Evapotranspiration, irrigation water applied, and vegetative growth relations of young apricot trees under different irrigation regimes

Abstract

This study was carried out between 2004 and 2008 to investigate effects of different irrigation regimes on crop water use and vegetative growth of drip-irrigated young apricot trees. 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 greatest irrigation water and evapotranspiration values were observed in the S5 treatment while the smallest values were observed in the S6 treatment. A linear relationship was found between irrigation water applied and evapotranspiration in the experimental years (R2 = 1.00). Both the crown diameter and trunk diameter values showed statistically significant differences among treatments in the experimental years. The S5 and S4 treatments showed the highest crown and trunk diameter values, while the lowest crown and trunk diameter values were found for the S1 in 2004, 2005 and 2006, and for the S6 treatment in 2007 and 2008. Furthermore, it was found that there was a positive polynomial relationship between both the crown diameter and trunk diameter and evapotranspiration (R2 = 0.89 and 0.96). When considering irrigation treatments and vegetative growth parameters as a whole, the best developments were obtained at S5 and S4. However, taken into consideration relationships between tree development and evapotranspiration, the S4 treatment has been more productive. © 2011 Academic Journals.