Demand-Driven Technologies for Sustainable Maize ... - IITA

266Figure 1. Profiles of colonizing responses of S. calamistis to different maizegenotypes, using S5 20-2 as a reference [H = High; M = Medium;L = Low; VL = Very low (ICIPE, 1990)].VH H M L VLFigure 2. Profiles of colonizing responses of S. calamistis to different maizegenotypes, using Tzmi 407 as a reference [VH = Very high; H =High; M = Medium; L = Low; VL = Very low (ICIPE, 1990)].ProfilesFigures 1 and 2 present the profi les developed by calculating the ratiosof the mean values of each type of response in a tested genotype tothose of the susceptible S5 20-2 and Tzmi 407, respectively. Greaternumbers of responses in the low grade indicate greater resistance ofa genotype to colonization by S. calamistis. Out of fi ve responses inthe low grade, S5 9-1 had four responses and S5 11-1 had three (Fig.1), which may account for their resistance. On the other hand, Tzmi407 had two responses in the high, and one in the medium grade,resulting in its susceptibility. Results presented in Figure 2 showedthat when Tzmi 407 was used as reference genotype, S5 9-1 had 3responses in the very low grade, while S5 11-1 had 4 responses in thelow grade, which would account for their high level of resistance.