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Growing barley for malt and feed 全文
1943
Harlan, Harry V. (Harry Vaughn) | Wiebe, G. A. (Gustav A)
The nutritive value of Korean Lespedeza proteins and the determination of biological values of proteins for growing dairy heifers
1943
Swanson, Eric W. (Eric Wallace) | Herman, Harry August
A new scientific method of studying the growing season for farm and truck crops grown in the United States
1943
McColm, George L.
All out for safeguarded profits convoyed to you ... over 30 years' experience in breeding and growing better tomato seed excelsior! 全文
1943
Effect of irrigation treatments on stem rot severity, plant development, yield, and quality of rice
1943
Cralley, E.M. | Adair, C.R.
Experiments were conducted to study the effect of irrigation, treatments on the severity of stem rot, tillering, plant height, yield, and milling quality of rice. Stem rot severity was slightly reduced by withholding water from experimental plots for certain periods prior to harvest and by alternate draining and submergence during the latter part of the growing season. The average yields, however, were somewhat higher from plots irrigated normally; that is, submerged continuously during the latter part of the growing season. The data indicate that early draining, when practiced in fields lightly infested with stem rot, does not increase the yields of rice. Various draining treatment when compared with the normal irrigation practice failed to increase plant height, tillering, weight of panicle, or yield, nor did they improve the milling quality of the rice.
显示更多 [+] 显示较少 [-]Response of geographical strains of grasses to low temperatures
1943
Rogler, G.A.
The purpose of this study was to obtain information on the resistance to low temperature of seedlings and mature plants of geographical strains of grasses. Agropyron cristatum, A. smithii, and Bromus inermis are classified as cool temperature species because they make their maximum vegetative growth in the cool period of the growing season. Bouteloua gracilis, B. curtipendula, Andropogon furcatus, and Panicum virgatum are classified as warm temperature species because they make their maximum vegetative growth during the warmest period of the growing season. Strains of the warm temperature species from the same general geographic origin react similarly to the winter climate at Mandan, N. Dak. The average field survival of these species decreases as their origin becomes more southerly. There has been no injury to the cool temperature species in the field regardless of origin. There is a definite tendency for seedlings of warm temperature species of northern origin to survive in greater proportion after artificial freezing than those of more southern origin. With cool temperature species the only significant differences were obtained with A. smithii. Seedlings of this species from the south were less resistant to cold temperatures than those from the north. Under all treatments the A. cristatum seedlings gave higher survival than those of A. smithii and seedlings of A. smithii gave higher survival than those of B. inermis.
显示更多 [+] 显示较少 [-]Chlorotic dieback of flax grown on calcareous soils
1943
Flor, H.H.
Chlorotic dieback, a nonparasitic disease of flax, is associated with certain unproductive soil areas in the Red River Valley of North Dakota. When flax is grown experimentally in soils representing successively deeper soil layers, the disease is least severe in surface soil and increases in severity for each successively lower horizon. Chemical tests of soil from an unproductive area, as well as the growth of flax in such soils that had been steamed, or leached, failed to indicate the presence of a toxic substance. Flax grown in unproductive soils to which mineral amendments had been added responded favorably to the addition of phosphate. The chlorotic phase of the disease was more pronounced in the wetter soils, but plants grown in both wet and dry soils were stunted and showed symptoms of leaf necrosis and stem dieback. The disease symptoms were most severe at low soil temperatures and showed progressive diminution in intensity with rise in soil temperature ranging from 12 degrees to 25 degrees C. Flax growing in unproductive soil responded more favorably to increases in soil temperature than did that growing in productive soil. Applications of phosphate to the Bearden silt loam corrected its unproductiveness and the chlorotic dieback symptoms. Similar applications to the Fargo clay soil were only partially corrective. It is suggested that the flax trouble at low soil temperatures is caused, at least in part, by deficiency or unavailability of essential minerals, especially phosphate, in the highly calcareous alkaline soil.
显示更多 [+] 显示较少 [-]Effect of boron deficiency on the soluble nitrogen and carbohydrate content of alfalfa
1943
Scripture, P.N. | McHargue, J.S.
1. Alfalfa was grown in purified sand culture in the greenhouse under conditions where boron was deficient. Extracts of the plant tissue were obtained by means of a press and analyzed for nitrogeneous constituents and reducing sugars. 2. Soluble nitrogen compounds, including amides, ammonia, and nitrogen in other forms, were found to be present in larger proportions in the boron-deficient plants than in those growing normally. 3. Sugars were found to be present in excess in the boron-deficient plants. 4. The possibility that boron may be involved in protein metabolism is suggested.
显示更多 [+] 显示较少 [-]Effect of fertilization of a crowley clay loam on the chemical composition of forage and carpet grass, Axonopus affinis
1943
Fraps, G.S. | Fudge, J.F. | Reynolds, E.B.
Protein, phosphoric acid, and lime were determined in total forage and carpet grass clipped at monthly intervals through two growing seasons in 1938 and 1939 from plots of a Crowley clay loam at Beaumont, Texas, which had received six different fertilizer treatments with and without lime. Unfertilized carpet grass and forage were often deficient in phosphoric acid, less frequently in protein, and not at all in lime. Sodium nitrate produced a significant increase in yield but did not affect the chemical composition of total forage or carpet grass. Ammonium sulfate alone increased the yield of forage to some extent but had little effect on chemical composition. Muriate of potash had no effect upon either the yield or chemical composition. Superphosphate greatly increased the yield and the protein, phosphoric acid, and lime content of total forage and of carpet grass. It decreased the number of samples which were deficient in phosphoric acid for animal production. Lime alone increased yield of forage 45 to 53%. It also increased the protein, phosphoric acid, and lime in the total forage and in carpet grass. Variations in yield and chemical composition were much greater with different dates than with different fertilizer treatments. Protein and lime decreased from early spring until July and increased from then until late fall. Phosphoric acid was high in the early spring samples and then fairly constant throughout the remainder of the growing season. Rainfall in 1939 was sufficiently lower than that in 1938 to cause a large reduction in yield, but the difference in rainfall did not significantly affect the chemical composition of forage or carpet grass.
显示更多 [+] 显示较少 [-]Response of soybeans to experimental defoliation
1943
Gibson, R.M. | Lovvorn, R.L. | Smith, B.W.
The reaction of Biloxi and Tokyo soybeans to light, medium, and severe defoliation treatments at 10-, 20-, and 30-day intervals was studied during the 1940 growing season on a Congaree sandy loam soil. The results of this single trial may be briefly summarized as follows: 1. There was a highly significant interaction between the degree and frequency of defoliation. 2. Complete defoliation at any frequency was too severe for satisfactory growth. 3. Medium defoliation treatments resulted in significantly higher leaf yields than the light or severe treatments. 4. The leaf yields of the two varieties did not differ significantly. Tokyo leaf yields were less affected by varying degrees and frequencies of defoliation than those of Biloxi. 5. Weights of stems and roots were inversely related to severity of defoliation treatments. 6. Any degree of defoliation resulted in a decrease in the weight of seed produced. Yields tended to be inversely related to the severity of the defoliation. 7. Defoliation treatments caused greater reductions in seed yields of Tokyo than of Biloxi, but Tokyo produced more beans under all treatments.
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