Fruit Yield and Quality Attributes of Various Strains of ‘Gala' and ‘Fuji' Apples Under An Evapotranspiration-Based Drip Irrigation

In a long-term study between 2004 and 2007, fruit yield and quality of several strains of ‘Gala’ and ‘Fuji’ apples (Malus x domestica Borkh) were examined under a drip irrigation system using crop evapotranspiration (ETc), adjusted by percentage of ground shade. The strain-rootstock combinations used in this study represent the most commonly planted ‘Gala’ and ‘Fuji’ trees in the apple industry. ‘Pacific’, ‘Brookfield’, ‘Treco’ and ‘Buckeye’ Gala strains (all on RN29 rootstock) had higher fruit yield in most years, resulting in significantly higher cumulative yields than ‘Scarlet’, ‘Royal’, ‘Ultima’ and ‘Crimson’ Gala strains on Bud9 rootstock. ‘Brookfield’, ‘Treco’, ‘Gale’, ‘Buckeye’ Gala on RN29 rootstock had similar average fruit weights and their weights were often higher than those in ‘Scarlett’, ‘Royal’, and ‘Ultima’ Gala on Bud9 rootstock.  ‘Buckeye’ and ‘Gale'  Gala fruits had higher visual red color ratings compared to the other strains every year.  ‘Beni Shogun’ and ‘September Wonder’ matured earlier, while ‘Desert Rose, Autumn Rose’, ‘Myra’, ‘Top Export’, ‘Nagafu 12’, and ‘Nagafu 6’ Fuji strains matured later.  ‘Desert Rose Fuji’ had more red color than several other strains of ‘Fuji’  ‘Top Export’ had striped fruit and maintained its firmness after five months of storage at 0 C.    Considering all yield and quality attributes, we recommend ‘Buckeye’ and ‘Gale’ Gala strains and ‘Desert Rose’, ‘Top Export', 'September Wonder’, and ‘Beni Shogun’ Fuji strains on RN29 rootstock with a drip irrigation system under climate conditions of Intermountain west region of the U.S.A.