Fertilization weather conditions: The growth of open-air vegetables is greatly affected by natural conditions such as light, temperature, air, and heat. To increase the effectiveness of foliar fertilization, it is necessary to master the temperature, humidity, and wind direction during fertilization. Generally, the suitable temperature for fertilization is 20-28 ℃, and the air humidity is 60-70%. At this time, the stomata of vegetable leaves open, and the leaves absorb nutrients more and faster. If the temperature is high and the humidity is low, the fertilizer solution on the leaves will evaporate and dry, resulting in poor absorption effect, And it is prone to fertilizer damage and burning of leaves. Therefore, foliar fertilization should be applied in the evening after 7-10 am and 16 pm, and should be applied on windless and cloudy days. In addition, in the cold and rainy seasons of winter and spring, cold and heat resistant foliar fertilizer should be sprayed, and in the hot and dry seasons of summer and autumn, drought resistant and cooling foliar fertilizer should be sprayed.
Different vegetable types have different fertilizer requirements. For example, leafy vegetables like nitrogen, legumes like phosphorus and potassium, Chinese cabbage, cauliflower, radish, etc. are more sensitive to boron fertilizer, while leguminous and cruciferous vegetables are more sensitive to molybdenum fertilizer. Short term vegetables require less fertilizer, while continuous flowering and fruiting vegetables require more fertilizer. Potato and taro vegetables avoid chlorine, and onion and garlic vegetables avoid molybdenum. Therefore, the application of foliar fertilizer to vegetables should vary according to different types, and scientific fertilizer selection should be achieved to seek benefits and avoid harm.
During the growth and development stages of vegetables, there are differences in the proportion and amount of demand for nutrients. Generally, the amount of fertilizer required during the seedling stage is low, while during the flowering and fruiting stage, it is high. Therefore, when applying foliar fertilizer, it is necessary to spray a small amount of small leaves in the early stage to supplement nutrients and promote seedling strength.
Vegetables grow with lush branches and leaves, abundant flowers and strong fruits, indicating sufficient supply of fertilizer and water, good growth, and less topdressing; If there are yellowing, few flowers and small fruits, serious pests and diseases, growth obstruction, and poor growth, it indicates that vegetables lack nutrients and nutrients. At this time, it is necessary to carefully identify the reasons, apply fertilizer according to the symptoms, and timely supplement the necessary nutrients. If tomatoes suffer from navel rot, calcium fertilizer should be considered for supplementation. If cucumbers suffer from excessive growth and melon deficiency, nitrogen control and phosphorus and potassium supplementation should be taken.
