Foliar Zinc Sprays Affected Yield and Bioactive Compounds of Granny Smith Apple

In this study, effects of foliar Zn sprays at different periods on yield, fruit quality attributes, bioactive compounds and micro-macro elements of 'Granny Smith' (Malus x domestica Borkh.) apples grafted on MM111 rootstocks were investigated. Experimental treatments were arranged as control (without Zn sprays), Zn-1 [Zn sprays 1 month after full bloom (when the fruit had a size of a walnut)], Zn-2 (Zn sprays 1 and 2 months after full bloom) and Zn-3 (Zn sprays 1, 2 and 3 months after full bloom). Experimental trees were sprayed with 0.2% Zn (ZnSO4.7H(2)O). Compared to control, Zn sprays increased yields. SSC values of Zn-2 and Zn-3 treatments were lower than the control and Zn-1 treatments. The total phenolics and total flavonoids of Zn-treated fruit were lower than the control fruit. The greatest vitamin C and antioxidant activity were obtained from Zn-2 and Zn-3 treatments, respectively. Zn-2 and Zn-3 treatments had greater zinc and phosphorus concentrations than the control treatments and Zn-sprayed fruit had greater nitrogen and potassium concentrations than the control fruit. It was concluded based on present findings that Zn treatments could be used as an effective tool to increase yield, antioxidant activity and mineral elements of 'Granny Smith' apples.

Automated summary

This study investigated the effects of foliar Zn sprays at different periods on yield, fruit quality attributes, bioactive compounds, and micro-macro elements of 'Granny Smith' apples. The results showed that Zn-2 and Zn-3 treatments had higher antioxidant activity and mineral element concentrations, indicating their potential as effective tools to improve the quality and nutritional value of the apples.