The growth process of soybean

Soybean is one of the most important food crops in China. It is an annual herb of the genus Leguminosae. It is cultivated all over China and widely cultivated all over the world. Its life has to go through six growth stages: seed germination, seedling growth, flower bud differentiation, flowering and pod formation, seed filling, and ripening. Let's take a look at the growth process of soybean.

Seedling emergence stage

The radicle of the soybean seed first protrudes from the micropyle of the ovule and is called germination when the radicle is as long as the seed. Hypocotyl elongation, seed coat off, cotyledons with Hypocotyl elongation exposed the soil surface, when cotyledons unfold, it is called seedling. Under suitable conditions, seedlings can emerge 4-6 days after sowing. More than half of the cotyledons were unearthed in the field.

Seedling stage

The seedling stage of soybean is from emergence to flower bud differentiation. After emergence, two cotyledons expand, the young stem continues to elongate, and the two opposite leaves expand immediately, which is called single leaf stage. As the young stem continues to elongate, the first compound leaf is called the 3-leaf stage. In the third leaf stage, the growth rate of aboveground part was slow, and the underground root system grew faster and formed nodules. At the end of this period, the root system was initially formed, and more water and nutrients were needed at the beginning. The seedling stage is about 20-25 days, accounting for 1. 5% of the whole growth period. This period is a long-rooted period, so we should pay attention to squatting seedlings and strengthen field management to achieve complete seedlings, uniform seedlings and strong seedlings, so as to lay the foundation for high yield.

Flower bud differentiation stage

The period from the beginning of flower bud differentiation to the beginning of flower bud differentiation of soybeans is about 25-30 days. When 4-5 compound leaves appeared, the lower part of the main stem began to branch and flower buds differentiated at the same time. The process of flower bud differentiation begins with the appearance of hemispherical primitive flower buds, then the formation of event sheets in front of it, and then the formation of keel, wing and flag petals, and then the differentiation of annular stamens. The pistil begins to differentiate in the center of stamens, and the ovule primitive body appears, then enters the ovule and anther primitive body, and the flower organ grows gradually, and finally forms flower buds, pollen and embryo sac to complete flower bud differentiation. During the period of flower bud differentiation, plants enter the period of both reproductive growth and vegetative growth, at this time, fertilizer and water management must be strengthened, and attention must be paid to the coordination of vegetative growth and reproductive growth, so as to meet the requirements of strong plants, many branches, many flower buds and flower health.

Flowering and podding stage

The flowering stage of soybeans is from the beginning to the end of flowering, the flowers are very small, and the number of flowers on each flower cluster varies with different varieties and cultivation conditions. The rate of falling flowers and pods is high, so the number of pods per flower cluster is less. Most of soybeans bloom at 6: 9 am, and it takes 3-7 days from budding to flowering. After the ovule is fertilized, the chamber gradually expands to form a soft and small green young pod, which is called pod when the pod is 1 cm long. The growth of pods is first increased, then widened, and finally thickened. The flowering and podding period is the most vigorous period for the growth of soybeans, which requires the most water and nutrients, as well as sufficient light. On the basis of complete seedlings, strong seedlings and many branches in the early stage, the management of fertilizer and water should be strengthened at flowering stage, and the permeability should be good, so as to meet the requirements of more flowers, more seeds and less shedding.

Bulging stage

Soybeans begin to expand from the inside of the bean to the maximum volume and weight and stop being called the filling stage. The accumulation of dry matter in seeds increased slowly within 10 days after flowering, and increased rapidly in the following 7 days, and most of the dry matter accumulated in about 21 days after flowering. The grain filling period is about 30-40 days. The seed water content is about 90% when the bulging grain is finished. The seed filling stage is an important period for the formation of soybean seeds, at this time, whether the growth of soybean is normal or not will determine the number of seeds per inch, grain weight and seed chemical composition. At this time, drought or waterlogging caused by heavy rain can cause the decrease of dead English, chaff grain and grain weight and seriously affect the yield. To ensure the normal development of the plant should meet two conditions, the plant itself is rich in storage matter, the root system is not senescent, the assimilation of leaves is exuberant, and there is an adequate water supply.

Mature stage

The leaves of soybeans are detached by yellow, and the beans are dehydrated, showing the inherent characteristics of the variety. At this time, the water content of the seeds has dropped to less than 15%, until there is a slight sound in the English when the plant is shaken, that is, the mature stage. At this time, we should reduce soil moisture, speed up the drying of seeds and plants, facilitate timely harvest, and at the same time prevent greedy green and late ripening caused by too much fertilizer and water, affecting timely harvest and stubble. The sunny and dry weather during this period can promote maturity and improve quality.