Yield and Physiological Response of Autumn King and Scarlet Royal Table Grapes to Cane and Spur Pruning Systems

Abstract

The type of training system affects vine growth and productivity; however, there is a lack of knowledge on the suitability of pruning systems for some recently introduced (Vitis vinifera L.) cultivars. In this study, we provide the growers with science-based information about the response of two table grape variates to cane and spur-pruning systems to develop the best cultural practices. In 2013, a vineyard was established at Kearney Agriculture Research Center, Parlier, California using “Autumn King” and “Scarlet Royal” table grapes (Vitis vinifera L.) grafted on Freedom rootstock. The performance of the three-year-old vines was assessed under two pruning systems, Quadrilateral cordon training (spur-pruning) and Head training (cane pruning). Data from the 2016 and 2017 seasons showed no significant differences in leaf area, chlorophyll content, Normalized Difference Vegetation Index (NDVI), and pruning weight between the two pruning systems in both cultivars. In both seasons, marketable yield did not vary between the two pruning systems in the Scarlet Royal. However, Autumn King marketable yield was significantly reduced when using the Quadrilateral cordon training (spur-pruning). Petioles nutrient analysis at bloom showed a non-significant increase in nitrate content in the cane pruned vines of both varieties. No significant difference was observed in cluster weight, berry physical, or chemical composition. It seems that both training systems could be used for Scarlet Royal. However, the cane pruning system in Autumn King produced higher yield without affecting cluster and berry quality. The different responses of the two varieties could be due to the genetic background and growth behavior. Our data confirmed the notion that the different responses to the training methods by various grape varieties may involve the genetic background, growth behavior, as well as nutrient uptake and usage by the vines. Establishing the proper training system for each grape variety is essential.