields with less base fertilizer, poor water and fertilizer conservation, insufficient after-stress and pale leaf color before heading. When the weather is fine, urea 2-3 kg per mu is applied at the full heading stage, mainly to prolong the leaf function period, accelerate the filling and increase the grain weight. If it is cold and rainy, it is better not to apply nitrogen fertilizer, but to apply topdressing outside the root. Spraying urea with 1% concentration and 0.3% potassium dihydrogen phosphate on the leaves in the afternoon can promote grain filling and increase seed setting and grain weight.

3. Prevention and control of diseases and insect pests. Panicle neck blast, bacterial blight, stem borer, rice planthopper, leafhopper, etc. often occur during heading and fruiting period of rice. It is necessary to prevent and control timely according to forecast and field inspection to avoid losses. To control panicle and stem blast, spray 75% tricyclazole 30- 40g mixed with 50kg water when the bud is broken, and spray 1-2 times after full panicle to control branch blast and grain blast. Bacterial blight was controlled by spraying Yekuling 200g mixed with 50kg water in time, stem borers were controlled in time according to the forecast time, 50% fenitrothion 20ml mixed with 50kg water was used for control, rice planthopper leafhopper was controlled by 10% imidacloprid WP 10g mixed with 40- 50kg water or 10% once net 10- 20g mixed with 50kg water per mu.