Management Methods and Technical Key Points for the Late Growth Stage of Rice Cultivation

Pest and Disease Control

1. Diseases: The main disease requiring control attention in the late growth stage of rice is rice blast. After rice heading, take the opportunity to apply pesticide 2 to 3 times, with an interval of about 7 days. Apply about 100 grams of tricyclazole wettable powder per mu, diluted in 30 kg of water for foliar spraying.

2. Insect pests: The main pests in the late growth stage of rice are white-backed planthoppers, brown planthoppers, armyworms and rice leaf folders. All four of these pests have long-distance migratory and outbreak characteristics, and timely control should be noted. The Shoulei insecticide series produced by Guangxi Jiuhe can be selected -- the dedicated insecticide for rice leaf folders mixed with the dedicated insecticide for rice planthoppers, both at 30 ml per mu, diluted in 45 to 60 kg of water for foliar spraying. The control effect is particularly excellent.

Water and Fertilizer Management

Strengthening irrigation management in the late stage of rice is very important for preventing premature senescence of rice, raising soil temperature to promote early maturity, controlling rice blast and increasing yield. In the late stage, rice needs more water, and the root system needs more oxygen. Both water and oxygen are supplied by the soil, which easily creates a contradiction between water and air in the soil. To resolve this contradiction and achieve the goal of nourishing roots and preserving leaves, we should start from three aspects:

1. Reinforce the field ridges, dredge drainage, lower the groundwater level, and enhance the vertical permeability of the soil. Through vertical percolation, harmful substances such as salts, alkalis and hydrogen sulfide in the soil are carried away, while oxygen dissolved in water is brought into the lower soil layers, enhancing root vitality.

2. Implement shallow-water irrigation, and in the late grain-filling stage implement intermittent irrigation with alternating wet and dry conditions. The water layer should be 2 to 3 cm; wait for it to seep dry naturally, and when the field is firm enough that feet do not sink and the soil does not crack, then irrigate the next round of water. The water cutoff period should be well controlled, generally about 40 days after full heading of rice, or 7 to 10 days before harvest. For paddy fields with a high groundwater level and heavy salinity and alkalinity, water retention should be the priority, and the water cutoff period should be appropriately delayed to prevent soil salinization and premature senescence of rice.

3. Apply supplemental foliar fertilizer and plant growth regulators. After full heading of rice, it is not advisable to apply nitrogen fertilizer to the root zone; instead, applying foliar fertilizer and plant growth regulators is an auxiliary measure to prevent premature senescence and delayed maturity with excessive vegetative growth. Spraying foliar fertilizers such as rare earth potassium dihydrogen phosphate at the conventional rate can promote grain filling and promote early maturity and increased yield; generally 1 to 2 applications are sufficient.