What to Do About Onion Bulb Rot? Causes and Control Methods
Onion, also known as the bulb onion, originated in West Asia, and is now cultivated in every region of China, with relatively large market demand and significant economic benefits, so it is now grown by many farmers. However, many problems are encountered during cultivation that affect yield and marketability, and onion bulb rot is one of them. Below, Qinnong Net brings you the causes of onion bulb rot and control methods. Let's take a look.
1. Rot caused by diseases
Onions suffer from the invasion of many diseases during cultivation, which harm the normal growth and development of the onions, and in severe cases cause a large number of plants to die. There are many diseases that cause onion bulb rot, such as onion dry rot, onion dry rot, onion bulb rot disease, onion black aspergillus disease, onion black aspergillus disease. The characteristics of these diseases differ, but in the later stages they all cause the onion bulb to rot.
Control methods: Great importance must be attached to disease control. Before planting, disinfect the soil and seeds to eliminate pathogens in the soil and carried by the seeds. During cultivation, strengthen fertilizer and water management, apply more phosphorus and potassium fertilizer, and improve disease resistance. When some diseased plants are found, remove them from the field and disinfect the diseased holes, then spray the corresponding chemicals for control.
2. Rot caused by physiological disorders
So-called physiological disorders refer to some diseases caused by improper management during onion cultivation. For example, when onions lack calcium, it causes onion bulb rot; when onions sprout during storage, nutrients are consumed in large amounts, causing the bulbs to soften and become hollow, leading to rot; in the late stage of onion bulb growth, leaves and leaf tips turn yellow, so there are no new leaves to replenish the leaf sheaths, causing hollowness and loosening of the leaf sheaths. When watering or raining, water flows into the bulbs, causing bacterial infection and rot; in addition, mechanical damage caused by some reason during planting, harvesting and storage can also lead to pathogen infection and rot; and an unsuitable storage environment with high temperature and humidity makes onions sprout and take root, causing rot.
Control methods: Treat each cause of rot according to its specific cause. For example, if calcium is deficient, supplement calcium in time. When fertilizing, apply organic fertilizer appropriately to ensure the supply of trace elements. Manage planting, harvesting and storage well to avoid rot caused by the above reasons.
3. Rot caused by insect pests
The insect pests that cause onion bulb rot are mainly onion maggots or root maggots. They are common pests during onion cultivation, and mainly the larvae cause damage below ground, gnawing on the bulbs, so that the onions cannot grow normally, and in severe cases the leaves wither, turn yellow and rot.
Control methods: Use a combination of agricultural control and chemical control. Unless absolutely necessary, try not to use chemical control. Before overwintering, completely remove weeds and residues in the field to prevent adult insects from laying eggs, or prepare attract-and-kill chemicals and attract egg-laying, and natural enemies can also be used for control. During outbreaks of pests, chemical control can be used, but pay attention to the concentration and dosage of the chemicals to avoid phytotoxicity to onions.
The above are the causes of onion bulb rot and control methods brought to you by Qinnong Net. We hope it helps you. To learn more about onion cultivation knowledge, please keep following Qinnong Net.