Yield and Quality Response of Young ‘Gala, Galaxy’ Trees under Different Irrigation Regimes

This study was conducted in 2007–2008 to determine the effects of different irrigation regimes on yield, quality and water-yield relationships of young dwarf ‘Gala, Galaxy’ apple trees in Isparta-Turkey. Irrigation water was applied based on a ratio of class A pan evaporation (rates of 0.0 (kcp0), 0.25 (kcp1), 0.50 (kcp2), 0.75 c (kcp3), 1.00 (kcp4) and 1.25 (kcp5)) with 5-day intervals. The effects of irrigation regimes on yield and fruit weight were statistically significant. Seasonal evapotranspiration was measured as 246.5–608.2 mm and 289.3–631.9 mm in 2007 and 2008, respectively. Water use efficiency lead to a yield ranging from 0.0023 to 0.0055 t ha−1mm−1 and from 0.0033 to 0.0111 t ha−1mm−1 and irrigation water use efficiency varies from 0.0009 to 0.0073 t ha−1mm−1 and from 0.0045 to 0.0186 t ha−1mm−1 in 2007 and 2008, respectively. The annual average yield response factor, ky, was 1.22. As a result of the research, it was concluded that the irrigation schedule for the 0.75 kcp3 treatment, applying 0.75 of evaporation from class A pan, could be used in the irrigation of young dwarf apple trees without evident reduction in yield and that high water use efficiencies could be obtained.