Yesterday, a friend called and said that his corn was fine when it first came out of the seedlings, but the leaves began to yellow these days, asking what was the cause? How to solve it? In fact, there are many reasons for the yellowing of corn leaves, if you want to solve, you must distinguish what causes it, and then take targeted measures to play a better effect, otherwise it is difficult to alleviate.
1, low temperature: sowing is too early, after the emergence of seedlings will often encounter low temperature, the emergence of yellow seedlings, especially this year's temperature is unstable, compared with previous years the temperature is relatively low. Under normal circumstances, when the temperature rises, the corn leaf color will slowly turn green. Generally speaking, the temperature rises quickly, but the ground temperature rises relatively slowly, in order to promote the rapid increase of the ground temperature, it can be achieved through medium cultivation, so this time can be shallow and medium cultivation between the rows to achieve the purpose of rapidly increasing the ground temperature.
2. Insufficient bottom fertilizer: the bottom fertilizer is not applied when the corn is sown, or the phosphorus fertilizer in the bottom fertilizer is insufficient, which often leads to yellowing of the leaves of the seedlings. In this case, fast-available phosphorus fertilizer should be applied in time to alleviate the yellow seedlings caused by phosphorus deficiency. The amount of phosphorus required at the seedling stage of maize is small, but the lack of phosphorus will affect the normal growth and development of maize, and even if the phosphorus fertilizer is increased in the later stage, it is difficult to make up for the impact caused by the lack of phosphorus at the seedling stage, so the phosphorus fertilizer should be supplemented in time after emergence.
3. Herbicide drug damage: As long as the herbicide before the seedling or the herbicide after the seedling is excessive or the concentration is high, it will cause drug damage after spraying, resulting in yellowing of corn leaves. Therefore, when spraying herbicides, we must strictly follow the instructions for the use of the product, and must not be sprayed repeatedly. Due to the use of herbicides for many years, there will be more or less residues of agents in the soil, and everyone should prefer to have a small concentration rather than an excess when dispensing pharmaceutical liquids. In addition, once there is a drug damage, irrigation conditions should be timely irrigation, no irrigation conditions can also spray water on seedlings, while brassicalide plus foliar fertilizer can be sprayed to quickly alleviate the drug damage and promote the normal growth of seedlings.
4. Drought: Corn seedlings are drought tolerant but not flood-tolerant, but when the drought is severe, it will also affect the normal growth and development of maize seedlings and cause yellowing of leaves. The method of alleviating the developmental obstruction caused by drought at the seedling stage is generally to adopt shallow and medium farming, and the people often say that "there are three points of water under the hoe", that is, the drought can be alleviated through medium cultivation during drought.