Generally, Chinese cabbage begins to enter the balling stage after the lotus sitting period. The so-called lotus sitting period is the period in which the base grows outward or collapses, forming a period of dense leaf clusters, at which time the leaves are green or pale green. The leaves of the ball are light green, generally overlapping and growing inward, and as the top buds continue to differentiate, the leaf ball continues to increase. The fresh-leaved leaves appeared to be dry, and the farmers called it "burning heart." This kind of "burning heart" seedlings also have a spherical shape, but the leaves are faded like paper, and the heart leaves in the bag are severely ulcerated, and the whole plant is completely unrecovered.
According to many years of observation and testing, the dryness of the heart of Chinese cabbage is mainly caused by calcium deficiency in the plant. Calcium is one of the indispensable elements in the cell wall of Chinese cabbage. If calcium is deficient, it will cause the cells to disintegrate, causing the body's water supply to be out of tune and dry. Calcium is poorly active in plants, and heart leaves are very sensitive to calcium deficiency. The more you lack, the greater the proportion of heart dryness.
There are three reasons for the deficiency of calcium in Chinese cabbage: one is the potential calcium deficiency in the soil; the other is the partial application of nitrogen fertilizer, which has an antagonistic effect on calcium in the soil and weakens the activity of calcium; the third is the drought and rain during the birth period. Failure to irrigate in time also affects the ability of the soil to supply calcium. In addition, boron deficiency also affects the quality of the core.
In order to improve the yield and quality of Chinese cabbage and prevent "burning heart", we should focus on the management of fertilizer and water, and promote root and leaf protection.
First, we must promote hair roots. The main root of Chinese cabbage is hypertrophied, and a large number of lateral roots are produced. The secondary roots are divided into two, three, and four lateral roots. The root system is developed to improve the ability of fertilizer and fertilizer. Therefore, before the live broadcast or transplanting of the seedlings, it is necessary to finely level the ground, and to achieve a virtual reality, soil pine grass net.
Second, the formula should be applied to the fertilizer. Each mu of base fertilizer should be used to produce 3,000 to 5,000 kilograms of farmer's fertilizer, 20 to 30 kilograms of superphosphate, 10 to 15 kilograms of potassium fertilizer or 100 to 150 kilograms of plant ash. In particular, there is no shortage of calcium. Topdressing 4 to 5 times, in which the nitrogen fertilizer is properly controlled at the beginning of the ball, and the top dressing should be applied after the ball is finished. The high concentration of human excrement is best.
Third, we must adjust the water with water. In the case of continuous drought, it should be irrigated once every 15 days, but the irrigation should be stopped 10 days before harvest to prevent the water content of the leaf ball from being too high and difficult to store.
Fourth, we must promptly control pests and diseases. It is mainly downy mildew, soft rot, aphids, cabbage caterpillars, etc., combined with the control of pests and diseases, combined with boron fertilizer. Among them, spraying speed-learn boron 700 to 1000 times liquid twice. Author: Zhang Yuhong
Source of information: Hunan Science and Technology News
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