INFESTAÇÃO DO MILHO NO CAMPO PELO COMPLEXO DE PRAGAS DA ESPIGA

Resumo

Através do exame das espigas colhidas das 26 variedades do Ensaio Nacional do Milho, safra 1970/71, procurou-se determinar a porcentagem de ataques da lagarta da espiga, da traça dos cereais, do caruncho do milho e da broca da cana, e a intensidade de dano por espiga, da lagarta da espiga e da traça dos cereais, em condições naturais de infestação de campo. Verificou-se grande variação do gemoplasma em relação ao ataque destas pragas, sendo que a variedade Phoenix- 76 sofreu a maior porcentagem de ataque da lagarta da espiga e as menores porcentagens de ataque da traça dos cereais, de broca da cana e do caruncho do milho. Abstract Natural field infestation in the ear by corn insect pests. In the ears of 26 varieties of com it was deterrnined the percentage attack d the corn earworm, of the angoumois grain moth, of the rnaize weevil and of the sugar-cane borer under natural field infestation. The attack intensity of the corn earworm and of the angoumois grain moth was also studied. There were great germplasm variation regarding the attack of these insects. The Phoenix-76 variety showed the greatest percentage of com earworm attack and the smallest percentages of attack of the other pests. It was verified in some varieties high percentage of attack of corn earworm or angoumois grain moth with little ear damage.