Studis On Germination,Competitive Effect And Chemical Control Of Common Cocklebur (Xanthium Strumarium L.) (Ramtouk) In Sorghum (Sorghum Bicolor L.)

Abstract

This study was carried out at Khartoum University, Faculty of Agriculture in the laboratory and semi-controlled glasshouse during the growing season 2005-2006 to study the (i) The germination of common cocklebur (Xanthium strumarium) (Ramtouk). (ii) Effect of different densitites of common cocklebur (0, 2, 4, 6 plants/plot) on growth and yield of Sorghum (Sorghum bicolor).. (iii) The efficacy of the following herbicides, which were sprayed 4 weeks after weed emergence: - Atrazine (Gesaprim 80 W.P.) at rate of 0.25, 0.5, 0.75 kg/feddan. - 2,4-D (72 EC) at rates of 0.4, 0.8, 1.2 L/feddan at rate of 0.25 kg/feddan + 0.4 L/feddan. The study revealed that Xanthium strumarium fruit contain two seeds with different size and different germination percentages. The discreincreasement in the density of the weed grown with sorghum showed significant reduction in sorghum seedling dry weight sorghum plant height, sorghum leaves number and sorghum plant shoot dry weight. viii Maximum reductions in the above mentioned parameters was obvious at the higher weed densities as compared to the control. Sorghum yield was significantly reduced by the various densities of Xanthium in term of number of grain/head, weight of grain/plant and sorghum final yield (tons/ha) as compared to the weed free control. The herbicides, atrazine and 2,4-D and their mixture showed significant reduction in the weed number and the weed dry weight as compared to the control.