What is tomato soy sauce fruit? Causes and preventive measures

Many vegetable growers have reported that a large number of their tomatoes developed soy sauce fruit. The so-called soy sauce fruit is when a large number of brown markings appear on the fruit surface. The spots vary in size and occur only on the peel, without affecting the flesh. Soy sauce fruit seriously affects the quality of the fruit and greatly reduces returns, so it needs attention. Now let us take a look together at the causes of tomato soy sauce fruit and the preventive measures.

I. Causes of tomato soy sauce fruit

1. Calcium deficiency

The main cause of soy sauce fruit in tomatoes is calcium deficiency. Calcium deficiency reduces the hardness of the cell walls of the tomato peel, making the peel thinner and highly susceptible to infection by pathogens. In pursuit of yield, many farmers apply large amounts of nitrogen fertilizer and potassium fertilizer, which causes the root system to resist the uptake of calcium, making it very easy for tomatoes to take up insufficient calcium.

2. Improper management

For autumn-winter tomatoes, if nitrogen fertilizer is applied in a one-sided way, with low temperature and high humidity, poor ventilation and excessive planting density, diseases in the greenhouse can also become severe, and fruit at the front end of the same greenhouse compartment is more severely affected; large-fruited varieties are more severely affected than cherry tomatoes. In addition, improper management that causes abnormal fruit coloring can also form soy sauce fruit.

3. Lycopene cannot be produced normally

During the color-turning stage of tomatoes, chlorophyll is decomposed and lycopene is formed, making the fruit surface bright. The optimal temperature for lycopene formation is 24 degrees. If the temperature is higher than 28 degrees or lower than 15 degrees, lycopene formation will be inhibited. If leaf removal causes direct sunlight to fall on the fruit surface, it will also inhibit lycopene production. Excessive application of nitrogen fertilizer can also increase chlorophyll in the plant, which likewise inhibits lycopene formation and leads to a large number of tea-brown spots on the fruit surface.

II. Preventive measures

1. Calcium supplementation

When tomatoes enter the coloring stage, calcium needs to be supplemented in time to balance the calcium-to-potassium ratio. Many farmers develop calcium deficiency problems because they apply too much potassium fertilizer. Therefore, during the coloring stage, it is recommended to use calcium and magnesium foliar fertilizer and spray it 2 times in succession, which can promote tomato coloring and prevent soy sauce fruit.

2. Ventilation management

During tomato cultivation, attention must first be paid to temperature regulation, and ventilation must be done well. If ventilation between the small rows is poor, then leaf thinning can be used to ensure light penetration and air movement, so that tomato quality can be guaranteed.

3. Fertilization

If the soil EC value is too high, normal soy sauce fruit can also be a fertilization problem. At this time, the amount of fertilizer applied needs to be controlled and reduced, and 2-3 rounds of clear water irrigation can be given during the growing season, which can alleviate the soy sauce fruit situation.

  The above is an introduction to the causes of tomato soy sauce fruit and preventive measures. We hope it can help you. If you want to learn more related knowledge, please stay tuned to us.