abstract the aim of this study was the identify cyanobacterial flora of rice–fields in dargaz, to interaction between cyanobacteria by culturing in solid medium bg-110 in laboratory was investigated. nostoc piscinale and nostoc spongiaeforme were identified as strongest and weakness species, respectively, regarding secondary metabolits producing (allelochemicals).the algal pairs were classified...

among several pests of rice as one of the main agricultural products in iran, rice borer, chilo suppressalis is one of the most important pests of this crop. use of pesticides coincided with the occurrence of this pest in the northern region of iran in 1972. at present in order to control this pest, more than 12000 tones of pesticides granules are used annually. ecological effects of pesticides...

food. Almost two billion people—one third of the world’s population—depend primarily on rice for basic nourishment. Rice fields cover more than 360 million acres of land around the globe and yield 560 million tons of grain every year. But farmers plant much more rice than they harvest, because insects, bacteria, viruses and fungi often claim a substantial portion of each crop. One of the most d...

The objectives of this work were estimate the reaction rates of hydrolysis of carbosulfan to carbofuran and subsequent degradation of this last compound in irrigated rice fields, and the respective half life, in aquatic environment and soil solution, by mean of numerical solution of differential ordinary linear equations system that describes the kinetics of insecticide concentrations. The resu...

BACKGROUND AND AIMS Direct seeding of rice is being adopted in rainfed and irrigated lowland ecosystems because it reduces labour costs in addition to other benefits. However, early flooding due to uneven fields or rainfall slows down seed germination and hinders crop establishment. Conversely, early flooding helps suppress weeds and reduces the costs of manual weeding and/or dependence on herb...

Bipolaris oryzae causes rice brown spot disease which reduces rice yield with substantial global impact. Streptomycetes isolated from rice fields of Guilan Province, Iran, showed antifungal activity against the tested pathogen. From five active Streptomyces spp. isolates, isolate G showed high antagonistic activity. To determine its taxonomical identity, its colonies character...

The effect of urea on the oviposition behaviour of culicine vectors of Japanese encephalitis was studied in rice fields. Gravid females had a strong preference for oviposition in urea treated areas in rice fields, while no such preference was exhibited in untreated areas. The egg laying declined in the area where urea treated water surface had a mechanical barrier, which allowed volatile fracti...

Although bubble ebullition through water in rice paddy fields dominates direct methane (CH4) emissions from paddy soil to the atmosphere in tropical regions, the temporal changes and regulating factors of this ebullition are poorly understood. Bubbles in a submerged paddy soil also contain high concentrations of carbon dioxide (CO2), implying that CO2 ebullition may occur in addition to CH4 ebu...

The rice stink bug [Oebalus pugnax (F.)] is one of the important pests commonly found in Arkansas rice fields. When outbreaks in fields reach critical levels, an insecticide application is an option. Pyrethroid and organophosphate insecticides usually give excellent contact mortality, but both groups lack any significant residual activity. Two insecticides, dinotefuran and clothianidin, were te...