Leaf and Stem Traits and Herbage Quality of Multifoliolate Alfalfa

Abstract

AbstractMultifoliolate (MF) alfalfa (Medicago sativa L.) cultivars, with four or more leaflets per leaf instead of three, have been marketed for greater nutritive value and intake potential than standard trifoliolate (TF) alfalfa cultivars. A field study to determine the effect of harvest regimes on MF expression of alfalfa cultivars and germplasm, and to determine the association of MF expression with herbage yield, herbage quality, and leaf and stem traits, was conducted on a Tallula silt loam (coarse‐silty, mixed, mesic Typic Hapludoll). Four MF and two TF alfalfa genotypes were subjected to bud and first‐flower cutting regimes. Multifoliate expression on a leaf number basis (MF leaf number/total leaf number) ranged from 5 to 70%. Relative MF entry ranking was consistent across years and harvest regimes. Expression of the MF trait was not correlated with herbage yield. For all seasonal harvests and harvest regimes, MF expression was correlated with leaf concentration (r = 0.48) and number of leaflets per leaf (r = 0.84), but was not consistently associated with node number or plant height. Expression was not correlated with total herbage crude protein concentration, and at best explained 25% of the variation in acid detergent and neutral detergent fiber concentration. A TF genotype developed for superior herbage quality had leaf concentration, forage quality, and intake potential similar to MF genotypes with high MF expression levels. Multifoliolate alfalfa genotypes have the potential to produce higher quality herbage than some TF types; however, this can be achieved only with high MF expression levels.