Gibberellic acid reduces clusters rot of ‘Sauvignon blanc’ grapes

Pricila Santos Da Silva,Marcelo Barbosa Malgarim,Paulo Mello-Farias,Carlos Sebastián Pérez Lamela,Caroline Farias Barreto,Marines Batalha Moreno Kirinus

doi:10.1590/0100-29452019486

Abstract

Abstract The ripening of grapes is impaired by climatic conditions due to the prolonged rainy season and thus facilitates the proliferation of diseases such as grape clusters rotting, caused by the fungus Botrytis cinerea, even before the ideal harvesting point. The aim of the study was to evaluate the effect of gibberellic acid (GA3) on rot and on physical-chemical quality of ‘Sauvignon Blanc’ grapevine. The experiment was carried out in the production season of 2016 and 2017 in Campanha region in Rio Grande do Sul, Brazil. The GA3 treatments were at the doses of 0 (control); 2; 4; 6 and 8 mg L-1 of GA3. The percentage of clusters rotting and maturation index decreased, however, the titratable acidity increased with GA3 doses. The cluster and rachis length increased with application of GA3. The cluster width; cluster, rachis and berry mass and the soluble solids were not influenced by application of GA3. In ‘Sauvignon Blanc’ grapevine, GA3 reduced the percentage of clusters rotting and improved the cluster and rachis length characteristics and titrable acidity.

Highlights

The grapevine (Vitis vinifera L.) is one of the most cultivated fruit trees in the world, the excellence of wine quality is directly related to grape quality (MORENO et al, 2011)
Some plant regulators can be used in order to stretch the grapevine cluster and reduce the incidence of cluster rot caused by the fungus Botrytis cinerea
The average percentage of ‘Sauvignon Blanc’ grape clusters caused Botrytis cinerea fungus in 2016 and 2017 season decreased on average by 14.88% with GA3 treatments compared to the control that obtained the average value of 21.34% (Figure 1)

Summary

Introduction

The grapevine (Vitis vinifera L.) is one of the most cultivated fruit trees in the world, the excellence of wine quality is directly related to grape quality (MORENO et al, 2011). The grapes quality may be affected by the high rainfall volumes, especially during grape maturation, with significant losses due to the occurrence of cluster rot caused by the fungus Botrytis cinerea (GIOVANNINI, 2008). This problem is aggravated in grapevines such as the ‘Sauvignon Blanc’ cultivar because it presents small and compact clusters, as well as causing economic losses and degrading grape and wine quality (KY et al, 2012). Some plant regulators can be used in order to stretch the grapevine cluster and reduce the incidence of cluster rot caused by the fungus Botrytis cinerea. The morphological characteristics of grape clusters and berries can be improved with the use of plant regulators, such as GA3 (BHAT et al, 2011)

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Conclusion