grand cherry (physalis divaricata) is considered as the most problematic weed in sugar beet farms in alashtar county, iran. special experiments involving chemical control of this weed were carried out using trifluralian, etalfluralian and chloridazon herbicides under laboratory conditions. the experiments were designed in a randomized complete block design in three replications, carried out in ...

A cross-cultural comparison between U.S. and Hong Kong preschoolers examined factors responsible for young children's analogical reasoning errors. On a scene analogy task, both groups had adequate prerequisite knowledge of the key relations, were the same age, and showed similar baseline performance, yet Chinese children outperformed U.S. children on more relationally complex problems. Children...

The rapid evolution of herbicide resistance poses a significant threat for conventional agricultural practices. In practice, herbicide resistance seems to be a very complicated problem to deal with. Extension can play a significant role in managing herbicide resistance educating farmers on the main advantages and disadvantages of the available methods aiming to control and minimize herbicide re...

Martin M. Williams II Corresponding author. U.S. Department of Agriculture—Agricultural Research Service, Invasive Weed Management Research, University of Illinois, 1102 S. Goodwin Ave., Urbana, IL 61801; [email protected] The critical period for weed control (CPWC) identifies the phase of the crop growth cycle when weed interference results in unacceptable yield losses; however, the effect of ...

Canada thistle is the most invasive and challenging weed in grazing systems in the Upper Midwest (Doll, personal observation) and its membership on the noxious weed lists of many states demonstrates its tenacity against conventional control tactics. The resilience of this weed can be credited to its ability to effectively reproduce through both seed production/dispersal and its extensive root s...

A Research Committee was established by the Weed Science Society of America to outline the direction of weed science research during the next decade. Weeds adversely affect humans in both agricultural and nonagricultural environments. It is the opinion of the research committee that weed science will be advantageously positioned for the future if research focuses on research decision processes,...

in order to determine the critical period of weed control and investigation the effect of periodical control and interference of weeds natural population on yield and yield components of winter canola (brassica napus l. cv. okapi) in west region of tehran an experiment was carried out at research field of tarbiat modarres university, tehran, iran on 2004-5 growing season. fourteen experimental ...

the recent decades emphasis on reducing pesticide use especially herbicide has led to increased interest in alternative weed control methods. the purpose of this study was to evaluate the hilling time and simultaneous interseeding of two cover crops as living mulch to control weeds in potato and to determine the impact of these actions on potato yield. a randomized complete block design as spli...

Controlling weeds in organic farming systems requires the use of many techniques and strategies in order to achieve economically acceptable weed control and yields. Weeds can always be pulled or cut out, but the question is simply how much can a grower spend in terms of time and money to reduce weed pressure. The more a grower is able to reduce weed pressure (seed and perennial propagules) the ...