| Popis: |
In a series of greenhouse experiments extending from June, 1941, to June, 1944, inclusive, beets (Beta vulgaris) and tomatoes (Lycopersicon esculentum) were grown in media of controlled composition to determine what, if any, effect a deficiency of boron or manganese might have on quality which was measured by the amounts of moisture, sugar, alcohol soluble and insoluble nitrogen, carotene, ascorbic acid, thiamin, and riboflavin that were present. Boron was selected for study because it is an essential element for most if not all of the important crop plants (3, 7). Symptoms of boron deficiency can be easily recognized (4) and the many reports in the literature indicate that there is a rather widespread deficiency of this element; soils lacking boron adequate for good crop growth have been reported in over half of the forty-eight states (11) with noticeably large areas along the Atlantic seaboard, in the Great Lakes region, and in the Pacific Northwest. A very good list of important papers which deal with boron in plants and substrates is appended to the paper by Parks, Lyon, and Hood (10). Manganese was selected for further study for reasons somewhat similar to those enumerated for boron, but especially because of the report by Hester (5, 6) that this element seemed to have a definite effect on the vitamin C content of the tomato. |
