The growth period of maize refers to the number of days from sowing to maturity of new seeds. The length of the growth period varies with the variety, sowing date, light, temperature and other environmental conditions. Generally, the growth period is short in the case of early-maturing varieties, late sowing and high temperature, and vice versa.

the whole growth period of maize can be divided into sowing, emergence, three-leaf, seven-leaf, jointing, tasseling, flowering, filling, milk ripening and maturity. The sowing date is the date of sowing, and more than 6% of the seedlings with a height of about 2~3 cm in the whole field are unearthed. When the jointing stage is over 6% in the whole field, the basal stem nodes of the plants begin to elongate.

at the big bell mouth stage, more than 6% of the upper leaves in the whole field showed bell mouth shape. More than 6% of the plants in the whole field have tassel tips exposed from the top leaves for 3~5 cm at tasseling stage. At the silking stage, more than 6% of the plants in the whole field exposed their bracts.

at the mature stage, more than 9% of the plants in the whole field have hardened seeds, which show the inherent color and luster of the variety, and the milk line of the seeds disappears. The process of maize growth and development can be divided into seedling stage, ear stage and grain stage.

seedling stage:

refers to the period from emergence to jointing, which is dominated by vegetative growth and centered on root formation. Emergence is the period from sowing to seed germination, with 5% emergence in the field and seedlings 2 cm high.

heading stage:

refers to the period from jointing to heading. This period is the most vigorous growth period, in which vegetative growth and reproductive growth go hand in hand. This period can be divided into jointing stage, big bell mouth stage and small bell mouth stage. The jointing stage is the period when young panicles are differentiated, and stems with 2~3 cm can be felt by hands near the ground.

the big trumpet stage is the stage when the leaves of the stick begin to be drawn out, but they have not yet been unfolded, forming new leaves that are clustered, flat, hollow and trumpet-shaped, and the female ear enters the floret differentiation stage, and elastic spikelets can be felt between the upper unfolded leaves and the unexpanded leaves.

Flowering-grain stage:

It refers to the period from heading to fruiting, and it is a stage with reproductive growth as the center and grain completion. Includes tasseling stage, pollen-scattering stage and fruiting stage.

Trifoliate stage:

refers to having three unfolded leaves and one unexpanded new leaf (that is, three leaves and one heart). Corn plants have the strongest tolerance to herbicides in corn fields at the 3-5 leaf stage, so the manufacturers of herbicides all indicate that they should apply herbicides at this growth stage.

jointing stage is the phenological period of crops:

it is called jointing stage when the first annular protrusion at the base of cereal crops is about 1cm above the ground, and it is called field jointing stage when 5% of the plants in the whole field reach jointing stage.

Extended information:

Three stages of corn maturity and identification methods

Corn maturity needs to go through three stages: milk maturity, wax maturity and complete maturity.

When you look at the position of milk line, the filling order of corn grain is: the middle ear is faster than the lower part and faster than the upper part. From a grain: from the grain part to the base. In the process of filling, the line from the top to the base of the grain can be seen from the back of the grain embryo, and there is an obvious boundary, which is called milk line.

According to observation and measurement, when the milk line is at the position of one third from the top, the 1-grain weight is 299g, which is 9.9% of the grain weight at maturity. When the milk line is half of the grain, the 1-grain weight is 323 grams, which is equivalent to 98.9% at maturity; When the milk thread is at the base and disappears, the 1-grain weight is 329 grams, reaching the maximum.

Second, look at the number of green leaves: when the bracts of the ear are yellow and there are still 7-8 green leaves in the middle and upper parts of the plant, the 1-grain weight is 318 grams, which is equivalent to 92.9% of the grain weight at maturity; When the bract leaves of the ear are yellow and there are about 5 green leaves in the plant, the 1-grain weight is 333 grams, which is 98.8% of the grain weight at maturity. When the bracts are yellow and loose, and the plants have only 1-2 green leaves, the 1-grain weight is the highest, which is 345g.

third, look at the filling time: from the results of corn harvest by stages, it is known that 5 days after pollination, the maximum 1-grain weight is 344 grams; 45 days after pollination, the 1-grain weight was 3369 grams, equivalent to 98.8% at maturity; 4 days after pollination, the 1-grain weight is 313 grams, which is equivalent to 9.9% maturity; After 5 days of pollination, the grain weight began to decline due to respiratory consumption. After 55 days of pollination, the 1-grain weight was 336 grams, a decrease of 1.8%.

essentials of maize planting

stabilize planting area and promote diversified planting. On the basis of keeping the corn planting area relatively stable, the dominant producing areas should adjust measures to local conditions, steadily promote the moderate development of silage corn, fresh corn and special corn, and actively explore and demonstrate the application of multiple planting modes such as corn-soybean, corn-peanut intercropping and rotation.

improve sowing quality and lay a good foundation for harvest. Establish the concepts of "seven-point planting and three-point management" and "seven-point relying on agricultural machinery and three-point relying on agronomy", guide farmers to prepare improved varieties and fertilizers before sowing summer corn, train and guide agricultural machinery operators to do mechanical debugging before sowing and sowing, promote the standardization of agricultural machinery operation processes, ensure the quality of corn sowing and lay a good foundation for a bumper harvest of autumn grain;

Select varieties according to local conditions, select and coat seeds before sowing, and the seed treatment should be promoted in the whole village, concentrated and contiguous, unified chemicals and unified techniques to ensure the effect of pest control; Scientifically choose working machinery, and sow early when the previous crop is harvested;

Appropriate density and reasonable close planting, isolated planting of fresh corn, using methods such as space isolation, time isolation and natural barrier isolation; Apply base fertilizer scientifically and sufficiently, advocate the application of slow and controlled release fertilizer, and apply base fertilizer laterally and deeply to prevent burning seeds and seedlings.

strengthen seedling management and consolidate the group foundation. Irrigation with mulch water as early as possible, and the appropriate relative content of soil moisture should be 7%-75% when sowing; Chemical weeding before sowing; Irrigation in case of drought and drainage in case of waterlogging; Prevention and control of diseases, weeds and pests at seedling stage.

pay close attention to the management of ear stage to ensure the number of grains per ear. Pull out small and weak plants that are diseased in the field; Topdressing panicle fertilizer can promote large panicle, and nitrogen fertilizer should be the main fertilizer at panicle stage, with topdressing urea of 2-25 kg per mu, while avoiding topdressing nitrogen fertilizer at jointing stage; Timely prevent drought and flood disasters;

In the plots with high lodging risk, chemical control agents can be sprayed when the leaves of maize 7-11 are unfolded to control the plant height, optimize the population structure, promote the strong stems and reduce the lodging probability.

strengthen the management of grain period, increase grain and regain high yield. Artificial pollination, artificial emasculation and auxiliary pollination can be carried out in high-yield fields; Supplementary application of flower fertilizer, high-yield field and corn field with integrated water and fertilizer, < P > can be combined with watering or topdressing urea while raining, or spraying potassium dihydrogen phosphate and urea; Drought prevention and drainage, corn should be watered in time in case of drought at grain stage and drained in time in case of waterlogging at later stage, so as to avoid the decrease of root activity and premature senescence and lodging of plants.

timely mechanical harvesting, timely storage and processing. Reasonable determination of the suitable harvest time of corn, the harvest time of summer corn in the whole province can generally be controlled in early October; Ordinary corn should be dried and stored in time after harvesting, and the kernels should be dried immediately after mechanical harvesting. Fresh corn ears should be sold or processed in time after harvesting, and silage corn should be silaged as soon as possible.

Baidu Encyclopedia-Corn

Ministry of Agriculture and Rural Affairs of the People's Republic of China-refers to corn production technology.