In- r:he present experiment; was ' dnben in tbe Sector -uritohuasi on: the District oii JuarfGiiéfri "'· · Provine e and Departament of San Martfn, in exempt texture soil. with pH of 7, 72, mean fetility with type of tropical diy furest, a rainfaill of 1 047 nun/year and an average temperature of 26,3 ºC. The objetives of the present investigation work were measured the efect of the diferen dose of the herbicide Fluamop applied in pulverization to 25 and 50 days after the sowing; their bis action .fitotoxic to tbe cultivation of cowpea; the degree of control of undergrowtbs; their incidence on the grain yieldand to make the económic analysis of the treatments througb the relationship benefit/cost The statistic design utlised was tbe block designs thoroughly randomiced with 9 treatmentsand 4 repetitions. The ñtitoxic e:ffect was evaluated to 4 and 5 days after the aplication, no obt...