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Farm management in the Ozark region of Missouri
1921
Dixon, H. M. (Harrison Morton) | Purdom, J. M.
The relation of the number of bacteria in milk to quality and yield of cheese
1921
Hucker, George J.
Farm management in the Ozark region of Missouri : a study of the organization and operation of a number of representative farms
1921
Dixon, H. M. (Harrison Morton),, 1888- | Purdom, J. M.
Alberta Moth Trap
1921
Agriculture and Agri-Food Canada | University of Lethbridge Library
An Alberta Moth Trap hanging on a fence post.
Afficher plus [+] Moins [-]The standardization of courses in field crops
1921
Wentz, J.B.
In general, there is a tendency on the part of educational institutions toward the standardization of work offered. How far we can go in the standardizaiton of courses in agricultural subjects may be questioned but certainly all will agree that a great deal could well be done in this direction. At the present time there are listed in the catalogs of the agricultural colleges of the United States 133 differently named courses in field crops. When these courses are classified according to ground covered the number is reduced to 47, and of the 47 only 20 are offered by more than one or two colleges. Almost any field crops department of the country should be able to select all its courses from among this comparatively small group of 20. Table 2 shows that there is great irregularity in the positions of the field crops courses in the college curricula. Table 3 shows great variation in the number of hours devoted to the courses by different colleges. There is some excuse for this variation due to differences in importance of some crops in different parts of the country, but even here there probably could be more uniformity.
Afficher plus [+] Moins [-]USDA Office of the General Counsel legislative histories | Office of the General Counsel | United States. Department of Agriculture. Office of the General Counsel
1921 | 1971-1991
The USDA Office of General Counsel Legislative Histories Collection consists of 517 bound volumes of major pieces of federal agricultural law and associated resources. The volumes are arranged by Congressional Session then by Public Law number. Within each Public Law section, there is a summary of the law and an index and summary of history of the bill. Other legislative documents are filed after the summaries in chronological order. Types of documents vary per Public Law, but primarily consist of bills, hearing transcripts, digests of the Congressional Record, and committee reports. The collection was donated by the United States Department of Agriculture (USDA), Office of the General Counsel (OGC) in 2018. The bulk of this collection is from 1941-1971.
Afficher plus [+] Moins [-]Inheritance of disease resistance in the common bean
1921
McRostie, G.P.
Investigations of the inheritance of resistance to the bean anthracnose fungus indicate a single factor difference between resistance and susceptibility where only the alpha strain of the fungus is concerned in the cross. Where both the alpha and beta strains are concerned a two-factor difference is indicated and a 9:7 ratio in F2 is obtained. In both instances resistance is dominant over susceptibility. F1 and F2 results of crosses involving the inheritance of susceptibility to the bean mosaic organism indicates a partial dominance of susceptibility over resistance to this disease. A two-factor hypothesis is advanced to account for the inheritance of resistance and susceptibility, Such an hypothesis is borne out by the totals of the observed F2 ratios between resistant and susceptible plants and by the fact that approximately one sixteenth of the F2 plants were severly infected with mosaic and bred true for this character in the F3. Inoculation results of F2 hybrids from crosses involving the inheritance of susceptibility to root rot indicate susceptibility ot this disease to be dominant over resistance. That this was the case had been indicated by the fact that a few F1 plants, which had been grown on infested ground, showed good infection. A tentative two-factor hypothesis to account for the inheritance of susceptibility to root rot, with a 9:7 ratio in the F2 between susceptible and resistant plants, is advanced to explain the results obtained. The fact that the susceptible plants were in the majority in the F2 and that a large number of the F3 families from these plants did not breed true while the F3 families from resistant F2 plants in almost all cases bred true, is in accord with the hypothesis advanced. The necessity of establishing an arbitrary dividing line between resistant and susceptible forms adds considerable difficulty to the proving of any hypothesis to account for the inheritance of susceptibility to bean root rot. A number of promising strains of beans have been isolated which show resistance to anthracnose. A few hundred heavily podded F2 types have been selected which show resistance to both root rot and mosaic and which should also be resistant to the beta strain of the anthracnose fungus. Further testing should isolate some very desirable resistant commercial types from these selections.
Afficher plus [+] Moins [-]Een cytologisch onderzoek aan eenige soorten en soortsbastaarden van het geslacht Saccharum
1921
Bremer, G.
Within the wild cane, Saccharum spontaneum, 56 bivalent chromosomes are found in a regular division of pollen mother cells, indicating a somatic chromosome number 112.Several well known varieties of sugar-cane, S. officinarum, appeared to have 40 chromosomes in the haploid phase and 80 in the somatic phase. But in these canes, meiosis was often seriously disturbed, reducing the fertility. This was also so with the very thin Indian canes Chunnee and Ruckree 11, having 90-91 chromosomes somatically.In relation to the reduced fertility of S. officinarum, it was remarkable that hybrids between S. officinarum (n = 40) and S. spontaneum (n ~ 56) were very fertile, since usually hybrids between species with different chromosome numbers are partly fertile or totally sterile. However the hybrids between the above species did not have 40 + 56 = 96 chromosomes, but 40 + 40 + 56 = 136 chromosomes. This was also so for Kassoer, a similar interspecific hybrid found wild, that was especially used for hybridization with S. officinarum.Cytological research of Kassoer and the hybrids from crosses of S. officinarum with S. spontaneum demonstrated that 68 bivalents could be counted in the metaphase of reduction division.The doubling of the S. officinarum chromosomes from 40 to 80 is probably due to longitudinal splitting of the S. officinarum chromosomes during fertilization in the zygote, thus providing (2 x 40) + 56 = 136 chromosomes.
Afficher plus [+] Moins [-]Een cytologisch onderzoek aan eenige soorten en soortsbastaarden van het geslacht Saccharum
1921
Bremer, G.
Within the wild cane, Saccharum spontaneum, 56 bivalent chromosomes are found in a regular division of pollen mother cells, indicating a somatic chromosome number 112.Several well known varieties of sugar-cane, S. officinarum, appeared to have 40 chromosomes in the haploid phase and 80 in the somatic phase. But in these canes, meiosis was often seriously disturbed, reducing the fertility. This was also so with the very thin Indian canes Chunnee and Ruckree 11, having 90-91 chromosomes somatically.In relation to the reduced fertility of S. officinarum, it was remarkable that hybrids between S. officinarum (n = 40) and S. spontaneum (n ~ 56) were very fertile, since usually hybrids between species with different chromosome numbers are partly fertile or totally sterile. However the hybrids between the above species did not have 40 + 56 = 96 chromosomes, but 40 + 40 + 56 = 136 chromosomes. This was also so for Kassoer, a similar interspecific hybrid found wild, that was especially used for hybridization with S. officinarum.Cytological research of Kassoer and the hybrids from crosses of S. officinarum with S. spontaneum demonstrated that 68 bivalents could be counted in the metaphase of reduction division.The doubling of the S. officinarum chromosomes from 40 to 80 is probably due to longitudinal splitting of the S. officinarum chromosomes during fertilization in the zygote, thus providing (2 x 40) + 56 = 136 chromosomes.
Afficher plus [+] Moins [-]The agronomic placement of varieties
1921
Mooers, C.A.
In conclusion, I will summarize the situation as follows. The fourth paragraph of the summary relates, however, to a matter barely mentioned previously, but is germane to the general subject. Certain improvements are needed in the conduct of varietal trials with a view to scientific accuracy. Increased attention should be given to at least the following points: a. The proper stand for each variety. b. The importance of a standard variety. c. The necessity of conducting varietal trials on soils which are truly representative of productivity conditions of the regions to which the results are to be applied. Nine simple relationships appear to exist between varieties of corn with regard to grain production on soils differing in productiveness. The location of varietal curves with reference to a standard will make possible better founded and more accurate selection of a suitable variety for a given condition. Data from a date-of-planting experiments enable the plotting of a curve by means of which the approximate date of ripening of a variety can be predicted with a fair degree of accuracy. All three of the curves obtained, one each from an early, a medium, and a late maturing variety, appeared to be arcs of a circle with the same radius, but with different centers. A practical method of calculating the most favorable number of plants per acre has been worked out, the variety to grown and the productiveness of the soil in the average season being the factors taken into consideration. The range of its adaptability and all necessary modification to give it wider application need to be determined. There remains to be determined in particular the productive vigor of every important variety over its possible territorial range. With this factor in hand we would, as I am viewing the subject, be able to say that a scientific basis for the agronomic placement of varieties not only of corn but of other crops was on the high road to successful completion.
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