Show New Chemical Weapons To Combat Weed Pests Farmers and householders waging waging wag wag- ing war on crab grass and other troublesome weeds and grasses can look for help from two new ons The weed killing chemicals bear the jaw-breaking jaw names of sodium isopropyl and mixed carbonate They have been tested by federal and state agricultural experiment stations with excellent results against many weeds and grasses not economically economically economically eco eco- or satisfactorily controlled controlled controlled con con- trolled by other chemicals or practices practices practices tices the announcement said They are being used in active experimental tal programs but are not yet available available available avail avail- able commercially The second-named second herbicide is the one that combats crab grass as aswell aswell aswell well as barnyard orchard and blue bluegrass bluegrass bluegrass grass cattails and similar plants It has a like hormone-like action which attacks the root structure of the weed and arrests growth immediately immediately immediately immedi immedi- by preventing seed development development development develop develop- ment even though no effect is apparent apparent apparent ap ap- ap- ap parent on the surface for the first week or longer It also is used effectively effectively effectively in combination with D 24 against some leaved broad weeds not affected by D 24 used alone The sodium isopropyl is described as a complete killer which should be applied directly to crop plants It shows promise for pre-emergence pre treatment in spray or dust form and has been used with success in the chemical weeding weed ing of growing crops |