Leafy Portions Research Articles

Antimicrobial Activity of Desert Plants

THE desert is an area in which less than 20 per cent of the ground surface is covered with vegetation. Although there are approximately 5,000 species of plants, less than 1 per cent of these have been investigated for antimicrobial activity1–10. This communication is concerned with the extracts prepared from the leafy portions of 25 plant specimens collected at the Brooklyn Botanic Gardens.

Nitrogen in Paddy Soils

Green manures are perhaps the most self-supporting manures in the tropics and are often claimed to be quite as effecient as Ammonium sulphate in rice production. This is of course, not surprising, seeing that they contain nearly 3-4% of nitrogen on dry weight basis, and a carbon/nitrogen ratio of about 10. The leafy portion in green manures is naturally richer in nitrogen content than the stems and the decomposition may be noted in two stages, with the leaves figuring in the first stage and stems in the second. Thus green manures serve as a mixture of a quickly efficacious, concentrated nitrogenous fertiliser similar to ammonium sulphate and a more slowly-acting manure similar to compost or cattle manure.

Hemagglutinating Substances for Human Cells in Various Plants

Summary Saline extracts of the seeds of 262 varieties of plants belonging to 63 families were tested for hemagglutinating activity against human erythrocytes. Of these, 191 showed no hemagglutinating activity, and 46 showed non-specific agglutinating activity, and 46 showed non-specific agglutinating activity for all types of human cells tested. Extracts of the seeds of 25 varieties were more or less blood-group specific, and several in particular were specific for group A1 and A2 cells. Extracts of leafy portions or fruiting bodies of 9 species showed activity in the case of only 1 species. No specificity for the M, N, or Rh antigens was detected. The theoretical implications and possibly practical application of these observations are discussed.