Poda e desbaste no cultivo de nogueira-pecã em plantios adensados

Abstract

Pecan trees planting under high density is questioned, because when grown, plants have problems with shading branches, causing yield reduction. The objective of the present study was to evaluate two methods of pruning and thinning trees in terms of vegetative development, yield and quality of pecan fruits under a high plant density system. The commercial orchard was established in 2009 under a 7m x 7m spacing in Santa Rosa, in the northwest region of Rio Grande do Sul, Brazil. The study was conducted between July 2018 and February 2020. In experiment 1 “Hedge pruning and central pruning in a high density pecan orchard”, trees from the cultivar ‘Melhorada’ were used and the treatments consisted of: 1) without pruning; 2) Hedge pruning and 3) central pruning. Experiment 2 “Production and development of pecan with thinning of trees in a high density planting orchard”, was constituted with cultivars ‘Barton’ and ‘Melhorada’ and the treatments were 1) without thinning (7m x 7m) and 2) with thinning (14m x 10m). The presence of dry branches, as well as fruit production and quality were evaluated. In experiment 1, central pruning increased fruit yield and reduced the number of dry branches. Both pruning methods reduced the number of fruits with closed pericarp and the quality of fruits was not altered in most of the evaluated variables, only the length of the fruits, the thickness of the skin and the luminosity of the kernels were changed. In experiment 2, trees thinning increased photosynthetically active radiation (RFA), increasing the growth of branches and reducing the number of dry branches. The production with the thinning of trees increased in the cultivar ‘Melhorada’, however in the cultivar ‘Barton’ there was no effect. Both cultivars had reduced productivity with thinning, due to the reduction of trees. Thinning also increased fruit yield with an increase in mass and size. Aiming at an immediate productive and phytosanitary improvement, central pruning is more advantageous. Trees thinning has improved in phytosanitary and fruit quality.