Evaluación del comportamiento de la variedad Tannat frente a diferentes coberturas vegetales en la fila como alternativa al uso de herbicidas

Given the effects of climate change on vitiviniculture, it is prudent to seek alternatives to current vineyard management to achieve sustainable production over time that allows producers to meet their production objectives.

In the present work, the use of pastures under the row accompanied by irrigation is proposed as an alternative to traditional vineyard management. Using, in turn, different sources and forms of nitrogen application. Looking to measure the effect of these on the Tannat variety, through the study of yield, physiological balance of the plant and the final composition of the berries.

The practices were carried out in the 2022 - 2023 harvest, in a vineyard located in the department of Canelones. The vineyard under study was trained on a vertical shoot positioning system, with unilateral guyot pruning. The planting density is 4000 plants per hectare and rows oriented north-south.

The inter-rows were kept with grass cover as usual, while in the rows different treatments were tested, which were white clover (Trifolium repens), one and two years old fescue (Festuca arundinacea) and herbicide.

Three fertilization methods were used, consisting of urea applied to the soil, foliar urea and coron (foliar nitrogen fertilizer), in addition to a control without fertilization. Irrigation was also used in order to maintain control of water stress that could be caused by competition with pastures.

In the results obtained, it should be noted that the data are influenced by an important year effect, since it was an atypical year in terms of rainfall and temperatures. This is reflected in the water potential which, in turn, had a significant influence on several parameters such as vegetative growth and reproductive development, masking the possible differences between herbicide and cover crop treatments.

According to the different pastures used, in the clover treatment, promising results were obtained with respect to the levels of foliar nitrogen and yeast assimilable nitrogen. Values significantly higher than the rest of the treatments were achieved in both parameters, although they were not reflected in other parameters, such as the potential exposed leaf area or yield.

The different fertilization methods did not provide clear data. But, in general, better results were observed in the treatments with foliar fertilizers. Considering that, in these methods, less nitrogen units were applied, this would indicate a higher efficiency of use by the vine plants.