DA RESISTÊNCIA À LAGARTA DA ESPIGA, DA ESPESSURA DO PERICARPO E OUTRAS CARACTERÍSTICAS AGRONÔMICAS(1)

ABSTRACT GREEN CORN: EVALUATION OF EARWORM RESISTANCE, PERICARP THICKNESS AND OTHER AGRONOMIC CHARACTERS The varieties IAC Azteca Centenario, IAC Maya Latente, IAC-1 and IAC-VD 2 and the hybrid Cargill 742 and Agroceres 162 were evaluated for resistance to corn earworm, pericarp thickness and other agronomic charac­ters, in a trial planted at May 1987 in the Pariquera-Acu Experimental Station, State of Sao Paulo, Brazil. The earworm infestation was estimated by the revised Widstrom scale and the presence of caterpillar exit holes in the husk. The kernel pericarp was measured with a comparative watch, using kernels soaked in glicerol solution and dried kernels. The other agronomic characters studied were: final stand, plant and ear height husk percentage of the ear; number, yield, total weight and medium weight of commercial ears; grain weight; and resistance to Exserohilum turcicum (Pass.) Leonard and Suggs. Except for the IAC-VD 2, all varieties were less productive than the hybrids. In relation to E. turcicum, Cargill 742, IAC Maya Latente and IAC-VD 2 were resistant Agroceres 162 was intermediated; and IAC-1 and IAC Azteca Centenario were susceptible. Similar results were obtained with the evalu­ation methods to lhe earworm infestation - revised Widstrom scale and presence of caterpillar exit hole in the husk. IAC Azteca Centenario and IAC Maya Latente were respectively the less and the more damage by corn earworm. Pericarp thickness was higher in the kernel side, where the differ­ences among cultivars were also higher. Agroceres 162 and IAC Azteca Centenario had thicker pericarp.