A Detailed Guide to the Control of Common Pests and Diseases of Welsh Onion
Welsh onion is grown fairly widely in China and is one of the common crops, but during cultivation, pests and diseases often harm its yield and quality, bringing serious economic losses to growers. So what are the common pests and diseases of Welsh onion? How should they be controlled? Let's take a look at the detailed introduction below.
1. Soft rot
Soft rot is a bacterial disease that is highly prone to occurring in high-temperature, high-humidity environments. When the plant has mechanical wounds or insect-bored wounds, the pathogen invades through them and infects the plant. When the disease occurs, the aboveground stems and leaves lodge, the base of the stem rots, there is a foul odor, and the plant is very easy to pull out; in the later stages of the disease, the plant tends to wither and die.
Control methods: Pay attention to field humidity to avoid excessive water accumulation that leads to root rot. Be careful when earthing up to avoid damaging the plants. Strengthen pest control measures. At the onset of the disease, spray with copper hydroxide and agricultural streptomycin sulfate for control.
2. Purple blotch
Purple blotch mainly harms the leaves and flower stalks. When the disease occurs, water-soaked white spots appear at the affected sites, which then gradually become light brown circular or spindle-shaped, slightly sunken spots, and continue to expand, with the lesions turning brown or dark purple. The disease is more severe in warm, high-temperature summers, and severe in old fields and fields with insufficient fertility.
Control methods: Practice reasonable crop rotation, apply more organic fertilizer and phosphorus-potassium fertilizer to improve the plant's disease resistance. In the early stage of the disease, spray with chlorothalonil, oxadixyl, and iprodione for control.
3. Onion rust
Onion rust mainly harms the stems, leaves, and flower stalks of Welsh onion. When the disease occurs, orange-yellow or dark brown pustules appear at the affected sites, and in the later stage the lesions release rust-colored powder, which is also the origin of its name.
Control methods: Do a good job of fertilizer and water management
, increase phosphorus-potassium fertilizer, and in the early stage of the disease spray with mancozeb or chlorothalonil once every 10 days, for 2-3 consecutive times, for a relatively good effect.
4. Leafminer
Leafminers mainly cause damage as larvae. Their larvae bore into the leaves and continuously feed on the leaf mesophyll tissue, causing yield and quality to decline, and they also spread many diseases. The main outbreak period is from May to October.
Control methods: After harvest, thoroughly clean the field, take diseased and residual plants out of the field, and deep-plow the soil to destroy eggs overwintering underground. Poison soil can also be made to kill them. During the outbreak period, spraying abamectin gives a relatively good effect.
The above is an introduction to the control methods for common pests and diseases of Welsh onion. We hope it can help you. If you want to learn more related knowledge, please follow us.