What causes stunted cotton seedlings? A detailed guide to prevention and control methods
As the cotton planting area grows larger and larger, the problems that come with it are also increasing. Stunted cotton seedlings are one of them, seriously affecting cotton yield and quality and bringing huge economic losses to growers. So what causes stunted cotton seedlings, and what are the symptoms? How should they be prevented and controlled? Let's take a look.
1. Temperature and moisture
Transplanting usually takes place in May, which is a period of changing temperatures, with high heat and frequent rain and a large difference between day and night temperatures. During growth, cotton easily loses water, and if watering is not done in time, stunted seedlings result. In addition, a transplanting temperature as low as 12 degrees can freeze the plant's roots, stems and leaves, causing slow or stopped growth and forming stunted seedlings.
Prevention and control methods: Choose a reasonable and appropriate sowing time, and try to avoid transplanting during periods of changeable weather. If the climate is unsuitable, the transplanting time can be postponed. In addition, after transplanting, maintain the moisture the plants need for growth and water in time, but in rainy weather take good drainage and waterlogging prevention measures. When temperatures are low, ground temperature can be raised by covering with straw or plastic film; fertilizing is also a way to raise ground temperature, preventing low temperatures from damaging the root system.
2. Improper fertilizing
When base fertilizer is applied too shallowly, the plant's roots come into direct contact with the fertilizer, and the concentrated fertilizer damages the plant, causing root burn. Alternatively, if soil is not promptly earthed up after fertilizing and no water is given, the fertilizer decomposes slowly, and once heavy rain occurs, the plant suffers fertilizer damage, resulting in stunted seedlings. Generally, the larger the amount of base fertilizer applied, the earlier the rain after transplanting and the heavier the rain, the more severe the stunting of the plants, which is also accompanied by some physiological disease symptoms.
Prevention and control methods: Do not apply excessive base fertilizer. Base fertilizer must be worked deep into the soil layer, then covered with another layer of soil to prevent the roots from directly contacting the fertilizer. Each time you apply a top dressing, it can be mixed with water to make a dilute fertilizer solution, which also speeds up the plant's absorption.
3. Poor quality of cotton seedlings and transplanting
During seedling raising, improper management leads to poor seedling quality, with many weak and diseased seedlings far below normal seedlings, resulting in a very low survival rate at transplanting; even those that survive are very prone to thinning. In addition, poor land preparation at transplanting, transplanting too deep or too shallow, and incomplete soil covering will all cause seedlings to grow thin and weak or to shrivel and stop growing, resulting in stunted seedlings.
Prevention and control methods: Seedling raising must be carried out strictly. Whether it is the choice of seedbed, the choice of soil or seedbed management, try to meet the conditions the seedlings need for growth. When lifting seedlings for transplanting, do not cause damage to the seedlings, especially the root and stem parts. Remove weak and diseased seedlings. When transplanting, keep the depth neither too deep nor too shallow, and press the covering soil down firmly and bury it solidly.
4. Pests and diseases
After transplanting, soil and management factors can cause plants to be attacked by pests and diseases, which also forms stunted seedlings. For example, damping-off, anthracnose, Fusarium wilt, thrips, cotton aphids and other pests and diseases can cause plant leaves to curl, roots to grow thin and weak, and plants to be short, forming stunted seedlings.
Prevention and control methods: Do not be careless about pest and disease control. Focus on prevention. When pest or disease damage is found, treat it promptly. After treatment, apply 30-50 kg of urea per mu as a top dressing, plus a foliar spray of potassium dihydrogen phosphate solution, to promote recovery.
The above are the causes of stunted cotton seedlings and the prevention and control methods. We hope this helps you. To learn more about cotton cultivation, please stay tuned to us.