Revista de Agronom�a (LUZ): Vol 10, No. 2, 1993

Comparaci�n de Sistemas de conducci�n en Uvas de Mesa en California

Comparison of california table grape trellises

Fred Jehsen* y Mary Bianchi

University of California Kearney Agricultural Center 9240 South Riverbend Avenue, Parlier, California 93648 USA

Palabras claves: Vid, Sistema, Conducci�n, Uva de Mesa

Introduction: All California table grapes are grown with crossarm trellises, usually about one meter wide, attached to stakes at ea ch vine. Stake length is 2.1 m with 0.5 m driven into the soil. Although trellises ha ve be en in use for 60 years, no comparison of the various trellises has ever be en made.

Method: Seven trellises were compared for Thompson Seedless ant Flame Seedless, the two major varieties, the first head-trained cane-pruned ant the second cordon-trained ant spur-pruned. The Thompson trellises were 3 single crossarms 0.9, 1.2, ant 1.5 m long ant 4 double crossarms with similar length of upper crossarm ant lower crossarm, on which the canes were tied, at 0.5, 0.6, ant 0.9 m length with 0.36 m distan ce between crossan.

The Flame Seedless trellises included bilateral trained vines with single ant double crossarms ant quadrilateral Srained vines with single, double, ant triple foliar support crossarms. Yields ant me asures of frute characteristics were taken for three years.

Results: With Thompson Seedless, there were no significarle differences in packable yield except with the single 0.9 m wide trellis which was the lowest. The vines were of high vigor with a pruning weight of about S kilos per vine ant the 0.9 m trellis was too restrictive for these vines.

With Flame Seedless, the vines trained to quadrilateral cordons produced half again more frute than the vines trained to bilateral cordons. With more than one foliar support crossarm, yields were always lower than where only one foliar support crossarm was used. These vigorous vines required quadrilateral training and a 1.2 m wide foliar support crossarm to rea ch their productive potential.

Conclusions: Trellis design must be tailored to vine vigor for maximum production. Also, trellis conformation affects fruiting characteristics ant ease of cultural operations.