ENVIRONMENTAL CONTROL OF CLEISTOGAMY IN PRAIRIE GRASS (BROMUS UNIOLOIDES H.B.K.)

From herkogamy to cleistogamy--development of cleistogamy in periwinkle.

Periwinkle (Catharanthus roseus [L.] G. Don), an important medicinal plant, is an allogamous species in which the stigma is below the anthers. The receptive portion is at the base of the stigmatic head and thus automatic intra-flower self-pollination is excluded. The structure of the flower is of typical reverse herkogamy and pollination occurs through nectar-seeking insects. A few self-pollina...

Photoinhibition of germination in grass seed--implications for prairie revegetation.

Germination photoinhibition is not a recognized cause of revegetation failure; yet prolonged sunlight exposure can inhibit germination of several grass species. This research addressed susceptibility to photoinhibition of selected native grass species used to restore Canadian prairies, and reclamation treatments to alter environmental conditions in order to release seeds from photoinhibition. U...

Grass architecture: genetic and environmental control of branching.

Variation in grass architecture profoundly affects light capture, competition, and reproductive success, and is responsive to environmental factors such as crowding and nutrient limitation. Recent work in both model and crop systems has uncovered many aspects of the genetic control of branching, including conservation of the MONOCULM1 and MORE AXILLARY BRANCHING/DECREASED APICAL DOMINANCE/RAMOS...

Predicting Nitrogen Content in the Northern Mixed-Grass Prairie

Forage quality and quantity are important factors affecting livestock production from grazing lands. ‘‘Greenness’’ has been proposed as an indicator of herbage quality in semiarid environments, particularly nitrogen (N) content. The objective of this study was to assess the potential of estimating N content of forage using dead:green ratios and accumulated growing-degreedays (AGDD). Standing cr...

Competition of Western Wheat Grass with Relict Vegetation of Prairie