Browsing Journal of Range Management, Volume 24, Number 2 (March 1971) by Submit Date
Now showing items 21-23 of 23
Correlation of Weather and Fuel Variables to Mesquite Damage by FireTwenty-four 10-acre plots were burned in the Southern Mixed Prairie of Texas under a variety of weather and fuel conditions to determine their effect on ignition, burndown, and mortality of mesquite that had been top-killed by spraying. The number of trees that ignited on each plot varied from 33.6 to 94.9% of the total, whereas the number of trees that burned down varied from 14.4 to 89.1%. Mortality varied from 0 to 24%. Large trees were easier to burn down and kill than small trees. Equations that incorporate wind speed, relative humidity, and total fuel were developed to predict ignition and burndown.
Control of Larkspur with Herbicides Plus Nitrogen FertilizerPast attempts using herbicides to control larkspur (Delphinium barbeyi), one of the most serious poisonous plant problems to cattle in the Western United States, have been less than satisfactory. Preliminary research reported herein suggests that 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) plus ammonium sulfate placed around the base of the plant or urea and 2,4,5-T sprayed on the plant may give good control of larkspur with a single treatment during any stage of growth. Some results also indicate that nitrogen fertilizer alone may be an effective control for larkspur.
Botanical and Chemical Composition of Esophageal and Rumen Fistula Samples of SheepBifistulated wethers (esophageal and rumen) were used to collect samples of the diet while grazing shortgrass native range. Rumen samples were obtained by grab sampling rumen contents. The rumens were not evacuated prior to sampling. The esophageal and rumen grab samples were different botanically. There were fewer forbs and more grasses found in rumen samples. The nitrogen content of rumen samples was higher than that of esophageal samples. Rumen samples were lower in in vitro dry matter digestibility than esophageal samples. Rumen grab samples cannot be expected to yield quantitative botanical information on grazing animals diet or on nitrogen content and dry matter digestibility.