Postharvest Quality Evaluation of Red Globe Table Grapes Grown On Harmony and On Its Own Roots

Different rootstocks may influence some quality factors in the bunch and berries of table grapes (Harmon y Weinberger, 1966; Ezzahouanni y Williams, 1995; Gonzalez  y Muñoz, 2000): color, berry weight, pH, bunch looseness, acidity, Soluble Solids, among others. Reports include rootstock behavior in limiting soils, or extreme conditions. Nevertheless, if different rootstocks are grown non limiting soils may not induce major differences in berry and bunch quality (Ureta, 1993; Ansaldi, 2006; Sagardia, 2006). As consequence, post harvest behavior, should be similar.  Postharvest evaluations: Red Globe grape bunches were harvested from vines on Harmony roots and on its own roots at 18ª Brix and packed on the field in 7 kg carton boxes. (3 boxes per experimental units). Boxes were precooled and cold storage at -1ºC and 0ºC (pulp temp. 0ºC y 2ºC. and 90%RH). Evaluations on fruit condition at 30; 60; 90 y 120days of storage. Parameters measured: Loose berries (% weight); Browning of rachis (1=bright green to 5= dark brown); % rot berries; water loose % (by weight difference); dehydration, each 5 days while bunches were stored at 20 ªC after cold storage; also in all cases Soluble Solids, Acidity, skin color; polar and equatorial berry diameter and berry volume. Results shows that most of parameters analyzed did not present differences, in appearance, quality factors, chemical analysis and sensory evaluations. Some slight differences that appeared in some of the fruit analysis through the 120 days of cold storage, ware attributed to handling, and external factors, than being induced by the rootstock influences. Differences in titriable acidity observed at harvest time were maintained during for the 120 days of postharvest storage. No differences were found in the evolution of the parameters measured during 120 days of cold storage of Red Globe table grape from vines on Harmony and from its own roots. Differences identified at harvest, (malic acid; skin color) were maintained throughout cold storage postharvest life.