in order to evaluate the interference effect natural population weeds and plant density, an experiment with randomized complete block design in factorial arrangement with 4 replications was conducted in 2006 in a field experiment at ramin agricultural and natural resources university, khouzestan. treatments included two factor, plant density of corn at three levels (4, 7 and 10 plants m-2) and ...

Research has concluded that global warming will likely increase abundance and occurrence of insect pests and plant diseases in agricultural systems. Most of the evidence cited for this increase is based on either empirically derived information, simulation models developed from laboratory observations and/or environmental extremes that resulted in pest outbreaks. While these phenomena can help ...

Flea beetles in the genus Altica are herbivorous, urban agricultural pests that are morphologically difÞcult to distinguish. Host plant associations, therefore, have been used as an important species character in Þeld studies. Indigenous weeds in the Onagraceae, genus Oenothera, are known to serve as developmental hosts for the ßea beetle Altica litigata Fall. Although host plant speciÞcity in ...

This article analyzed the ecological succession between pests of crops as a result transition from traditional cotton-alfalfa crop rotation system to cotton-grain system. It was found that species composition, development and propagation characteristics harmful organisms in weeds around field, well intermediate crops, can be reduced by up 60-70%, protected entomophagous destructive effects pest...

Biological weed management is a system that incorporates the use of diverse biological organisms and biologically-based approaches including allelopathy, crop competition, and other cultural practices to significantly reduce weed densities in a manner that is similar to use of chemical herbicides alone. Interest in developing effective biological weed management systems continues to increase be...

Lesquerella fendleri is a new crop being cultivated in the arid Southwest for the hydroxy fatty acids found in its seed oils; however, little is know about the agricultural pests that will affect the seed production of this crop or the role the crop may have as a possible source or sink for current agricultural pests in the Arizona landscape. In the early spring, lygus bugs, some of our most im...

Plant quarantine system becomes an important pillar in the protection of biological diversities from threat plant pests and diseases. The implementation currently covers prevention spread pests, food safety, quality, genetic resources bio-agents, as well invasive alien species genetically modified organism. During 2014 to 2018, a total 232 frequency intercepted viruses, bacteria, fungi, nematod...

Plant tolerance to insect pests has been indicated to be a unique category of resistance, however, very little information is available on the mechanism of tolerance against insect pests. Tolerance is distinctive in terms of the plant's ability to withstand or recover from herbivore injury through growth and compensatory physiological processes. Because plant tolerance involves plant compensato...

Weeds can cause great economic and ecological harm to ecosystems. Despite their importance, comparisons of the taxonomy and traits of successful weeds often focus on a few specific comparisons - for example, introduced versus native weeds. We used publicly available inventories of US plant species to make comprehensive comparisons of the factors that underlie weediness. We quantitatively examin...

Microbial weed control represents an innovative means to manage troublesome weeds and utilize the naturally occurring biological herbicides produced by soil microorganisms. These compounds kill or hinder the growth of weeds so that beneficial plant species can gain a competitive advantage. The vast diversity of microorganisms in our environment is largely untapped, and the potential discovery a...