Effectiveness of herbicides and some plant extracts in controlling dodder on alfalfa

Bermudagrass (Cynodon dactylon L. pers.) extract at rate of 0.5 g crude material / 1 ml water gave the highest control on dodder (90%) and was as effective as metribuzin (4-amino-6tert-butyl-3-(Methylthio)-as-(triazin-5 (4H)-one) and higher than other rates of herbicides (glyphosate, DCPA). Tumble pigweed (Amaranthus albus L.) and johnsongrass (Sorghum halepense L.) extracts at 0.25/1 ml water were not significantly different in controlling dodder from DCPA (tetrahydro-3, 5-dimethyl-2H-I,3,5-thiadiazine-2-thione) and glyphosate (N-(phosphonomethyl) glycine) at all rates used. Phytotoxic agents were idenified as phenolic compounds different in distribution from species to other with chlorogenic and isochlorogenic acids found in all weed extracts, in addition to three unknown phenolic compounds were spotted. It was found that bermudagrass, johnsongrass and tumble pigweed extracts contained 0.0322, 0.0214 and 0.00993 mg phenolic compounds /g crade dry weight, respectively