Butachlor is the common name for the active herbicide ingredient 2-chloro-2',6'-diethyl-N-(butoxymethyl)acetanilide. The preparation and use of this compound to control the growth of undesired plants is described in U.S. Pat. No. 3,442,945. Other active herbicide ingredients described in this patent include 2-chloro-2'-tert. butyl-6'-methylacetanilide and 2-chloro-2'-tert. butyl-6'-methyl-N-(butoxymethyl)acetanilide. U.S. Pat. No. 3,574,746 describes the preparation and use of the active herbicide ingredient N-(2-butoxyethyl)-N-(2,6-dimethyl-1-cyclohexen-1-yl)-.alpha.-chloroacetami de.
Molinate is the common name for the active herbicide ingredient S-ethyl hexahydro-1H-azepine-1-carbothiolate, whose preparation and use is described in U.S. Pat. No. 3,198,786. Benthiocarb is the common name for the active herbicide ingredient S-(4-chlorobenzyl)N,N-diethylthiolcarbamate, whose preparation and use is described in U.S. Pat. No. 3,632,332. Butralin is the common name for the active herbicide ingredient N-sec. butyl-4'-tert. butyl-2',6'-dinitroaniline, whose preparation and use is described in U.S. Pat. No. 3,672,866.
In the treatment of rice, it is often desirable to use relatively high rates of the active herbicide ingredient to achieve more rapid or more complete control of the undesired grasses which compete with the crop. Such higher rates, however, can create a significant problem because of the increased level of the detrimental herbicidal effect on the rice crop.
The effect of 3-phenacyl phthalide on root geotropism in various plants is discussed in the literature. Tests of this compound on cress and ryegrass are described in Pesticide Science, Vol. 4, pgs. 473-84 (1973).