Supplementary Irrigation During the Last Cluster Drop Period for Higher Yield and Quality in Conventional Rain-Fed Hazelnut Farming

Abstract

This research was carried out to determine the effects of supplementary irrigation in the last cluster drop period by the drip irrigation method on yield and yield components in a conventional rain-fed 'Tombul' hazelnut orchard in Giresun province (Turkey) in 2015 and 2016. The experiment was designed as randomized plots with three replications. The plants in the ocak (multi-stem bush) were irrigated with drip irrigation in July and early August. In the study, irrigation water application was planned to be watered when 40% of the available water was consumed. Conventionally rain-fed plants were used in the control group. The results showed that the yield, kernel size, internal cavity, good kernel and kernel defects were significantly affected by last cluster drop period irrigation treatments in both years. The yield (grams per ocak with five stems) varied from 1520.36 g (control) to 2436.95 g (irrigation) in 2015 and from 765.06 g (control) to 1443.72 g (irrigation) in 2016. Kernel size was significantly higher in irrigated plants than in control plants in both years. The lowest internal cavity values were found in irrigated plants in both years. The rate of good kernel was higher in irrigation treatment than in control. In the study, the lowest defective kernel rates were determined in the irrigated plants in both years. As a result, irrigation during the last cluster drop period in 'Tombul' hazelnut had significant positive effects on yield and important quality parameters compared to conventionally rain-fed hazelnut orchards.