How to prevent tomato umbilical rot

In the early stage of tomato umbilical rot, water-stained green spots formed in the umbilical part of young fruit and green fruit, which gradually turned dark brown. Later, it expanded to the top of the fruit to half of the fruit surface. The pulp tissue of the diseased part rotted, lost water and contracted, and the top was sunken. Under wet conditions, black or red mold is formed.

 

Causes:

 

First, the imbalance of nutrients, the lack of calcium in the soil, tomato can not absorb enough calcium from the soil, and too much nitrogen, excessive growth of nutrients, affecting the absorption of calcium, causing physiological disorders around the umbilical cord, resulting in navel disease.

 

The second is the imbalance or instability of soil water supply, especially in the drought period. When the water supply is insufficient, the watering is not timely, the soil moisture changes drastically, the umbilical part of young fruit and green fruit loses a lot of water and causes tissue necrosis; or the application of unfertilized fertilizer Or the fertilizer is too thick to cause burning, which affects the normal absorption of water. In particular, the partial application of nitrogen fertilizer causes the plant to grow in length and aggravate the lack of calcium, which may also cause umbilical rot. In addition, the seedlings are not neat, which may also cause the occurrence of umbilical rot in some plants.

 

Precaution:

 

　　 1. Foliar application of calcium and boron fertilizer: During the expansion period of tomato fruit, choose calcium and boron fertilizer with higher concentration, spray about 45 kg per mu of fertilizer , add 50 g of ferric fertilizer per 15 kg of water + calcium fertilizer Mix 150 grams of spray. Spray again 1 day after 7 days . For tomatoes with mild umbilical rot, the application of broad-spectrum fungicides such as chlorothalonil or carbendazim can prevent the occurrence of other diseases while spraying the leaf surface micro-fertilizer. For the fruit with serious symptoms of umbilical rot, early picking and treatment, and timely spraying of boron and calcium fertilizer for the tender fruit without disease.

 

　　 2. Balanced fertilization: When the tomato is applied with top dressing or rushing fertilizer during the fruit expansion period, avoid using high potassium fertilizer. It is best to use a compound fertilizer with a balanced ratio of nitrogen, phosphorus and potassium (1 : 1 : 1) to avoid the absorption of calcium by the higher concentration of potassium in the soil. Organic fertilizer should be added to enhance the permeability of the soil and improve the absorption environment of the roots of the plants. Adjust the pH of the soil to neutral, and add lime fertilizer to the acid soil in time to avoid continuous cropping.

 

　　 3. Drought-resistance: In summer, high temperature and drought or heavy rain will often occur. If the soil is too dry or too wet, it will affect the normal absorption of calcium by the roots. It is also easy to induce the disease. It should be ensured that the soil is dry and wet. In case of dry weather, it is necessary to water the water in time. In case of heavy rain, it is necessary to discharge the water in the field in time.

 

(Source: Farmers of the Internet: Xinji City Plant Protection Station Chen Shu Qiao)