The Effect of Time and Rate of Combined Fertilizer (Nitrogen, Zinc, Boron) as well as Molybdenum Application on Fruit-Set and Fruit Quality in Grapevine cv. Siahe-e-Samarghandi

Siahe-e-Samarghandi is one of the most important cultivars of grapevine (Vitis vinifera) in Fars Province. Some problems of this cultivar are its sparse clusters with small berries and berries that are in different stages of growth. Foliar application of urea، zinc sulfate، boric acid 4، 3 and 1gL-1، respectively as well as sodium molybdate at the concentrations of 0، 0. 5، 1 and 1. 5 gL-1 were applied at the start of shoot growth (pre-bloom) and at the middle of blooming. The study was carried out as a factorial experiment in a Completely Randomized Block Design. Yield and shot berry، percent vitamin C، total acid and total soluble solids، chlorophyll content، shoot length، and leaf surface were investigated. Results showed that yield increased through an application of fertilizer composition and by an increase in molybdenum concentration sprayed at the middle of blooming. The highest shot berry was observed in control (with on Mo and fertilizer application). The lowest concentration of Mo rendered on increase in vitamin C. In conclusion، fertilizer composition spray along with Mo application at the middle stage of blooming proved to have positive effects on growth and yield، significantly reducing shot berry disorder.