Recent Rice Pest and Disease Occurrence and Control Methods

Since entering July, our city has experienced continuous rain followed by high temperatures after the rain, which is extremely favorable for the occurrence of rice pests and diseases in the later stage. Currently, most of the rice in our city has entered the booting to heading stage, which is precisely the susceptible period for rice pests and diseases. On August 7, our station conducted field surveys in Tangdian, Datun and other areas, and found occurrences of rice blast, sheath blight, and rice leaf roller, requiring urgent control. The specific situation is as follows:

Rice blast: Leaf blast was found on Yunhui 290 planted in Xinwafang, Datun, with a diseased leaf rate of 3.6%, disease index of 0.75, and an area of 2 mu.

Sheath blight: It occurs commonly. In severely affected fields, the diseased clump rate is 72%, the diseased plant rate is 42.8%, and the disease index is 11.35. In general fields, the diseased clump rate is 45%, the diseased plant rate is 29.3%, and the disease index is 7.79. The affected area is 15,000 mu.

Rice leaf roller: It occurs commonly, with a rolled leaf rate of 14.8-1.98%. There are large numbers of adults in the fields, with adult density of 1.6-7.8 per sq m, and the affected area is 15,000 mu.

Control recommendations:

1. Raise awareness and strengthen guidance. The agricultural comprehensive service centers of all townships must clearly recognize that whether the later-stage rice pest and disease control work is done well or not concerns the overall situation of increasing agricultural production and farmers' income throughout the city. It is essential to overcome any mentality and paralyzing thinking, and effectively carry out later-stage rice pest and disease control work.

2. Conduct comprehensive inspections and timely control. All townships should conduct a comprehensive field inspection, checking seedlings and prioritizing fields. For old outbreak spots where rice blast occurred in previous years (Kafang Doumuge, Tianxing, Jiasha Weiqiang); fields where leaf blast occurred in the earlier stage; fields with excessively vigorous seedling growth and dark green leaf color, especially high-quality conventional rice planting areas (Datun Longjing, Xinwafang), persist in applying pesticide comprehensively at the heading stage to prevent rice blast. "Better to believe it exists than not," "sacrifice the ticket to save the panicle," and solidly do a good job in later-stage ear blast prevention work.

3. Control methods

1. Rice blast: Tricyclazole is the preferred control agent. At the heading stage (5% ear emergence), use 75% tricyclazole wettable powder at 15-20 g/mu or 20% tricyclazole wettable powder at 100-150 g/mu for spray control. For severely affected fields, persist in spraying once more at the full heading stage to ensure control efficacy.

2. Sheath blight: 20% validamycin powder at 25 g, diluted with 100 kg of water for spraying.

3. Rice leaf roller: Choose 48% chlorpyrifos EC at 100 ml/mu or 98% cartap technical powder at 50 g/mu or 5% fipronil suspension concentrate at 40 ml/mu or 90% monosultap wettable powder at 50 g/mu, diluted with 50 kg of water for spraying.