INFLUENCE OF SOME HERBICIDES ON THE GROWTH AND PROPAGATIVE CAPACITY OF PURPLE NUTSEDGE (Cyperus rotundus L.).

          Pot experiments were conducted during the two summer seasons of 2005 and 2006 in the greenhouse of the National Research Centre to study the influence of the herbicides basagran, glyphosate, nominee and serious on the growth and propagative capacity of purple nutsedge. Treatments of purple nutsedge were carried out with these herbicides at the two concentrations for each herbicide after two weeks from sowing. The results revealed that the number of mother shoots was significantly reduced by both concentrations of glyphosate (7200&9600 ppm) and nominee (600&800 ppm). On the other hand, this result was obtained by the high concentration of basagran (3700 ppm) after 45 and 75 days from sowing. The results also indicated that basagran (2800&3700 ppm) and glyphosate (7200&9600 ppm) induced pronounced significant reduction in the growth of both aerial and underground organs of purple nutsedge, furthermore, growth of aerial and underground organs were completely inhibited by nominee (600&800 ppm) and serious (300&400 ppm) after 75 days from sowing. Determination of total carbohydrates indicated significant reduction with all herbicides reaching complete inhibition by nominee and serious. Similarly, estimating N, P and K revealed complete inhibition of these nutrients by the later two herbicides. In general, it could be concluded that while there was a regrowth of purple nutsedge by both herbicides basagran and glyphosate, complete inhibition occurred by both herbicides nominee and serious.