Cabbage yellow leaf disease is extremely harmful, what are the symptoms of cabbage yellow leaf disea

The nutrients in the soil are not well absorbed and utilized by crops. At this time, the cabbage leaves appear yellow due to the lack of fertilizer**. Therefore, in the dry and rainy weather, it is necessary to water in time to meet the needs of the normal growth of cabbage.

Use test strips to measure the pH value of the land to determine whether to water some weakly acidic rainwater or rice water to change the acidity value of the vegetable field, reasonable watering, scientific fertilization, and pay attention to the soil environment, you can avoid most of the yellowing problems.

The periphery is a pale yellow halo, and the periphery of the lesion on the back of the leaf is dark green. When the air is humid, a light gray mold is produced on the lesions on the back, that is, the conidia and conidia of the pathogen. In the later stages, the lesions become white and translucent, and finally rupture and perforate.

There are three reasons for the yellowing of cabbage leaves, one is not watered in time, the second fertilizer is not reasonably fertilized, and the third is that some areas have too much reduction, and it is necessary to use two percent of sulfuric acid to water in order for cabbage to grow vigorously. 1. There are many aphids, most of which are caused by sucking behind the leaves. 2. Lack of fertilizer.

Cabbage grows vigorously and needs to be topdressed frequently, otherwise the leaves are yellow. 3. Poor ventilation, too dense, stuffy. It prefers cooler climates.

Too high a concentration of fertilizer can cause problems with its absorption, which can lead to calcium deficiency. When the weather is dry, there is no timely watering, especially during the rosette stage, the lack of water will lead to a decrease in the fertilizer absorption capacity of the roots, resulting in a lack of nutrients in the cabbage, resulting in dry leaves. Natural conditions.

1) Do not plant cabbage in low-lying places and soak it in water frequently. (2) Crops are planted in rotation to avoid virus invasion. (3) Go to the agricultural station to select high-yield Chinese cabbage seeds.

For example, Shandong cabbage is famous all over the country. Do not keep the seeds for yourself.

In the later stage, the yellow spots form irregular yellow leaf spots, and if the ground is more humid, the back of the leaves will also grow gray-white mildew, so that the cabbage leaves turn yellow and dry from the outside to the inside, and only the part of the cabbage sum is left in serious cases. When we transplant cabbage seedlings, we must water enough on the first day and cut them into mounds for transplanting on the second day, so as to avoid damaging the roots and shorten the slow seedling period of cabbage.

First of all, the fibrous roots of cabbage will be fewer, and the vascular bundles will change from green to brown; The second is that the leaves will fade from the edges, turn yellow, and look like wilting.

The leaves of the plant will be yellow, and will continue to wither, causing the plant to die, affecting the yield of cabbage, and bringing very serious damage to cabbage.

It will make the cabbage grow very slowly, the leaves will roll, there will be insects on it, and the whole plant will be very thin, and there is a feeling of weakness and wind.