avoiding endocarp lesion and abscission of pistachio nut using lecithin-enriched calcium nitrate

Purpose: the pistachio nut is an important product primarily traded as dry nut in-shell kernels. any damage to the shell during growth and development can cause shell staining and kernel decay in pistachios, rendering them unsuitable for sale. this study aimed to mitigate these issues by evaluating the effects of various calcium nitrate solutions. research method: fruit samples from two pistachio cultivars, ’akbari’ and ’kaleh-ghoochi,’ were collected from 18-year-old trees with moderate tree vigor in a commercial orchard. the calcium nitrate solutions included a control sample (distilled water), 0.4% calcium nitrate, and 0.2% calcium nitrate enriched with lecithin, foliar applied two weeks after full bloom. findings: calcium nitrate treatments, both alone and enriched with lecithin, significantly reduced physiological disorders such as endocarp lesions and fruit abscission. in ’akbari,’ calcium nitrate treatments reduced issues such as nut ounce, shell staining, deformed nuts, blank nuts, endocarp lesions, early-split nuts, hull decay, and hull cracking. in contrast, kaleh-ghoochi also benefited from reduced occurrences of deformed nuts, early-split nuts, hull decay, and hull cracking. however, when treated with calcium nitrate enriched with lecithin, there was a notable reduction in blank nuts in kaleh-ghoochi, whereas calcium nitrate alone led to an increase in blank nuts. these calcium nitrate treatments resulted in positive outcomes and reduced fruit defects, thereby enhancing the overall quality and marketability of pistachios. notably, the combination of calcium nitrate and lecithin had a more pronounced impact on akbari, improving the pistachio nut’s hull appearance, firmness, and reducing water activity. research limitations: there were no limitations. originality/value: these findings suggest that calcium plays a significant role in enhancing the yield, quality, and marketability of pistachio fruit, providing practical insights for farmers aiming to improve their pistachio production practices.