Causes and control methods of cucumber yellow head with yellow veins and white spots

Cucumber "yellow head", refers to its stem vine growth point near the yellow, some leaves at the top of the veins are yellow albino, some are yellow spots or patches and so on. The causes are zinc and iron deficiency, root injury, drug damage, hormone poisoning and disease. Here, remind vegetable farmers to distinguish the cause and treat the disease.

Cucumber yellow head

First: zinc and iron deficiency.

Zinc and iron are trace elements, which are often ignored by vegetable farmers. over time, when cucumbers excessively absorb zinc and iron from the soil without supplement, resulting in a lack of zinc and iron in the soil, cucumbers are easy to "yellow head". First, the parietal leaf turns yellow, the leaf vein is still green, and then the leaf vein turns yellow, and the leaf margin gradually dies and dries up. In this regard, attention should be paid to the application of micro-fertilizer in the base fertilizer, such as ferrous sulfate about 2 kg / mu and zinc sulfate 1 min 2 kg / mu. After the appearance of symptoms, spraying foliar fertilizer containing zinc and iron in time can alleviate this symptom.

Second: root system injury.

If the root system is injured, the "yellow head" will be light, and the cucumber plant will die if it is serious. The main causes of root injury are too high or too low ground temperature and too much water and fertilizer. For example, in winter, cucumber root absorption decreased, stress resistance decreased, such as do not control fertilizer and water, easy to hurt roots. "the leaf depends on the root length", after the root system is injured, the ability to absorb nutrients decreases, then it is easy to appear "yellow head". Therefore, in winter, the amount of water should be reduced, small water should be irrigated, and the main fertilizer should be biological fertilizer or humic acid fertilizer or Apollo 963 chitin fertilizer, so that the cucumber root system can return to normal as soon as possible, so as to promote the leaves to turn green.

Third, drug damage occurs.

After the occurrence of drug damage, cucumber is first shown on the leaves, the leaf edge is dry or yellowed, the leaves are green and deformed, and spots or withered spots appear. When applying, the medicine should be dispensed strictly according to the prescribed concentration and dosage, and should not be mixed as much as possible, especially not with copper preparation or foliar fertilizer. After the occurrence of drug damage, it can be alleviated by spraying cytokinin mixed nucleotide leaf fertilizer (such as Lvfeng 95) in time.

Fourth, excessive dipping in melons.

It causes hormone poisoning and causes the parietal lobe to become yellow and stiff. After hormone poisoning, the top piece is stiff, the leaf margin curls upward, and the growth is slow or not long. The cucumber plants with hormone poisoning can be relieved by spraying Yunda 120 or Yunda whole tree fruit mixed nucleotide leaf fertilizer under the premise of suspending dipping melon.

Fifth, infection disease.

Such as brown spot, when the damage is serious, the top leaves have yellow spots, resulting in the yellow head of cucumber. In this regard, methyl topiramate or carbendazim can be sprayed with Baitai or Paohydantoin and other medicament control.