IN ORDER TO COMPARE EFFECT OF JOHNSON GRASS (SORGHUM HALEPENSE L.) CHEMICAL AND MECHANICAL CONTROLL ON YIELD OF CITRUS (SWEET LEMON), AN EXPERIMENT WERE CONDUCTED IN COMPLETELY RANDOMIZED BLOCK DESIGN WITH THREE REPLICATIONS IN 2007 AT SHAHID BEHESHTI COMPANY, DEZFUL. EXPERIMENTAL TREATMENTS WERE INCLUDING: APPLICATION OF GLYPHOSATE 5 L HA-1, FOCUS 3 L HA-1, NABU-S 6 L HA-1, ILOXAN 4 L HA-1, SUPER GALANT 750 CC HA-1, TOPIC 900 CC HA-1, MECHANICAL TREATMENTS WERE MOVERTWO TIMES-EVERY 15 DAYS, ONE MOVER, AND WEED FREE AND WEED INFESTED CHECK. THE RESULT SHOWED THAT DIFFERENCE AMONG THE LEVELS OF THE MECHANICAL AND CHEMICAL TREATMENTS ON TRAITS OF SWEET LEMON WAS SIGNIFICANTLY EFFECT. MOVER-TWO TIMES AND GLYFOZITE TREATMENTS WITH PRODUCE 2.6 AND 2.3 TONS LEMON PER HECTAR COUSED REDUCTION OF WEED DRY WEIGHT 565.7 AND 562.5 G M-2. ALSO, THIS TREATMENTS CONTROLLED SORGHUM 73 AND 94% THAN WITNESS WITH WEED, RESPECTIVELY.