Variation in the effectiveness of biocontrol agents on the weed Parthenium hysterophorus L. was evaluated at two properties (Mount Panorama and Plain Creek) in Queensland, Australia for four years (1996-2000) using a pesticide exclusion experiment. At Mount Panorama, higher levels of defoliation by the leaf-feeding beetle Zygogramma bicolorata Pallister and galling by the moth Epiblema strenuan...

Gene flow in crop-wild complexes between phenotypically differentiated ancestors may transfer adaptive genetic variation that alters the fecundity and, potentially, the population growth (λ) of weeds. We created biotypes with potentially invasive traits, early flowering or long leaves, in wild radish (Raphanus raphanistrum) and F5 crop-wild hybrid (R. sativus × R. raphanistrum) backgrounds and ...

bruchidius fulvus allard is a biological control agent of camelthorn weed (alhagi camelorum fisch.) in birjand region. efficiency of b. fulvus for biological control of camelthorn weed was studied by separate experiments in laboratory and natural conditions based on crd in 2009. so in average, 35±1.15 and 48±1.04% of the seeds in the legumes destroyed in the spring sampling (early of may) and i...

A fast-spreading weed, kochia (Kochia scoparia), has developed resistance to the widely-used herbicide, glyphosate. Understanding the relationship between the occurrence of glyphosate resistance caused by multiple EPSPS gene copies and kochia fitness may suggest a more effective way of controlling kochia. A study was conducted to assess fitness cost of glyphosate resistance compared to suscepti...

The relationship between seed mass variation and germinability in ten Abutilon theophrasti Medic. plants from a single agricultural population was examined under controlled environmental conditions. Seeds were collected in the autumn of 1995 and dry-stored in paper bags at 4°C until the start of trials in the spring of 1998. For each plant, between 549 and 1000 randomly selected seeds were sepa...

this experiment was set to study the allelopatic effect of aqueous and alcoholic extracts of artemisia, coriander, eucalyptus and cumin on growth of red root pigweed and lambsquarters weeds at laboratory and field in the university of tehran (karaj-iran) in 2008. the herbal plant samples were ground and powdered for extraction preparation, and were mixed with distilled water in a beaker. the ex...

allelopathy refers to the chemical inhibition or stimulation of one species by another which could influence on the growth or germination of other plant and used in control of weed in agricultural practices. in this sense in order to study the possibly allelopathic effects of lemon balm, bitter apple and lemon verbena medicinal plants on control of wild mustard weed, a laboratory experiment was...

       Seed dormancy has an important role in resistance and survival mechanisms of plants. Finding of some information about the range of primary dormancy and effective factors in dormancy breaking and optimal conditions of seed germination are necessary for weed control and other research purposes.  In this research, the seeds of 10 species of grass weeds in Tehran province fields (Echinocloa...

Important roles for biotic agents in integrated weed management include preventing seed production and weed emergence from the seed bank. Seed-attacking microorganisms have been described for a limited number of economically important weeds and serve as examples illustrating the potential for reducing weed seed production. Innundative releases of seed-feeding insects have also successfully redu...