02071naa a2200157 a 450000100080000000500110000800800410001910000110006024500920007126000090016352015670017265300170173965300160175665300130177277301280178510786742011-07-22       2000    bl uuuu     u00u1 u    #d1 aEpagri  aDamage evaluation of Helicoverpa zea on three corn hybrids in different planting times.  c2000  aThe corn earworm Helicoverpa zea (Lepidoptera: Noctuidae), is reported as one of the main pest on corn crop. The occurence is restricted to the last period of corn crop's development with technological difficulties in controlling the pest, even using chemical products. This study evaluated the number of damaged plants in three commercial hybrid corn, in nine different planting times in 1997/98. The experiment was conducted in the Research Center of Experimental Station for Small Properties - Epagri, located in Chapec??-SC, Brazil. Plants were arranged in a randomised block desing with nine treatments (planting times) and four replicates. The block areas were 27 m2 with 0,90 cm between lines and a population of 55.000 plants/ha. The corn hybrids evaluated were: Agroceres 1051 (normal cycle), Cargill 901 (super precocious) and Pionner 3099 (precocious). The evaluation was conducted on the harvest, by counting the number of damaged spike. The results showed that there were significant statistical differences between the percentage of damaged plants and the different planting times for hybrid Agroceres 1051 and Cargill 90. Rates of the damaged spike for Cargill 90, Agroceres 1051 and Pionner 3099 was 17%, 11% and 10%, respectively. The lowest number of damaged spike, for the three hybrid studied, was observed in the first planting time, in August. In the result analysis, the hybrids did not differ significantly with respect to earworm damage, although it was verified that Pionner 3099 was less damaged, while Cargill 90 was the most damaged.  acorn earworm  ahybrid corn  aZea mays  tIn: INTERNATIONAL CONGRESS OF ENTOMOLOGY, 21., 2000, Foz do Igua??u, PR. Abstracts... Foz do Igua??u, PR: SEB, 2000. p. 73.