Recently, when we visited Caidian District, Wuhan City, Hubei Province, Hanchuan City, Yunmeng County, and Jingshan County, Jingmen County, we saw that many large cotton fields were replanted with corn. Many farmers report that this year's corn crops have been reduced by production and then reduced. Each mu has reduced its income by 100 to 200 pounds due to climate and rust, and the market price per kilogram of corn is 0.2 to 0.3 yuan less than last year.
Why is this spring corn rust so serious? One is that the early spring corn grows well and the disease is not obvious. The farmers neglected the control of pesticide application and the relevant agricultural department did not put forward prevention as soon as possible. Second, it was a long period of continuous rainy weather this summer, with temperatures ranging from 25°C to 32°C. Occurrence of rust, spread invasion; Third, the late corn growing dense, poor application of pesticides, so that a large area outbreaks are difficult to prevent.
Judging from this year's survey, rust mostly occurs in the late growth period of corn. The pathogens mainly invade corn leaves, and may also involve leaf sheaths, bales and tassels. Corn rust is most likely to induce prevalence under conditions of moderate temperature (25°C to 30°C) and high humidity.
In view of the lessons learned from the occurrence of rust on corn production this year, we should pay attention to the following points in the prevention and control in the coming year: First, we must pay attention to the selection of corn varieties that are suitable for local planting, such as Daiyu 16, Ludan 50, etc.; For crop rotation, for other crops in the field where rust has occurred, three crops should be sowed in appropriate period, nitrogen fertilizer should be reduced appropriately, phosphorus and potash fertilizer should be added, density should be controlled reasonably, and permeability should be improved; Fourth, before 12 leaves of corn Spraying prevention, continued 10 or so days after the prevention of 1 or 2 times; 5 to the sporadic disease of the corn, at any time to remove the diseased plants and residual disease; Six to choose the right spray pesticides, one can use 0.2 Baume degree of lime sulfur, Two can be used 25% triadimefon WP 1000 ~ 2000 times, three available 25% propiconazole (enemydrone) EC 3000 times, four available 43% tebuconazole SC 5000 ~ 8000 times solution, five available 65% zeocin zinc wettable powder 500 times, six available 12.5% ​​speed Poly (R- oxadiazole) wettable powder 4000 ~ 5000 times liquid.
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