Gradual release of growth regulators for a delay in budding and growth of 'Chardonnay' and 'Pinot Gris' in Southern Brazil

G. de A. Meyer, J. Talamini, M.E. Bueno, L. Rufato, A.A. Kretzschmar, A. De R. Rufato
The wine industry in southern Brazil is affected by late frosts that cause losses in earlier varieties such as 'Chardonnay' and 'Pinot Gris'. The aim of this study was to develop a new form of application of growth regulators to delay budding of 'Chardonnay' and 'Pinot Gris'. The experiment was conducted in a commercial vineyard in Vacaria, RS, (28°32'11" S and 50°50'04" W and 972 m). The branches were pre-pruned with four buds, for the application of the products. The treatments were applied to the winter bud with concentrations (mg L- 1): naphthaleneacetic acid (NAA) 500, 1000, 1500, 2000 (sprayed) and abscisic acid sprayed 500, in paste form Splat®: 1 g applied the paste containing NAA: 500, 1000, 1500, 2000, Prohexadione calcium 75, 125, 250, 500, Trinexapac-ethyl: 200, 300, 400, 600 and untreated control. The stage of budswell and green tip was evaluated at 7 and 14 days after application. 'Pinot Gris' at 7 days delayed its phenology 14-25% in all doses of NAA with a decreasing linear trend. For application in paste form Splat® (Specialized Pheromone & Lure Application Technology) we observed different behavior for growth regulators applied at late phenological stages in different concentrations. NAA (500 and 1000), Prohexadione-calcium (125 and 500) and Trinexapac-ethyl (200 and 300) in doses mg L- 1 can be applied with Splat® to delay budding of 'Chardonnay' and 'Pinot Gris' and reduce the risks of damage in the budding by late frosts up to 7 and 10.5 days, respectively compared to control.
Meyer, G. de A., Talamini, J., Bueno, M.E., Rufato, L., Kretzschmar, A.A. and Rufato, A. De R. (2016). Gradual release of growth regulators for a delay in budding and growth of 'Chardonnay' and 'Pinot Gris' in Southern Brazil. Acta Hortic. 1115, 237-242
DOI: 10.17660/ActaHortic.2016.1115.35
Vitis sp., gibberellin synthesis inhibitor, vigor

Acta Horticulturae