Evaluation location: Iowa, United States
The evaluations were done in Ames, Iowa. Ten plants per accession were infested with about 300 European corn borer neonates per plant (distributed over 6 nodes) after pollen shed began. After 60 days, plants were split lengthwise and total inches of larval tunneling per stalk was recorded. The average inches of tunneling was calculated for each accession and then was compared to the year's overall average inches of tunneling in B52 a resistant check. For purposes of reporting data to GRIN, we converted centimeters of tunneling as a percent of the B52 resistant check tunneling. Ratings of resistant (1-3) were assigned to accessions which had centimeters of tunneling less than or equal to B52 (<100%), ratings of intermediate (4-6) were assigned to accessions which equalled 100-199% of the check, and ratings of susceptible (7-9) were assigned to accessions which were greater than 200% of the check. In 1993, 200 accessions were planted in test W9307. 53 were not tested due to field flooding. B52 averaged 30 cm of tunnelling in 1993. An unusually large number of accessions tested resistant in 1993 and is probably due to poor weather for the European corn borer.