Blossom End Rot
Blossom end rot is a condition that affects plants in the Solanaceae (such as tomatoes), Cucurbitaceae (such as watermelons), and Malvaceae (such as okra) families, among others. It is a physiological disorder rather than a result of pests or diseases. Blossom end rot does not spread between plants in the field or between fruits during transportation. Due to its physiological nature, traditional control methods like fungicides and insecticides are ineffective in managing this condition.
Blossom end rot (BER) manifests as a circular patch located at the end of the fruit where the flower was attached (the farthest end from the plant). The color of this patch ranges from greenish brown to black. As the patch grows larger, it becomes depressed, resulting in a flattened appearance at the affected end of the fruit. Although it can occur at any stage of fruit development, it is most commonly observed when the fruit is approximately one-third to one-half its full size.
Blossom end rot (BER) arises due to insufficient calcium levels in the fruits. The lack of calcium inhibits the growth of new cells. Additionally, this deficiency diminishes the permeability of cell membranes, resulting in cell swelling, subsequent leakage, and the breakdown of membrane structure.
The development of this disorder is influenced by various environmental factors, including uneven watering, rapid plant growth (especially if excessive nitrogen is provided early on), and rapidly increasing temperatures. These factors affect the plant’s ability to uptake water and calcium, thereby influencing the occurrence and intensity of blossom end rot. Another common contributing factor is planting too closely, which results in the destruction of crucial roots responsible for water and mineral absorption.
Blossom end rot (BER) leads to significant losses in fruit yield and quality due to internal fruit decay. Once fruits are affected by BER, there is no way to rescue them. However, you can take preventive measures to protect subsequent fruits from being affected. These measures include:
- Avoiding moisture stress: Ensure that the plants receive adequate moisture to prevent dehydration. During hot periods, it is recommended to water the plants two or more times a day. It is more effective to divide the watering into multiple sessions with smaller volumes rather than watering once with a larger volume.
- Mulching: Applying a layer of mulch to the soil can be beneficial in maintaining sufficient soil moisture during periods of water stress. Mulching helps retain soil water and reduce evaporation.
- Avoiding over-fertilization: Excessive nitrogen, particularly from ammonia-based sources, can lead to calcium tie-up in the soil during early fruiting. It is important to follow proper fertilization practices and avoid applying excessive amounts of nitrogen.
- Maintaining the soil pH: Keeping the soil pH between 6.0 and 6.8 promotes a favorable calcium balance in the soil. Conducting a soil test can help determine the pH level and provide guidance on correcting the soil if needed.
- Careful cultivation: When performing cultivation tasks, it is important to avoid working too close to the plants or excessively deep. This helps protect valuable feeder roots, ensuring their health and functionality.
- Application of calcium-rich foliar sprays: Utilizing foliar sprays containing calcium can help supplement the calcium levels in the plants and mitigate the risk of BER.
By implementing these preventive measures, you can minimize the occurrence of blossom end rot and safeguard the yield and quality of your fruits.