Selection among and within half-sib families in "Dentado Composto" maize variety for resistance to S. frugiperda and H. zea. ll cycle.

Abstract

The obtention of genetic parameters was studied for some characters of plant and ear of maize (Zea mays L.) cv. Composto Dentado. The material came from the second cicle of selection inter and intra families of half-sibs. Four hundred progenies were evaluated in a 10 x 10 simple lattice design, with one replicate for each place: Caruaru and São Bento do Una, PE, Brazil. The experiments did not receive phytosanitary treatments. They were isolated from the areas that received insecticide applications and lhe natural infestation was used. Data were colected for: plant height (PH), ear height (EH), number of ears per plant (NE), number of ear with loosed husk (NELH), S.frugiperda damage (SFD), H. Zea damage (HZD) and grain yield (GY). The variance analysis showed significance (P < 0.01) for all characters studied except for SFD. The estimate values for the additive genetic variance were high for PH, EH and GY and low for Lhe other characters. Considering the low values found for genetic variability concerning the characters HZ and SF, an environmental control more efficient ia the progenie evaluations is needed.