细化搜索
结果 1-4 的 4
Effect of clipping small grains on composition and yield of forage and grain 全文
1949
Hubbard, V.C. | Harper, H.J.
Twenty-four varieties of rye, barley, wheat, and oats, fall and spring sown, were moderately and severely clipped at intervals during the fall, winter, and spring of one to six years to determine forage production, chemical composition at various stages of growth, and effect of clipping on grain production. Severe clipping on the average produced slightly less forage and appreciably lower grain yields than moderate clipping. Moderate clipping to March 15 normally resulted in as high or higher grain yields were obtained from nonclipped checks. To avoid a reduction in grain yield clipping or grazing should be continued when dissection of the stem reveals developing spike at a height at which it may be lost by clipping or grazing. Cereals were not affected so adversely by severe clipping in favorable as in unfavorable growing seasons. Winter oat and winter barley varieties did not tolerate clipping so well as rye or most of the wheat varieties tested. Recommended winter wheat varieties commonly grown in Oklahoma and Texas, moderately clipped until March 5 and 15, produced average yields of approximately 0.75 to 1.75 tons of green forage per acre. Small grain clippings harvested in 1942-43 and 1943-44 were analyzed for nitrogen, phosphorus, calcium. The nitrogen content of rye and Cheyenne wheat was reduced by drought in the spring of 1943. Drought and cold weather reduced the phosphorus content of all small grain clippings in February 1943 and November 1943. The phosphorus content of rye clippings was 100% higher during the moist spring 1944 than in the dry spring of 1943. The calcium content of small grain clippings was not affected by variations in the moisture content of this soil. Small grain forage from plots severely clipped had a chemical composition similar to that from moderately clipped plots.
显示更多 [+] 显示较少 [-]The vitamin content of small grain and annual ryegrass clippings 全文
1949
Moyer, F. | Davis, V.E. | MacVicar, R. | Staten, H.W. | Heller, V.G.
Five common cereal grasses (Michigan Winter barley, Wintok oats, Balbo rye, Tenmarq wheat, Clarkan wheat) and annual ryegrass were clipped throughout the fall and winter growing season to simulate grazing and the clippings analyzed for carotene, riboflavin, pantothenic acid, nicotinic acid and thiamine. Significant differences in the concentration of all of these components were found in samples collected at different times. In general, differences between cereals were not statistically significant, although in one year significant differences in pantothenic acid content were disclosed. These cereal grasses contain appreciable amounts of carotene, riboflavin, nicotinic acid, and thiamine and a lesser amount of pantothenic acid. The vitamin content for all varieties for all season was as follows: carotene, 578; riboflavin, 28; nicotinic acid, 53; pantothenic acid, 19; and thiamine, 12 micrograms per gram of fresh tissue on a dry weight basis. Drying at 65 degrees C resulted in a significant loss in riboflavin content, no change in nicotinic acid content, and an apparent increase in pantothenic acid content.
显示更多 [+] 显示较少 [-]The effect of clipping to simulate pasturing winter wheat on the growth, yield, and quality of the crop 全文
1949
Cutler, G.H. | Pavez S, D. | Mulvey, R.R.
1. Clipping treatments to simulate pasturing winter wheat were carried out in the spring of 1945 on Brookston silty clay loam of rather high fertility, and in the spring of 1946 on Crosby silt loam of relatively low fertility. 2. On the Brookston soil, under very favorable temperature and rainfall conditions in March and April, the clipping treatments covering the period of April 1 to April 20 significantly increased the yield and quality of the grain; clipping treatments after this date greatly reduced the yield. 3. On the Crosby silt loam soil, under very favorable temperatures and rain fall in March but with less favorable weather conditions in April, all clipping treatments were followed by significantly reduced yields when compared with no treatment. 4. Reduction in plant height is directly correlated with delayed clipping. 5. Reduction in plant height in the clipped plant due to the reduction in length of the lower internodes. 6. The reduction in plant height combined with shortness of the lower internodes is closely related to lodging resistance. 7. The low lodging percentages are associated with an improved test weight and size of grain. 8. The maturity of the winter wheat crop (Fairfield) was delayed from no days to 5 days depending on date and number of clippings. 9. The clipping treatments with 29 to 31 days in the fruiting period yielded more than those with 24 to 27 days in the fruiting period. 10. From these rather limited data, it seems fair to conclude that when the weather conditions in Indiana in early spring (March and April) are very favorable and a rapid growth of plants is stimulated, clipping or pasturing in April may reduce plant height and increase lodging resistance.
显示更多 [+] 显示较少 [-]Messa a punto della priorità nella scoperta delle applicazioni nitriche in inverno ai frumenti | Placing a priority on open air applications of nitric on winter wheat
1949
Pasquinucci, Giovanni