Chemical weed control in the Ord River Valley. 2. Rice

Abstract

Three herbicides, CIPC (Isopropyl-N-(3-chloropheny1)-carbamate) EPTC (Ethyl-NN-dipropylthiol- carbamate) and Stam F-34 (3,4-Dichloropropionanilide), were tested for the control of barnyard grasses, Echinochloa colonum (L.) Link and Echinochloa crus-galli (L.) Beauv., in rice at Kimberley Research Station. The herbicides were tested at different rates and times of application on land lightly and heavily infested with weeds in crops of dry season rice, japonica variety Caloro, and wet season rice indica variety Meli No. 2 or Sircna. CIPC gave good control of weeds but did not increase crop yield ; furthermore, it was unreliable in its action and in one experiment reduced crop yield. EPTC, at 1 lb an acre active ingredient applied pre-sowing, gave good control of weeds but no increases in crop yield. Stam F-34, at 3-6 lb an acre active ingredient applied two to three weeks after crop emergence, gave good control of weeds in both wet and dry season rice and, as a result, crop yields increased.