The effects of microbial fertilizer applications on tree growth and development and fruit properties in apple growing

The research was conducted in 2022-2023 on the Red Chief apple variety grafted on MM106 rootstock in the apple orchard established in 2011 at Yozgat Bozok University Gedikhasanlı Bilal Şahin Agricultural Application and Research Center. The study was established to determine the effects of control (100% fertilizer), 50% reduced fertilizer, 100% reduced fertilizer (no fertilizer), and combinations of fertilizers with microbial fertilizer containing bacteria on fruit yield and quality and vegetative growth. The highest fruit weight was obtained from Control (100% fertilizer dose)+Bacteria treatment (170.57 g) and 50% reduced fertilizer dose +Bacteria (164.30 g) treatments. The lowest fruit weight was obtained from 100% reduced fertilizer dose (no fertilizer) (103,18 g). The highest fruit flesh firmness (kg/cm2) was determined in Control (100% fertilizer), 50% reduced fertilizer, and 100% reduced (no fertilizer) treatments. The lowest fruit flesh firmness was obtained from Control (100% fertilizer) + bacteria treatment with 6.50 kg/cm2. Water soluble dry matter content was 20.30% Brix in Control (100% fertilizer) + bacteria and 19.90% Brix in 50% reduced + bacteria treatments. Titratable acid content was highest in the Control (100% fertilizer) treatment with 0.59%. The highest yield per tree values were obtained from Control (100% fertilizer)+bacteria (22.35 kg/tree) and Control (100% fertilizer) treatments (19.63 kg/tree). When the effect of treatments on shoot length was examined, the highest values were found in Control (100% fertilizer), Control (100% fertilizer)+bacteria and 50% reduced fertilizer+bacteria treatments. The highest amount of nitrogen (N) in the leaf was determined in Control (100% fertilizer), Control (100% fertilizer) + bacteria and 50% reduced + bacteria treatments. The highest amount of P was obtained from Control (100% fertilizer) and Control (100% fertilizer) + bacteria treatments. The highest amount of K was measured in the 50% reduced fertilizer treatment.