Trifon M. GEORGIEV
Retired Professor of Agronomy, University of Rousse, Rousse 7000, Bulgaria

High significant correlation have been established among grain yield, plant height, and ear height, but not significant correlation among grain yield, stalk diameter, and stalk wind thickness in hybrid maize breeding experiments on 248 single crosses.
No significant correlation have been established among erect stalk percentage at harvest season, and grain yield plant height, ear height, and stalk diameter. Significant positive correlation have been established only between erect plant percentage and wind thickness.
Experiments on IWGO maize inbred suggest equal corn borer damage on thick and thin rind inbred.
The thicker rind of maize stalk is not barrier, as expected, for penetration of Ostrinia larvae in stalks.
Rind thickness in our experiments is more important characteristic for stalk lodging resistance, compared to resistance to Corn Borer damage.