Effects of allelopathic chemicals extracted from various plant leaves on weed control and wheat crop productivity

A study on allelopathic effect of leaf water extracts of eucalyptus,acacia,sorghum,shishum,sunflower,poplar,tobacco and congress grass on weeds control and growth of wheat cv. hashim-8 was conducted at faculty of agriculture,gomal university,dera ismail khan during 2012-2013. the findings of this study revealed that allelopathic chemicals in leaf water extracts of these plants significantly suppressed weeds growth by reducing weed density,fresh and dry weed biomass,and encouraged wheat yield and yield components such as days to 50% heading,plant height,tillers m-2,grain spike -1,1000-gain weight,biological and grain yield. even though minimum fresh and dry weed biomass and highest wheat grain yield and yield related components were observed in twice hand weeding treatment which is economically less feasible on large scale. however,our findings showed an alternative allelopathic technique to minimize weed infestation and boost wheat growth and yield using natural plant material. on the basis of present results,it is recommended that leaf water extracts of sorghum,sunflower and congress grass can be applied twice (30 and 60 das) during the growing season to control weeds and to enhance wheat grain yield. © 2015,pakistan botanical society. all rights reserved.