What are the causes of vegetable seedling damping-off and the control methods?

Vegetable damping-off, also called seedling meltdown, is a common phenomenon during the raising of melon and fruit vegetable seedlings in winter and spring, and it has a relatively large impact on production. It is most prone to occur from seedling emergence to around the appearance of the first true leaf. At first only a few seedlings fall over, and by the next day large patches of seedlings fall over and die, causing huge losses. So what causes vegetable damping-off? How should it be controlled? Follow the editor to take a look.

I. Causes of damping-off

1. Improper seedling raising

According to surveys of greenhouse vegetable seedling raising in many places, there are three main reasons for the symptoms of melon and fruit vegetables falling over and dying within a short time after emergence. First, the vegetable seeds carry pathogens and have not undergone any disinfection or sterilization treatment, so the seedlings show damping-off when they emerge; second, the soil contains soil-borne pathogens and has not undergone any suppression or sterilization treatment, so after emergence the pathogens infect the seedlings, often causing them to fall over and die; third, at emergence the environment is low-temperature, rainy, and highly humid, and this kind of environment very easily induces disease, and after infecting the seedlings very easily causes them to damp off and die.

2. Damage from diseases

Damping-off in melon and fruit vegetables is generally caused by damping-off disease, Rhizoctonia rot, and Fusarium wilt. Among them, damping-off disease generally occurs before the seedlings have 2 true leaves; Rhizoctonia rot generally harms solanaceous vegetables; and Fusarium wilt mainly harms cucurbit vegetable seedlings. These three diseases are the most likely to cause damping-off in greenhouse vegetables. Because their transmission routes differ, their control methods also differ, and prevention should be the main approach.

II. Control methods

1. Agricultural control

For agricultural control, first, the seedbed should be changed every year, and seedlings should not be raised on the same continuous cropping land; second, sufficient base fertilizer should be applied to the seedbed, and the base fertilizer must be fully decomposed, so that undecomposed fertilizer does not introduce pathogens and insect eggs; third, control agents should be applied together with the base fertilizer, which can effectively suppress soil-borne diseases; fourth, the seeds should be disinfected and sterilized, and the simplest method is to soak them in 55-degree warm water for 10 minutes, or seeds can be dressed with chemicals. Before sowing, carbendazim or thiophanate-methyl can also be used to disinfect and sterilize the soil.

2. Chemical control

In the early stage of seedling disease, a 500-fold dilution of copper sulfate solution can be sprayed on the seedbed or used as a root drench after planting, which can achieve an excellent control effect.

  The above is an introduction to the causes of vegetable damping-off and the control methods. I hope it can help you. To learn more related knowledge, please stay tuned to us.