Department of Plant Breeding, Punjab Agricultural University Ludhiana-141 004, Punjab (India).
Studies on the cumulative effect of anitbiosis in different maize varieties on the stalk borer, Chilo partellus (Swinhow), revealed that the maize borer multiplied by zero, 1.3, 1.3, 3.8 and 2.5 times of population at start, in the first generation on varieties Antigua Gr. 1, Ganga 5, Sangam, Ageti 76 and Basi local, respectively, in the first experiment initiated in the second week of August. It could not complete the second generation normally on any variety in this experiment due to hibernation period ahead. In the second experiment started in the end of May in next kharif season, this pest multiplied by 1.19, 1.38, 2.39, 2.41, 2.95 and 2.92 times the original population in the first generation, and by 0.31, 1.31, 1.62, 2.09, 2.50 and 3.41 times in the second generation on varieties Antigua Gr. 1,Ganga 5 (less suceptible) Sangam, Ageti 76, Partap (intermediate) and Bsi local (susceptible), respectively. The rate of population p of this pest, on thee six varieties over two generations was 0.37, 1.81, 3.87, 5.04, 7.38 and 9.96 times respectively, of the original population. In the successive third generation which approached hibernation, the of multiplication of maize borer was zero, 0.40, 0.65, 1.04 and 2.63 times on varieties Antigua Gr. 1, Ganga 5, Sangam, Ageti 76 and Basi local, respectively. The maize stalk borer multiplied by zero, 0.72, 2.52, 5.24 and 26.19 times the original population over three generations on these respective varieties. The antibiosis in these varieties did not seem to xhibit any additive effect on total developmental period of this pest. The findings suggest that Antigua Gr. 1 should be extensivly used in the breeding programme to develop maize varieties suitable for grain and fodder.
