In autumn, the temperature gradually decreases, the ground temperature gradually declines, the roots of vegetables are severely aged, and the absorption of nutrients is hindered. However, Qiuyan vegetables are in a prosperous period and are prone to calcium deficiency. At this point should be re-calcium, but be careful with chlorinated fertilizers. The general symptoms of calcium deficiency in vegetables are the Growth of new parts of the plant, such as apical buds, root hairs, fertility, atrophy and death. The new leaves are stuck, and the new leaves are often coke-edged and incomplete; the top of the fruit is easily sunken and dark brown appears and is necrotic.
Control measures: Control the amount of fertilizer, it is not appropriate to use too much fertilizer at a time, especially with chlorinated fertilizers such as ammonium chloride and potassium chloride, and timely irrigation to prevent soil drought, while spraying calcium fertilizer on leaves, can use calcium nitrate as spray Fertilizer, the concentration of 0.3% to 0.5%, generally spray once every 7 days, even spray 2 to 3 times can be effective. Tomato should be sprayed on the upper and lower leaves of inflorescence 2 to 3 on the flowering stage. Chinese cabbage sprays calcium when it enters the ball stage.
