The pepper seedling cultivation work started in late February. As of March 24, the pepper seedlings in the small shed had grown about 4 cm and more than 3 leaves (see the picture below). For early seedlings or well-managed seedbeds, the plant height can reach more than 5 cm. This time is a critical period for the development of pepper seedlings, and the probability of blight and damping-off is very high.

Yesterday, a pepper grower reported that the temperature has been relatively high in the past week, with the highest temperature reaching around 23°C at noon. Worried about scalding the seedlings, he opened the small shed around 10 a.m. and opened the greenhouse at around 4 p.m. When I was building a shed, I found a large number of pepper seedlings lying down. What was going on? The reason for the lodging of pepper seedlings

Many people will directly attribute it to diseases. In fact, this is unscientific. This is caused by a combination of climate reasons and disease occurrence.

Chili peppers are susceptible to blight and damping-off in the seedling stage. The pathogens usually exist at the base of the pepper seedlings. Under normal circumstances, the symptoms are asymptomatic and are no different from healthy seedlings.

Once the climate changes and high temperatures and humidity occur in the shed, the pepper seedlings will rapidly lose water and become wilted, showing obvious symptoms of water shortage. If the high temperature lasts for a long time, the pepper seedlings will appear lodging. Pepper seedbed blight and damping-off

These two diseases are common diseases in the seedling stage of pepper. The pathogenic bacteria survive in the soil and on diseased residues, and they are both soil-borne diseases. Damage the vascular parts of the roots and stems of crops. Symptoms: The base of the stem close to the ground loses obvious water, like being scalded by boiling water, constricting inward, and surrounding the stem. As the disease worsens, the vascular bundles are gradually infected, the nutrient transport channels are destroyed, and the nutrients absorbed by the roots cannot continue to be supplied to the above-ground parts.

The conditions that aggravate the occurrence of the disease are high temperature and high humidity. As the temperature rises faster, the temperature in the small shed will be higher. If the ventilation is not done properly at this time and the air convection inside and outside the shed is frequent, the symptoms will be completely severe: it will fall directly from the roots, gradually wither and die, and cannot return to normal. Farming operations will also aggravate the occurrence of these two diseases

During the pepper seedbed management period, there are two improper farming operations that will aggravate the occurrence of blight and damping-off, namely improper management of seedling removal and improper ventilation.

Peel seedlings: Due to broadcasting, the density of pepper seedlings in the seedbed is usually too high, which is not conducive to the cultivation of strong seedlings. Then, pepper growers usually trim the seedlings around three leaves. After trimming the seedlings, they spray water on the ground to eliminate the unevenness caused by trimming the seedlings.

During this operation, human factors will accelerate the spread of germs, and in severe cases will affect the seedbed. Especially spraying water on the ground will accelerate the infection of germs.

Excessive ventilation: The temperature in the small shed is too high, and it needs to be opened for ventilation and cooling. In this case, if the ventilation time is too long, burns will occur, which will directly lead to the occurrence of cataplexy and manifest itself. The symptom is "lodging". Prevention and control plan

These two diseases are relatively easy to control. "Nongbus" recommends using 3 metalaxyl and 1,000 times of hymexyl aqueous solution and 12 kinds of medium and trace elements seaweed liquid to spray evenly on the surface at intervals. Continuous use 2-3 times in 7 days can effectively prevent the lodging of pepper seedlings.

Of course, the time of medication is also very critical. I suggest that you spray before removing seedlings. This can disinfect the soil in advance and kill most pathogenic bacteria. Even if you do later farming operations, the impact will not be too great.