Pre-harvest exogenous application of growth regulators extends storability and maintains the seed potato quality

Abstract

Preservation of potato tubers is essential not only for their general marketability but also for their potential use as seed potatoes. In subtropical areas, the small and marginal seed potato growers stored their produce at ambient temperature and thus prolonging storability through diverse seed storage techniques. Application of exogenous growth regulators is one the approaches which affect the quality of potato tubers positively. The present study assessed the impact of exogenous growth regulation on the storage and post-harvest quality of potato tubers. The seed potatoes crop was treated with growth regulators at 45 and 60 d after sowing to determine their effect on physiological losses and quality of tubers in storage at ambient temperature during 2019–20 and 2020–21. Application of GA200 reduced the total weight loss by 23.7 and 24.5% during 1st and 2nd year, respectively, compared to the untreated control. Among the auxin treatments, the minimum weight loss was recorded with IBA200. At 120 d of storage, GA200 resulted in a higher tuber dry-matter and total phenol content, compared to the untreated control. IBA200 pre-harvest application led to lower sprouting characteristics, followed by IBA100, NAA50, and NAA25. The Pearson correlation analysis revealed that post-harvest quality was negatively correlated with total weight loss and disease incidence (soft and dry rot). Among all the treatments, Ethrel50 was the more susceptible to soft and dry rot incidence. IBAs exhibited superior efficacy over NAAs in the suppression of storage diseases. In conclusion, a pre-harvest application of GA200 at 45 and 60 d after sowing can prolong the shelf life of seed potatoes at ambient temperature while maintaining or improving their post-harvest quality.