Control methods of navel rot of flattened tomato with sunken black brown spot of navel

In recent years, navel rot of tomato in greenhouse has occurred from time to time, which is a physiological disease, which has a great impact on yield and affects the commercial value of tomato.

Tomato navel rot

First, symptom identification:

Umbilical rot can occur in tomatoes, such as thumbs, before coloring is ripe, and the spot occurs only in the navel of the tomato. The disease spot is dark green water-immersed at first, and soon becomes dark brown or black with a diameter of 1-2cm or larger necrotic spot, the lower tomato flesh is dried and contracted, the navel is sunken, sometimes cracked, the fruit becomes flattened and the flesh becomes sweet. In severe cases, the disease spot extends to half of the fruit surface, the tomato stops expanding, turns red early, and the pericarp is flexible, dull and worthless.

Second, the cause of navel rot:

First, during the tomato expansion period, the water supply is uneven, especially when the water absorption capacity of the root system is weak, the water supply is out of balance, and the growth of the fruit navel is blocked, resulting in navel rot; second, calcium deficiency causes physiological disorder of tomato navel cells, leading to the disease.

Third, affecting the conditions for the onset of umbilical rot:

Soil texture: strong sandy, serious water and fertilizer leakage, serious saline-alkali heavy land disease; topography: large slope, water and fertilizer easy to lose serious land disease; soil calcium content, soil calcium content, less organic acid, especially soluble calcium deficiency; in the growth stage, when a large number of tomatoes blossom and bear fruit, insufficient water supply, or late topdressing, suddenly increase the concentration of soil solution.

Fourth, prevention and control methods:

Controlling nitrogen application, balanced fertilization of nitrogen, phosphorus and potassium, and proper foliar spraying of calcium are beneficial to the prevention and control of navel rot.

The main results are as follows: 1. Combine with leveling ground and apply sufficient base fertilizer. Tomato base fertilizer is based on rotten organic fertilizer plus phosphorus and potassium fertilizer, such as calcium and potassium sulfate or compound fertilizer rich in nitrogen and potassium. For example, it is better to ferment 30kg superphosphate 40kg per mu into organic fertilizer.

2. Irrigate at the right time to prevent the soil from being dry and wet, so as not to make the soil too dry. When the first water is planted and the second water begins to set fruit, the amount of water should not be too large; when the third inflorescence is finished, the first ear is as big as an egg. Keep the soil moist, summer irrigation should be carried out in the early morning or evening, pay attention to frequent watering, shallow watering.

3. the combination of foliar and root calcium supplementation. Applying calcium fertilizer outside the root, the key period of absorbing calcium is within 30 days after fruit setting of tomato, so from the early flowering stage, 1% superphosphate or 0.1% calcium chloride or calcium compound fertilizer is sprayed on the leaf, once every 15 days, for 2 times in a row.