What Causes Root Rot in Welsh Onions? Latest Control Methods Explained

We are all surely familiar with Welsh onions. In recent years their price has been stable and their yield relatively high, so the growing returns are quite good, but during cultivation they often suffer from root rot. So what causes root rot in Welsh onions? And how should it be controlled? Let's find out together.

1. Causes of Root Rot in Welsh Onions

There are many causes of root rot in Welsh onions. If herbicides are used improperly, they can cause phytotoxicity, restricting the growth of Welsh onions, turning the leaves yellow and dry, and rotting the roots. With continuous cropping year after year, there are more pathogens in the soil, and serious disease is unavoidable, very easily causing root rot and dead plants in Welsh onions. When soil moisture is relatively high, permeability decreases, the roots cannot breathe normally, and the plant's stress resistance declines; over time the roots may even suffocate and die, causing root rot. Besides disease damage, damage from underground pests can also cause root rot. For example, root maggots bite and feed on the roots of Welsh onions, giving pathogens an opportunity to invade, which also causes root rot.

2. Control Methods

1. Scientific planting

When transplanting seedlings, first make the planting holes, and keep the seedlings upright when planting; do not plant them at a slant. Also pay attention to planting depth: it should not be too deep or too shallow, otherwise growth will be slower and the roots will not be able to breathe well. In addition, when planting, use north-south ridges, which is more conducive to Welsh onions receiving more and more even sunlight.

2. Apply sufficient fertilizer

Fertilizer determines the overall growth of Welsh onions. If fertilizer is insufficient, the plant's stress resistance and disease resistance are weak, and it is very easily invaded by pathogens. Fertilization should be based mainly on decomposed organic fertilizer, supplemented by chemical fertilizer, with rational use of nitrogen fertilizer and increased application of phosphorus and potassium fertilizer. On the basis of applying sufficient base fertilizer, topdress rationally, especially during the vigorous growth period of the white stalk, which is the most critical period for Welsh onion yield.

3. Rational watering

Watering Welsh onions should be done flexibly according to weather conditions, soil moisture, and cultivation conditions. In summer and autumn, temperatures are relatively high; at this time watering is mainly to promote root development. Apart from abnormally dry weather, reduce the amount of watering as much as possible, and at the same time do a good job of drainage after rain to avoid waterlogging and root rot.

4. Cultivation and earthing up

During the growing period, Welsh onions need 3-4 rounds of cultivation and earthing up. This can break up soil compaction, increase soil permeability, allow the root system to grow and develop well, and also prevent bending and lodging. In addition, weeds can be removed along with cultivation and earthing up; use chemical herbicides as little as possible, and even if they must be used, choose highly effective, low-toxicity ones.

5. Pest and disease control

Pest and disease control for Welsh onions must be done carefully. Before planting, disinfect and sterilize the soil by deep plowing and spreading quicklime to reduce the pest and disease baseline. When pests or diseases occur, apply the right treatment promptly to avoid expanding losses.

The above is an introduction to the causes of root rot in Welsh onions and its control methods. We hope it helps you. To learn more related knowledge, please stay tuned to us.