Agronomic evaluation and adaptability of Pinot gris to an environment with high grey mould disease pressure: a comparative analysis on 17 clones

The grapevine (Vitis vinifera L.) cultivar Pinot gris is an international variety that has spread world wide and is oneof the most important in Italy, especially in the northern regions where almost half of the world's total is grown. Over a three-year period (2019–2021), a comparative study was conducted on 17 clones to evaluate their agronomic aptitudes, susceptibility of grapes to Botrytis cinerea, fertility of buds, vigour, and oenological characteristics. We aimed to provide local viticulture with agronomic, sanitary status, and oenological indications that help to choose the genotype that best fits and enhances the clone/environment synergy. This is important given climate change, one of the most significant factors affecting viticulture. Hence, productive, qualitative, and health surveys were conducted on grapes during harvest. Vigour and vegetative/productive balance were also evaluated regarding the weight of the pruned wood. The Ravaz index and fertility of buds were studied when the inflorescences were separated and clearly visible (between DOY 131 and DOY 141 each year). The confirmation of the bunch was also evaluated (shape and number of wings) according to the Organisation Internationale de la Vigne et du Vin (OIV) descriptors. Through the use of digital photogrammetry, some descriptors of the cluster that most correlate with the severity of Botrytis cinerea were identified. In 2020 and 2021, microvinifications were carried out in white and with maceration of skins, respectively, following tested protocols. Sensory analysis of the wines was performed with a trained panel of experts. The study revealed interesting differences between clones concerning grapes' qualitative, productive, and sanitary aspects. Some clones stood out for their sugar accumulation, yield and resistance to Botrytis cinerea, as well as for the oenological olfactory profile. Statistical analysis highlighted that the severity of Botrytis cinerea and bunch rot was not correlated with the vigour of the plant but rather with the hardness of skin, content of soluble solids, soluble solids/total acidity ratio, pH, and total acidity. From the sensory analysis, several clones had a higher score for some descriptors in both study years and were more appreciated than others.