Do Traits Travel? Multiple-Herbicide-Resistant , an Alien Weed Species in Israel.

is the most common weed in soybean and corn in the USA and Canada. In Israel, it has been a minor riverbank weed. However, in recent years, growing densities of this plant have been observed in field crops, orchards, and roadsides.

Simulating sulfosulfuron fate in soil under different weather scenarios to support weed management decisions.

Background: Residual herbicides are an important component in many weed control strategies. Their herbicidal activity depends on their fate in soil, with respect to the required concentration for weed control in space and time. In this study, the effect of weather conditions on sulfosulfuron fate in soil, following pre-planting incorporation, and the predicted control efficacy of Egyptian broomrape in tomato, were analyzed for two sites using simulations in Hydrus-1D modeling software.

Different Mutations Endowing Resistance to Acetyl-CoA Carboxylase Inhibitors Results in Changes in Ecological Fitness of Populations.

Various mutations altering the herbicide target site (TS), can lead to structural modifications that decrease binding efficiency and results in herbicide resistant weed. In most cases, such a mutation will be associated with ecological fitness penalty under herbicide free environmental conditions. Here we describe the effect of various mutations, endowing resistance to acetyl-CoA carboxylase (ACCase) inhibitors, on the ecological fitness penalty of populations.

Unraveling the Transcriptional Basis of Temperature-Dependent Pinoxaden Resistance in .

Climate change endangers food security and our ability to feed the ever-increasing human population. Weeds are the most important biotic stress, reducing crop-plant productivity worldwide. Chemical control, the main approach for weed management, can be strongly affected by temperature.

Isoxadifen safening mechanism in sweet corn genotypes with differential response to P450-metabolized herbicides.

Three sweet corn genotypes, two inbred lines (IBER001 and IBER002) and their hybrid (ER00X), differ in their phenotypic responses to several P450-metabolized herbicides, used in sweet corn, namely, foramsulfuron, iodosulfuron, rimsulfuron and tembotrione. Foramsulfuron is a sulfonylurea herbicide commonly formulated with the safener isoxadifen that is used for selective post-emergence weed control in corn. Our goal was to elucidate the mechanism of these genotypes' responses to foramsulfuron and safener isoxadifen and examine the heritability of those responses.

Hyperspectral Technologies for Assessing Seed Germination and Trifloxysulfuron-methyl Response in (Palmer Amaranth).

Weed infestations in agricultural systems constitute a serious challenge to agricultural sustainability and food security worldwide. S. Watson (Palmer amaranth) is one of the most noxious weeds causing significant yield reductions in various crops.

Secondary Effects of Glyphosate Action in : Inhibition of Solute Transport from the Host Plant to the Parasite.

It is currently held that glyphosate efficiently controls the obligate holoparasite (Egyptian broomrape) by inhibiting its endogenous shikimate pathway, thereby causing a deficiency in aromatic amino acids (AAA). While there is no argument regarding the shikimate pathway being the primary site of the herbicide's action, the fact that the parasite receives a constant supply of nutrients, including proteins and amino acids, from the host does not fit with an AAA deficiency. This apparent contradiction implies that glyphosate mechanism of action in is probably more complex and does not end with the inhibition of the AAA biosynthetic pathway alone.

Effects of Environmental Conditions on the Fitness Penalty in Herbicide Resistant .

Herbicide-resistance mutations may impose a fitness penalty in herbicide-free environments. Moreover, the fitness penalty associated with herbicide resistance is not a stable parameter and can be influenced by ecological factors. Here, we used two accessions collected from the same planted forest, sensitive (S) and target-site resistance (TSR) to photosystem II (PSII) inhibitors, to study the effect of agro-ecological parameters on fitness penalty.

Thermal Time Model for Egyptian Broomrape () Parasitism Dynamics in Carrot ( L.): Field Validation.

Carrot, a highly profitable crop in Israel, is severely damaged by parasitism. Herbicides can effectively control the parasite and prevent damage, but for optimal results, knowledge about the soil-subsurface phenological stage of the parasite is essential. Parasitism dynamics models have been successfully developed for the parasites , and in the summer crops, tomato, sunflower, and red clover, respectively.

Climate change increases the risk of herbicide-resistant weeds due to enhanced detoxification.

Global warming will increase the incidence of metabolism-based reduced herbicide efficacy on weeds and, therefore, the risk for evolution of non-target site herbicide resistance. Climate changes affect food security both directly and indirectly. Weeds are the major biotic factor limiting crop production worldwide, and herbicides are the most cost-effective way for weed management.

Mechanism of glyphosate control of Phelipanche aegyptiaca.

Despite its total reliance on its host plant, the holoparasite Phelipanche aegyptiaca suffers from a deficiency of aromatic amino acids upon exposure to glyphosate. The herbicide glyphosate inhibits 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS), a key enzyme in the biosynthesis of aromatic amino acids. However, the functionality of the EPSPS pathway in the obligate root holoparasite Phelipanche aegyptiaca is not straightforward because of the parasite's total dependence on the host plant.

Non-target-site glyphosate resistance in Conyza bonariensis is based on modified subcellular distribution of the herbicide.

Background: Conyza spp. were the first broadleaf weeds reported to have evolved glyphosate resistance. Several mechanisms have been proposed for glyphosate resistance.

From sensitivity to resistance - factors affecting the response of Conyza spp. to glyphosate.

Background: Conyza bonariensis and C. canadensis are troublesome weeds, particularly in fields with minimum tillage, on roadsides and in perennial crops. The distribution of these difficult-to-control species is further increased by the spread of glyphosate-resistant populations.

Conyza species: distribution and evolution of multiple target-site herbicide resistances.

Distribution of Conyza species is well correlated with human interference. Multiple herbicide resistance is caused by the attempt to overcome resistance to one mode of action by overuse of another. Conyza canadensis (CC) and Conyza bonariensis (CB) are troublesome weeds around the world.

Developing Global Leaders for Research, Regulation, and Stewardship of Crop Protection Chemistry in the 21st Century.

To provide sufficient food and fiber to the increasing global population, the technologies associated with crop protection are growing ever more sophisticated but, at the same time, societal expectations for the safe use of crop protection chemistry tools are also increasing. The goal of this perspective is to highlight the key issues that face future leaders in crop protection, based on presentations made during a symposium titled "Developing Global Leaders for Research, Regulation and Stewardship of Crop Protection Chemistry in the 21st Century", held in conjunction with the IUPAC 13th International Congress of Pesticide Chemistry in San Francisco, CA, USA, during August 2014. The presentations highlighted the fact that leaders in crop protection must have a good basic scientific training and understand new and evolving technologies, are aware of the needs of both developed and developing countries, and have good communication skills.

Development and employment of slow-release pendimethalin formulations for the reduction of root penetration into subsurface drippers.

Subsurface drip irrigation supplies water directly to the root zone and is an efficient irrigation technology. One of the main challenges is preventing plant roots from clogging the drippers. With the aim of inhibiting root penetration, slow-release pendimethalin formulations based on its solubilization in micelles adsorbed and unadsorbed to clay were developed.

Evolution of herbicide resistance mechanisms in grass weeds.

Herbicide resistant weeds are becoming increasingly common, threatening global food security. Here, we present BrIFAR: a new model system for the functional study of mechanisms of herbicide resistance in grass weeds. We have developed a large collection of Brachypodium accessions, the BrI collection, representing a wide range of habitats.

Absorption, translocation and metabolism of metamitron in Chenopodium album.

Background: In recent years, common lambsquarters (Chenopodium album L.) populations from sugar beet fields in different European countries have responded as resistant to the as-triazinone metamitron. The populations have been found to have the same D1 point mutation as known for atrazine-resistant biotypes (Ser264 to Gly).

Variation in essential oil composition within individual leaves of sweet basil (Ocimum basilicum L.) is more affected by leaf position than by leaf age.

The aroma in sweet basil is a factor affecting the commercial value of the crop. In previous studies leaf age was considered to be a factor that influences the composition of essential oil (EO). In this study it was hypothesized that a single observation of the EO content in leaves from different positions on the main stem (young vs old) could predict the developmental changes in the plant during its life cycle.

Bioavailability of xenobiotics in the soil environment.

It is often presumed that all chemicals in soil are available to microorganisms, plant roots, and soil fauna via dermal exposure. Subsequent bioaccumulation through the food chain may then result in exposure to higher organisms. Using the presumption of total availability, national governments reduce environmental threshold levels of regulated chemicals by increasing guideline safety margins.

Microtubules are an intracellular target of the plant terpene citral.

Citral is a component of plant essential oils that possesses several biological activities. It has known medicinal traits, and is used as a food additive and in cosmetics. Citral has been suggested to have potential in weed management, but its precise mode of action at the cellular level is unknown.

Are herbicide-resistant crops the answer to controlling Cuscuta?

Background: Herbicide-resistant crop technology could provide new management strategies for the control of parasitic plants. Three herbicide-resistant oilseed rape (Brassica napus L.) genotypes were used to examine the response of attached Cuscuta campestris Yuncker to glyphosate, imazamox and glufosinate.

Altered pesticide use on transgenic crops and the associated general impact from an environmental perspective.

The large-scale commercial cultivation of transgenic crops has undergone a steady increase since their introduction 10 years ago. Most of these crops bear introduced traits that are of agronomic importance, such as herbicide or insect resistance. These traits are likely to impact upon the use of pesticides on these crops, as well as the pesticide market as a whole.

Determination of plant resistance to carbamate herbicidal compounds inhibiting cell division and early growth by seed and plantlets bioassays.

Herbicide-resistant plants can be generated by either traditional breeding procedures or genetic engineering. Analyses of plant responses to a newly developed herbicide or the tolerance level of a newly developed plant line to a given herbicide are based on various bioassays. Here, we describe several methods for quantitative measurements of plants' responses to propham application, as a model herbicide of the carbamate family.