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Mineral content and yield of grasses in the wet tropics as influenced by seasonal productivity, frequency of cutting and species Full text
1946
Schofield, J.L.
The lime and phosphoric acid content of 19 grasses was determined under monthly, two-monthly and three-monthly cutting systems over periods of between one and two years. This paper is the third of a series dealing with investigations into the yield and chemical composition of pasture grasses conducted at the Bureau of Tropical Agriculture in coastal northern Queensland.
Show more [+] Less [-]Preliminary information on sweet lupines in the United States
1946
McKee, R. | Hyland, H.L. | Ritchey, G.E.
Selected strains of nonalkaloid blue, yellow, and white lupines have been included in experimental plantings in the United States. Good growth and yields have been attained with nonalkaloid selections of the yellow and blue species, but only comparatively low yields have been obtained with the white species. It has been determined that varieties cross within species so that it is necessary to keep nonalkaloid selections isolated from high-alkaloid plantings. The possible value of nonalkaloid lupines for livestock feed is suggested and experiments to determine their feeding value are being carried on by the Florida Agricultural Experiment Station. A quick method for determining the presence of alkaloid is described.
Show more [+] Less [-]Water exchange between insects ans Air Moisture Full text
1946
Govaerts, J. | Leclercq, Jean
peer reviewed | It is well known that the weight of some fasting insects increases when they are exposed to an atmosphere saturated with water vapour. This phenomenon is generally considered to be due to the absorption of moisture from the air, and the insects concerned, such as Leptino-tarsa1, Chortophaga2,3, Cimex4 and Tenebrio (larvæ)5 are often called 'hygroscopic'. The weight change is obviously influenced by a series of factors. In order to isolate the factor of 'hygroscopicity', we have kept the insects in air saturated with water vapour, the vapour being derived from water containing 8 percent of heavy water ; the vapour also contains 8 percent of heavy water. The concentration of heavy water in the insects was determined after various exposures to this vapour by the method of Linderstrom-Lang
Show more [+] Less [-]Water exchange between insects ans Air Moisture Full text
1946
Govaerts, J. | Leclercq, Jean
peer reviewed | It is well known that the weight of some fasting insects increases when they are exposed to an atmosphere saturated with water vapour. This phenomenon is generally considered to be due to the absorption of moisture from the air, and the insects concerned, such as Leptino-tarsa1, Chortophaga2,3, Cimex4 and Tenebrio (larvæ)5 are often called 'hygroscopic'. The weight change is obviously influenced by a series of factors. In order to isolate the factor of 'hygroscopicity', we have kept the insects in air saturated with water vapour, the vapour being derived from water containing 8 percent of heavy water ; the vapour also contains 8 percent of heavy water. The concentration of heavy water in the insects was determined after various exposures to this vapour by the method of Linderstrom-Lang
Show more [+] Less [-]Wartime exile
1946
McKee, Ruth Eleanor
The WRA historian's account of the people who were evacuated and of the factors which determined their wartime exclusion from their homes on the Pacific Coast. Beginning with a brief chapter on two early-17th century voyages from Japan to the New World and scattered arrivals of Japanese castaways during the 19th century, this report continues with a detailed treatment of the mass migrations of Japanese immigrants from 1884-1908 -- when immigration was curtailed -- factors determining the distribution of the Japanese immigrants along the West Coast, the rise of anti-Japanese sentiment in the region, the facts of the Japanese birth rate, dual citizenship, language schools and other habitually misunderstood and misrepresented issues, a description of the social, economic and cultural life of the immigrants and their children, and finally the events and pressures which culminated in the Executive Order which empowered the Commanding General of the area to evacuate the entire minority.
Show more [+] Less [-]Correlation of Equilibrium Moisture Data Full text
1946
Whitwell, John C. | Tonert, Richard K.
These equilibrium moisture regain studies were initiated in an attempt to extend the data on equilibrium moisture in textile fibers as determined by Wiegerink and others. In the course of the correlation, it became evident that further material of value to the general problem of drying and concentration could be extracted from these and related data by calculations dealing with water solutions and silica gel. The combined information is now presented without an attempt to include the extrapolations and corrections for all of the textile data. The data are correlated by the use of Othmer charts. The constant regain lines on these charts are extended statistically to a common point of intersection charac teristic of any one fiber in any one process of sorption or desorption. The location of this common point is interpreted in light of the restriction of the water molecule on the fiber and the relative swelling property of the material. Regions of moisture regain are found which give conclusive evidence of pure adsorption uncomplicated by swelling. Another paper, "Statistical Methods for Equilibrium Moisture Correlations," by Professors Whitwell and Toner and Mr. P. J. McCarthy, will appear in the July issue.
Show more [+] Less [-]The salt tolerance of guayule
1946
Retzer, J.L. | Mogen, C.A.
A series of studies were conducted on irrigated 1-, 2-, and 3-year-old guayule plantations in areas where salt concentrations had killed the plants or retarded their growth. The several growth conditions were correlated with differences in salt percentages as determined by the electrical conductance method on soil paste. It was found that guayule usually was killed or did not grow following transplanting where salt concentrations were 0.6% in either the first or second foot. In those cases where the shrub did survive, the growth was poor. Guayule grew well where the salt concentration did not exceed 0.3% in the 5-foot profile. Growth was increasingly retarded as the salt concentrations in the surface 2 feet increased from 0.3% to 0.6% and where the salt was 0.6% or greater in and below the third foot. As the osmotic pressures increased due to the increasing salt content and the total soil moisture stress increased the rubber percentages increased, but the shrub sizes and consequently the pounds of rubber decreased. The study included both alkaline and neutral salts. When compared to yields from soils free of salts, it is concluded that guayule production is not feasible on soils containing salts in excess of 0.3% in the 5-foot profile.
Show more [+] Less [-]Potash and lime requirements of cotton grown in rotation with peanuts
1946
Skinner, J.J. | Nelson, W.L. | Collins, E.R.
The potash and lime requirements of cotton grown in rotation with peanuts on five soil types were studied in North Carolina over a 6-year period. Applications of 24 and 48 pounds of K2O were made to cotton and applications of 0, 25, and 50 pounds of K2O to peanuts. Acid and nonacid-forming fertilizers were applied to cotton. The effect on cotton of dolomitic limestone applied in the row for peanuts was determined. Yields of cotton, nutrient uptake, and the exchangeable bases in the soil were considered. The yields of cotton were significantly increased on four of the soils studied by the use of a complete fertilizer furnishing 48 pounds of K2O per acre as compared to one furnishing 24 pounds of K2O. The soil on which there was no significant response contained 0.19 m.e. of exchangeable potassium. The other soils studied contained 0.07 to 0.10 m.e. Twenty-five pounds of K2O applied to peanuts did not greatly increase cotton yields. Fifty pounds of K2O increased the cotton yields on three soils. Forty-eight pounds of K2O applied directly to cotton gave higher yields of cotton on every soil studied than either 25 pounds or 50 pounds of K2O to peanuts in addition to 24 pounds to cotton. Peanut yields were not significantly affected by these potash treatments. These results favor applying enough potash to cotton for both cotton and peanuts when grown in rotation. Nonacid-forming fertilizers increased the yields of cotton on a soil which had a pH of 5.0, 0.24 m.e. of exchangeable magnesium, and a saturation of 23% with calcium. Dolomitic limestone applied to peanuts also increased the yields of cotton on this soil.
Show more [+] Less [-]Ação do tártaro emético sôbre o coração isolado do cão Action of emetic tartaronthe isolated heart of the dog Full text
1946
Bernardo Figueiredo Magalhães | S. Americano Freire
Em 1944, MAGALHÃES & DIAS estudaram, no cão e no homem, a ação do tártaro emético, em doses tóxicas e terapêuticas, respectivamente, sôbre o eletrocardiograma. Concluiram que havia sinais de sofrimento miocárdico, que "deviam relacionar-se a um "deficit" de oxigenação, determinado pela diminuição do sangue circulante. Êste, por sua vez, deve estar ligado à estase, função da vaso-dilatação". O presente trabalho é um complemento do anterior. Empregaram-se nas experiências corações isolados de cães em aparelho de Hérlitzka, sôbre os quais passavam soluções de tártaro emético em concentrações variadas. Mostrou o tártaro emético ter as seguintes ações: I - Diminúe a contrabilidade. II - Diminúe a condutividade. III - Aumenta a excitabilidade. IV - Produz a síncope imediata, reversivel, expontânea. V - Êstes fenômenos tóxicos são reversíveis, depois de substituir a solução de tártaro emético em Locke, por Locke puro.<br>In 1944 Magalhães and Dias (Memórias do Instituto Oswaldo Cruz) studied the action of emetic tartar in the dog and in man in toxic and therapeutic doses, respectively, on the electrocardiogram. They concluded that there were signs of miocardic suppering, that must be connected with a deficiency of oxigenation, determined by the diminution of the circulating blood. The latter, in its turn, must be connected with stagnation, function of the dilatation-vessel. The present work is a complement to the former one. In the experiments, isolated hearts of dogs were used in Herlitzke apparatus; solutions of emetic tartar in varied concentrations, being passed over them - the emetic tartar produced the following actions: - I - It diminishes the contractibility; II - It diminishes the conductibility; III - It increases the excitability; IV - These phenomena are reversed, if the solution of emetic tartar in Locke, is substituted by pure Locke.
Show more [+] Less [-]Effect of crop residues on soil temperature
1946
McCalla, T.M. | Duley, F.L.
Soil temperatures were determined under the quantities of residues used in the system of subsurface tillage, or stubble mulching, as compared with soil temperatures when using heavy mulches or the conventional system of plowing. Heavy mulches, such as an 8-ton per acre application of straw, have lowered soil temperatures as much as 17.7 degrees C at the 1-inch depth. For a period of 3 or 4 months after the application of a straw mulch at the rate of 2 or 3 tons per acre, soil temperatures may be reduced from 3 degrees to 6 degrees C at the 1-inch depth and 2 degrees to 4 degrees C at the 4-inch depth. However, with the stubble mulch system of farming, soil temperatures were not reduced appreciably below that of plowed land after 6 to 9 months. In such farming, only amounts of residues equal to those grown on the land were returned to the surface of the soil, while decay and fragmentation of the residue continued. Soil temperature of the mulched plots lagged behind air temperature and this difference reached a peak on clear days around 1 to 2 o'clock. Soil temperature reached the lowest point for the day along with the air temperature at about 5 a.m. At this time mulched and bare plots usually had almost the same temperature. It was during the day that the temperature of the bare soil exceeded the mulched soil. The temperature, after considerable decay had taken place, at the time of widest differences was only a few degrees lower on the mulched soil. Generally, soil temperature under mulches did not appear to be unfavorable to plant growth where an amount of residues equal to that grown on the field was used. Due mainly to shading, a growing crop on the land decreased the temperature differences between the mulched and unmulched soil.
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