The widespread use of chemicals for the control of diseases, insects, and weeds in the production of alfalfa seed has caused concern with regards to what effect these materials may have on the inherent reproductive potential of the plants. It has been reported that captan (N- (trichloromethylthio)-4-cyclohexene-1,2-dicarboximide) has both a morphological and physiological effect on some plants. The action of this chemical with regards to alfalfa reproduction has not been reported. Demeton (0,0- diethyl O(and S)-2-(ethylthio) ethylphosphorodithioate) is another chemical used in alfalfa seed production for which the direct effects on reproduction have not been studied. Adverse effects have been reported on a number of plant species with the use of organic phosphate insecticides. A selective herbicide, 4(2,4-DB), (2,4-dichlorophenoxybatyric acid) shows promise of being satisfactory for the control of broad-leaf weeds in alfalfa. Work reported on studies of forage and seed yields is quite varied as to the effect of 4(2,4-DB) on alfalfa.