Improving 'Piyarom' date palm fruit quality with fruit thinning and bunch covering treatments

Abstract

‘Piyarom’ dates are one of the most important commercial date cultivars grown in Iran but fruit quality and postharvest losses can be a problem. Thinning and the use of bunch covers were examined to improve the date fruit quality. Three different levels of fruit thinning were applied (without thinning, removal of one third of total strands from terminal tips during pollination and removal of one third of terminal tips of central strands in early kimri). In addition, the effects of bunch covers were assessed with the use of polyethylene bunch covers that were applied in the early stages of Khalal. The results showed that bunch covering reduced the lightness of the fruit but increased bunch weight, fruit length, total antioxidant activity and total phenolic compounds compared to the control. Thinning during pollination increased the weight of the fruit compared to the control. The thinning during Kimri stage increased the percentage of Tamar and ascorbic acid content. These results show that the use of covers play a positive role in increasing quality and bunch weight and thinning at both pollination and Kimri ripening stage is recommended to produce high quality ‘Piyarom’ dates.