What are the symptoms and causes of iron deficiency in grapes?

Grapes are a very popular fruit, and their planting area in our country is also very large. However, when we grow grapes, many deficiency diseases often appear, seriously affecting the yield and quality of grapes. Among them, iron deficiency is one, so what symptoms does iron deficiency in grapes have? And what causes it? Today the editor brings you the symptoms and causes of iron deficiency in grapes, so let's take a look below!

I. Symptoms of iron deficiency

The form of iron in the grape plant generally exists as a high-molecular compound, and it will not easily move within the grapevine. Therefore, if grapes are deficient in iron, it will first show on the young leaves. The young leaves gradually lose green, and except for the leaf veins, which are unaffected, all other parts turn completely yellow, though the old leaves will not be affected. If the symptoms are severe, then the leaves will turn brown and necrotic from bottom to top, and then dry up and fall off. The growth of the new shoot parts becomes poor, the inflorescences turn yellow and fall off, and the fruit-setting rate will also decrease significantly. This seriously affects the yield and quality of grapes and reduces the planting benefits of farmers.

II. Causes of the disease

1. Insufficient iron element

Compared with other fruits, grapes have a greater demand for iron, so they are also very sensitive to the iron element. And if the planting soil is sandy soil with strong leaching and there is a lot of rainfall, then soil erosion is relatively serious, and the iron element is easily washed away, resulting in iron deficiency in the soil. At the same time, if there are consecutive years of high yield, then most of the iron element in the soil will be absorbed. And if the iron element is not supplemented in time and the amount of organic fertilizer used is too small, then it will cause a serious iron deficiency phenomenon in the soil.

2. Unsuitable soil

Soil is also one of the main causes of iron deficiency in grapes. The availability of iron in the soil will also change with changes in the soil PH value. If the soil PH value is around 8 and contains a large amount of calcium carbonate, then the soluble iron salts in the soil will become insoluble, causing the total iron content in the soil to be too high while lacking available iron, and the grape roots cannot absorb it. Furthermore, if the soil is too sticky and heavy, has poor drainage and irrigation, and the temperature is too low, then the ferrous ions in the soil are easily fixed, causing the grape roots to be unable to absorb them and resulting in iron deficiency symptoms.

3. Fertilization reasons

Around June to July each year, the vegetative growth and reproductive growth of grapes are in the same period. At this time, the demand for fertilizer is also very large, and many fruit growers habitually apply fertilizer by flushing it with water, and the fertilizer is mainly compound fertilizers such as nitrogen, phosphorus, and potassium, ignoring the application of iron fertilizer. At the same time, after irrigation, the available iron in the soil plow layer will move downward due to leaching, causing the available iron content in the root-dense area to decrease and resulting in iron deficiency symptoms. In addition, there is an imbalance in the nutrient ratio, for example, an inappropriate ratio of trace elements such as zinc, copper, and magnesium, causing antagonistic effects among the elements and affecting the absorption of the iron element by the grape roots.

The above is a brief introduction to the symptoms and causes of iron deficiency in grapes. That is all for today's introduction. This article is for reference only, and I hope it can help everyone!