(1) seedling stage (sowing-jointing)
Growth characteristics: it is the vegetative growth stage of root length, leaf increase and stem-leaf differentiation, and it is the period that determines the number of leaves and nodes of corn. The root system is the growth center of the whole plant, and a strong root system is basically formed at jointing stage; Leaves are the growth centers of aboveground parts. Drought tolerance and fear of waterlogging.
Main objectives and measures: promote root system development, cultivate strong seedlings, and achieve the requirements of "four seedlings" of early seedlings, full seedlings, full seedlings and Miao Zhuang.
(2) Heading date (jointing-heading)
Growth characteristics: The ear stage is the key period in the life of maize. According to the differentiation characteristics of male and female ears, it can be divided into jointing stage, small bell stage, big bell stage, booting stage and heading stage.
Main targets and measures: promoting leaf area increase (especially upper and middle leaves) and stout stems (promoting Ye Zhuang stems); Promote multi-spike and large spike; If the vegetative growth is too vigorous, it should be properly controlled to avoid late lodging and premature aging. It is necessary to apply fertilizer skillfully and give priority to fertilizer and water to prevent water shortage ("neck drought") during tasseling. Pull out weak plants (big trumpet stage), and pay attention to the prevention and control of corn borer. Use Trichogramma for biological control or sprinkle 1.5 kg ~ 2.0 kg phoxim granules into heart leaves per mu.
(3) Grain stage (tasseling-full maturity)
Reproductive characteristics: vegetative growth stops, and the reproductive growth period is the period that determines the quantity and weight of grain.
Main objectives and measures: protect leaves, improve photosynthetic intensity, prolong photosynthetic time and promote multi-grain and grain weight.