This work was conducted on fruitful Valencia orange trees grown in sandy soil under drip irrigation system planted in a private
orchard located at Cairo-Alexandria Desert Road for three seasons (2016 to 2019) to investigate the effect of irradiated compost and/or bio-fertilizer on Valencia orange trees.
Concerning the studied vegetative growth parameters results could be suggested that adding 5 kg irradiated compost at 20 KGy + 30 ml bio-fertilizer /tree was the most enhancing shoot length, diameter, number of leaves/shoot as well as leaf area increment % .
Regarding to yield and fruit quality, all treatments were significantly enhanced fruit yield and fruit quality with the superiority of using combination between organic + bio-fertilizer (5 kg/tree irradiated compost at 20 KGy + 30 ml bio-fertilizer). Furthermore, the thickest fruit peel thickness (5.2 mm) resulted by non-irradiated compost + 30 ml microbine. Juice TSS %, vitamin C, and TSS/acid ratio were impressively enriched by using non/or irradiated compost and/or bio-fertilizer. Moreover, all treatments were enhanced N, P and K uptakes by trees and this was reflected on the vegetative growth and yield as well as the three leaf elements concentration.
The aim of this study was to improve Valencia orange vegetative growth, yield and fruit quality and to reduce the excessive use of mineral fertilizers. Thus, we concluded that the use of 5 kg irradiated compost at 20 KGy + 30 ml bio fertilizer) /tree during January can be suggested under similar conditions.