Уточнить поиск
Результаты 1-5 из 5
The corn belt family farm in an industrial era
1944
Johnson, O. R. (OIiver Ray)
Duración del poder atrayente que sobre el Dacus oleae (Rossi) ejercen las soluciones del fosfato amónico Полный текст
1944
Gómez-Clemente, Federico | Bellod, Martín
Las experiencias que sobre este asunto iniciamos en el año 1944 (1) las hemos continuado en el 1945, procurando que se desarrollaran durante todos los meses en los que en esta región deben realizarse los trabajos de lucha contra el Dacus oleae por el procedimiento de los mosqueros de vidrio con soluciones de fosfato amónico, o sea desde primeros de julio a primeros de noviembre. Las realizadas el pasado año las comenzamos el 18 de agosto y no comprendieron, como es natural, la época de más calor, cuando la evaporación tanto del agua como de la sustancia volátil de la sal (amoníaco) es más rápida. También hemos determinado en estos ensayos el tiempo que tarda en evaporarse el líquido de los mosqueros.
Показать больше [+] Меньше [-]William A. Taylor memory book. Scrapbook journaling 1891-1933 1910-1933 Полный текст
1944
Taylor, William A. (William Alton)
The William A. Taylor Memory Book is a working copy of an album compiled by friends of Dr. William A. Taylor, former Chief of the U. S. Department of Agriculture's Bureau of Plant Industry (BPI), and presented to him in 1944. The memory book highlights the personnel and work of the Plant Industry Station in Beltsville, Maryland in the 1940s. It contains reminiscences, reproductions of congratulatory letters, and photographs. Robert L. Taylor (no relation to William A. Taylor) preserved this working copy. The finished book was presented to Dr. Taylor by Dr. J. R. Magness. It was an edited version of the working copy, containing fewer materials.
Показать больше [+] Меньше [-]Nutrient balance in corn growing in southern states as revealed by purdue plant tissue tests
1944
Drake, M.
A study of the nutrient status in corn plants grown on soil fertility plots of the Alabama, Georgia, and Mississippi agricultural experiment stations was made with the Purdue plant tissue test technic. This was an efort to determine whether a deficiency in nitrogen, or potash or a lack of nutrient balances, or some other factors might be the principal causes for the numerous low corn yields in the South. In general, a lack of nitrogen was found to be the major factor limiting the yields of corn as shown by the plant tissue tests and by harvested results. Unless winter legumes were well fertilized with phosphorus and potassium, nitrogen was available in such small quantities for the corn that followed the legume that the plants were deficient in nitrates by tasseling time. Corn plants growing on plots where large crops of vetch had been plowed under consistently tested high in nitrates to the roasting ear stage. The plant tests showed that the practice of growing corn without until about 40 days after planting generally resulted in nitrogen starvation during the early growth period. In cases where cotton or some other well-fertilized crop did not precede the corn crop, as on the Georgia river terrace soil, the corn plants tested very low in phosphates. In general, the plant tissue that the amounts of phosphorus and potassium were adequate in the plants to balance the limited supply of nitrogen. omparing the amount of nitrogen which needs to be added as to produce 1 bushel of corn in the southern states with that needed in Indiana, it was found that in both regions approximately pounds (+/- 0.5) of nitrogen are required to make a bushel of corn.
Показать больше [+] Меньше [-]Photographs of dairy farmers at the Graham School, 1944-1946 Полный текст
1944-1946
The Photographs of Dairy Farmers at the Graham School consists of two black-and-white formally posed photographs of large groups of dairy farmers attending courses conducted by the Graham School. The photographs are accompanied by numbered keys to the individuals pictured. The keys list names, addresses, names and locations of farms, and the chief breeds of cattle raised. The farmers pictured are chiefly from the United States Midwest and Ontario, Canada. One photograph is labeled "The Graham School, Toledo, 1946." One key is labeled "Graham School, Sherman Hotel, Chicago, Illinois 1944."
Показать больше [+] Меньше [-]