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Proclamation | Whereas the fact has been determined that a dangerous peach disease known as the phony peach disease exists in certain counties of Alabama
1942
Paterson, Haygood
A study of the inclined point quadrat method of botanical analysis of pasture mixtures Full text
1942
Arny, A.C. | Schmid, A.R.
Data have been presented showing that percentages of certain species in pasture mixtures determined from readings from the inclined point quadrat apparatus were over- or underemphasized when compared with determinations from dry weights. A method of correcting for the overemphasis of Kentucky bluegrass alone, Kentucky bluegrass and crested wheatgrass together, and for the underemphasis of alfalfa from the readings from the point quadrat apparatus in the mixtures studied in 1941 was derived and used for that purpose. With a few exceptions, the percentages of these species as determined from the corrected readings from the point quadrat apparatus approached rather closely the percentages determined for them from dry weights.
Show more [+] Less [-]"?Cuscuta flossdorfii"? Hicken Full text
1942
T. G. Yuncker
In 1922, while reviewing the South American species of Cuscuta, the writer studied a specimen collected by Hieronymus, February 2, 1883, in the Sierra Achala de Córdoba, Argentina. This specimen is deposited in the herbarium of the Botanical Instituto at Dahlem. It was determined at that time that the specimen represented a species new to science and was so publishced under the name of Cuscuta brevisquamata Yuncker.
Show more [+] Less [-]The mineral content of various clones of white clover when grown on different soils
1942
Robinson, R.R.
Eight clones of white clover were increased vegetatively and grown in the greenhouse on five widely different soils. Yields of dry matter and the contents of calcium, phosphorus, and potassium were determined. Marked differences were obtained in both yields of dry matter and in the mineral content of the different clones. Clones that were relatively high in calcium on one soil were also relatively high in calcium on other soils. Relative differences in phosphorus and in potassium content tended to be maintained on different soils, but the agreement was not as close as in the case of calcium. No relation was found between the mineral content of the clones and their ability to grow at low levels of lime and phosphate.
Show more [+] Less [-]The dissemination of prickly pear seed by jack rabbits
1942
Timmons, F.L.
The occurrence of prickly pear seeds in the droppings of jack rabbits that had fed upon the ripened fruits was determined from collections made in and near a cactus infested pasture at Hays, Kans. The droppings collected in the pasture contained an average of about 2.5 seeds per pellet, while those collected in nearby uninfested fields only occasionally contained seeds. The germination of the seeds found in the jack rabbit droppings was about 50% greater than that of seeds taken from dried fruits at the same time. Jack rabbits evidently are important agents in the dissemination of viable prickly pear seed and presumably in the spread of prickly pear plants through western Kansas pastures.
Show more [+] Less [-]A biological reduction method for removing free iron oxides from soils and colloidal clays
1942
Allison, L.E. | Scarseth, G.D.
1. A method is described for the removal of "free" iron oxides from soils and colloidal clays which employs the principle of microbial reduction and subsequent solution. 2. The effectiveness of this method was determined by comparing it with the chemical method described by Truog, et al., and with the untreated colloidal clays. 3. The removal of iron oxide coatings from colloidal clays increased their base exchange capacities in proportion to the amount of this constituent removed. 4. Aside from being a helpful research technic, the biological method, herein described, is a valuable teaching device for demonstrating the reltionship between energy materials and important soil transformations, a relationship that is frequently not fully appreciated.
Show more [+] Less [-]Melkproductiecontrole in het Zuidhollandse Utrechtse kaasdistrict
1942
Schiere, C.
Milk recording is an important factor in checking the profitability of dairy farming. In the cheese district considered, where full-cream Gouda cheese is produced on the farm, the customary records of milk yield and fat content were insufficient, because output was determined by the cheese yield of the produced milk, which in its turn depended largely on the casein content of the milk. It was found that the rather weak correlation between fat and casein contents could not serve as a basis for prediction of the cheese yield in practice. Therefore a simple method was devised for estimating the yield of fat-free cheese. This factor was found, however, to correlate sufficiently well with fat content and density of the milk. Consequently, a multiple regression equation was calculated between percentage cheese yield, and fat content and density, that could successfully be applied in profitability checks and for breeding programmes.
Show more [+] Less [-]Melkproductiecontrole in het Zuidhollandse Utrechtse kaasdistrict Full text
1942
Schiere, C.
Milk recording is an important factor in checking the profitability of dairy farming. In the cheese district considered, where full-cream Gouda cheese is produced on the farm, the customary records of milk yield and fat content were insufficient, because output was determined by the cheese yield of the produced milk, which in its turn depended largely on the casein content of the milk. It was found that the rather weak correlation between fat and casein contents could not serve as a basis for prediction of the cheese yield in practice. Therefore a simple method was devised for estimating the yield of fat-free cheese. This factor was found, however, to correlate sufficiently well with fat content and density of the milk. Consequently, a multiple regression equation was calculated between percentage cheese yield, and fat content and density, that could successfully be applied in profitability checks and for breeding programmes.
Show more [+] Less [-]Varietal reaction to bunt in the western wheat region of the United States Full text
1942
Holton, C.S. | Suneson, C.A.
The reaction of 83 varieties and hybrid selections of winter wheat to bunt was determined by growing them in uniform nurseries at 11 localities in the western United States and at Kearneysville, W. Va., and inoculating them with spores obtained from commercial wheat fields n the vicinity of each nursery location, or from a composite of collections from commercial wheat fields in the entire Pacific Northwest. None of the varieties was bunt-free at all of the stations, although 36 varieties averaged less than 10% bunt and 7 averaged less than 1%. Five resistant varieties were involved in the production of 26 of the 27 most highly resistant hybrid selections. In 8 of the 12 nurseries the majority of the infected varieties and selections had less than 10% bunt. The prevalence and distribution of race groups of the bunt fungi were indicated by the reaction of the host testers included in the nurseries each year. One or more of the more virulent races appear to be fairly prevalent throughout the western region.
Show more [+] Less [-]A "fração argila" dos solos do Estado de São Paulo e seu estudo roentgenográfico Full text
1942
Paiva Neto, J. E. de
In the beginning of this work a brief idea was given on what is understood as "clay", on the scientific methods applied to the study of the matter "clay" as well as on its conception with regard to the edaphic studies. A description is given of the methods of total and natural mechanical analyses which were employed in the agro-geological Department. The work is illustrated by a graphic showing the fractions of the mechanical analysis of the chief great soil types of the State of São Paulo. The fraction clay is then studied by chemical way in the following sequence : 1.° total chemical analysis, 2.° partial chemical analysis, 3.° chemical analysis of the Helmholz layer and 4.° study of the fixation of the ion Ca+ + in the already mentioned Helmholz layer. The first analysis separates and attacks the hydrated aluminium silicates, the hydrated oxyds of iron and aluminium, manganese, etc. In this analysis the relationship between silica and sesquioxyds was determined. The second type of attack or chemical analysis does not affect the hydrated silicates of aluminium, all others go in dissolution. In this analysis were determined chiefly the sesquioxyds in their free form in the clay complex. For the study of the Helmholz layer, i.e. the determination of changeable ions, solutes of NH4Cl N/l, HNO3 N/5, KCl N/l, etc. were used, percolation of these liquids being made through a layer of air dried soil. The relationship between soil and liquid was always 1:10. In this analysis, principally the cations K+, Ca++, Mg++, Al+ + +, H+ etc. were determined. With such determinations the calculations of the following values were obtained: S = sum of the changeable bases in ME; T = total value in ME of the sorptive power of the complex in each 100 g dried soil at 110° C. and V = percentage of saturation of the complexes with bases. Finally, the qualitative radiographic analysis of the fraction clay was carried out by means of the Debye-Scherrer-Hull method. For these studies the Siemens-Berlin apparatus was used, the transformer of which runs with all0-220 volts 60-cycle alternating current. The bulb has a copper anti-cathode and is fed by a current of 13 m.A. of intensity and the difference of potential is of 30,000, 35,000 and 47,000 volts. The flash of X-rays goes through the nickel filter in order to free it of the b irradiations which are deleterious. In this way, inciding vertically on the preparation, radiations CuK a with l = 1,539 A are obtained. The sensible film used was a Lawe-Film-Agfa, with an exposure going from 11/2 to 2 hours with 35,000 V. The chassis has a diameter of 57 mm. More than 500 radiographs of soil samples were taken, of those proceding from all districts of the State, 79 of which are presented in the present work. With this material the different constituents of the clay minerals contained in our soils were known. Thus, in the soils over the Archean geological formation, kaolinite is represented most frequently and abundantly ; the hydrargillite also appears commonly. The soils over the Glacial formation contain the same representatives and oscillations as those just mentioned. In the Corum-batai formation, quartz is the most important constituent. The Botucatu formation (lava) is that which gave origin to our legitimate red soils ; the mineralogical clay constituents of these soils are : 1.° large amount of hydrated oxyds of iron up to 35% of Fe2O3 for each 100 g of soil at 110° C. ; 2.° hydrargillite and 3.° kaolinite. The amount of the latter in the clay complex ranges between 9 and 25%. The sandy soils existing in the geological formations of lower and upper Baurú bear in their clays the following mineralogical constituents : 1.° kaolinite, 2.° montmorrillonitic type (on the upper Baurú only), 3.° hydrargillite (more common on the lower Baurú) and 4.° quartz, generally, in small percentages. These researches made it evident that the constituents of the clay fraction of our soils commonly have a small sorptive power related to the cations; it follows hence that they do not show a great power of retention of manure with the exception of the montmorrillonitic type.
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