Experimental trials were laid out at the Agronomy Reserch Farm of Punjab Agricultural Univer sliy, Hissarfor two' years in the rabi season 9f 1~67-68and 1968-69 to study the response of 2, 4-0ichlorophenoxy acetic acide applied at " different crop stages to wheat (Kalyan-227 andC-306) ..The soil of the experimental area l s of sandy loam type and received about 118 and 36 mm of rainfall during the crop seoson for the year 1967-68 and 1968-69 respectively; Results of the exper lrnentclear lyIndtcate that" senstive stage of the wheat  crop to the .aoplic atio n of 2.4-D is at seedling'stage (Spray 15 daysafter so..yin:g). At this stage, ths leaves of the pl ant s were oniontike in nature, Various abnormalities of the spikelets like numerous sterile spikes, curvature of the soikelets, erect spikes occured due to which the yield of the wheat crop was reduced si{J-Oificantely as compared to all other treatments. The best tlrne for spraying 2, 4-D appl ication was found from 30-45 days in ~alyan 227 and 45 days after sowing. In C·306 varieties of wheat. At earlier and Iaterstaqes, the weed mortalities' was found to be less as compared to optimum stages and thus had competition with wheat crop 'resulting in reduced crop yield. .