Five preventive management measures for the late growth stage of rice
When rice enters the late reproductive stage, it is a critical time for yield formation, and the following “five preventions” must be carried out well.
1. Prevent fertilizer deficiency. For fields where no nitrogen fertilizer was applied at the mid stage and where fertilizer deficiency and premature aging appear at the late stage, 2-3 kg of urea per mu can be applied at the booting stage as a booting fertilizer. For those growing normally and robustly, apply foliar fertilizer once each at the initial heading stage and the full heading stage, using 150 g of potassium dihydrogen phosphate plus 0.5 kg of urea mixed with 60 kg of water per mu each time, sprayed on the leaves after 5 p.m. on a sunny day. For those growing excessively vigorously, use 0.2-0.3 kg of rice vinegar and 1 kg of superphosphate mixed with 50 kg of water per mu for foliar spraying at the booting stage, initial heading stage, and grain-filling stage.
2. Prevent “neck obstruction.” When temperatures drop during the rice heading stage, and sometimes when cold-dew wind weather occurs, heading becomes difficult and neck obstruction occurs. Timely spraying of “920” can prevent the “neck obstruction” phenomenon and has an obvious yield-increasing effect. Generally, use 1-1.5 g of “920” together with 250-300 g of potassium dihydrogen phosphate mixed with 50-60 kg of water per mu, and spray when 50%-60% of the panicles have emerged from the boot.
3. Strictly prevent cold dew wind. Cold dew wind has a great impact on rice growth and must be guarded against. 1) 2-3 days before the arrival of cold dew wind, apply additional plant ash or spray potassium dihydrogen phosphate on the leaves to enhance the plants' cold resistance. 2) For seedlings that have begun heading, spray a 20 ppm “920” solution on the panicles a few days before the cold dew wind appears to promote earlier full heading. 3) When the cold dew wind arrives, irrigate the field to maintain a 7 cm deep water layer to help preserve heat. 4) After the cold dew wind passes, spray potassium dihydrogen phosphate on the leaves of rice plants that have already reached full heading.
4. Prevent excessive irrigation. Water management at the late stage of rice is an important link, and excessive irrigation must be avoided. Generally, during the heading and flowering stage, maintain a 5-6 cm deep water layer, so that heading occurs with water present, or adopt the irrigation method of irrigating by day and draining by night. After full heading, adopt the irrigation method of alternating dry and wet, with dry and wet alternating. Water should be cut off 7-10 days before rice harvest to promote maturity, but water should not be cut off too early.
5. Prevent diseases and insect pests. At the late stage, rice is susceptible to damage from rice planthoppers, rice neck blast, sheath blight, and other diseases and insect pests. If not controlled in time, this will seriously affect the harvest. For pests such as rice planthoppers, pesticides such as metolcarb and MIPC can be used for control; for neck blast, pesticides such as tricyclazole can be used for control; for sheath blight, validamycin can be used for control.