Agronomic performance of 21 new disease resistant winegrape varieties grown in northeast Italy

The goal of the field trial was to evaluate the agronomic performance of 21 (10 red and 11 white) winegrape varieties obtained from recent breeding programmes for disease resistance developed in Hungary, Germany, and Italy. The tested red varieties were as follows: ‘Cabernet Carbon’, ‘Cabernet Eidos’, ‘Cabernet Volos’, ‘Julius’, ‘Merlot Khorus’, ‘Merlot Kanthus’, ‘Monarch’, ‘Prior’, UD. 31.103, ‘Vinera’. The tested white varieties were as follows: ‘Aromera’, ‘Bronner’, ‘Fleurtai’, ‘Johanniter’, ‘Muscaris’, ‘Souvignier Gris’, ‘Sauvignon Kretos’, ‘Sauvignon Nepis’, ‘Sauvignon Rytos’, ‘Solaris’, ‘Soreli’. ‘Merlot’ (red) and ‘Glera’ (white) were included as control. The experimental vineyard was established in Castelfranco Veneto on the plain, in 2014. Spray treatments were applied against downy and powdery mildew, by using only copper and sulphur. Grape production, grape quality, and phenology were recorded over a six-year-period, while disease resistance (downy mildew, powdery mildew, black rot and anthracnose) was detected only during a few years. The most significant findings were: a) all varieties showed a good level of downy mildew resistance, especially ‘Cabernet Carbon’, ‘Monarch’, ‘Prior’, UD 31.103, ‘Muscaris’, ‘Solaris’, ‘Souvignier Gris’, ‘Bronner’, ‘Fleurtai’, ‘Aromera’; b) no powdery mildew attacks were detected in any variety; c) ‘Monarch’, ‘Muscaris’, ‘Solaris’ and ‘Souvignier Gris’ also showed a high level of resistance towards black rot and anthracnose; d) red grape varieties had an earlier bud burst as compared to ‘Merlot’, and, concerning ripening, some varieties were earlier than ‘Merlot’, other ones were later; e) white varieties had a later bud burst but an earlier ripening time as compared to ‘Glera’; f) grape production and quality changed significantly depending on the varieties, being titratable acidity higher than 6.4 g L-1 tartaric acid and pH lower than 3.5; also the year affected in a significant way those parameters as well as the interaction between the genotype and the year. In conclusion, the tested varieties behaved positively in terms of environmental sustainability.