Avaliações morfológicas e produtivas de genótipos de Desmanthus spp. sob diferentes intensidades de corte no semiárido pernambucano

Abstract

The knowledge and practice of cultivation of native forage plants, along with their growth information is crucial for obtaining forage in semiarid region. The objective was to evaluate the morphological characteristics and productivity of five genotypes of Desmanthus spp., Submitted to two cutting intensities (20 and 40 cm of soil) in Semi-arid of Pernambuco. The research was conducted Academic Unit of Serra Talhada, Federal Rural University of Pernambuco, during the year 2014. The treatments were randomized in blocks, distributed in a split plot design with three replications. The plots received the genotypes and the subplots cutting intensities. Genotypes were derived from collections made in three cities of Pernambuco: Caetés (7G), Santa Cruz do Capibaribe (31D) and Petrolina (50J). In addition, two other genotypes were coming from the state of Sergipe (10AU and 13AU). The plant spacing was 0.5 mx 0.5 m each parcel owned total area of 8.0 m². After 90 days of transplantation, we performed a uniformity cut. Three reviews were subsequently carried out at intervals of 60 days. Was evaluated plant height, number of leaves / branch, stem diameter and crown diameter, leaf area index and light interception. In these same intervals were harvested. The cut material was separated into fractions stem, leaf and pod, are dried and given the weight of total dry matter, leaves, pods and fodder, beyond the leaf / stem ratio and pod / stalk. Data were subjected to analysis of variance and means compared by Tukey test at 5% probability. The 7G and 31D genotypes were superior to others in terms forage production (stems + leaves), with averages of 1102.06 kg DM ha -1 and 867.23 kg DM ha-1, respectively. The cuts have significantly influenced the total dry weight of stems, pods and fodder of different genotypes. Forage production was higher in cuts to 20 cm. In the third cut production 50J genotype leaves, the intensity of 40 cm, significantly reduced compared to other cuts up to 20 cm. The leaf / stem ratio was affected by interaction between the cutting intensity and genotypes in which case the 13AU showed higher leaf / stem to 40 cm, higher than the average obtained in the cut to 20 cm. The 10AU genotype had the highest pod relations / stem the three cuts. The 7G and 31D genotype presented higher leaf / branch. The IAF and the light interception also had an effect of the cuts. These variables were significantly higher in the third cut. The differences presented by genotypes, especially the 7G and 31D indicate the chance to select promising materials for cultivation in semi-arid region of Pernambuco, with productive and morphological characteristics desirable fodder plants.