Effects of anti‐transpirant di‐1‐<i>p</i>‐menthene, sprayed post‐veraison, on berry ripening of Sangiovese grapevines with different crop loads

Abstract

Background and Aims The effect of global warming on grape ripening has led to the development of strategies for delaying sugar accumulation. This study evaluated the effectiveness of the application of the film-forming anti-transpirant di-1-p-menthene on the berry ripening of Sangiovese grapevines with different crop loads. Methods and Results Over 2 years, the vines with high (H) or medium (M) crop load (leaving about one bunch for every two shoots) were sprayed (T) or not (C) with the anti-transpirant film-forming spray post-veraison (as assessed by a colour change). The di-1-p-menthene treatment inhibited leaf photosynthesis during bunch ripening for about 30 days, limiting berry sugar accumulation. Yield per vine was related to TSS, with di-1-p-menthene-treated vines showing the greatest effects. Increments of 1 kg of yield corresponded to a reduction of about 0.67°Brix in the Control vines and of 0.79°Brix in the treated vines. Conclusions The temporary reduction of photosynthesis reduced berry TSS. In high crop-load vines, the application of di-1-p-menthene delayed TSS accumulation more than the high crop load. Significance of the Study The anti-transpirant applied during post-veraison delayed the accumulation of sugar in berries more than the high crop load.