1.The damage of salt injury
“Salt damage” is an important factor affecting yield in greenhouse cultivation, so it is imperative to solve the “salt damage” in melon and vegetable greenhouses. Blindly excessive fertilization, relying solely on fertilizer for yield, will inevitably lead to a rapid increase in the accumulation of salt in the soil, is bound to cause the occurrence of fertilizer damage (salt damage), how to solve and avoid the harm caused by blind fertilization?
First of all, adjust the farm manure, chemical fertilizer and microbial fertilizer application ratio. The decomposed farmyard fertilizer accounted for 65% of the total growth period, the chemical fertilizer accounted for 30% of the total growth period, and the microbial fertilizer accounted for 5% of the total growth period. Chemical fertilizers should be based on the physiological needs of different crops and reduce chlorine and sodium content. In addition, the correct choice of fertilizer types and fertilization methods, as far as possible to apply non-negative components of fertilizer, such as urea, potassium nitrate, calcium phosphate, diammonia phosphate, etc., as far as possible to reduce the residual accumulation of salt in the soil.
2.herbicide damage
The most common injuries caused by plant growth regulators are seedling collapse malformation and leaf fern virus symptoms. In good weather conditions, “drug damage” symptoms are not easy to be detected or symptoms are mild, but after continuous rainy weather, plants can not carry out normal photosynthesis, root absorption will appear problems. Therefore, at this time the plant poisoning symptoms will be highlighted. Prevention and control measures have the following points:
First, do a good job of prevention.To master the correct concentration, method and site of use of plant growth regulator, for example, bottle gourd, the use of etheprofen can promote the early opening of female flowers of the main vine, but the use must be 4-6 true leaves, early use is prone to drug damage.
Secondly, determine the appropriate concentration.If the concentration is too low, it cannot produce the desired effect; If the concentration is too high, it will destroy the normal physiological activities of the plant and even harm the plant. The concentration effect of plant growth regulators is much more complex than that of general pesticides. The concentration of the same plant growth regulator used by different crops varies greatly, and is related to the growth of crops.
Again, pay attention to climatic conditions.
When the temperature is too low, foliar absorption is slow. The temperature is too high, the liquid water is easy to evaporate, easy to cause the unabsorbed agent precipitation on the leaf surface, harmful to the tissue. When applied under dry climate conditions, the concentration of liquid medicine should be reduced; In the season of abundant rain, the concentration should be increased appropriately.
3.Fertilizer damage
Scientific fertilization To prevent one application of fertilizer is too large, to the base fertilizer after the soil or fully mixed with the soil; Topdressing should be advocated for deep application of soil, timely irrigation after application, can not be spread on the ground fertilizer
Balanced fertilization Potassium fertilizer should be applied in proper amount, in different times or in different layers; Do not mix zinc, iron and other trace element fertilizer and phosphate fertilizer directly, it is best to mix with decomposed organic fertilizer and nutrient package fertilizer.
Post time: Oct-25-2022