Allelopathic potential ofIpomoea tricolor (Convolvulaceae) in a greenhouse experiment.

The allelopathic potential ofIpomoea tricolor, a plant used in Mexican agriculture to control weeds, and tricolorin A, the major phytogrowth inhibitor present in the so-called "resin glycosides" of this plant, have been evaluated by testing leachates of the plant and the compound on the germination and radicle growth ofAmaranthus hypochondriacus, Echinochloa crusgalli, Senna uniflora, I. tricolor, andI. purpurea. The allelopathic potential ofI. tricolor was evaluated in a greenhouse experiment with dryI. tricolor mixed with sterile and nonsterile soil in pots.A. hypochondriacus was sown in pots containingI. tricolor, 2-chloro-4-(ethylamino)-6-(isopropylamino)-1,3,5 triazine (Gesaprim) or 1-glyphosphate, and the glyphosphate salt of isopropylamine (Faena), two different commercial herbicides used as a comparison toI. tricolor. Number and dry weights of different monocotyledonous and dicotyledonous weeds andA. hypochondriacus growing in the different treatments were measured.Ipomoea and Faena herbicide had a similar inhibitory effect on monocots.