Desenvolvimento fenológico de videira ‘Niágara Rosada’ (Vitis labrusca) cultivada com e sem cobertura

Abstract

With the encouragement of diversification of production, grape cultivation has intensified in the different regions of Rio Grande do Sul, especially in family-owned farms. Beside the consumption of fresh fruit, the grape has great potential for the production of various products (wines, juices and jellies), both on an industrial scale and for consumption by the family itself. The use of plastic cover can be considered the latest agricultural input, aiming at increasing production and quality, where conventional techniques have already been exhausted, appearing as an alternative in crop protection in the face of climatic adversities. Studies that evaluate the behavior of plants in different growing environments are fundamental to understand the adaptive processes of the species. From this, the objective of this work was to evaluate the micrometeorological conditions and the phenological behavior of 'Niagara Rosada' grapevine in cultivation systems with and without cover. The experiment was carried out in a family property of Pelotas, RS, during the 2014/2015 and 2015/16 crops in a 'Niagara Rosada' cultivar, on the Paulsen 1103 grafted scion, in the trellised conduction system. In four of these cultivation lines there was a cover with impermeable plastic (CC) and another without cover (SC), these being the two treatments of this experiment. Measurements of micrometeorological variables such as: temperatures and solar radiation (global, reflected) and phenological monitoring were performed. The use of polyethylene cover on grapevine cultivation allows thermal gain to the environment and attenuates Global Solar Radiation on the vine canopy. In a crop under the influence of El Niño phenomenon: no change in the duration of the cycle of the vine in the cultivation with coverage in relation to the uncovered is identified; the plastic cover provides better use of the solar radiation present in the atmosphere; it is not possible to detect changes in average and minimum air temperatures by the presence of the plastic cover in grape cultivation. In year without influence of El Niño phenomenon, the use of cover provides environmental conditions to abbreviate the maturation phase of the fruits, with reduction of the total cycle in days; the maximum daily air temperatures are increased by the use of the plastic cover, making them reach values that exceed those ideal for growing the vine.