Morphological and physiological studies of prairie grass (Bromus willdenowii Kunth)

This thesis reports the results of seven indoor and outdoor studies on the growth of prairie grass( Bromus willdenowiiKunth) . In five studies comparisons were also made with ryegrass( Loliumspp.). Leaf and tiller production were quantified for undisturbed growth and growth under different cutting regimes. Water soluble carbohydrate reserves for regrowth were also determined. Particular attention was given to the effects of reproductive development on partitioning of biomass, tillering, herbage quality and yields. Field studies also investigated the effects of disease, plant populations, tillering, natural reseeding and frequency of defoliation.Compared to ryegrass, prairie grass had a high leaf appearance rate but low site filling, which resulted in low tiller numbers. Prairie grass had large tillers with long wide leaves, resulting in high herbage production. Plants were able to tiller profusely in the field to compensate for plant death. High reproductive development occurred in prairie grass which had large effects on yields, herbage quality and tillering. Vegetative and reproductive plants performed best under infrequent defoliation regimes.