Reduced efficacy and enhanced degradation of carbetamide after repeated application in Australia

Following reports of poor weed control, the effectiveness of repeated applications of carbetamide atid propyzamide in controlling Lolium rigidum Gaud, (annual ryegrass) was examined under field conditions. Repeated applications of carbetamide or propyzamide were less effective in controlling L. rigidum than an initial application. A single application of carbetamide or propyzamide was sufficient approximately to halve the efficacy of a subsequent treatment with the satne herbicide. Laboratory incubations of soil linked the poor performance of carbetamide upon repeated application to an enhanced deg-radation rate. We conclude that the repeated application of carbetamide or propyzamide results in less effective weed control under field conditions and that this can be partially avoided by rotation between carhetamide and propyzamide.     

The physical appearance of the vulva in ureaplasma infected ewes

The vulvar labia of ewes naturally infected with ureaplasma were significantly more swollen and red than those of uninfected ewes. Similar changes were observed following experimental infection of previously uninfected ewes. These differences, although statistically significant, were not sufficiently marked to be useful in diagnosing infection by clinical examination.     

Molecular characterization and marker based chemotaxonomic studies of Podophyllum hexandrum Royle

Detailed chemical studies and RAPD analysis were done in different populations of Podophyllum hexandrum collected from high altitude regions of North Western Himalayas. Random amplified polymorphic DNA (RAPD) analysis revealed a high degree of genetic diversity among the 12 collected accessions, attributed to their geographical and climatic conditions. HPLC analysis also revealed variation in the concentration of two major marker compounds which lead to the identification of a chemotype. The study demonstrated that RAPD and chemical markers are very useful tools to compare the genetic relationship and pattern of variation among such prioritized and endangered medicinal plants.