Application of laminarin and calcium oxide for the control of grape powdery mildew on Vitis vinifera cv. Moscato

Erysiphe necator is favourably influenced by the increase in temperatures and remains the main pathogen threatening grape in Northern Italy. In the present work, the efficacy of laminarin and calcium oxide in the control of grape powdery mildew was evaluated, comparing them to sulphur. Two tests were carried out on potted grape “Moscato” plants in 2017, and two field trials were carried out in Italy during 2016 and 2017 on a vineyard of the “Moscato” variety. Laminarin and calcium oxide showed, for the first time, to significantly reduce powdery mildew, and this occurred in all trials. However, laminarin was less effective than sulphur in potted trials and in 2016 field trial, and both laminarin and calcium oxide were less effective than sulphur in 2017 field trial.