The Effect of Microbial Fertilizer Applications on Grape Yield, Quality and Mineral Nutrition of Some Early Table Grape Varieties

Abstract

In this study, a commercial microbial fertilizer (Bio fertilizer) containing 3.5×10⁷ cells/mL of Chlorella vulgaris algae with a pH ranging from 3.5 to 5.5 was used. Four applications of microbial fertilizer; 1) control (no fertilizer), 2) leaf treatment, 3) soil treatment, 4) soil plus leaf treatment were performed in the experiment. The effects of the treatments on grape yield and cluster, berry and juice characteristics of 4 years old Trakya ilkeren, Yalova incisi and Prima grape varieties were investigated.  In addition, the effects of these applications on macro and micro element contents of leaf samples were examined during the veraison. Microbial fertilizer application was done 5 times starting with the shoot length of 20cm and including the veraison time. The highest yield (6076 g /vine, 3038 kg/da), bunch weight (300.1 g) and 100 berry weight (622.6 g) as well as other berry characteristics and maturity index (60.21) values were obtained from the Yalova incisi variety. It has been determined that the most suitable fertilizer application was soil+leaf application with the highest yield (4059 g/vine, 2030 kg/da) and bunch weight (249.7 g).  It has been observed that soil application caused earlier maturation of the grapes. The content of nutrients in the leaf samples was different in terms of varieties except nitrogen and manganese. The highest K content was found in Trakya ilkeren; while highest Ca, Mg and Fe were found in Yalova incisi and highest P, Fe and Zn were in the Prima variety. There were no significant differences in leaf N, P, Mn and Zn contents between fertilizer applications. For the other elements, the highest values were obtained from leaf application followed by soil plus leaf applications.