Key points of Technical Management of Summer Maize after disaster

Summer corn is an important crop in autumn in our province, and this waterlogging does great harm to summer corn in our province. According to the actual situation, experts in the provincial corn industry system put forward some suggestions on post-disaster management for farmers' reference.

? Technical suggestions on post-disaster corn management (Professor Cui Yanhong, Hebei Agricultural University)

1. Eliminate stagnant water in the field. If there is obvious stagnant water in the field, we should do everything possible to eliminate the stagnant water in the field and reduce the soaking time of corn plants.

2. Ploughing and dispersing soil moisture. For plots that have excluded stagnant water in the field or that have only been damaged by waterlogging, ploughing and hoing can be carried out in time when the field can enter the field.

3. Supplement and apply quick-acting fertilizer. In view of the fact that the summer corn in our county will enter the big trumpet mouth period, it is suggested to combine the big trumpet mouth period topdressing with post-disaster fertilizer management. The plots that have not yet applied panicle fertilizer can apply 20-25 kg urea per mu and the plots that have already applied panicle fertilizer can apply 5-10 kg urine per mu. Topdressing must be applied deeply in trenches or in combination with ploughing to avoid spreading. When it clears up after rain, urea 0.5% + potassium dihydrogen phosphate 0.2% is used for foliar topdressing in time, and when spraying, it must be ensured that urea and potassium dihydrogen phosphate are completely dissolved and mixed, so as to avoid leaf burns caused by excessive local concentration and aggravate the degree of damage; generally, it can be sprayed twice in a row, with an interval of about 7 days.

4. Corresponding field management measures can be taken according to the specific situation of lodging in the land where lodging occurs.

At present, ① and summer corn are in the stage of small trumpet mouth, after lodging, they generally do not need to take special management measures, and will slowly restore their upright growth after rain.

In ② and summer sowing plots washed down by floods, the leaves of the plants are often buried in silt, making it difficult for the plants to restore upright growth on their own. after the disaster, the soil on the leaves should be removed as soon as possible, or the buried leaves should be cut off with a sickle to help the plants restore upright growth as soon as possible.

③, summer sown corn with sediment in the heart leaves after lodging often leads to difficulties in the extraction of the heart leaves; this kind of land can use a sickle to cut off the heart leaves after the disaster to help the follow-up leaves to extract. But cut off as few leaves as possible, and try not to hurt the apical growth point of the plant.

2. suggested control techniques for diseases, insect pests and weeds of summer corn after waterlogging (Professor Zhang Jinlin of Hebei Agricultural University)

1. Improve the awareness of weed control: at present, most summer corn has entered the ridge closure, and 10% 200~300mL/ mu of oxamidophosphonate water agent can be selected to weed through the directional spray between rows of corn. However, in the use of glyphosate for inter-row directional weeding of corn, try to keep the sprinkler as low as possible to reduce spraying to corn to prevent drug damage.

2. The control of corn leaf spot disease: according to the characteristics of more rainfall this year, all kinds of leaf spot disease mainly caused by brown spot disease will occur more seriously. At present, fungicides are still mainly used to control corn brown spot, and the recommended agents are: (1) 10% difenoconazole water dispersible granules or 12.5% diniconazole wettable powder or 25% propiconazole suspension 2000-2500 times; (2) 10% pyrimethrin suspension 1000m 1500 times; (3) tebuconazole or benzoate protective fungicides are not recommended. Carbendazim and methyl topiramate are generally effective and are not recommended.

3. To strengthen the prevention and control of pests such as brown-footed breast beetle: the adults of brown-footed breast beetle gnawed on the middle and upper leaves or leaf center of corn to form reticular holes. When the number of insects is high, it can eat up the leaves and residual veins, resulting in yield loss. Prevention and control suggestions: (1) timely removal of weeds to effectively reduce the harm of brown foot horn breast beetle; (2) timely chemical control of adults, recommended insecticides: thiazide or pyramidone or acetamiprid + cyhalothrin.