WOLF PLANT EFFECTS ON WATER RELATIONS, GROWTH AND PRODUCTIVITY IN CRESTED WHEATGRASS

When improperly managed in pastures, crested wheatgrass (Agropyron des ertorum (Fischer ex Link) Schultes) develops wolf plants because of th e long-term persistence of inflorescences. The objective of this study was to test the hypothesis that the wolf plants have no effect on the growth and water relations of grazed or subordinate plants in crested wheatgrass. Treatments applied to wolf plants included killing with g lyphosate, mowing to a 10-cm stubble, killing with glyphosate + mowing to a 10-cm stubble, and a control. Rates of vegetative and reproducti ve development, tiller and whole plant weights, tiller replacement and xylem water potentials of leaves were determined for subordinate plan ts for 2-3 yr following treatment. The presence of wolf plants had no consistent effect on the water relations or on growth of subordinate p lants of crested wheatgrass. Because they play no apparent beneficial role in the water status and productivity of crested wheatgrass, manag ement techniques should be implemented to exploit the forage produced by wolf plants. Accessing this forage can substantially increase the g razing capacity of crested wheatgrass pastures.