Detailed Explanation of Key Points for Rice Field Management in August

I. Apply rice field herbicides at the right time. To eliminate weeds in the rice field, rice field herbicides should be applied at the right time. This saves labor (no need for intercultivation) and money (about 2 yuan per mu for chemicals), and can also resolve the conflict of weeds competing with rice seedlings for fertilizer and light, which restricts the normal growth and development of rice seedlings. The specific method is: 5-7 days after transplanting, use 20 grams of Caodaolong or 60-100 grams of Dingbian per mu, mixed with urea (combined with topdressing), fine sand or dry mud powder 30-40 jin, and broadcast after the dew has dried, maintaining a shallow water layer for 4-5 days.

II. Achieve scientific fertilization. More than 70% of the late rice in our province is hybrid rice, with few original transplanted seedlings, and more than half is also seedling throwing, with a short seedling period and insufficient sturdiness. Therefore, leaf-promoting fertilizer should be applied early, with 20-25 jin of urea per mu 5-7 days after transplanting; leaf-strengthening fertilizer should be applied at the right time, with 10-15 jin of compound fertilizer per mu (or 20 jin of urea and 25 jin of potassium chloride) 15-20 days after transplanting. Around the Autumn Equinox, it is best to broadcast 100-150 jin of lime powder per mu, which can both strengthen the seedlings and enhance resistance to diseases and pests. From mid-to-late September to early October, apply about 10 jin of compound fertilizer per mu as fertilizer for strengthening the panicle and grains.

III. Carry out timely and reasonable irrigation and drainage. Although rice needs a relatively large amount of water during its growth period, from the perspective of its normal physiological requirements, it is afraid of both drought and waterlogging. Therefore, shallow irrigation should be maintained from transplanting to the peak tillering stage, and soaking should be avoided, to promote early growth, rapid development, and sturdy growth of the rice plants, after which the field should be kept moist. In high-yield rice fields with deep soil layers, field drying in the middle and late stages should also be carried out properly, and only during the ten days before heading should a shallow water layer be maintained on the field surface to meet the water requirements for booting and heading. Afterwards, the water layer on the field surface should be drained away, and it is sufficient to keep the soil layer moist.

IV. Strengthen the prevention and control of diseases and pests. First, conscientiously and regularly go deep into the field to investigate and do a good job in forecasting and prediction, especially in areas where diseases and pests have historically occurred severely. If disease or pest damage is found, it must be treated promptly, continuously, and thoroughly. For newly introduced rice varieties, their resistance to diseases and pests should also be carefully observed. The disease that occurs most in late rice is sheath blight. From the peak tillering stage to the young panicle formation stage, if high temperatures are encountered along with continuous rain and high relative humidity in the field, densely growing rice fields are prone to this disease. If found, spray promptly with 1 jin of 1% Jinggangmycin mixed with 200-300 jin of water, or spray with a 1000-fold solution of 50% thiophanate-methyl wettable powder. If the occurrence is severe, spray again after 5-7 days. In terms of insect pests, the second and third generation stem borers only occur in certain years and certain areas. The more commonly occurring pest is mainly the rice leaf roller. It mostly occurs from mid-to-late September to early October, damaging the flag leaf and the second and third leaves below the top. When the damage is severe, it not only affects normal heading and flowering, but also directly leads to an increase in blighted grains and a decrease in 1000-grain weight, greatly affecting yield. For this disease, spray 18% bisultap aqueous solution 40 grams per mu mixed with 100-120 jin of water, or use 90% crystalline trichlorfon 1000-fold, spraying 150-200 jin per mu. It is best to spray in the evening, and if it rains within six hours after spraying, respray as soon as possible.