Developmental Morphology of Blue Grama and Sand Bluestem

Abstract

The purpose of this investigation was to study the normal growth and development of blue grama and sand bluestem. Blue grama and sand bluestem exhibited contrasting forms of growth, regrowth, and perenniality. Blue grama had culmless vegetative shoots and 12% reproductive shoots. Sand bluestem had culmed vegetative shoots and 36% of the shoots became reproductive. Regrowth of blue grama from active shoot apices proceeded rapidly after cutting when soil moisture was adequate. Good productivity, however, depended greatly on essentially free expansion of the leaf blades of phytomers 3 through 6. Good leaf growth and early drying of lowermost leaves when not utilized made sand bluestem suitable for grazing in June, when prompt regrowth of leaves from apical meristems occurred. Close harvesting in early July stopped all active shoot expansion. After grazing sand bluestem in June, a rest period in July should allow good plant development under dry land conditions. With favorable soil moisture conditions in July a close harvest near mid-July stopped first crop growth and promoted development of new tillers and high productivity of second-crop herbage of sand bluestem in late summer and fall.