BIOHERBICIDAL ACTIVITY OF SOME WINTER WEEDS AGAINST SOME CROPS

The study aims at investigating the allelopathic effects of twelve weed species including anagallis arvensis, plantago lanceolata, medicago polymorpha, ammi visnaga, phragmites australis, silybum marianum, emex spinosa, malcolmia africana, calendula arvensis, rumex crispus, fumaria indica and cirsium arvense on seed germination, seed inhibition, seed germination time, seed germination index and seed vigor index of the test crops (wheat, maize and sunflower). a laboratory experiment was laid out in a completely randomized design in march 2010 in the department of weed science, the university of agriculture, peshawar, pakistan. rumex crispus inhibited the seed germination up to 80% and 70% in both wheat and sunflower, respectively while the seed of maize showed high tolerance against all extracts except fumaria indica extract that inhibited the maize seed germination up to 40%. in the present study, sunflower proved more susceptible to all extracts and maize was more tolerant to the phytotoxicity of all the weeds.