Components of Plant Height in Different Height Groups of Bread Wheat

Genetic variation for components of height in different height group varieties are reported. There were significant differences for all internodes, except the basal first, within tall, single (d₁) and double (d₂) semidwarfs, and for only two uppermost internodes (6th & 7th) in the triple (d₃) semidwarfs. The fifth internode did not show any significant differences in all the four height groups. However, between different height groups, the differences were significant for the 5th internode also. The number of internodes was usually six in tall, single and double semi-dwarf varieties and five in triple semidwarf varieties. The results suggested that the most lodging resistant genotype could be the one with greatly expanded upper two internodes and condensed lower four internodes.