DESENVOLVIMENTO DE VIDEIRAS (Vitis labrusca) OBTIDAS POR ENXERTIA DE MESA

Abstract

Viticulture is a branch of agribusiness in Brazil and in the world of great economic and social importance. The selection of the rootstock is fundamental, since its choice affects the vegetative growth of the plant, improves the distribution of nutrients and favors the formation of flower buds, thus increasing productivity. With the use of seedlings resulting from table grafting, it is possible to reduce the formation time of the vine by up to one year in relation to the conventional one, in a method that initially performs the planting of the rootstocks with the grafting in the following year. The objective of this work was to evaluate the development of American grapevines (Vitis labrusca) undergoing table grafting in comparison with the practice of conventional grafting. To carry out the experiment, vine seedlings grafted on the '101-14 Mgt' rootstock were used, which were planted in September 2020, at a spacing of 2.5 x 1.0 m. The experimental design was in randomized blocks in a 2x3 factorial, the first factor being the different grafting techniques (table grafting and conventional grafting) and the second factor the different grapevine cultivars (Niagara Branca, Niagara Rosada and Bordô). The cultivars were tested in the 2020/2021 and 2021/2022 cycles, evaluating survival, plant height, stem diameter, dry and fresh mass of the plants, spad index, enzymatic estimates, leaf water potential, chlorophyll fluorescence and nutritional analysis. For the SPAD index, the grapevines grafted using the table technique showed higher chlorophyll contents. Regarding chlorophyll a fluorescence, in the 2021/2022 cycle, the burgundy cultivar showed greater energy loss due to chlorophyll a fluorescence. For the 2022/2023 cycle, grapevines grafted using the table grafting technique showed greater non-photochemical energy loss. For an antioxidant enzyme and leaf water potential, the vines that were grafted with the table grafting technique showed greater water stress, consequently a higher concentration of antioxidant enzymes. It is concluded that the grapevines grafted with the table grafting technique provide less vegetative development. Regarding the biochemical estimates, the energy loss by chlorophyll a fluorescence and the peroxidase enzyme levels were higher for the grapevines grafted on the table technique, thus indicating that these grapevines were in a condition of stress.