Bacterial Blight of Onion Symptoms and Treatment

What is bacterial blight? How do you get rid of bacterial blight? What causes bacterial blight? Let’s find out about bacterial blight of onion symptoms and treatment guidelines!

Bacterial Blight of Onion Definition

Bacterial blight of onion meaning: What is the bacterial blight of onion?

Bacterial Blight of Onion Causes

What causes bacterial blight of onion? What is the most common cause of bacterial blight of onion?

Bacterial blight is brought on by Pseudomonas syringae pv. porri. The name “pathovar” (pv.) means that this pathogen only affects plants in the allium group. It does not affect other crops, such as tomato, celery, and bean, which are vulnerable to other P. syringae pathogens. The pathogen is an aerobic, Gram-negative bacterium that can be isolated on standard microbiological media. It makes the cream-colored colonies that are typical of most pseudomonads. When grown on Kings medium B, this organism makes a pigment that spreads and glows blue under ultraviolet light.

Several other bacteria are harmful to alliums. Slippery skin disease is caused by Pseudomonas gladioli pv. alliicola. It leads to a water-soaked bulb rot that at first only affects a few fleshy scales. At room temperature, however, these infected scales quickly lead to a lot of rotting inside the bulb. Sour skin is caused by Pseudomonas cepacia, which makes the inner fleshy scales pale yellow or light brown as they rot. Bacterial streak and bulb rot of sweet onions happen in the US and are caused by Pseudomonas viridiflava.

Soft rot is caused by Erwinia carotovora subsp. carotovora is linked to very wet conditions in the field or poor handling at harvest. As a result, the bulb gets a watery rot with a strong smell. Another bacterial disease is onion bacterial blight, caused by a seed-borne Xanthomonas species. This problem mostly happens in tropical and subtropical areas and causes long, yellow spots that may have wet edges. The spots later turn brown and die.

Bacterial Blight of Onion Symptoms

Signs and symptoms of bacterial blight of onion – What are some symptoms of bacterial blight of onion?

Young leaves have water-soaked, yellow stripes or lesions that split and rot as they age. As the plant grows, the leaves can curl up and twist.

The pathogen makes yellow spots around wounds on leaves that are getting old. Flower stalks are especially vulnerable. They get deep, wet sores that leak bacterial exudate. Lesions on older stalks are sunken, start out yellow, then turn brown. While growing in greenhouses, the disease can spread to leek transplants. Leaves of transplants get long, yellow spots that turn brown. Most lesions happen at the ends of the leaves.

Bacterial Blight Disease Cycle

Pseudomonas syringae pv. porri is spread by seeds, so the disease can start in the field with direct-seeded leeks or in greenhouses with transplanted leeks. When the pathogen is in the seedling, transplant, or field stage, it needs splashing water from rain or overhead sprinkler irrigation to spread. The bacterium can live in the leftover parts of a leek crop, but it won’t live in the soil once the leftover parts have completely broken down.

Bacterial Blight of Onion Treatment Guidelines

Treatment of bacterial blight of onion – What is the best treatment for bacterial blight of onion?

Use seed that does not have a lot of the pathogen. Appropriate seed treatments can also help control seed-borne inoculum. Move away from allium crops to reduce inoculum from crop residues. Irrigate with drip or furrow systems. Copper sprays may slow the spread. Don’t add too many high-nitrogen materials.

I hope you understand bacterial blight of onion symptoms and treatment guidelines.