effect of the brown midrib-3 gene on the maturity and yield of forage maize

Results from two trials with normal and brown midrib‐3 (bm3) types of LG11, Inra 188, Inra 240 and Inra 258 showed the bm3 mutant gene delayed silking by an average of 3 days, decreased whole plant dry matter (DM) concentration by 20 g kg−1 and the proportion of ear by 4·6 percentage units. Comparable yields of DM were obtained from normal and bm3 crops. The organic matter digestibility and yield of digestible organic matter of the bm3 plants was 0.06 units and 14% higher respectively than their normal counterparts. Measurement of the physical strength and resistance to lodging of normal and bm3 plants showed the bm3 gene reduced stem strength, which was highly correlated to stem diameter, stem weight and rind thickness. However, the major difference in plant lodging was between genotypes with Inra 240 plants less resistant to lodging than other genotypes. These results show that although the bm3 gene slightly increased lodging, genotype susceptibility is the major contributing factor to plant lodging.