Avaliação de porta enxertos clonais do gênero Prunus spp. para pessegueiro, nas condições edafoclimáticas de Chapecó

Abstract

The peach tree in Brazil is propagated in its entirety by grafting on rootstocks of sexual origin. Considering that rootstocks are a conditioning factor in fruit production and considering that it can cause changes in plant development, fruit and even incompatibility between grafts, the present work has the objective of evaluating the adaptation and behavior of different portals - Prunus grafts or hybrids grafted with BRS-Libra canopy under the climatic conditions of Chapecó. The experimental orchard is located at the Federal University of Fronteira Sul, composed of 24 rootstocks for peach trees, asexually propagated and grafted with the BRS-Libra canopy cultivar, counting on the autoratified treatment of the canopy itself, totaling 25 treatments. The spacing used is 5x2 m and the conduction system used is in the form of ipsilon. The experimental design was a randomized block design, with 4 replicates and 25 treatments, with each replicate being constituted by one plant. The work was divided into two chapters. In the first chapter the vegetative, phenological and reproductive variables were evaluated. In the second chapter the nutritional behavior, gas exchange index and xylem water potential were evaluated. The rootstocks Flordaguard, Mexico Fila 1, De Guia, I-67-52-4, Autoenraizado, Nemared, G x N.9 presented higher crown volume. Vigorous plants showed greater need for pruning intervention. The rootstocks Flordaguard, Rosaflor and BRS-Libra Autoenraizado, produced fruits with lower average mass, but consequently in greater number per plant, with higher estimated average productivity. The lowest yields were found in the Santa Rosa, Rigitano and P. Mandshurica rootstocks. The rootstocks significantly influenced the xylem flow in the first and last collection. The second collection had no significant difference between the rootstocks with a mean of -0.82 MPa. For the variable green mass of the leaf the first collection, obtained an average of 10.95 g and in the second average collection of 16.90 g. The third sample did not differ significantly with a mean of 13.02 g. The rootstocks, Mexico Fila 1, Tsukuba-2, Tsukuba-3, GF 677 have the highest photosynthetic rates. The foliar chemical analyzes showed significant differences between the rootstocks tested only for P, Ca and Mg in the three collections evaluated.