Discussion 



This study demonstrates how effectively competition re- 

 stricts growth of Idaho fescue. A partial removal of competi- 

 tion stimulates a substantial increase in herbage volume; elim- 

 ination of competition permits a very great increase in vol- 

 ume. However, only a partial reduction in competition is 

 almost as effective as complete elimination for increasing 

 flower stalk production since both treatments nearly quadru- 

 pled the number of flower stalks. 



Leaf and flower stalk lengths appear to be relatively rigid 

 characteristics of Idaho fescue. Neither changed when plant 

 vigor was increased by reducing competition. Apparently, un- 

 der a normal climatic regimen, healthy Idaho fescue plants 

 achieve their potential height growth even under the stress of 

 full competition from associated vegetation. 



Although heavy clipping is very detrimental to herbage 

 production, it is even more harmful to flower stalk produc- 

 tion. Leaf and flower stalk lengths are also reduced by heavy 

 clipping, but these changes are relatively small compared to 

 changes in herbage volume and flower stalk numbers. Since 

 the number of flower stalks also increases most readily fol- 

 lowing reductions in competition, this characteristic is appar- 

 ently a better indicator of Idaho fescue vigor than either leaf 

 length, flower stalk length, or herbage volume. 



The detrimental effects of clipping on Idaho fescue be- 

 come progressively less as competition decreases. For exam- 

 ple, extreme clipping reduced herbage volume the following 

 year about 85 percent under full competition, 65 percent 

 under partial competition, and 45 percent under no competi- 

 tion. Elimination of competition completely offsets the ef- 



9 



