Effect of Bunch Bagging on Ripening Rate and Control of Sunburn Disorder in Date Palm Fruit cv. Medjool

Date palm is one of the important crops mainly grown in the arid regions of the Middle East and North Africa as well as in the southern warm and dry areas in Iran. One of the most important factors that reduces the quality and commercial value of date fruit is sunburn disorder during fruit growth and development. Therefore, this research was carried out to evaluate the effect of kraft paper, black, white, and blue cloth, green greenhouse netting, straw bag, and without bag (control) at the khalal stage on the ripening rate and sunburn incidence of cv. Medjool using randomized complete block design with eight replication in in Umm al Tameir research station, date palm and tropical fruits research, Ahvaz, in 2020 and 2021. The bags' ends were open and remained on the trees until harvest. The results showed that the bunch weight, the kimiri, khalal and date fruits proportions were affected by year. In 2021, average bunch weight (5.83 kg), kimiri percentage (8.6%) and khalal percentage (28%) were more than 2020, while in 2020 the percentage of date fruits (10.48%) was more than 2021. The rate of kimiri at harvest was lower in black cloth than in others bags. In 2020, bunch bagging with green greenhouse netting, white cloth, and kraft paper increased rutab rate by 9.81%, 12.99% and 11.37%, respectively, as compared to control. Bagging did not affect fruit size and weight. All kind of bags decreased the incidence of sunburn disorder. Kraft paper bag significantly decreased the percentage of dried fruits to 6.78% as compared to control with 9.93%. The rate of fruit decay was not affected by bagging. Considering the results of this research, it was concluded that black and white cloth bags were more effective in reducing sunburn disorder and fruit decay rate of palm date fruit cv. Medjool.