Onion root rot prevention and treatment method

Onion root rot symptoms

It mainly infects the root system and is initially water-soaked, and then produces brown spots, does not grow new roots, and the plants are short, withered, and even die.

Onset law of onion root rot

The pathogen is very virulent and can survive in the soil for a long time. It will overwinter in the surface soil of 12-18 cm with the diseased body in the form of oospores and hyphae. When the spring conditions are suitable, the germs germinate to produce sporangia, and invade the host by zoospores or directly growing out of the germ tube. In addition, the hyphae that live in the soil can also produce sporangia, which can cause tripping by invigorating the seedlings with zoospores. Spore sacs and zoospores can be produced on the diseased seedlings, which are spread by rainwater, irrigation water, fertilized manure, agricultural implements and seeds.

Onion root rot pesticide control method

1 seed disinfection before planting. It is also the most common first step to reduce the disease.

The amount of seed disinfection: Because the seed is compared with the soil, the area is small. Therefore, seed dressing can use a relatively low drug. 600-800 times solution of carbendazim or 800-1000 times solution of carbaryl

2 soil disinfection before planting. The second step is to reduce the disease.

Soil disinfection is relatively higher than the use of seed disinfectants. 1200-1500 times solution of carbendazim or 1500-2000 times solution of carbaryl

3 roots after onset. The third step is to reduce the disease.

The root irrigation is similar to the soil disinfection, and the application area is large, so the dosage is the same. 1200-1500 times solution of carbendazim or 1500-2000 times solution of carbaryl

The part of the onion for consumption is the underground fat bulb (the onion). According to its skin color, it can be divided into three types: white skin, yellow skin and red skin: white scale bulbs are small, white or slightly green on the outside, tender meat, juicy and spicy, good quality, suitable for raw food.