A Trellis System with Opti-Panels Protects Vineyards from Environmental Constraints and Reduces Canopy Management Labor
William Peacock,* Yosepha Shahak Ravid, Nicholas
Booth, Jonathan Destler, Nadav Ravid, Atiako Kwame Acheampong,
and Daniel Farkas
*UC Cooperative Extension Tulare County (Emeritus), 17428 Ave
344, Visalia, CA, 93292 (wlpeacock@ucdavis.edu)
A novel trellis system technology, Opti-Panel, integrates photo-selective panels into the traditional gable trellis framework. The panels consist of high-density translucent polyethylene with custom red or pearl color, and special UV protection engineered to last 10 years. This system protects table grapes from frost, hail, hot spells, wind, and rain. The trellis/panels position shoots and keep the center of the gable (‘Y’) free of foliage and well-illuminated all season. The system was evaluated over the past three years in San Joaquin Valley on eight table grape cultivars (Ivory, Krissy, Sweet Globe, Allison, Adora, Autumn King, Autumn Crisp, and Scarlotta). Several rain events in October of 2021 provided an opportunity to evaluate the efficacy of the panel system in reducing cluster rot pre- and postharvest. Adora, Autumn King, and Allison rot levels under panels were one-third of those under the conventional annual white plastic cover. Incipient, postharvest decay levels of Botrytis cinerea, Aspergillus niger, Penicillium spp., and Cladosporium were lower. Postharvest Botrytis level in Scarlotta under the panels was lower (0.3%), compared to conventional plastic cover (4.6%) or an uncovered control (11%). Similar results were obtained with Adora and Autumn King. In most cases, the red panels outperformed the pearl. The panels and conventional plastic cover both provided rain protection, but condensation and humidity were much less in the well-ventilated trellis/panel system, accounting for the decrease in decay. On 19 June 2021, a hot spell occurred, and the Allison cultivar suffered serious heat damage (51%), while the damage was much less under the panels (17%). The panels naturally positioned and held shoots in place with no additional labor. Shading in the fruiting zone was eliminated by the panels, as was the need for leaf removal to facilitate spray coverage, providing additional labor-saving. Panels increased berry size, with other fruit characteristics unaffected.
Funding Support: Opti-Harvest, Inc.
