Tomato navel appears five star mark, what causes it, and how to prevent it?

It is caused by the inhibition of local lycopene formation in tomato fruits, which is easy to occur in the case of partial application of nitrogen fertilizer and excessive growth of tomato plants, especially when there is more nitrogen fertilizer, less potassium fertilizer, boron deficiency and dry soil, the disease is the most serious. Prevention and control methods First, scientific fertilization and fine land preparation, application of sufficient decomposed organic fertilizer, timely and appropriate amount of top dressing, pay attention to the reasonable coordination of nitrogen, phosphorus and potassium fertilizer, and avoid partial application of nitrogen fertilizer. Prevent excessive soil drought.

The second is to spray potassium dihydrogen phosphate several times, and spray boron and calcium appropriately.

The appearance of five-star marks on the navel of tomatoes may be due to the following reasons:

1.Boron deficiency: Boron deficiency in tomatoes will cause obvious concentric shrinkage of the fruit, and the umbilicus will turn black, affecting the quality.

2.Calcium deficiency: Calcium deficiency can lead to black marks on the navel of tomatoes, accompanied by fruit cracking.

3.Magnesium deficiency: Magnesium deficiency can cause yellowing of tomato leaves, affecting photosynthesis and thus fruit quality.

4.Overwatering: Overwatering can cause the soil to become too moist, affecting the absorption of nutrients by the roots, which can lead to poor fruit development.

In order to prevent these problems from occurring, the following measures can be taken:

1.Scientific fertilization: apply enough decomposed organic fertilizer, timely and appropriate top dressing, pay attention to the reasonable coordination of nitrogen, phosphorus and potassium fertilizer, and avoid partial application of nitrogen fertilizer.

2.Several sprays of potassium dihydrogen phosphate: spray boron and calcium appropriately.

3.Ensure sufficient water: watering should be appropriate, not overwatered, and at the same time pay attention to the drainage of the soil to avoid the soil being too wet.

By taking the above measures, you can effectively prevent the problem of five-star marks in the navel of tomatoes.

Tomato navel rot is more common on young fruits in the rapid expansion stage. At the beginning of umbilical rot, the top of the fruit is water-stained, blue-green, with a diameter of 1 2 cm and a sunken lesion, with the development of the fruit, the lesion expands to about half of the fruit, and soon becomes dark green or black. The flesh tissue of the affected part of the fruit shrinks significantly flattened or depressed, the epidermis is somewhat leather, and the healthy part of the affected fruit turns red in advance.

Lesions are susceptible to bacterial infection when wet, resulting in dark green, black, or pink mold on the lesions.

Tomato navel rot is a physiological disease caused by calcium deficiency, and the prevention and control should be prevented by strengthening cultivation management. First of all, it is necessary to strengthen fertilizer management, and the base fertilizer is mainly biological bacteria organic fertilizer, combined with land preparation and application of superphosphate. When topdressing, attention should be paid to the combination of nitrogen, phosphorus and potassium fertilizers, and nitrogen fertilizers should not be applied partially.

For acidic soils, lime should be added to ensure that the soil is not deficient in calcium. In the high temperature and dry climate of early summer, the amount of top dressing should not be too much each time. Within 1 month after tomato fruit set, it is a critical period for calcium absorption, and it can be sprayed 600 times a day up to 2116 + 1% superphosphate extract, or calcium chloride plus 5 ml of naphthalene acetic acid solution, or calcium nitrate + 6000 times love more liquid, starting from the first fruit stage, spray 1 time every 10 days, spray 3 times in a row, and the prevention effect is very good.

The second is to ensure the balance of water in tomato plants**. Tomato planting should be irrigated with soil moisture in advance, early spring planting should not be watered, after the seedlings, depending on the soil moisture can be properly watered 1 time to slow the seedling water, after entering the fruiting period should strengthen the water of the **, special attention should be paid to the fruit expansion period should keep the soil moist, do not dry and wet, do not cause drought. The watering time should be early in the morning or evening, not at noon.

In addition, timely pruning, removal of diseased old yellow leaves, thinning flowers and fruits, can reduce the competition for calcium between fruits and reduce the occurrence of umbilical rot.

This sick tomato fruit is called navel rot fruit, also called top rot fruit. That is, the navel of the fruit first forms a dark green water-soaked spot, and then gradually turns into a black spot depression.

Causes: Mainly caused by calcium deficiency at the top of the fruit.

Precautionary measures: First, ensure water balance**;

the second is to use plastic film mulching to reduce the leaching of soil calcium;

the third is to apply more organic fertilizer and use nitrogen fertilizer rationally to prevent plants from growing and over-densifying;

The fourth is calcium supplementation, every 10-25 during the fruit setting period

Spray 1 superphosphate or 0 5 calcium chloride per day.

It is difficult to prevent such diseases after they occur, and they should be actively prevented.

Umbilical rot is a physiological problem, caused by calcium deficiency, and cannot be prevented in advance.

After fruit set, calcium fertilizer is often sprayed on the foliar surface, which can be mixed with other pesticides, and top dressing should be applied in a balanced manner to reduce the amount of nitrogen fertilizer. Nitrogen fertilizer and calcium fertilizer have antagonistic effect, and if there is more nitrogen fertilizer, the root system will not absorb calcium fertilizer well. Watering fertilizer should be watered frequently with small water, and water supply fertilizer should be balanced.

Tomato virus disease virus fruit, prevention first, first of all, to control aphids, finger spine planthoppers, etc., to control the source of infection. Hydrochloric acid can be used. Morpholinoguanidine, riboside triazole.

Morpholine, bitter. Calcium. Sulfur compound, mushroom polysaccharides, Ningnanmycin, phytoling, etc., plus zinc plus amino acids, foliar fertilizer and imidacloprid spray.

Spray 2 to 3 times continuously every 5 days.

There are many reasons for the formation of tomato cavitary fruits, such as improper spraying of hormones, after spraying hormones on the calyx, peduncle and flower bud two days before flowering, the fruit development rate is faster than that of normal pollination, and it promotes ripening, but the placenta is more underdeveloped and leads to cavities in the ovary; or insufficient light, photosynthetic products are reduced, and the nutrients transported to the fruit are in short supply, and a cavity is formed; or the terrain is weak, the nutrients in the late growth stage cannot keep up, the carbohydrate accumulation is less, and there are also hollow fruits; or insufficient watering during the peak fruiting period; Or leave too much fruit, nutrients ** do not go up and form a hollow.

Tomato stiff fruit is a physiological disease, which refers to the fact that when the young tomato fruit grows to the size of soybean, it will no longer develop and enlarge and stiffen, and the occurrence site is generally on the first fruit spike and the top fruit spike. Causes: poor pollination, insufficient nutrition, improper use time for flower and fruit preservation.

Prevention and control methods: 1. Train robust tomato seedlings to enhance the ability to resist adverse environments 2. Use tomato or 2,4-d and other growth hormones to dip flowers, the concentration is generally required to be low when the temperature is high, and the concentration is high when the temperature is low. 3. Implement artificial assisted pollination, pay attention to keeping warm during the flowering period of tomatoes 4. Strengthen fertilizer and water management to ensure fertilizer and water to promote the expansion of tomatoes.

5. Prevent and control low temperature and weak light, and maintain a certain temperature difference between day and night.