A Protocol for the Control of Spongy Tissue Disorder in Alphonso Mango by Pre-Harvest Treatments

Spongy tissue (ST) of Alphonso mango is the most important physiological disorder which causes grave loss of fruit quality in ripe fruits without showing external symptoms. Until recently, there was no remedy to overcome the malady, as there were speculations regarding the nature of its origin. However, following the crucial findings that the disorder arises due to the premature onset of germination associated events in the seed of the developing fruit, field experiments were initiated to develop a protocol to treat the disorder. Results clearly showed that application of salt solutions as a pre-harvest spray between 60 and 70% fruit maturity gave significant reduction in the incidence of the malady. Among the treatments, application of nutrient mix containing a mixture of macro and micronutrients and sea water produced fruits with an ST incidence level of <5%. Analysis of data revealed that the osmotic effect generated by hypertonic salt solutions was primarily responsible for withholding the movement of water from mesocarp to seed thus preventing the onset of germination-associated events and consequently a reduced incidence of spongy tissue. Pre-harvest application of the nutrient mix containing macro and micronutrients or sea water on developing fruits between 60 and 70% maturity stage effectively reduced the incidence of ST to <5% compared to 54.3% in control, besides improving the shelf life and fruit quality. The study also demonstrated that treatment of fruits before reaching 60% maturity or after crossing 70% maturity was not as effective in reducing ST incidence. The method offers an easy, effective, economical and eco-friendly solution to overcome the dreaded disorder at the field level thus allowing farmers to produce superior quality Alphonso fruits free from the malady.