Ginger, alias Dioscorea zingiberaceae, is a perennial herb, but it can only be cultivated as an annual vegetable in China, because the climatic conditions in China are not suitable for ginger to grow for many years. Ginger is not cold-resistant, so it will wither when it encounters frost, and it will be forced to harvest and sleep, so as to see you next year.

Ginger is a condiment, but it is also an important cash crop. Because of its high yield, simple management, easy planting, rich nutrition, wide use, storage and transportation resistance, it has become an important economic source for farmers in many areas. For example, in Anqiu area, the planting area of ginger is very large, and with the increase of export volume in recent years, the planting area has increased year by year, which has become a pillar industry of the local economy.

Speaking of the yellowing of ginger, I think of the scene when I first came to work here. A ginger farmer came to us with several yellow Jiang Miao in his hand to analyze what caused it. I just graduated and came here at that time, and I was not very familiar with the cultivation of ginger. I told him without thinking that it was yellow leaves caused by the lack of trace elements, but he shook his head gently and said no, because he used foliar fertilizer several times, but the effect was not ideal. Another colleague asked Jiang Nong for a long time and finally determined that it was high temperature chlorosis.

due to the lack of rain that summer, his shading measures were not in place, which led to the yellowing of ginger leaves and the decline of chlorophyll in leaves under the irradiation of high temperature and strong light. Supplementing foliar fertilizer alone had certain effects, but it could not fundamentally solve the problem. The best way is to build a shade net, reduce the light intensity and the temperature of the growing environment, and spray foliar fertilizer to solve the yellowing problem of ginger leaves. Jiang Nong nodded frequently, thanked his colleagues, looked back at me again and turned away. It was this glance that made me deeply ashamed. I deeply realized the famous saying that "it is better to read thousands of books than Wan Li Road". It is not unreasonable to know that this matter needs to be done. Later, when I serve farmers again, I will come to their fields for actual observation to obtain first-hand information and formulate reasonable solutions when I can't determine the cause.

The yellowing of ginger leaves is caused by ginger blast, virus disease and underground pests such as root nematodes, but the most common cause is physiological. Yellowing of ginger leaves caused by germs, viruses, pests, etc. occurs locally, and rarely occurs in the whole field, unless your ginger field is low-lying and the whole field is flooded.

Then we will focus on the yellowing of leaves caused by physiological diseases of ginger.

1. High-temperature chlorosis

Ginger high-temperature chlorosis is a common phenomenon in southern ginger areas, because its onset conditions are high temperature and strong sunshine.

Ginger originally originated in tropical forest areas, which makes it resistant to high temperature, strong light, cold and humidity. Its most suitable growth temperature is 2? 28℃。 In summer, when the temperature exceeds 3℃ and the leaves of ginger are exposed to strong light, the leaves will start to turn yellow, and the chlorophyll content in the leaves will decrease, which will seriously affect the normal growth of the plants, leading to short stature and even withering. Therefore, in summer, we will find that ginger is almost stagnant, and there are few branches in the whole summer.

The high temperature chlorosis of ginger is mainly caused by the deterioration of the growth environment. By adjusting the temperature and light to improve the growth conditions of ginger, it can restore its normal growth.

1. Building a sunshade net can reduce the intensity of light, improve the environmental temperature of ginger growth, increase the relative humidity of air and keep the soil humidity.

2. Intercropping and interplanting with tall crops can play the role of shading and cooling through tall crops.

3. Spraying foliar fertilizers, such as phytochemicals and other compound trace element fertilizers, has a certain effect.

Second, trace element deficiency

If you are a ginger grower, if your ginger leaves turn yellow, and it is not caused by diseases and insect pests or high temperature chlorosis, which stage does it most often occur?

the yellowing of ginger leaves caused by the lack of trace elements most often occurs when ginger enters the "three-branch" period, and it is also called the "mountain" or "penholder" period, that is, there are three ginger stems, one main stem and two branches.

at first, the upper leaves of ginger turned yellow, then turned white, and finally dried up. Ginger can't expand, the root system is underdeveloped, the plants are short and thin, and the photosynthesis is reduced.

The yellowing phenomenon of ginger leaves caused by the lack of trace elements has been aggravated in recent years. The reason is that the use of organic fertilizers is getting less and less because the planting of ginger is increasingly dependent on chemical fertilizers, and ginger is a crop that likes full-fertilizer, and it especially likes organic matter. After years of ginger planting plots, organic matter is seriously lacking, coupled with unreasonable fertilization, lack of trace elements such as iron, magnesium, copper, zinc and manganese.

prevention and control methods

1. Dig the land deeply, and through leveling the land, the ripe soil will press down and the raw soil will float up.

2. When applying fertilizer, we should apply more organic fertilizers, high-quality soil miscellaneous fertilizers, and timely supplement medium and trace element fertilizers.

3. After the emergence of ginger, some amino acid liquid fertilizers can be applied with water, and foliar fertilizers can be sprayed timely according to seedling conditions, such as amino acid foliar fertilizers and foliar micro-fertilizers.

I said that ginger likes organic fertilizer, but some people will say that I used manure and other organic fertilizers, but it caused the yellowing of ginger leaves. Then why? Is it wrong? Let's talk about the problem of yellowing of ginger leaves caused by organic fertilizer.

Third, the harm of organic fertilizer

I dealt with this matter last year. A ginger farmer came to ask about the yellowing of ginger leaves. I went to his ginger field and saw that nearly half of the ginger leaves in the whole field were yellowed, that is, the last ten ditches of ginger were almost yellow. The height of Jiang Miao is less than half that of others. When a ginger is pulled out, the swelling of the ginger is very small. There are no or few roots on the mother ginger and the child ginger, and most of the roots are on the sun ginger. The whole piece of ginger is clustered together, like ginger with dense seedlings.

The leaves of ginger on the ground are twisted and do not stretch, the leaves are not soft, they break when they are folded, and they are brittle and hard, and the middle and lower leaves are severely yellowed.

I found that his ginger ditch was black. I asked him what fertilizer he had washed, and he said that he had washed with thin pig manure. And I also found that when I pulled out this ginger tree, the soil attached to the root system turned black. I asked him again, did you use a lot of pig manure? He said a lot. Because I know he keeps big pigs at home.

I see, he used pig manure that was not fully decomposed, which caused yellowing. Without knowing it, he felt that his ginger was not growing well. Recently, he washed a thin pig manure urine, which aggravated the wound and sprinkled salt on it.

Using organic manure that is not fully decomposed, especially chicken manure, will release ammonia and nitrous acid gas when they are fermented underground. These toxic and harmful gases will hurt the root system of ginger, and some of the root system of ginger is meaty and tender, which will rot after this toss, and the new root can not grow normally, which makes the supply of water and fertilizer insufficient, thus leading to yellowing of leaves.

prevention and control methods

1. Remember not to use organic fertilizer that has not been thoroughly decomposed. Organic fertilizer must be fully decomposed before use.

2. In ginger fields where organic fertilizers are used, we must pay attention to spreading evenly, and pay attention to deep ploughing and fine harrowing.

3. Observe the growth and development of plants after fertilization, and water them in time.

In the case of this ginger farmer, I can only ask him to apply some functional products for root cultivation and protection, such as biological bacterial fertilizer, or just water, and spray foliar fertilizer containing amino acids, brassinolide, Tianda Zhuangmiaoling, etc.

In a word, there are many reasons that can cause the yellowing of ginger leaves. Besides the physiological reasons mentioned above, there are other etiologies such as yellowing of twisted leaves caused by thrips, anthracnose, leaf blight and so on, but those etiologies are only local yellowing of leaves or yellow stripes and yellow spots. For the yellowing of ginger leaves, we must pay attention to observe and see what causes it. Only in this way can we treat the symptoms and get the best cure effect, so as not to let others give you a white look.