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An agricultural geography of some semi-arid parts of the Mediterranean Region in relation to the agricultural problems of West Punjab Texto completo
1950
Bhatty, M. A.
This study has been divided into four principal parts. In the first part the physical background has been described. The chapter on structure and relief purports to give only an outline in the context of which the other physical and cultural factors may be considered. Detailed descriptions of areas studied closely in the field or from large-scale maps has been given under agricultural regions. The account of climate, hydrography, vegetation and soil similarly treats only of essentials in relation to agriculture and its problems. The factor of variabil¬ ity of rainfall in Barbary has been given.special attention and some correlations have been established, i.e. between autumn rainfall and the total area sown and between spring rainfall and the yields. | The second part treats of the cultural background. In this section, two aspects have been studied in special detail. European colonization in Barbary and its impact on the native cultivators of Barbary has been discussed in relation to its history and development. The modes of life and settlement in Barbary have been described regionally after a detailed examination of physical, cultural and economic factors. | In the third part a number of outstanding agricultural problems have been examined in considerable detail with special reference to recent developments. The account of irrigation embraces the traditional and modern systems, their influence on crops and on the cultivators. Settlement of newly irrigated regions has also been examined in some detail. For Barbary the problem has been documented by studies in the field. Thereafter, water¬ logging and saline soils, soil erosion and dry-farming are treated rather generally mainly on the basis of documentary material. Attention has however been drawn to the most pressing problems to be faced today and the types of solutions that have been attempted. | The final part includes first an account of land-use and agricultural methods.followed by a brief description of the product¬ ion and distribution of principal crops. Then, in the chapters on agricultural regions, all the factors described earlier have been integrated. Most of the micro-geographical studies made in the field and from 1:50,000 maps are incorporated into these chapters. The division of Barbary into agricultural regions and their detailed description with the help of sample regional and farm studies thus constitutes the principal result of this study. | A brief account of present attempts towards modernisation is followed by the Conclusion in which several constructive suggestions have been made in relation to the population problem and the low standard of living. | Throughout the study, the emphasis has been placed on Barbary which was the region studied in the field and on which a large proportion of documentary research war carried out. West Punjab stands, as it were, in the background. A fuller understanding of the agricultural landscape and of the problems of agriculture which has followed the study of Barbary may later lead on to an attempt at a closer survey of West Punjab on the basis of field work.
Mostrar más [+] Menos [-]Growing an orchard in Kansas
1950
Barnett, R. J. (Robert John)
Inheritance and interrelation of some agronomic and chemical characters in an interspecific cross in soybeans, Glycine max x G. ussuriensis
1950
Weber, Charles R.
Nuevo procedimiento de lucha contra el Dacus oleae Rossi Texto completo
1950
Gómez-Clemente, Federico | Bellod, Martín
Nos proponemos, al desarrollar esta parte de la ponencia (I*) dedicada a la plaga conocida con el nombre de «mosca» o «gusano» de la aceituna (Dacus oleae Rossi), exponer los daños que dicho insecto ocasiona en España; los estudios y experiencias realizados por nuestras Estaciones de Fitopatología Agrícola sobre un nuevo método de lucha contra dicho insecto; las observaciones llevadas a cabo para conocer la biología del mismo en relación con los factores climáticos, y, finalmente, como consecuencia de dichos estudios y experiencias, proponer a este Congreso el método de lucha que creemos más ventajoso por su eficacia y coste. (I*. Esta ponencia fué presentada al XIII Congreso Internacional de Oleicultura, celebrado en Sevilla en noviembre de 1950)
Mostrar más [+] Menos [-]Los nombres de los insectos Texto completo
1950
Del-Rivero, José M.
La designación entomológica de un insecto constituye su nombre científico y la expresión con que se le apellida en la vida corriente su nombre vulgar. Los nombres científicos se dan en latín y los vulgares en el idioma y dialectos del país de que se trate. Es evidente la necesidad de que la nomenclatura entomológica sea estable y de que cada insecto tenga su nombre científico único, de forma que quede inequívocamente determinado y sea común a todas las naciones del mundo, pues ello facilita las relaciones entre los técnicos que se ocupan de esta especialidad y también las actividades comerciales e industriales con ellas relacionadas. Sin embargo, la división de los géneros en otros nuevos, la asignación de unas especies a géneros distintos y otras modificaciones, variantes e incluso criterios que surgen como consecuencia natural de la evolución de la Entomología y de todas las ciencias en general, hacen que no se pueda alcanzar la debida estabilidad y uniformidad en el terreno puramente científico, como muy bien reconoce Metcalf (1) en su interesante trabajo sobre esta cuestión, Parece paradójico a primera vista que frente a los cambios que sufren los nombres científicos de los insectos, las denominaciones vulgares ofrezcan una fijeza mucho mayor. Pero ello es natural por el carácter vernáculo (2) de la mayor parte de los nombres vulgares y por la rutina de las cosas populares.
Mostrar más [+] Menos [-]Ensayos de aclimatación de Leptomastix dactylopii Howard, parasito del “cotonet” o “algodón” de los agrios (Pseudococcus citri Risso) Texto completo
1950
Gómez-Clemente, Federico
Desde hace varios años la Estación Fitopatológica de Burjasot (Valencia) sigue con interés los problemas relacionados con el estudio de los insectos que impiden el desarrollo de los perjudiciales a las plantas, manifestado en el cultivo y propagación de ciertos parásitos y depredadores, que proporcionan algunos óptimos resultados contra determinadas especies fitófagas y en la importación de otros posiblemente utilizables para combatir plazas extendidas len muestro país. Una de las primeras importaciones fué la del coleóptero coccinélido Cryptolaemus Montrouzieri Muls., que se alimenta del Pseudococcus citri Risso, plaga de los naranjos y limoneros, de gran importancia económica y difícil de combatir acudiendo a los métodos químicos de lucha. El Cryptolaemus es una especie eminentemente útil, aunque su eficacia no puede compararse a la del Novims cardinalis, enemigo de la «Cochinilla acanalada» (Icerya purchasi Mask), que ocupa el primer lugar entre los insectos auxiliares del agricultor. Le resta eficacia la dificultad con que tropieza para encontrar el alimento necesario al desaparecer el Pseudococcus citri de los naranjales una vez comienza la estación fría. sin embargo, actualmente se encuentra aclimatado en muchas comarcas del litoral mediterráneo, haciendo aparición en cuanto se inicia el ataque de la cochinilla.
Mostrar más [+] Menos [-]John Monroe Brewster papers, 1950-1970 Texto completo
1950-1970
Brewster, John M. (John Monroe)
The John Monroe Brewster Papers include correspondence, research notes, photographs, and a manuscript of a book of Brewster's writings that was published posthumously. The book is titled, A Philosopher among Economists: Selected Works of John M. Brewster (Philadelphia: J. T. Murphy Co., 1970).
Mostrar más [+] Menos [-]Norman Mitlin papers, 1950-1979 Texto completo
1950-1979
Mitlin, Norman
The Norman Mitlin Papers consist of 29 boll weevil articles (1964-1977) authored by Mitlin, 30 of Mitlin's handwritten laboratory notebooks (1953-1975) from the Boll Weevil Research Laboratory, drafts, correspondence, and photographs. Most of the articles deal with the development of insect sterilization methods. There is correspondence between Mitlin and Mississippi State University, where he taught graduate school classes, and documentation related to his training.
Mostrar más [+] Menos [-]Payne/National 4-H Fellowship collection 1931-1950 | National 4-H Fellowship collection Texto completo
1931-1950
The Payne/National 4-H Fellowship Collection includes photographs, publications, scrapbooks, programs, monthly reports, newsletters and news clippings, and correspondence detailing the activities of 4-H Fellows.
Mostrar más [+] Menos [-]An investigation of buried viable seeds under pastures of varying crop histories Texto completo
1950
Dawson, M.
Author was awarded a Bachelor of Agricultural Science rather than a Masters. | It is a common occurrence to find recently ploughed or surface cultivated areas periodically heavily infested with seedlings of various plants. These seedlings have their source in the buried seed populations often surprisingly large in both total numbers and in the number of species. These seeds have been lying in the soil for varying lengths of time and germinate on being given suitable environmental conditions. The severity of the infestation usually varies with the time of the year, often being heavy in certain months, so much so that in some cases the time of sowing of crops or pastures may be dictated by this consideration alone. But whatever efforts may be made to avoid the handicap that weeds present, it will always remain a problem at some period in the rotational life of an area. The ability of many plant species to reappear in areas recently ploughed is due principally to dormancy of seeds. Hence once land has become clothed with a natural cover of vegetation it is virtually impossible for any agency to destroy it permanently, for many seeds that may shatter on the ground will remain in a dormant state and the small proportion of these that germinate in any year may reach maturity and add more seeds to those already present in the soil. Samples were taken from fields under pasture for varying periods. Of the six fields examined, one has never been cropped and has been down in pasture for sixty years, while the other five have had different cropping histories. Details are given for the method used in taking core samples with Laboratory procedure in selecting representative samples from bulked soil. Statistical analysis shows the method used in the field was sufficiently accurate. The method used in separating seeds from the soil and subsequent drying, identification and extraction are discussed. Details of the germination techniques used and data showing how the various seed species respond to the different germination methods is given. The buried seeds are classified into arable, arable and pasture and pasture. Between fifty and sixty different species of seeds were identified, most of them were potential weeds. The results show that although most of the buried viable seeds found may be classified as Pasture species, the highest total populations with one exception were from the fields recently sown down after arable cropping. Confirmation has been given to the results of earlier investigations that many grasses must survive by means other than buried seeds.
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