Impact of some Reducing Abiotic Stress Substances on Valencia Orange Tree Growth and Productivity

During 2021 and 2022 seasons, we tested the effect of applying Potassium silicate (0.1%), Selenium (50 ppm), and Nile power compound (0.2%), either as single treatments or their combination, on antagonizing water stress-induced deterioration in Valencia orange trees. We observed the growth, nutritional status, yield, and fruit quality of the trees grown in clay soil under a flooding irrigation system. Experimental water stress was induced in the orchard by irregular irrigation periods during blooming and fruit set, that caused a negative effect on tree yield and fruit quality. The irrigation was delayed by three days from the time the trees needed to be watered in all trees during the two seasons. Various treatments were sprayed four times, instituted in the 1^st week of March, May, July, and September. The tested treatments proved to be effecting against abiotic stress by significantly enhancing all tree growth characters under study i.e., leaf pigments, nutrient content, yield, and fruit quality over the control treatment. Moreover, Nile power compound and Selenium treatments were better than Potassium silicate in this respect. Generally, using the Nile power compound, selenium, and potassium silicate as a mixture were preferable than using each one alone during the two experimental seasons.
To help mitigate the negative impact of water stress on the fruiting of Valencia orange trees, a recommended approach is to spray potassium silicate (0.1%), selenium (50 ppm), and Nile power compound (0.2%). This application should be done four times a year, during the first week of March, May, July, and September.