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dc.contributor.author | Henrici, M.![]() |
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dc.contributor.editor | Theiler, Arnold, Sir, 1867-1936 | |
dc.contributor.editor | Union of South Africa. Department of Agriculture | |
dc.date.accessioned | 2020-12-22T08:16:18Z | |
dc.date.available | 2020-12-22T08:16:18Z | |
dc.date.created | 2020 | |
dc.date.issued | 1926 | |
dc.description | Includes bibliographical references | en_ZA |
dc.description | The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format. | en_ZA |
dc.description.abstract | 1. The chlorophyll-content of Bechuanaland grasses is not constant throughout the year, but varies from a very high initial value on young leaves, decreases according to the duration and intensity of drought periods, and increases again after rains. 2. Even during periods of twenty-four hours the chlorophyll-content varies greatly, decreasing from early morning to midday, and increasing again during the ensuing night. Decrease and increase depend upon meteorological factors ot the moment, so that on rainy days the variation lies within a few per cent., but on extremely dry and sunny days may extend to 30 per cent. 3. High nocturnal temperature favours a higher general chlorophyll-content throughout the day. Low nocturnal temperature is associated with low chlorophyll, even although the soil moisture is adequate. In both cases, however, chlorophyll destruction and chlorophyll synthesis are regarded as occurring concurrently, the actual content at any time representing the equilibrium between the two processes. 4. The values found in 1923-24 were higher than those found in 1924-25 owing to differences in nocturnal temperature in the two seasons. In the 1923 growing season the chlorophyll-content of the grasses of the Vryburg District was higher than that of European grasses; in the 1924 season about the same, or rather lower. Since the average chlorophyll-content is different in the two seasons, the data cannot be directly compared. What is termed a low value for 1923 would be high for 1924. Apart from nocturnal temperature, other factors, as yet uninvestigated, may play a role. | en_ZA |
dc.description.librarian | ab2020 | en_ZA |
dc.format.extent | 13 pages : tables | en_ZA |
dc.format.medium | en_ZA | |
dc.identifier.citation | Henrici, M 1926, ‘The chlorophyll content of grasses in Bechuanaland’, 11th and 12th Reports of the Director of Veterinary Education and Research Part 1, pp. 259-271. | en_ZA |
dc.identifier.issn | 0330-2465 | |
dc.identifier.uri | http://hdl.handle.net/2263/77463 | |
dc.language.iso | en | en_ZA |
dc.publisher | Pretoria : Government Printer and Stationery Office | en_ZA |
dc.rights | ©1926 Union of South Africa, Dept. of Agriculture (original). © 2020 University of Pretoria. Dept. of Library Services (digital). | en_ZA |
dc.subject | Veterinary reports | en_ZA |
dc.subject | Veterinary medicine | en_ZA |
dc.subject | Grasses -- Bechuanaland | en_ZA |
dc.subject | Chlorophyll | en_ZA |
dc.subject.lcsh | Veterinary medicine -- South Africa | |
dc.title | The chlorophyll content of grasses in Bechuanaland | en_ZA |
dc.type | Article | en_ZA |