We are studying the mechanisms involved in the evolution and spread of herbicide-resistant weed populations. So far, we have identified more than 15 weed species that confer resistance to various herbicide groups. We elucidated the biochemical and molecular mechanisms involved in the resistance of grasses and broad-leaf weeds to various herbicides. We also study the relationships between the resistance trait, ecological fitness and response to environmental factors. We developed a rapid method for detection and identification of resistant plants. We investigate the molecular and biochemical bases for the herbicide-resistance grasses and parasitic weeds. We also investigate the impact of using transgenic cotton (''Roundup Ready). on the crop management and the environment in Israel
We directed our research to the elucidation of the growth stages in which weeds are most vulnerable to control measures, and to the understanding of the mechanisms involved in crop selectivity. We contribute to the improvement of weed management and reduce herbicide input in Israel's major crops - wheat and cotton. Using regular and transgenic cotton resistant to the herbicide glyphosate (''Roundup Ready), we are developing an improved weed management program, including the control of troublesome weeds such as purple nutsedge(Cyperus rotundus).
We are trying to reduce the hazard of environmental damage due to herbicides by designing clay-based formulations, which will reduce leaching and migration of herbicides in soil. The herbicides are sorbed on clays whose surfaces were modified from hydrophilic to hydrophobic by adsorption of suitable organic cations. Such modified surfaces better bind hydrophobic herbicide molecules, thus reducing their concentrations in soil solution and consequently extend their biological activity. Different approach is manifested for anionic herbicides: Slow release is achieved by using organic cations with a large hydrophobic part and very small critical micelle concentratio(CMC) , such as octadecyltrimethyl ammonium (ODTMA). The anionic organic molecules bind well to the positively-charged micelles which attract electrostatically their negatively-charged head groups and whose interiors provide a hydrophobic environment for the organic ligand. Then positively charged mixed micelles adsorb on negatively-charged clay (montmorillonite), which forms aggregates.
We study the biology of parasitic weeds - field dodder (Cuscuta campestris) and broomrape(Orobanche spp), their interaction with host plants and response to herbicides. We elucidating the mechanisms involved in resistance of certain host plants to parasitic weeds at the biochemical and molecular levels.