ABSTRACT-Several herbicides are registered for selective weed control in sugar beet; however, no single chemical herbicide can control all weeds in beet fields. Frequently, two or more herbicides may have to be combined sequentially or as tank mixed to achieve adequate broad-spectrum weed control. In order to evaluate the effects of some combinations of broadleaf herbicides on sugar beet yield ...

Atrazine and metolachlor were more strongly retained on earthworm (Lumbricus terrestris L.) castings than on soil, suggesting that earthworm castings at the surface or at depth can reduce herbicide movement in soil. Herbicide sorption by castings was related to the food source available to the earthworms. Both atrazine and metolachlor sorption increased with increasing organic carbon (C) conten...

Modern herbicides make major contributions to global food production by easily removing weeds and substituting for destructive soil cultivation. However, persistent herbicide selection of huge weed numbers across vast areas can result in the rapid evolution of herbicide resistance. Herbicides target specific enzymes, and mutations are selected that confer resistance-endowing amino acid substitu...

Adsorption of the chloroacetanilide herbicides acetochlor, alachlor, metolachlor, and propachlor was determined on soils and soil components, and their structural differences were used to explain their sorptivity orders. On all soils and soil humic acids, adsorption decreased in the order: metolachlor > acetochlor > propachlor > alachlor. On Ca(2+)-saturated montmorillonite, the order changed t...

Glyphosate is the most widely used herbicide in the world for several reasons, including: 1) high level of effectiveness, 2) flexibility in application, 3) large margin of crop safety in glyphosate resistant crops, and 4) safety to applicators and the environment. Glyphosate was used for more than 20 years before weeds developed resistance to the chemical. This relative low risk of glyphosate r...

The means by which many herbicides kill susceptible plants are presently unknown (1, 3). Although it is not essential to know the mode of action in order to develop and use a herbicide efficiently, the screening processes by which herbicides are discovered are based upon comparative biochemistry. Selective herbicides with low nmammalian toxicity (2) must take advantage of differences in metabol...

Cyanoacrylates are potent inhibitors o f photosynthetic electron transport (PET) and are po­ tentially useful probes o f the photosystem II herbicide binding site. A series o f cyanoacrylates was synthesized and the Hill inhibition activities evaluated in order to select compounds suita­ ble for radioactive synthesis. A cyanoacrylate, 2-(2-nitrophenoxy)ethyl 3-benzylamino-2cyano-2-pentenoate, w...

Pesticides are typically applied as mixtures and or sequentially to soil and plants during crop production. A common scenario is herbicide application at planting followed by sequential fungicide applications post-emergence. Fungicides depending on their spectrum of activity may alter and impact soil microbial communities. Thus there is a potential to impact soil processes responsible for herbi...

Since transgenic, bromoxynil-resistant cotton and glufosinate-resistant canola were introduced in 1995, planting of transgenic herbicide-resistant crops has grown substantially, revolutionizing weed management where they have been available. Before 1995, several commercial herbicide-resistant crops were produced by biotechnology through selection for resistance in tissue culture. However, non-t...