Identifying manageable factors determining carbohydrate accumulation in reserves and root growth of grapevines after harvest

Abstract

Two surveys and four field trials were conducted across the Riverina and Hilltops regions in NSW to investigate the importance of the post-harvest period for vine productivity in Semillon. The surveys were used to gain an understanding of the level of variation in post-harvest reserve accumulation between and within vineyards. The four field sites were used to examine the impact of post-harvest treatments on reserve accumulation and productivity in following seasons. After two seasons, up to 60% yield increases were observed on the high reserve treatment, and 50% reductions in yield on the low reserve treatments. A similar effect was seen on pruning weights, but in both cases the treatments responses decreased in the lower yielding vineyards. Treatments designed to duplicate severe mechanical harvester damage to the canopy had a lesser impact on productivity. A key difference between regions was the greater accumulation of root reserves in the Riverina, which was probably related to post-harvest irrigation. The survey results showed that normal variation in reserve concentrations were not as great as that induced with the deliberate post-harvest treatments. However, the study suggests there is considerable potential for more targeted management of reserve levels to control vine vigour and productivity.

Summary

The four field sites received treatments, which altered length and effectiveness of the post-harvest period. Starch reserve accumulation and productivity in following seasons were altered. The study suggests there is considerable potential for more targeted management of reserve levels to control vine vigour and productivity.