Causes and Control of stiff seedlings of Cotton

During the transplanting period, cotton seedlings are often affected by abnormal climate, weak seedlings, inadequate cultivation measures and other factors, which slow down the growth process and reduce the yield of cotton. The causes and control of cotton stiff seedlings are introduced as follows:

First, reasons

1. The quality of cotton seedlings is poor. The ① seedling bed is insufficient to fertilize and form small and weak seedlings, the growth potential is poor, and the living trees are slow. ② nursery bed was improperly managed to form tall seedlings and prosperous seedlings. After transplanting, too much water was lost and the planting injury was serious.

two。 The temperature is not suitable. In many places, the temperature in early May is still unstable, and early-planted cotton often suffers frost damage due to the attack of low temperature and cold spell, and its growth is restrained. When transplanting cotton in late stubble, because of high temperature and large evaporation, the injury of cotton seedlings was serious and the slow seedling period was long.

3. It will be planted in rainy days. Planting cotton after wheat is practiced in some places. The time for planting cotton after harvest is relatively tight. In order to reduce the use of watering during transplanting, some cotton farmers rush to plant on rainy days. Because the soil is moist, the soil structure is destroyed by artificial trampling, and the soil will be seriously hardened after drying, making it difficult to root the cotton seedlings. In some fields, the water accumulation time is long, the soil temperature is low, and the soil permeability is poor, which reduces the water and fertilizer absorption capacity of cotton seedling roots, thus inhibiting the growth of cotton.

4. Drought and loss of water. If there is no watering or insufficient watering during transplanting, if there is a continuous drought and the soil moisture is seriously insufficient, the old roots will be injured, the new roots can not grow, the upper part of the cotton plant will wilt, and the growth will be inhibited to form small and old seedlings.

5. Improper application of base fertilizer. Some cotton farmers are used to using the pond opener to open the planting hole, and apply the base fertilizer directly into the hole, and then transplant cotton, which will make the roots of cotton seedlings come into direct contact with chemical fertilizer and cause seedling burning. The root system of cotton seedling was injured and the lower leaves fell off.

6. Diseases and insect pests. Cotton seedlings could not grow normally due to diseases and pests such as red spider, cotton aphid, thrips, blight and anthracnose.

II. Prevention and control methods

1. Cultivate strong seedlings. In order to cultivate strong seedlings, we should pay attention to fertilizing the soil, select the big bowl (bowl diameter above 7cm), do a good job of promoting the whole seedling with high temperature and high humidity, adjust the temperature and fertilizer to raise the strong seedling, and refine the strong seedling before planting.

two。 Transplant at the right time. In order to avoid the influence of low temperature and cold current on cotton, early stubble cotton was transplanted in sunny day when the soil temperature of 5cm was more than 16 ℃, and cotton was not planted in June. After wheat and oil, cotton should be stubble and transplant early, so as to harvest and transplant at the same time, and strive to end transplanting in early June.

3. Cover with plastic film. Mulching plastic film to increase temperature and moisture is an important measure to prevent cotton from freezing at low temperature and promote early development, especially for early planting cotton. Cotton was ditched and applied well before transplanting, with 20%-25% nitrogen fertilizer, 50%-60% potassium fertilizer, and all phosphate fertilizer. Cover with plastic film after rain or after making moisture. Punching holes in the film during transplanting can not only transplant early and eliminate fertilizer damage, but also retain moisture and improve soil temperature.

4. Improve the quality of transplanting. ① should be transplanted in sunny days, not in rainy days. When transplanting ②, it is necessary to strengthen the soil to ensure that the bowl body is integrated with the soil and do not plant "hanging seedlings". ③ opened holes, raised bowls, placed bowls, blocked soil and watered them at the same time, watering enough water, not planting diseased seedlings, lean seedlings, strong seedlings and broken seedlings, and transplanting large and small seedlings separately. The basic fertilizer was applied to the whole layer in the hole of ④. About 7 days before transplanting, Anjia Fei Shun cotton line was evenly scattered on the topsoil layer, and then the land was ploughed and leveled.

5. Strengthen the post-planting management. ① ploughing and loosening soil to break soil consolidation can increase temperature and air permeability, promote root growth of cotton seedlings, and enhance the ability of cotton seedlings to absorb fertilizer and water. For the fields with insufficient basal fertilizer, drought and lack of water, and cotton seedlings growing slowly after planting, ② should apply small fertilizer in time, irrigate large water (usually ammonium bicarbonate 15kg per 667m2), or spray foliar fertilizer to promote the growth of cotton seedlings as soon as possible. ③ should do a good job in the prevention and control of diseases and insect pests at seedling stage.