Show now new chemical weapons to combat weed posts pests farmers and householders waging war on crab grass and other troublesome weeds and grasses ca can n look tor for help from two new wea weapons P the weed killing chemicals bear the jaw breaking names ol of sodium isopropyl and mixed chloro phenyl carbonate they have been tested by federal and state agricultural experiment stations with elc excellent ellent results against man many y weeds and grasses not economically no or satisfactorily controlled by other chemicals or pra practices c the announcement said they are being used in active experimental programs but are not yet available commercially the second named herbicide Is the one that combats crab grass as well as barnyard orchard and blue grass cattails coattails cat tails and similar plants it 11 has a hormone like action which attacks the root structure of the tha weed and arrests growth immediately by preventing seed development even th though ough no effect is apparent on the surface for or the first week or longer it also is used eflee in combination with 2 4 D against some broad leaved weeds not affected by 24 2 4 D used alone the sodium isopropyl is described as a complete killer which should not be applied directly to crop plants flints it shows show promise for or pre emergence treatment in spray or dust form and has been used with success in the chen chemical acal weeding of growing crops |