Chinese pests and diseases will continue to occur seriously from August to October. Among them, corn, rice and cotton pests and diseases will be prominent, locusts included. The detailed analyses are as follows:
Medium and late pests and diseases will occur seriously in corns (Grade IV), with an occurrence area of 40m hectares. Among them, the occurrence of corn borers, army worms, aphids, locusts, leaf mites and monolepta hieroglyphica will be 27m hectares, that of big and small curvularia leaf spot, maize head smut, brown spot is expected to be 13m hectares. There would be plenty of rainfalls in most of the Southeast, North China, and eastern part of the Northwest, Huanghuai and eastern Jianghuai in July and August, really positive to the occurrence of corn pests and borers. As a result, corn pests and disease, especially the latter will be much more serious than last year.
Occurrence of medium and late rice pests and diseases reduced about 10% over last year, but still serious, which is also expected to be Grade IV. The occurrence of pests will be 45m hectares, and the pest index will be above Grade IV. Rice leaf roller and rice planthopper will occur more seriously, Grade V. While the occurrence of diseases will be less serious, which is expected to be moderate (Grade III) to serious (Grade IV), with an occurrence of 18m hectares. Rice blast and rice sheath blight are the major diseases.
Medium and late pests and diseases will occur moderate in cotton (Grade III). Among them, the occurrence areas of cotton bollworms, cotton aphids, cotton leaf roller and tobacco whitefly reach 17m hectares, Cotton wilt disease will occur 3m hectares. Hygrophilous diseases including cotton mirids and wilt disease are generally more serious than last year.
Locusts will occur slightly (Grade II) in autumn, and the occurrence area is expected to be 0.7m hectares nationwide, about 8% to 10% less over last year. Among them, 0.4m to 0.45m hectares needs further control, almost the same as last year. North China is still the major disaster area, and the occurrence period will be late July to late August.
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