The causes and control methods of the latest rotten head of onion

Rotten onion occurs more commonly in onion planting areas, which causes serious economic losses to farmers, so farmers should strengthen their understanding of the disease and play a good role in prevention and control. So how to prevent the rotten head of onions? Let's get to know it with the editor.

1. The disease resistance of varieties is poor.

There are obvious differences in disease resistance among onion varieties. if you choose varieties with weak disease resistance, it is very easy to have rotten heads, so it is necessary to produce varieties with strong disease resistance now. For example, Kamuyi, Kongzhi Yellow, Fuxing, Dongke Apple Onion, Koste, Daqing Yellow Peel and so on.

2. Unbalanced nutrition

Onion is the peak period of nitrogen demand in the early growth stage, if nitrogen deficiency will result in small nutrients, low bulb maturity and decreased yield, if too much nitrogen fertilizer is applied, it will lead to soft onion tissue and increase the chance of bacteria invasion. after entering the bulb expansion stage, if nitrogen fertilizer is applied partially, calcium deficiency will occur, resulting in hindrance to the growth and development of roots and growth points. Cause bulb expansion and quality, cause rotten head. Therefore, in the cultivation of onion is to apply fully mature organic fertilizer, reasonable collocation of nitrogen, phosphorus and potassium, not partial application of nitrogen fertilizer, but also consider the intake of trace elements such as calcium, magnesium, sulfur, copper, boron and so on.

3. Leaf sheath flows into Rain Water

At this time, this is also one of the main reasons for the rotten head of onion. In the late stage of bulb expansion, the first to second leaves were withered and yellow, and the leaf tips of 34th leaves were yellowed. At this time, the bulb was hollow because there were no new leaves to enrich the leaf sheath, resulting in the loose wrapping of the leaf sheath. In case of continuous rainy days or sprinkler irrigation, water will flow along the leaves into the bulb, the bulb is extremely vulnerable to decaying bacteria infection and rot. So after the bulb expands, the plants in the field begin to lodge, to suppress all the upright plants, to prevent Rain Water from flowing into the bulb, and to harvest in time to prevent rain from rotting.

4. Wound infection

In the process of onion field management, harvest, drying, transportation and storage, onion is extremely vulnerable to mechanical damage and wounds, while onion larvae eating bulbs in the ground will also cause wounds, which will lead to decay. Therefore, mechanical damage should be reduced as much as possible. Before planting, 50% phoxim EC can be used to irrigate roots or 50% phoxim EC 1000 times to control underground pests.

The above is an introduction to the causes and control methods of rotten onions. I hope I can help you. If you want to know more about it, please follow us.