Journal of Range Management, Volume 41, Number 1 (January 1988)
http://hdl.handle.net/10150/635567
2024-03-28T17:59:25ZJournal of Range Management, Volume 41, Number 1 (January 1988)
http://hdl.handle.net/10150/650508
Journal of Range Management, Volume 41, Number 1 (January 1988)
Complete digitized issue.
1988-01-01T00:00:00ZThe effect of clipping on the growth and miserotoxin content of Columbia milkvetch
http://hdl.handle.net/10150/645253
The effect of clipping on the growth and miserotoxin content of Columbia milkvetch
Majak, W.; Quinton, D. A.; Douwes, H. E.; Hall, J. W.; Muir, A. D.
The growth and miserotoxin content of Columbia milkvetch (Astragalus miser Dougl. var. serotinus (Gray) Barneby) were examined in clipping trials at 2 rangeland sites in southern British Columbia during 1984 and 1986. Growth was determined by measuring the freeze-dried weight of each plant and miserotoxin levels were estimated by a rapid screening method that simplified sample preparation for spectrophotometric determination. In both years and at both sites, growth and toxicity were substantially reduced in response to early clipping in the spring. In comparison to untreated plants, the aboveground biomass of clipped plants was reduced by at least 50% during a 6-wk period of regrowth. A similar reduction was also observed in the miserotoxin content of clipped plants. The results indicate that early grazing may reduce the potential hazard of timber milkvetch to livestock.
1988-01-01T00:00:00ZTemperature requirements for mountain rye, Hycrest crested wheatgrass, and downy brome germination
http://hdl.handle.net/10150/645251
Temperature requirements for mountain rye, Hycrest crested wheatgrass, and downy brome germination
Buman, R. A.; Abernethy, R. H.
In this study we determined that mountain rye (Secale montanum), crested wheatgrass (Agropyron cristatum × desertorum 'Hycrest'), and downy brome (Bromus tectorum) have similar germination temperature requirements and thus have the potential to germinate under similar soil temperature regimes, a feature which could be advantageous for subsequent seedling competition of mountain rye or crested wheatgrass against downy brome. Germination temperature profiles were compared using a thermogradient germination plate. Fifty-six different day/night temperature regimes were utilized for the comparisons. The bivariate spline model was found to be the best model for predicting germination-temperature response of the 3 species. Mountain rye and downy brome produced high germination under widely fluctuating (20-30 degrees C, 16 hr day/5-10 degrees C, 8 hr night) temperature regimes with crested wheatgrass demonstrating an optimum germination temperature over a 10-20 degrees C day/25 degrees C night regime. One of the 2 downy brome sources evaluated exhibited a much broader optimum germination temperature range. However, the differences in germination temperature profiles obtained were not of a magnitude likely to be biologically or ecologically significant due to the relatively high germination obtained over a wide range of fluctuating day/night temperatures for all 3 species.
1988-01-01T00:00:00ZTechnical Notes: Secar bluebunch wheatgrass as a competitor to medusahead
http://hdl.handle.net/10150/645249
Technical Notes: Secar bluebunch wheatgrass as a competitor to medusahead
Goebel, C. J.; Tazi, M.; Harris, G. A.
A search continues for native perennial range grasses which will compete successfully with introducted annual grasses. Secar blue-bunch wheatgrass (Agropyron spicatum) is a recently released cultivar selected for seedling vigor. Medusahead (Taeniatherum asperum) seeds germinated in about one third the time, were less inhibited by cold temperatures typical of range conditions, and seedlings grew more than twice as fast as Secar in a 30-day trial. Indications are that even this new cultivar will not compete successfully with vigorous medusahead seedlings without initial weed control.
1988-01-01T00:00:00Z