The adoption of genetically modified (GM) crops has increased dramatically during the last 3 years, and currently over 52 million hectares of GM crops are planted world-wide. Approximately 41 million hectares of GM crops planted are herbicide-resistant crops, which includes an estimated 33.3 million hectares of herbicide-resistant soybean. Herbicide-resistant maize, canola, cotton and soybean a...

The synergistic interaction between mesotrione, a hydroxyphenylpyruvate dioxygenase (HPPD)-inhibiting herbicide, and atrazine, a photosystem II (PS II)-inhibiting herbicide, has been identified in the control of several weed species. A series of dose–response studies examined the synergistic effect of these herbicides on a susceptible (S) wild radish population. The potential for this interacti...

Use of efficient methods of weed control with as regards environmental sustainability as well as increased crop yield and also weed resistance to herbicides is essential. In order to, an experiment was conducted in 2012 in the Damavand jaban in Iran. Experiment treatments were compared in a split plot design by a randomized completely block design with 3 replication. The used variety of maize w...

BACKGROUND The widespread occurrence of ALS inhibitor- and glyphosate-resistant Amaranthus palmeri has led to increasing use of protoporphyrinogen oxidase (PPO)-inhibiting herbicides in cotton and soybean. Studies were conducted to confirm resistance to fomesafen (a PPO inhibitor), determine the resistance frequency, examine the resistance profile to other foliar-applied herbicides and investig...

The green alga Chlamydomonas reinhardtii provides a tractable genetic model to study herbicide mode of action using forward genetics. The herbicide norflurazon inhibits phytoene desaturase, which is required for carotenoid synthesis. Locating amino acid substitutions in mutant phytoene desaturases conferring norflurazon resistance provides a genetic approach to map the herbicide binding site. W...

The two primary sites of herbicide action in photosynthetic electron transport are the inhibition of photosystem II (PS II) electron transport and diversion of electron flow through photosystem I (PS I). PS II electron transport inhibitors bind to the DI protein of the PS II reaction center, thus blocking electron transfer to plastoquinone. Inhibition of PS II electron transport prevents the co...

As new herbicide-resistant crops come to market, it can be assumed that there will be a dramatic increase in use of 2,4-D and dicamba. Weed resistance could follow suit, and so a better understanding of the mechanism is urgently needed. In this issue of Journal of Experimental Botany (pages 3223–3235), Goggin et al. report on their analysis of 2,4-D resistance in wild radish. An elegant combina...

Green pigweed [Amaranthus powellii S. Wats.] is a competitive, annual, broadleaf weed that can significantly reduce soybean yield due to rapid early growth and biomass production. As consequence of green pigweed’s high competitiveness with crops, the species generally managed use herbicides; this may, however, lead selection resistance. A biotype resistance MCPA, mecoprop, dichlorprop-p, aminoc...