What should be noted at each stage of corn from sowing to harvest? What medicines are good for pests and diseases?
It is now the spring plowing season, and we are making full preparations for the crop seeds about to be sown. Today the editor will introduce to you What should be noted at each stage of corn from sowing to harvest? What medicines are good for pests and diseases? Let's take a look.
March to early-to-mid April: pre-sowing preparation period
To prevent various pests and diseases throughout the whole growth period, the main measures are as follows:
1. Soil treatment
In areas with severe underground pests, soil treatment should be carried out. The method is: 5% phoxim granules at 45 kg per hectare.
2. Agricultural control
Clear weeds in the field and at the field edges to reduce virus sources. Before sowing corn, in plots with more weeds, non-selective herbicides can be used for spray weeding.
Mid-to-late April to mid-May: spring corn sowing period
The main targets for control are underground pests, smut, seedling blight, bacterial wilt, viral diseases and weeds, etc.
1. Seed treatment
To control damage from underground pests, head smut, seedling blight and bacterial wilt, an appropriate amount of phoxim plus 3% difenoconazole seed coating agent (or tebuconazole, 20% triadimefon, 34% carbendazim · thiram, etc.) can be used for seed dressing. In areas with severe maize rough dwarf disease and mosaic virus disease, long-acting systemic insecticides should be used for seed dressing.
2. Chemical weeding
(1) Post-emergence herbicides
In the selection and combination of herbicides, atrazine is the main one, with an appropriate amount of acetochlor and other herbicides. Suitable herbicide rates: 40% atrazine 100 g/mu, combined with 48% or 72% metolachlor 100 mL/mu, or 50% acetochlor 75-100 mL/mu. For plots with older weeds, glufosinate or glyphosate 200 mL/mu can be added. Mix the above herbicide doses with 60 kg of clean water, mix evenly, and spray on the ground before seedling emergence to seal the soil.
(2) Soil sealing and weeding after sowing and before seedling emergence
① Corn fields mainly infested with grassy weeds should use herbicides such as acetochlor and metolachlor.
② Corn fields mainly infested with broadleaf weeds should use agents such as atrazine, flumetsulam, 2,4-D butyl ester, acetochlor and metolachlor.
③ Corn fields with mixed grassy and broadleaf weeds should use acetochlor · atrazine, metolachlor · atrazine, s-metolachlor · thifensulfuron-methyl, oxazinone · acetochlor, acetochlor, s-metolachlor, pendimethalin, atrazine, simazine and other agents for spray control. The best application time is after sowing and watering the emergence water, when the soil is moist, or the water amount can be appropriately increased or decreased according to the soil moisture content.
Late May to mid-June:
Spring corn seedling stage to jointing stage, summer corn sowing period
Spring corn mainly controls cutworms, leaf-eating pests, corn borers and brown spot disease, etc.; summer corn mainly controls underground pests, smut, seedling blight and viral diseases.
1. Cutworms
Control methods such as light trapping, manual catching or trichlorfon poison bait can be used.
2. Leaf-eating pests
Leaf-eating pests such as armyworms, beet armyworms, cotton bollworms and tiger moths can be controlled with acephate, hexaflumuron, diflubenzuron and beta-cypermethrin, etc.
3. Corn borers
Use phoxim and acephate granules placed in the whorl for control.
4. Brown spot disease
Use triazole fungicides such as triadimefon, diniconazole and propiconazole for spray control.
July: spring corn booting to heading and grain-filling stage
Summer corn jointing stage to booting stage
The main control targets for spring corn are corn smut, leaf spot disease, armyworms, red spiders and corn borers, etc. For summer corn, it is cutworms, leaf-eating pests, corn borers and brown spot disease, etc.
1. Corn smut and leaf spot disease
Control can be carried out with 10% triadimefon wettable powder, 12.5% diniconazole wettable powder and other agents.
2. Armyworms
Control can be carried out with 2.5% deltamethrin emulsifiable concentrate, 90% trichlorfon crystal and other agents.
3. Red spiders
1.8% abamectin emulsifiable concentrate, 73% propargite emulsifiable concentrate, 15% pyridaben emulsifiable concentrate and other agents.
4. Corn borers
Bacillus thuringiensis wettable powder, 3% phoxim granules, 30% acephate emulsifiable concentrate and other agents for control.
5. Weeds
In response to weed germination in the middle and late growth stages of corn caused by various reasons, glufosinate and rimsulfuron can be selected for targeted spraying between corn rows. When applying, the spray nozzle should be fitted with a protective hood to avoid splashing onto corn plants and causing phytotoxicity.
August: spring corn grain-filling to maturity stage
Summer corn heading to grain-filling stage
For spring corn, it is mainly to prevent leaf spot disease, corn borers and aphids, etc.; for summer corn, it is to prevent corn smut, leaf spot disease, armyworms, red spiders and corn borers, etc. For aphids, imidacloprid, acetamiprid emulsifiable concentrate, dimethoate or pyrethroid agents can be used for spray control. The control agents for other pests and diseases are the same as above.