The Latest Prevention and Control Measures for Abnormal Onion Growth
Onion, also known as cong tou and round onion, is a common vegetable in our daily lives. It not only has extremely high nutritional value, but can also help prevent and control osteoporosis symptoms, and also has anti-cancer and anti-aging effects, with certain health benefits for high blood pressure and cardiovascular and cerebrovascular diseases. During the cultivation process, abnormal growth often occurs, so how should abnormal onion growth be prevented and controlled? Follow the editor to learn more.
1. Strictly select varieties
During production, it is best to use local superior varieties, so that the onions grown can be guaranteed. If introduction of varieties is needed, then according to the response of the introduced variety to low temperature and day length, choose as much as possible a variety with strict requirements for low temperature. Superior varieties are the prerequisite for high yield and quality. In addition, before planting, seeds should also be strictly selected, carefully chosen, and strong seedlings cultivated.
2. Choose a suitable sowing period
Onion is a vernalization-type plant. Sowing too early will cause the seedling age to be too long and the seedlings to be too large, exceeding the critical size required for vernalization, making it very easy for vernalization or incomplete vernalization to occur, causing abnormal bulb growth. Therefore, the correct sowing period should be chosen according to variety characteristics and climate features. Generally, autumn sowing is from September to October, while spring sowing is generally from March to April.
3. Strengthen fertilizer and water management
Fertilizer and water have a great impact on onion growth. If irrigation is too much and nitrogen fertilizer is excessive, the seedlings will become too large, delaying or inhibiting bulb formation. Therefore, attention should be paid to the application of phosphorus and potassium fertilizers, avoiding partial application of nitrogen fertilizer, so as to prevent overly late growth of the aboveground parts and the occurrence of bolting and delayed bulb expansion. Before and after the emergence of spring-sown seedlings, the soil needs to be kept moist, with frequent watering and light intertillage. The vigorous leaf growth stage and the bulb expansion stage are the periods when onions have the greatest demand for fertilizer and water. Water and fertilize at the right time. Per mu, 15 kg of diammonium phosphate, 20 kg of diammonium phosphate, and 3--5 kg of potassium sulfate can be applied as topdressing.
4. Prevent and control insect pests
The main pest to prevent and control is the damage caused by root maggots. Dimethoate and dichlorvos can be applied with irrigation water. Raw manure is prohibited for use as fertilizer because root maggots are attracted to raw manure. Fully decomposed organic fertilizer should be used, applied evenly and deeply, with seeds and fertilizer kept separate. For plots where root maggot damage has already occurred, watering should be done frequently, and if necessary, flood irrigation can be used, but irrigation should be coordinated with onion growth.
The above is an introduction to the prevention and control measures for abnormal onion growth. We hope it can help you. To learn more related knowledge, please stay tuned to us.