Variation of leaf area index and leaf water potential of young dwarf apple trees under different irrigation methods

In this research which was carried out inSuleymanDemirel University Research and Application Farm during 2007 and 2008 years, apple leaf area index (LAI) and leaf water potential (LWP) were observed in Jersey Mac (V1) and Williams Pride (V2) young apple varieties budded on M9 rootstock irrigated with different irrigation methods. Drip (D), subsurface drip (SD), surface (S) and undertree micro sprinkler (M) irrigation methods were used in the research. The amount of applied irrigation water was as much as 100% of Class A Pan evaporation measured during five days irrigation intervals. The amount of irrigation water was ranged between 348.3 (D, SD) – 1186 (S, M) mm depending on irrigation methods during the experimental years. Furthermore, maximum and minimum crop evapotranspiration values were determined as 426.1 (DV2) and 1334.7 (MV2) mm respectively. LAI values related to treatments ranged from 0.32 to 0.52 in 2007, 0.73 to 1.12 in 2008. LAI values increased by approximately 126.3% for all treatments. In both years, generally, the highest LAI values were observed in drip irrigation (D) for both varieties. Linear correlation (r=0.99, n=16) was obtained between fruit yields and leaf area index (LAI) values of the apple trees. Leaf water potential (LWP) measurements were repeated one day before and after irrigation during the irrigation period. The measurements were also conducted once along a day in the middle of the season. Changes in value of LWP were similar among the treatments