Effectiveness of control strategies against Botrytis cinerea in vineyard and evaluation of the residual fungicide concentrations

Abstract

This investigation was undertaken to test different control strategies against Botrytis cinerea vineyards. Two commercial vineyards, “Barbera” and “Moscato,” located in Piedmont (Northern Italy) were divided into seven plots and treated with different combinations of fungicides including fenhexamid, pyrimethanil, fludioxonil + cyprodinil, iprodione, and boscalid, a new carboxamide compound. An integrated strategy including a chemical (pyrimethanil) and a biocontrol agent (Trichoderma spp. t2/4ph1) was also included. At harvest, the percentage of bunches and berries attacked by B. cinerea and the concentration of the chemical fungicides were determined. All the pesticide residues at harvest were below the maximum residue level (MRL), except when two applications of pyrimethanil per season were applied. Boscalid was the most effective active ingredient against B. cinerea among the tested chemicals. When boscalid application was followed by a treatment with pyrimethanil, its efficacy was similar to that shown by two treatments of pyrimethanil. However, this second strategy was not feasible due to the risks of resistance development in the pathogen and to the residue accumulation as indicated by the analysis.

Keywords:

• Boscalid
• fungicide
• grapevine
• grey mold
• residue
• wine

Acknowledgments

This research was carried out with in the framework of the projects “Risk evaluation, prevention and management of the presence of mycotoxins in the Piedmont grapes and wine chain,” funded by the Piedmont Region, and “Evaluation and prevention of the risk of ochratoxin A in the Piemontese wine chain,” funded by the CRT Foundation. Moreover, the authors gratefully acknowledge Dr. Giovanna Gilardi for her help in the realization of the trials and Dr. Jeanne Griffin for her linguistic advice.

Notes

∗Values followed by the same letter within the same cultivar are not statistically different by Duncan's Multiple Range Test (P < 0,05).