In Santa Cruz County, Granny Smith conversions to organic show early success

Abstract

Conventional and organic semidwarf Granny Smith apple production systems were compared during 3 years of conversion to certified organic management on California's Central Coast. Yields were significantly higher in the organic production system in 1989 and 1991 due to significantly greater fruit load. Growth indicators such as tree girth, terminal growth, leaf area, and so on, did not generally differ, but tissue levels of nitrogen were generally higher in leaf and new wood bark tissue in the conventional system, while phosphorus levels were generally higher in tissue of the wganically managed trees. Key sconomic pest damage did not differ significantly in any year, although fruit and leaf damage due to some lepidopterous secondary uests was greater in some years in the conventional system. Apple kaf hoppers showed significant hcreases in leaf damage in the organic system. Price premiums for wganic apples consistently proiuced higher per-acre return for this system.