Two simultaneous experiments were conducted at Juana Díaz and Isabela, Puerto Rico, to evaluate five chemical strategies and mechanical cultivation for weed control in bean (Phaseolus vulgaris L.) cv. Arroyo Loro established with drip irrigation. The strategies were 1) trifluralin (0.75 kg/ha) preplant incorporated (PPI), followed by (fb) bentazon (0.75 kg/ha) and sethoxydim (0.37 kg/ha) postemergence (POST); 2) bentazon (0.75 kg/ha) POST fb sethoxydim (0.37 kg/ha) POST; 3) metolachlor (2.80 kg/ha) preemergence (PRE) fb bentazon (0.75 kg/ha) and sethoxydim (0.37 kg/ha) POST; 4) imazethapyr (0.06 kg/ha) PRE fb bentazon (0.75 kg/ha) and sethoxydim (0.37 kg/ha) POST; 5) trifluralin (0.75 kg/ha) PPI; and 6) mechanical cultivation. All plots were mechanically cultivated, including those of treatment number six, at four weeks after planting (WAP). Drip irrigation was applied three times per week until two weeks before the harvest of dry beans. Metolachlor PRE fb bentazon POST caused 40% phytotoxicity to bean, significant (P < 0.05) at 3 WAP; phytotoxicity declined to 6% at 6 WAP in Juana Díaz. At Isabela, bentazon POST, imazethapyr PRE fb bentazon POST and metolachlor PRE fb bentazon POST caused 20% phytotoxicity in bean at 3 WAP, which declined to less than 8% at 6 WAP. Trifluralin PSI alone or fb bentazon POST and metolachlor PRE fb bentazon POST reduced density of broadleaves in Juana Díaz by 71, 95 and 55%, respectively, compared with the density of broadleaves in non-treated plots at 3 WAP. At 6 WAP, trifluralin PSI fb bentazon and sethoxydim POST and metolachlor PRE fb bentazon and sethoxydim POST reduced density of grasses by 85% and 94%, respectively. Trifluralin PSI, imazethapyr PRE, and metolachlor PRE, all combined with bentazon and sethoxydim POST, as well as trifluralin PSI alone, reduced density of broadleaves in Isabela at 3 WAP by 80%, 53%, 61% and 76%, respectively. The strategy of trifluralin PSI fb bentazon and sethoxydim POST improved yield of green-shelled beans in Isabela, with a 68% increase over yield with mechanical cultivation. This strategy also improved yield of dry beans in Juana Díaz, with a 55% increase. All chemical strategies, except bentazon fb sethoxydim POST, increased yield of dry beans in Juana Díaz, compared with that of mechanical cultivation. The results obtained confirm the efficacy of chemical strategies based on trifluralin PPI, metolachlor or imazethapyr PRE, either alone or followed by bentazon and sethoxydim POST for the control of weeds in beans with drip irrigation.