2. When the soil moisture reaches more than 80% of the field capacity, because of too much soil moisture and insufficient air, the seeds are easy to rot, which affects the emergence of seedlings.
3. Temperature has a great influence on the emergence speed. When the temperature is 10 ~ 12℃, seedlings will emerge 18 ~ 20 days after sowing; When the temperature is 15 ~ 18℃, the emergence time is 8 ~ 10 days; Under the condition of 20 ~ 35℃, seedlings can emerge in 5 ~ 6 days, and the emergence rate is the highest. When the temperature exceeds 40℃, the seedlings stop developing.
4. Generally speaking, the oxygen content in the soil can fully meet the needs of maize seed germination and emergence. However, if the soil is too wet, or the sowing is too deep, or the soil hardens in the rain after sowing, it will cause insufficient oxygen, prolong the emergence time, increase nutrient consumption and make the seedlings thinner.
Extended data:
The prevention and control of aphids should be strengthened at seedling stage, and 90% trichlorfon wettable powder can be sprayed with 2000 times solution.
When 50% phoxim emulsion 300mL/hm2 and 70% carbendazim wettable powder 1 125g/hm2 are mixed at the big trumpet stage, the harm degree of pests and diseases can be reduced by one-time control.
4.5% beta-cypermethrin 1000 times solution was used to control the two-spot firefly beetle at the tasseling stage and spinning stage of corn.
The corn borer was treated with 1000 times trichlorfon solution or sprayed with 22.5-30.0kg/hm2 phoxim granules in the heart leaves.
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