Hibridação artificial e desempenho agronômico de guandu forrageiro nas condições edafoclimáticas do Cariri - PB

Abstract

The present work had as objectives, to verify if there is genetic variability in a collection of pigeonpea for traits of importance in forage production, as well as to estimate genetic parameters; to determine if there is a better time/period of the day to carry out artificial crossings in pigeonpea for forage purposes, as well as to verify the existence of the effect of environmental factors such as temperature (°C) and relative humidity (%) on the efficiency of the fertilization. The work was carried out in the field and in a greenhouse, belonging to the Center for Sustainable Development of the Semi-Arid, at the Federal University of Campina Grande in Sumé-PB. For the evaluation of the forage potential of pigeonpea genotypes, 22 genotypes belonging to Embrapa Caprinos e Ovinos, Sobral/CE, were evaluated: FLVMH, FLCRM, FGCVIF, FGEXP, 99FG41, 98FG38, 97FG36, 96FG34, 94FG30, 93FG18, 92FG27 , 91FG21, 82FG09, 66FG103, 65FG102, 28FG25, 18FG19, 102FG52, 101FG50, 100FG42, 07FG08 and the commercial cultivar BRS Mandarin. The characters evaluated to express the forage potential of the genotypes were: plant height (ALT) (m); estimates for fresh mass forage productivity (PRODF) (kg ha-1); dry mass forage productivity (PRODMS) (kg ha-1); yields of grains plus pods (PRODG+V) (kg ha-1) and for grain yields – PRODG (kg ha-1). There is great genetic variability among the pigeonpea genotypes in the evaluated collection for all studied characters. The coefficients of genetic variation (CVg) and heritability in the broad sense (ha2) indicate a favorable situation for selection of genotypes in all traits analyzed. Genotypes 18FG19, 94FG30 and BRS Mandarim showed the best phenotypic performances among the evaluated characters, combining low plant height with high productivity for the other characters. In determining the best period to carry out an artificial crossing in pigeon pea in the region of Cariri Paraibano, accession G-MO/03-18J, belonging to the germplasm bank of the Pigeon Pigeon Improvement Program of the CDSA/UFCG, was used to carry out the artificial crossings and accession 82FG09, belonging to Embrapa Caprinos e Ovinos, Sobral/CE. A total of 14 treatments were submitted to analysis of variance, where four are related to the times/periods of the day when artificial crossings were carried out and ten controls. There is no evidence that there is a better time/day shift to carry out artificial crossings in the pigeon pea breeding program for forage purposes. Effects of environmental factors, such as temperature and relative humidity, did not cause differences in fertilization resulting from artificial crossings carried out from 7:00 am to 8:00 am, from 9:00 am to 10:00 am, from 4:00 pm to 5:00 pm and from 6:00 pm to 7:00 pm, for the characters Weight of pods (g), Number of grains per pod and Weight of 5 grains.