proposed rule. amitraz atrazine ethephon ferbam lindane propachlor and simazine proposed tolerance actions by means of this rule and on the basis of available data the agency proposes the following changes to existing federal regulations for the pesticide atrazine currently there is only one active registration for use of atrazine on perennial rye grass and that use is restricted. because the label restricts grazing and cutting for feed the agency has determined that the tolerance on perennial rye grass is no longer needed and should be revoked. therefore epa is proposing to revoke the tolerances for the combined residues of atrazine in or on rye grass perennial at 15 ppm. because epa no longer considers sugarcane fodder and forage to be significant livestock feed items their tolerances are no longer needed and therefore should be revoked. consequently epa is proposing to revoke the tolerances in for sugarcane fodder and sugarcane forage. epa is proposing to decrease the tolerances on corn pop stover to 0.5 ppm corn fodder field to 0.5 ppm and to revise the commodity terminology to corn field stover and corn sweet stover to 2.0 ppm. epa is proposing to decrease the tolerances from 0.25 to 0.20 ppm for corn sweet kernel plus cob with husks removed and corn grain and revise the terminology to corn field grain and corn pop grain. epa is proposing to decrease the tolerance for combined residues of atrazine in or on nut macadamia from 0.25 to 0.20 ppm. epa proposes decreasing and revising the tolerances for the combined residues of atrazine in or on sorghum grain at 0.25 ppm to sorghum grain grain at 0.20 ppm and sorghum fodder at 15 ppm to 0.50 ppm. epa is proposing to decrease the tolerance on sugarcane cane from 0.25 to 0.20 ppm. epa is proposing in to decrease the tolerances on wheat grain to 0.1 ppm and wheat straw to 0.5 ppm. epa is proposing in to revoke the duplicate tolerance on wheat straw and establish a tolerance on wheat forage at 1.5 ppm. in addition based on field trial data that showed atrazine residues of concern as high as 1.11 ppm on wheat forage and adjusting for the difference in dry matter between hay and forage 88 vs. 25 the agency expects combined residues of about 3.9 ppm on wheat hay and therefore determined that a tolerance should be established on wheat hay at 5.0 ppm. consequently epa is proposing to establish a tolerance on wheat hay at 5.0 ppm.