Top rot of fruits of several varieties of fruits and vegetables (help for producers)

Top rot, also known as BER (Blossom-End Rot), is a common physiological disorder in vegetables such as tomatoes, peppers, squash and watermelons. This phenomenon manifests itself as a dark sunken spot on the flower end of the fruit, caused by a lack of calcium in the developing fruit.

According to Marija Janjić, agricultural adviser from the Vranje PSSS, the cause of top rot lies in the lack of calcium, i.e. the insufficient amount of this mineral in the fruit tissue. Calcium is crucial for the stability of cell membranes and provides structural strength to both the fruit and the plant itself.

One of the main causes of top rot is variation in soil moisture. Too much or too little water can reduce the plant’s ability to absorb calcium. Also, an excessive amount of nitrogen can cause rapid vegetative growth, which leads to a decrease in calcium in the fruits, because the plant uses more nitrogen than is necessary for healthy fruit development. Conditions that damage the root system, such as soil compaction or disease, can also reduce the plant’s ability to absorb calcium.

Can top rot be remedied in the fruits of peppers, tomatoes, squash and watermelon?

In order to prevent top rot, regular watering and maintenance of constant soil moisture is recommended. The soil should not dry out or be flooded. If there is a lack of calcium in the soil, it should be added through foliar spraying or by applying fertilizers such as calcium nitrate.

Janjić advises vegetable growers to avoid excessive nitrogen fertilization and to perform an agrochemical analysis of the soil at the beginning of production planning. Adhering to recommended fertilizer formulations and rates for fertilizing pepper crops can help maintain optimal soil pH, which is typically between 6.2 and 6.8 for most crops. This pH range allows the smooth absorption of nutrients.

In addition, it is recommended to use mulch to conserve soil moisture and regulate temperature. Also, excessive pruning of tomatoes should be avoided, as this can disrupt the balance between vegetative growth and fruit development. Regular soil testing for basic fertility parameters enables monitoring of nutrient levels and adjusting fertilization practices according to needs.

Janjić emphasizes the importance of improving soil structure with organic material to improve water retention and root health. These measures can significantly reduce the incidence of top rot and ensure healthier fruit development.

Source: Good morning