BACKGROUND When applied at the correct plant stage and dose, herbicides are highly toxic to plants. At reduced, low herbicide doses (below the recommended dose) plants can survive and display continuous and quantitative variation in dose-survival responses. Recurrent (directional) selection studies can reveal whether such a phenotypic variation in plant survival response to low herbicide dose i...

A web-based system was developed to advise on the relative efficacy of different herbicides for mixes of weed and crop species at different times of the year in a forestry or farm forestry setting. The system assumes that weed identification and impact assessment or prediction have already been accomplished and that there are no cost-effective non-chemical alternatives. The expert system produc...

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. Wide screening of the responses of the accessions to fou...

Hybridization of Brassica napus L. (oilseed rape) and Raphanus raphanistrum L. (wild radish) has been demonstrated, and may be the first step towards introgression of transgenes in this wild relative. If wild radish were to display a new adaptive advantage by expressing the transgene, this could modify the ecological balance of species within the agro-ecosystem. To determine if transgenes remai...

Annual and perennial weed control trials were retreatedin Butte, Solano and Yolo counties. The diversified locations continue to provide a vital basis for applicable information on walnut tree tolerance to herbicides and on weed control efficacy. Herbicidal control of a wide spectrum of annual or perennial grass and broadleaf plants has been evaluated for the winter and summer periods of 1980. ...

The uptake of the triazine herbicides, atrazine and terbutryn, was determined for two freshwater photosynthetic microorganisms, the green microalga Chlorella vulgaris and the cyanobacterium Synechococcus elongatus. An extremely rapid uptake of both pesticides was recorded, although uptake rate was lower for the cyanobacterium, mainly for atrazine. Other parameters related to the herbicide bioco...

The recent shift from transplanted to wet seeded rice (Oryza sativa L.) in South East Asia has resulted in major weed problems which require more labour and energy for their control. Field experiments were conducted during 1994±1996 on a Chromic Vertisol in central Luzon, the Philippines, to study the effect of water, tillage and herbicide levels on total water use, weed growth and yield of wet...

2,4-Dichlorophenoxyacetic acid (2,4-D) was the first synthetic herbicide to be commercially developed and has commonly been used as a broadleaf herbicide for over 60 years. It is a selective herbicide that kills dicots without affecting monocots and mimics natural auxin at the molecular level. Physiological responses of dicots sensitive to auxinic herbicides include abnormal growth, senescence,...

H erbicide resistance is the inherited ability of a plant to survive and reproduce following exposure to a dose of herbicide that would normally be lethal to the wild type. In a plant, resistance may occur naturally due to selection or it may be induced through such techniques as genetic engineering. Resistance may occur in plants as the result of random and infrequent mutations; there has been...