Ecofriendly treatments to improve pomegranate trees production and tolerance to climate change

Abstract Background Pomegranate is capable of growing in different agro-climatic conditions ranging from tropical to sub-tropical. Where vegetative growth, nutritional and physiological status of pomegranate plants oscillate at high temperatures waves in the summer season. While we can overcome the cracking and sunburn of fruits, which are the main problems confronting pomegranate cultivars due to their significant impact on the quality of fruits. Methods The present research was conducted over the course of two consecutive seasons in 2021 and 2022. The study focused on ten-year-old trees that were cultivated in sandy soil inside a private orchard situated 70 km away from Cairo on the Cairo-Alexandria desert road in Egypt (30 o 13′31.4″N30 o 39′09″E). The aim of the present work was to evaluate the effect of foliar spraying of Wonderful pomegranate trees with some nutrients (B, Zn, Fe, Mn, Ca and Cu), amino acids and irradiated licorice on vegetative growth, fruit physical, quality and chemical and leaf chemical parameters. A randomized full-block design with three duplicates was employed in the study. Using the recently computed least significant difference values at the 5% level, averages were compared. Results The results indicated that foliar spraying with nutrients, amino acids and licorice extract (irradiated or not) alone or in combination significantly increased the vegetative growth and leaf total chlorophyll content compared to the control. Also, they significantly increased fruit length, diameter, weight, and number/tree and thus yield. As compared to the control, all treatments significantly reduced the number of sunburned and cracked fruits leading to decrease the percentage of un-marketable fruits. The juice content of anthocyanin, total sugars and total soluble solids increased significantly in response to all treatments compared to the control while the acidity% greatly reduced. When these treatments were used instead of the control, the content of N, P, K, Fe, Zn, and Mn in the leaves was also positively increased. Conclusions In conclusion, foliar spraying of “Wonderful” pomegranate trees with a mixture of nutrients (B, Zn, Fe, Mn, Ca, Cu) and amino acids or irradiated licorice extract can be considered as a suitable management of the problem of sunburned or cracked fruits while improving the physical and chemical fruit quality with increased productivity.