EFFECTS OF SPRAY VOLCK OIL IN DIFFERENT TIMES ON THE CLUSTER CHARACTERS OF GRAPE (KOLAHDARI VAR) IN NORTH KHORASAN CONDITION

ABSTRACT In order to study the effect of Different Times foliar application of Volck Oil on cluster characters of grape (Kolahdari var) this experiment was conducted in a factorial experiment in a Randomized Complete Block Design (RCBD) with three replications in 2013. The first factor, the time of spraying as the major factor was carried out in three levels including one week before flower formation, one week after the full bloom and two weeks after the full bloom. Various concentrations of oil as the secondary factor had four levels including oil spraying concentrations of 0 (control), 0.5, 1 and 1.5%. The characteristics studied in this research included: cluster weight, length and width of cluster, the number of clusters and percentage of cluster thinning. The results showed that application of different levels of oil and its spraying time had significant impact on length and width of the cluster, cluster weight and the percentage of cluster thinning. (P ≤ 0.01) Generally, among various concentrations of Volk oil, using 1.5 % Volk oil one week after the full bloom had the greatest effect on the studied characteristics which caused reductions in the number of the cluster and hence increased length and width of cluster and their weights