Abstract

This study was carried out to investigate effects of different irrigation regimes on fruit pomological properties of drip-irrigated young apricot trees in 2005 and 2008. Six different irrigation treatments were used: 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 not irrigated after harvest in all the years of study. The effect of different water application levels on fruit weight, fruit diameter, fruit height, seed weight, and flesh / seed ratio was found statistically insignificant. Regression analysis showed that there were significant relations among fruit yield, some quality characteristics, vegetative growth, and evapotranspiration in both 2005 and 2008. Also, the yield per tree and evapotranspiration were related with high R² values of 0.97 and 0.76 in 2005 and 2008, respectively. The fruit yield values showed an increasing trend depending on an increase in the tree crown volume, and trunk cross-section area in the experimental years. Fruit quality relationships weredifferent according to the years and quality properties. In 2008, fruit weight reduced while fruit yield increased with fruit diameter and fruit height of more than about 47 and 38 mm, respectively. Thus, it was understood that yield increased, depending on the number of fruit rather than the weight of fruit. 

Key words: Apricot, class a pan, drip-irrigation, evapotranspiration, fruit yield and quality, regulated deficit irrigation, vegetative growth.