Decline of new vineyards in Southern Spain

Abstract

Context and purpose of the study – In-season vineyard pest management relies on proper timing, selection, and application of products. Most of the research on pest management tends to focus on the influence of regional conditions on these aspects, with an emphasis on product timing and efficacy evaluation. One aspect that is not fully vetted in various vineyard regions is application (sprayer) technology. The purpose of this study was to determine the influence of regional conditions on sprayer performance in commercial wine grape vineyards in eastern Washington.

Material and methods – Three commercially available sprayer technologies were optimized and assessed in the 2016 and 2017 production seasons. The sprayer technologies evaluated were: multi-fan heads, pneumatic, and electrostatic. Data were collected in commercial Vitis vinifera wine grape vineyards at two growth stages, 50% bloom and pea sized berries using a fluorescent tracer (Pyranine) to track deposition within the vineyard. Aspects of the sprayers that were evaluated were spray deposition patterns in the canopy and in-field drift (aerial and vineyard floor). Sprayer deposition was collected on 5cm x 5cm plastic cards. These cards were placed in 5 canopy zones (upper sides, upper middle, and both sides of fruit zone), on the vineyard floor in the first 3 rows downwind from the sprayer, and on aerial poles collecting drift in 0.3-meter increments above the canopy for 0.9-meters in the first 3 rows downwind from the sprayer. Sprayer data collected in the vineyard was used to evaluate total spray deposition of each sprayer.

Results – All sprayer technologies showed consistent in-canopy deposition and drift patterns at both canopy growth stages. The greatest deposition found in the canopy; the Quantum Mist had 95.57% and 98.48%, the Gregorie had 97.35% and 97.08%, and the On Target had 91.79% and 80.12% of total spray deposited in the canopy at the 50% bloom and pea-sized berry growth stages, respectively. Aerial and floor drift was relatively minimal with these technologies. The Quantum Mist had aerial drift of 1.65% and 0.01%, and floor drift of 2.78% and 1.51% for the two growth stages, respectively. The Gregoire had aerial drift of 0.09% and 0.08%, and floor drift of 2.56% and 2.84% for the two growth stages, respectively. The On Target had aerial drift of 0.42% and 4.05%, and floor drift of 7.79% and 15.83% for the two growth stages, respectively. Aerial and floor drift were highest in the row closest to spray application, indicating that longer-distance drift is relatively low with modern spray technologies. Ultimately, the information generated from this project will be used to help optimize sprayer selection for different vineyard sites.