Effects of different irrigation regimes on vegetative growth, fruit yield and quality of drip irrigated apricot trees

Abstract

This study was conducted during five growing seasons from 2004 to 2008 to investigate effects of different 
irrigation regimes on vegetative growth, fruit yield and quality of Salak apricot trees in semi-arid climatic 
conditions. There were six irrigation treatments, five of which (S1, S2, S3, S4 and S5) were based on adjustment 
coefficients of class A pan evaporation (0.50, 0.75, 1.00, 1.25 and 1.50). The other treatment (S6) was regulated 
deficit irrigation treatment that was irrigated by applying 100% of class A pan evaporation until harvest, but was 
not irrigated after harvest. During the experimental years, the lowest values of irrigation water and 
evapotranspiration were obtained by S6 and S1 treatments, respectively, while the highest values were obtained 
for the S5 treatment. There were statistically significant vegetative growth differences among the treatments. 
The highest vegetative growth values were observed for the S5 and S4 treatments, while the lowest value was 
observed for the S6. Yields per tree and per unit crown volume did not show statistically significant differences 
among treatments in all the years studied, while the yield per unit trunk cross-sectional area showed statistically 
significant differences among treatments only in 2008. The S1 treatment showed higher yields per unit trunk 
cross-sectional area and per unit crown volume than other treatments, while S5 treatment showed higher yield 
per tree than other treatments in all the years studied. There were no statistically significant fruit quality 
differences among the treatments. Consequently, the S1 treatment is recommended for apricot trees under the 
experimental conditions.