Tomato Fruit Coloring Problems:

Among the most critical physiological diseases (symptoms):

Irregular ripeness, spotted ripeness, blotchy ripening, internal browning, internal browning-gray wall, white wall, cloudiness, yellow shoulder, and other names that express symptoms. The characteristics of this physiological condition prevailed in the fruits of tomato crops at this time of the year, especially in some varieties, specifically after many areas were exposed to the aforementioned exceptional weather conditions.

Symptoms of the irregular ripening of tomato fruits:

On the surface of the tomato fruits affected by irregular ripening (spotted staining, etc.), poorly colored, irregularly shaped areas appear, and there is no separation between them and the rest of the surface of the fruit color in the natural color characteristic of the cultivated variety.

Poorly colored areas remain green, yellow, yellowish red, or pale red, varying from small scattered spots to large areas that cover the surface of the fruit.

Causes of irregular ripening in tomato fruits

First: varieties and hybrids of tomatoes:

Certain tomato varieties and hybrids are particularly susceptible to the phenotypic manifestations of irregular ripening, such as spots and speckles, provided they are cultivated in conditions that encourage the formation of this physiological trait.

Second, the lack of nutrients

A deficiency of potassium and boron and an imbalance in nitrogen fertilization increase the symptoms of irregular ripening (spotted-speckled, etc.) on tomato fruits.

Third: 

The fruits are exposed to low heat, inadequate lighting, and high relative humidity.

Symptoms of irregular ripening (spotted-speckled) on plants and tomato fruits increase when the fruits are exposed to low temperatures, poor lighting, or shading, especially when the relative humidity is high. The first, in which the vegetative growth of tomato plants increases the shading,

Fourth: Infection with the tobacco mosaic virus

Infection of tomato plants with the smoke leaf mosaic virus can cause fruits with symptoms similar to those of irregular ripening (spotted-speckled).

Preventing irregular ripening symptoms in tomato fruits

In general, there is no way to treat tomato fruits that show symptoms of irregular ripening (spotted, speckled, etc.). However, these symptoms can be prevented by doing the following:

First: cultivation of the appropriate variety or hybrid of tomatoes:

Varieties and hybrids susceptible to infection should not be planted in conditions that contribute to the spread of these symptoms. These varieties and hybrids are distinguished by their tolerance of unsuitable emergency environmental conditions. This was observed in some cultivars currently grown under the conditions of Salhia and Ismailia.

Second: Applying balanced fertilization programs

A good, balanced fertilization program should be applied to feed tomato plants. This program considers all the factors specific to tomato cultivation and focuses on adding potassium in inappropriate, balanced quantities.

Third: Follow an appropriate irrigation program.

It is necessary to provide the right amounts of irrigation water per the variables controlling the irrigation programs to prevent long-term increases in ground moisture underneath and around the plants, as was the case in March 2020.

Fourth: Avoid agricultural treatments that lead to vegetative growth, which blocks the light from the fruits.

Fifth, use growth regulators and plant hormones only when necessary.

Sixth: rationalizing the use of pesticides, especially copper compounds, especially during the fruit coloring stage.