Agriculture Commons^™

Extending Interval From Seventeen To Nineteen Days In The Melengestrol Acetate - Prostaglandin Estrous Synchronization Program For Heifers, G. H. Deutscher

West Central Research and Extension Center, North Platte

Two experiments were conducted to determine whether extending the interval between removal of melengestrol acetate (MGA) from feed and injection of prostaglandin F_2α (PGF) from 17 to 19 d would affect synchronization of estrus, conception, and pregnancy rates of beef heifers. In both experiments, heifers were fed MGA for 14 d, and PGF was given at either 17 or 19 d after cessation of MGA feeding. Heifers were observed for estrus and artificially inseminated for 5 d after PGF injection.

In Exp. 1, 240 yearling heifers were randomly assigned to either a 17- or a 19-d …

Apparent Thermal Conductivity Of Mulch Materials Exposed To Forced Convection, Simon Van Donk, Ernest W. Tollner

West Central Research and Extension Center, North Platte

Soil temperature controls plant growth and many related processes in the soil. A mulch or crop residue covering the soil may alter soil temperatures significantly. Available simulation models often lack experimental data for the mulch thermal conductivity and its dependence on air velocity. The apparent thermal conductivity (k) of wheat straw, pine straw, tire chips, dry sandy soil, and the thermal resistance of Bermudagrass sods were measured using a guarded hot plate at air velocities between 0 and 5 m/s. For all mulch materials, k ranged between 0.1 and 0.6 W m^–1 °C^–1, and increased …

Measurement And Modeling Of Heat Transfer Mechanisms In Mulch Materials, Simon Van Donk, Ernest W. Tollner

West Central Research and Extension Center, North Platte

Crop residues or mulches affect soil temperature influencing plant growth and related processes in the soil. A hot/cold plate combination was used to quantify heat transfer through several common dry test mulch materials (rubber chips, pine straw, wheat straw) and identify and quantify heat transfer mechanisms with the goal of modeling apparent thermal conductivity of the mulch. Mulch material bulk densities ranged from near 0 kg/m³ to 33 kg/m³ , mulch thickness ranged from 61 mm to 140 mm and test temperatures ranged from 20°C to 45°C. To determine the effect of thermal radiation on heat transfer, measurements …

‘Butterbowl’ Squash, A Novel, Flatshouldered Globe Butternut, Dermot P. Coyne, James M. Reiser, Durward Smith, Aly Ibrahim, Lisa Sutton, Dale T. Lindgren

West Central Research and Extension Center, North Platte

Butternut squash (Cucurbita moschata Duch. Ex Poir) is one of the most popular winter squashes grown in the United States. However, current consumers not only bake but also microwave squash. The flesh is much thinner at the bulb end of the fruit around the seed cavity than in the neck of the typical butternut squash so that the whole fruit does not cook uniformly during the microwave process. A smaller butternut type squash with a more uniform flesh thickness around most of the seed cavity would be expected to cook more uniformly in the microwave and would be useful …