PLANT MORPHOGENESIS FOR SCIENTIFIC MANAGEMENT OF RANGE RESOURCES 



97 



many years. Also, we have known that heavy 

 grazing in the fall is beneficial to plants and im- 

 proves range condition (9). Therefore, grazing 

 should begin at about the time of head exsertion 

 and may be continued through late summer and 

 late fall. 



Appropriate seasons of grazing for big blue- 

 grass, crested wheatgrass, and bluebunch wheat- 

 grass can be integrated in a pasturing sequence 

 as illustrated in fig. 3. 



Some grasses are better adapted to a specific 

 season of grazing or to periodic harvest, but some 

 are well adapted to season-long grazing. A good 

 example is blue grama, which has culmless vege- 

 tative shoots and a very small percentage of 

 shoots becoming reproductive in natural stands. 

 On the shortgrass plains of Colorado where this 

 grass is dominant, season-long or year-long graz- 

 ing is a good practice that need not prevent addi- 

 tional fencing and development of livestock 

 water. Since correct stocking rates and the 

 amount of herbage needed to sustain plant 

 growth and nourish livestock have been defined 

 (#), we should not be anxious to recommend 

 complex systems of rotation grazing just because 

 they have been good in other areas. 



Literature Cited 



(1) Ayuko, L. J. 



1968. THE DEVELOPMENTAL MORPHOLOGY OF SIDEOATS 

 GRAMA AND SWITCHGRASS IN NORTHEASTERN 



Colorado. Thesis. Colo. State Univ., Fort Col- 

 lins. 74 pp. 



(2) Bement, R. E. 



1969. A STOCKING-RATE guide for beef production 

 on blue-grama range. .7. Range Mangt. 22 : 

 83-86. 



(3) I). F. Hervey, A. C. Eversox, and L. O. 



Hylton, Jr. 



1961. use of asphalt-emulsion mulches to hasten 

 grass-seedling establishment. J. Range 

 Mangt. 14: 102-109. 



(4) Boyd, L., and G. S. Avery, Jr. 



1936. grass seedling anatomy : the first inter- 

 node of avena and triticum. Bot. Gaz. 97 : 

 765-779. 



(5) Branson, Farrel A. 



1953. two new factors affecting resistance of 

 grasses to grazing. J. Range Mangt. 6: 165- 

 171. 



(6) 



1956. quantitative effects of clipping treatments 

 on five range grasses. J. Range Mangt. 9 : 

 86-88. 



(7) Cook, C. AV.. and L. A. Stoddart. 



1953. some growth responses of crested wheat- 

 grass following herbage removal. J. Range 

 Mangt. 6: 267-270. 



(8) Cooper, J. P. 



1954. studies on growth and development in lo- 

 LIUM. IV. genetic control of heading re- 

 sponses in local populations. Ecol. 42 : 521- 

 556. 



(9) Craddock. G. W., and C. L. Forsling. 



1938. the influence of climate and grazing on 

 spring-fall sheep range IN SOUTHERN IDAHO. 

 U.S. Dept. Agr. Tech. Bull. 600. 



(10) Da vies, I. 



1969. THE INFLUENCE of management on tiller 

 DEVELOPMENT AND HERBAGE GROWTH. Tech. 



Bull. No. 3. Welsh Plant Breeding Sta.. 

 Aberystwyth, Great Britain. 



SPECIES 



SEASON 



OF GRAZING 









BIG BLUEGRASS 

 CRESTED WHEATGRASS 



TWO CROPS 



ONE CROP 

 BLUEBUNCH WHEATGRASS 



_j; 







_» 





■Hi 



















APRIL 



MAY 



JUNE 



JULY 



AUG. 



FALL 



Figure 3. — Appropriate seasons of grazing for big bluegrass, crested wheatgrass, and bluebunch wheatgrass. 



