How to identify crop defects

Crops that are under- or under-absorbed by a desired nutrient will show signs of deficiency in overall appearance and color. Typical symptoms are: crops are short, pale yellow or reddish spots or streaks, leaves are yellow-green or very dark blue-green, yield is reduced.

Identification of symptoms of deficiency is confusing. The reason is that the symptoms of deficiency caused by two or more different nutrients may be almost the same, or the symptoms of deficiency caused by one nutrient mask the symptoms of deficiency of another nutrient. Symptoms of deficiency sometimes change with the climate (changes or disappears between humidity and drought), and some crops have potential deficiency. Also note that you should not mistake the symptoms of viruses or fungi, insects, etc. for symptoms.

How to solve the problem of crop deficiency?

To this end, the author consulted the agrochemical experts in the new direction of Guangxi, and summarized the common symptoms of some crops as follows:

Nitrogen deficiency

- Crop growth is blocked (common symptoms of all deficiency), growth is not flourishing, and plants are short.

- The overall chlorosis of the plants (common symptoms of all deficiency), the leaves turn yellow from the tip of the leaves (the leaves are chlorotic), and the old leaves are yellow-green.

-- The lower old leaves die early, and the upper leaves remain green (sometimes mistaken for water shortage).

Phosphorus deficiency

- Crop growth is blocked.

- The leaves are dark green and appear purple and brown (sometimes on the stem) from the tip of the leaf.

-- Delayed crop maturity and greed.

- The fruit is malformed and the grain is not full.

Potassium deficiency

- Crop growth is blocked.

- The leaves appear chlorotic from the tip of the leaf to the root of the leaf along the outer edge.

- The outer edge of the leaves is yellow or red; in severe cases, the leaves turn brown, withered and dead (leaf edge necrosis); leaves are wilting.

-- Easy to fall.

- The leaves of the tree are pale yellow, red, the tip of the leaves shrinks, and the leaves curl.

- The fruit is small, has lesions or spots, and has poor storage resistance.

Magnesium deficiency

- There is chlorosis between the veins, and the veins are still green (typical strip-like chlorosis; magnesium is a component of chlorophyll required for plant photosynthesis). In severe cases, spots and dead (tissue necrosis) begin to appear from the old leaves at the bottom.

Sulfur deficiency

- The entire plant is yellow (sometimes mistaken for nitrogen deficiency).

- The leaves on the upper part of the crop, even the young leaves, are pale yellow.

- Crop maturity is postponed.

Calcium deficiency

-- The young leaves are yellow to black and the leaves are curled (brown spots).

- Crops are wilting.

- Fruit rot (tomato).

-- Root deformity.

Zinc deficiency

-- Lobular disease.

- Short twigs with typical tillering growth on fruit trees.

- chlorotic streaks (white streaks) appear between the veins in the lower part of the leaves.

- Some leaves are olive green or grayish green (very similar to phosphorus deficiency).

Boron deficiency

- The leaves frequently appear deformed and curled, the leaves are thick and brittle, and there are white irregular spots between the veins.

- The growth point of the terminal bud is necrotic, the tiller grows at the tip, the growth is inhibited, and the internodes are shortened.

-- Water-like necrosis or cavities on the roots of sugar beet and other root crops and on the stems of other crops.

- The fruit is small and the shape is not good, and cork tumors and lesions often appear.

-- Low grain yield due to incomplete pollination.

Iron deficiency

- Typical chlorosis (often occurring on calcareous soil) along the entire length of the leaf between the green veins of the young leaves.

The above is only the common symptoms of crop deficiency, identifying plant defects, but also need rich field experience. The new direction of agrochemical experts told the author that although the symptoms of deficiency can make farmers generally grasp the situation of crop malnutrition, even if the crop can be supplemented with appropriate nutrients after discovery, the obvious symptoms of deficiency will be corrected quickly. Insufficient nutrients in a given period will still have an irreversible impact on crop yield and quality.

Therefore, scientific farming methods are used to ensure the nutrient supply of crops throughout the growing season, to select suitable fertilizers, and to prevent crop nutrients from being insufficient.

The formula fertilizer in the new direction of Guangxi is formulated according to the "large formula and small adjustment" after scientific soil testing. It also adds a variety of medium and trace elements necessary for plant growth, which can promote the absorption of nutrients by crops and ensure the growth of crops. The nutrient supply makes the crops balanced and eats well without wasting.