Spongy Tissue Defect is a common quality issue in Alphonso mangoes. It appears as yellowish, corky, or whitish tissue in the pulp, often near the seed. While the outer fruit may look healthy, the affected pulp has a mealy texture and unpleasant taste, making it unsuitable for consumption or commercial sale.
Causes of Spongy Tissue in Alphonso Mangoes:
- Physiological Factors:
- Incomplete ripening due to uneven distribution of nutrients and moisture.
- Heat stress during fruit development, especially in regions with high daytime temperatures.
- Post-Harvest Handling:
- Improper harvesting techniques, including harvesting fruits too early or under excessive heat.
- Inappropriate storage temperatures leading to metabolic imbalances.
- Nutritional Deficiencies:
- Low levels of calcium, potassium, or other nutrients during fruit development.
- Imbalanced fertilization practices.
- Genetic Factors:
- Alphonso is inherently more prone to spongy tissue due to its physiological and genetic characteristics.
- Orchard Conditions:
- Poor orchard management, including lack of proper irrigation or mulching, exacerbates the issue.
Solutions to Address Spongy Tissue Defect:
Pre-Harvest Strategies:
- Nutrient Management:
- Ensure balanced fertilization, with a focus on calcium, potassium, and boron. These nutrients improve fruit firmness and reduce physiological disorders.
- Apply organic manure and biofertilizers to enhance soil health.
- Irrigation Management:
- Maintain consistent moisture levels, especially during the flowering and fruit development stages.
- Avoid water stress, particularly in the pre-harvest period.
- Canopy Management:
- Prune trees regularly to ensure proper light penetration and air circulation, which helps in even ripening.
- Mulching:
- Use organic mulches around the tree base to regulate soil temperature and moisture.
- Shade Nets:
- Install shade nets during periods of high heat to reduce thermal stress on the fruits.
Post-Harvest Strategies:
- Harvesting at the Right Stage:
- Harvest fruits when they are physiologically mature but not overripe.
- Avoid harvesting during the hottest part of the day.
- Hot Water Treatment:
- Treat harvested mangoes with hot water at 50–55°C for 5–10 minutes. This reduces spongy tissue and post-harvest diseases.
- Ripening Protocols:
- Avoid artificial ripening using chemicals like calcium carbide, which can exacerbate the defect.
- Ripen fruits at controlled temperatures of 20–22°C with adequate ventilation.
- Cold Storage:
- Store fruits at an optimal temperature of 12–14°C to prevent chilling injuries while ensuring even ripening.
Long-Term Measures:
- Breeding and Selection:
- Develop or adopt Alphonso cultivars with reduced susceptibility to spongy tissue through grafting or breeding programs.
- Research and Farmer Training:
- Conduct research to understand the genetic and environmental factors contributing to the defect.
- Train farmers in best practices for pre-harvest and post-harvest management.
- Use of Growth Regulators:
- Application of plant growth regulators like gibberellic acid (GA3) can improve fruit quality and reduce physiological disorders.
By combining these strategies, Alphonso mango growers can effectively minimize the spongy tissue defect, improving fruit quality and ensuring better marketability.
