Common diseases and treatment methods of watermelon seedlings, seedling growth is small, leaves are slow, fresh leaves are grayish green, leaves are thickened, shrinkage, and tissue is stiff; cotyledons and true leaves turn yellow, underground roots are yellow, and even Browning, less whitening roots. The zombie seed is different from the growth point caused by the improper use of foliar fertilizer and pesticides, the leaf shape becomes smaller, the leaf edge is reversed, and the leaves become thicker and wrinkled and twisted.
Once the watermelon seedlings are dead, the recovery is very slow, which will delay the favorable growing season and seriously affect the yield and benefits. The dead seedling is the main physiological obstacle in the watermelon seedling stage.
cause:
1 The temperature of the seedbed is low, especially the soil temperature is low, which can not meet the basic temperature requirements of the watermelon root system.
2 The seedling bed is sticky and has high soil water content. It is difficult to develop roots under the conditions of high humidity and poor ventilation. The roots have poor absorption capacity. After continuous planting, it is rainy and the dead seedlings are particularly serious.
3 improper preparation of nutrient soil. In the seedbed or planting hole, the organic fertilizer which is not decomposed or not fully mixed is used to cause burning root or excessive application of chemical fertilizer, or the chemical fertilizer is applied to the root, and the soil solution concentration is high and the root is damaged.
4 seedlings are of poor quality. At the time of planting, the seedling age is too long, the root system is too much during the planting process, or the operation is rough during the site preparation and planting, and the roots are overhead, and the roots are not in close contact with the soil, which affects the hair roots.
5 After the underground pests damage the roots, the root system is seriously injured or killed.
Prevention:
1 Choose loose or well-ventilated garden soil or paddy soil for nutrient soil, try not to use soily and sticky river mud.
2 Improve the nursery environment, use the geothermal line or plastic film to cover the seedlings, improve the ground temperature, cultivate normal growth, develop the root system, and the seedling age is moderate (30 to 35 days from the root seedlings, 40 to 45 days from the grafted seedlings).
3 Apply the decomposed organic fertilizer to the seedbed, apply the compound fertilizer away from the root, or spray the foliar fertilizer to prevent the root injury.
4 timely and appropriate amount of water, so as not to reduce the bed temperature and ground temperature, adverse root growth.
5 When planting, use high-deep deep ditch to strengthen drainage, and appropriately increase the application of acupoint fertilizer (fertilized organic fertilizer and chemical fertilizer) to promote root growth.
6 pay attention to refining before transplanting.
7 timely colonization, to prevent the impact of low temperature after colonization, choose cold tail warm head for sunny planting.
8 Prevent ants and other underground pests.
Chang Miao
Watermelon seedlings grow too vigorously, appearing long, showing internode elongation, petiole and leaf body lengthening, leaf color light green, thin leaf, soft tissue.
Cause: The watermelon seedbed is under-illuminated, the temperature is too high, and the soil and air humidity are high. During the process of grafting watermelon, the rootstock and scion are not properly controlled in temperature, light and gas, and it is easy to appear. Changchang Miao has poor adaptability to low temperature and is prone to freezing damage.
Control measures: Reasonably adjust light, temperature and humidity. The temperature of the seedbed is managed in stages, ventilation and dehumidification are timely, and the illumination is increased to avoid excessive temperature. Reduce the night temperature and increase the temperature difference between day and night. Appropriately reduce temperature and humidity under conditions of insufficient light.
This article URL: Common diseases and treatment methods in watermelon seedling stage
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