engleski

European corn borer (Lepidoptera : pyralidae) tunneling os corn hybrides

Selection of OS corn hybrids has tradition of more than 120 years. Many valuable material has create and today is sown on vide areas in Croatia. European Corn Borer (Ostrinia nubilalis Hübner) is one of the major pests of corn. The aim of this study was to evaluate the tolerance of some OS hybrids against this pest. Field trials were conducted during three years (1999-2001) on two localities. Five OS corn hybrids were evaluated: OSSK 247 ; OSSK 332 ; OSSK 444 ; OSSK 552 and OSSK 644. Dissection of corn stalk was done during harvest period. Intensity of attack of ECB (%) was determined, as well as position and length of damage (cm/plant), and grain yield (t/ha). Average intensity of attack caused by ECB during three years of investigation was 34, 2%. The lowest attack intensity were determined in 2000 with the average of 9, 6%, and the greatest was in 2001 with the average value of 60, 9%. Length of damages on corn stalk was least in 2000 when average damage was 0, 48 cm/plant, while in 2001 year, 5, 46 cm/plant were damaged. In 1999 when attack intensity was 34, 2%, the length of damage on the stalk was 0, 95 cm/plant. The greatest length of damage on hybrids were recorded in 2001, when hybrid OSSK 444 has damage of 16, 62 cm/plant, OSSK 552 has 13, 54 cm/plant, and OSSK 644 has 10, 68 cm/plant, and the attack intensity was in the same time over 90% in those hybrids. Three years trials showed that if attack intensity was under 40%, the greatest length of damage on corn stalk was in average 1, 58 cm. If the intensity of attack was over 50%, the average length of damage on the corn stalk was 5, 78 cm/plant. Significant positive correlation occurred between intensity of attack and length of damage (r=0, 80-0, 99). All hybrids used in this trials showed tolerance to ECB and reached satisfying results.

corn ; ECB ; intensity of atack ; damage on corn stalk

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