SUMMARY Simazine loss from soil to surface runoff water produce both a decrease in the effectiveness of the soil chemical treatment and a water quality hazard in receiving waters. Simazine has been found in 30% of wells sampled in Fresno and Tulare counties, California and some contamination has been attributed to simazine use in citrus orchards. Contamination of receiving water from herbicides...

If an herbicide application fails to control a targeted weed community sufficiently, farmers may try to eliminate surviving weeds with a follow-up application (hereafter ‘‘respray’’). Despite the implications of resprays on the spread of herbicideresistant weeds, respray frequencies and causal factors are poorly understood. A two-part survey of glyphosate-resistant soybean fields and custom app...

Weed management is an important consideration in implementing new cropping systems. In the semi-arid region of the Pacific Northwest, grower interest is increasing in no-till spring cropping systems because of wind erosion from traditional winter wheat Triticum aestivum L./dust-mulch fallow (WWF). However, no-till represents a major shift in production practices and is likely to produce new wee...

We assessed the effects of cultivating two genetically modified (GM) glyphosate-tolerant soybean varieties (Glycine max (L.) Merr.) derived from Event 40-3-2 and a Japanese conventional variety on arthropods under field conditions, with weed control using glyphosate and conventional weed control for two years. Plant height and dry weight of the conventional variety were significantly larger tha...

Alligator weed Alternanthera philoxeroides (Mart.) Griseb. is an amphibious plant that aggressively invades aquatic and terrestrial environments. It has invaded at least 14 countries and is difficult to control. The present study investigates the effectiveness of herbicides and physical removal in eliminating patches of aquatic alligator weed in an early stage of invasion. This paper firstly de...

Pest control is one of the areas in which population dynamic theory has been successfully applied to solve practical problems. However, the links between population dynamic theory and model construction have been less emphasized in the management and control of weed populations. Most management models of weed population dynamics have emphasized the role of the endogenous process, but the role o...

a field experiment was conducted in research farm of isfahan university of technology, isfahan, iran in 2011 . various weeding periods were investigated on growth and yield of potato under drip tape and furrow irrigation systems. a split plot arrangement was used in a randomized complete block design with three replications. irrigation treatments were included in main plots and periods of weed ...

Certified Crop Advisors of Arkansas and members of the Arkansas Crop Consultants Association were surveyed in fall 2006 through direct mail to assess current weed management practices and needs in rice from both a research and educational perspective. Consultants reported scouting 564,000 of the possible 1,400,000 acres (40%) of rice grown in Arkansas. Preemergence herbicides most often recomme...

in order to evaluate the effects of crop cultivars and living mulchon sunflower yield and weed control, a field experiment was carried out as factorial arrangement based on a randomized complete block design with three replications in 2013. treatements were sunflower cultivars (‘azargol’, ‘allstar’, ‘farokh’) and weed control treatments (weed-free, weed-infestation and intercropping of fagopyru...

Weed communities in agronomic fields are dominated by annual species. Summer annuals initiate growth each spring from seeds found in the upper soil profile (Figure 1). In most fields, a small percentage of the emerging plants survive and contribute new seeds to the soil seedbank. Historically, most research of the annual weed life cycle has focused on seed dormancy and emergence (A), effect of ...