What about the twisted heart leaves of corn? how to control the long tail of summer corn?

Recently, many farmers have reported that the heart leaves of some corn seedlings in corn fields are distorted and cannot be spread out. In serious cases, they are in the shape of a big whip, and the phenomenon of corn with a long "ox tail" has also occurred in previous years. The causes and preventive measures of corn heart leaf distortion are introduced as follows:

Corn heart leaf twist

First, herbicide damage. Corn performance: serious dwarfing, heart leaves twisted, can not expand, and there is a phenomenon of bifurcation, twisted leaves are not damaged. Cause: corn seedling herbicide containing nicosulfuron was used. There are four reasons: 1. The purity of domestic nicosulfuron is not enough, which causes drug damage. two。 High temperature time spraying, or re-spraying, causing drug damage. 3. Corn is over 5 leaf age, or liquid medicine is sprayed into the heart, causing distortion, whitening of leaves, or rotten heart. 4. Herbicides were applied too late to produce onion-like leaves, mainly because some hybrid varieties of corn were sensitive to herbicides and could not pull out the panicle normally.

Preventive measures: after the occurrence of drug damage, such as corn heart leaf distortion is not very serious, does not affect panicle extraction, topdressing nitrogen fertilizer and watering, corn can return to normal growth after a week. If the twist is serious, it should be broken, fertilized and watered, foliar fertilizer and zinc and boron fertilizer added.

Second, caused by pests. It is mainly caused by thrips and Swedish flies. Peel off the outer leaf, the base of the heart leaf has been wrinkled, there are holes. The main manifestations are as follows: the heart leaves of corn are twisted, the leaves are damaged and wrinkled, and holes appear on the leaves. There is a transparent film on the front of the corn leaves, some heart leaves have mucus, the heart leaves can not stretch normally and twist like "fine twist" or "oxtail", and some heart leaves have been broken. The main reason is that summer corn is damaged by thrips or Swedish flies at 5-6 leaf stage.

Preventive measures: should be early prevention and treatment, heart leaf curl, and then use medicine, the effect is not good. First of all, 20 grams of 10% imidacloprid wettable powder or 20-30 grams of 5% acetamiprid wettable powder were sprayed with 30 kilograms of water. For corn heart leaves. In the middle and later stage, the damaged heart leaves of corn should be broken manually, the twisted parts should be opened, and some foliar fertilizer should be added after drug control.

Third, physiological diseases. Excessive application of nitrogen fertilizer, excessive nutrition and excessive nutrition are also related to the characteristics of varieties.

Preventive measures: after it is found, it should be peeled off manually to assist male extraction.

Fourth, the reason of the weather. Continuous torrential rain and low temperature are disadvantageous to the growth of corn, and the physiological disorders of corn are particularly prominent in some corn varieties that are sensitive to climate and environment. This weather will make the corn grow an "ox tail": the upper leaves are wrapped together and bend and droop. So that the corn can not heading normally.

Preventive measures: immediately cut off the corn leaves of the upper 1cm 4 with scissors, or cut them up and down with a knife to break the twist heart, and apply zinc fertilizer, foliar spraying plant growth regulators such as gibberellin (1 gram plus water 15,30kg) or Tianfengsu (1000 times liquid), 5 times every 7 days, twice in a row.