Determining Weed Maps and population characteristics of Irrigated Wheat Fields for Sistan and Baluchestan Province
Received date: 28 Aug 2010 Accepted date: 16 Oct 20101- Baluchestan Agricultural and Natural Resources Research Center, Iranshahr, Iran.
- Sistan Agricultural and Natural Resources Research Center, Zabol, Iran.3- Iranian Research Institute of Plant Protection, Tehran, Iran.
A study was done to map weeds in irrigated wheat fields from 2001 to 2006 in Sistan and Balochistan province. In this study, 44 sample wheat fields were selected and weed species were counted in each sampling point and population indices were calculated. In each fields longitude, latitude and altitude were recorded using GPS. These data were used for producing weed map using GIS. Results showed that annual yellow sweetclover (Melilotus indicus (L.) All.), common mallow (Malva neglecta Wallr.) and prostrate knotweed (Polygonum aviculare L.) were dominant broadleaf species in irrigated wheat fields of Sistan and Balochistan province. Dominant grass weed species were japanesse brome (Bromus japonicus Thunb.ex murr), winter wild oat (Avena ludoviciana L./Dur.) and Canarygrass (Phalaris minor Retz.). Hoary cress (Cardaria draba (L.) Desv.), field bindweed (Convolvulus arvensis L.), camel’s thorns (Alhagi pseudalhagi (M.Bieb.) Desv.) and Salsola spp. were the most important disturbing plants prior to harvesting in irrigated wheat fields of Sistan and Balochestan province. • Key words: Weed mapping, geographic information system (GIS), abundance index, (AI), frequency, uniformity, mean field density.
Influence of wild mustard (Sinapis arvensis L.) different densities on yield and yield component of winter wheat (Triticum aestivum L.)
Received date: 25 May 2010 Accepted date: 16 Sep 20101- Ph.D.students of Azad university of Research and Sciences, Khozestan.2- Associate professor, Faculty of Agriculture, Shahid Chamran University, Ahwaz.3- Assistant professor, Faculty of Agriculture, Shahid Chamran University, Ahwaz.4- Professor, Ramin Agricultural and Natural Resource, University.5- Associate professor, Faculty of Agriculture, Shiraz University.*: Corresponding author's E-mail:
A field study was conducted in Fars at Agricultural Experimental Station of Firooz Abad Islamic Azad University in 2006 to evaluate wild mustard densities on wheat yield and yield component. Increasing wild mustard density decreased grain yield, wheat dry matter, spike per plant and seed per spike. Wild mustard had no effect on wheat height and wheat seed weight per 1000 seed. Reduced grain yield ranged from 3.1 to 29.9% at 1 to 16 wild mustard per m2, respectively. At 16 plant per m2wild mustard reduced wheat spike per m2 by 16.2% and seed number per spike per m2 by 19.6%, when compared to weed free check. Results also showed that increase in wild mustard dry weight, due to increase in mustard density, had negative effect on wheat dry weight. Wild mustard must be controlled either before or shortly after wheat emergence if detrimental effects on wheat are to be minimized.
Comparative evaluation of the effects of salinity and drought on germination and seedling growth of Barnyardgrass (Echinochloa crus-galli L.) and Rice (Oryza sativa L.), and its relationship with their competition under stress conditions.
Received date: 06 Mar 2009 Accepted date: 27 Jun 20101- M.Sc. Student of Weed Science, University of Birjand. Iran.
- Assistant Professor, University of Birjand, Iran.*: Corresponding author's E-mail:
An experiment was conducted at Pakdasht barley fields in 2004 & 2005 growing seasons to study the effect of chemical control on weed seed bank in rotation systems. Corn-barely rotation with and without chemical application was implemented. Method of sampling was systematic (zigzag) and the time of the sampling stages were in two dates; before sowing and after harvesting of barley. To compare the diversity between farms, Shannon-Weiner diversity index was calculated. Weed seed bank densities in chemical managed farms (CMFs) was generally lower than those without chemical control (NCMFs). At first sampling, average weed seed bank populations in CMFs, were 49 and 31 seeds kg-1 of soil, and for NCMFs were 136 and 177 seeds kg-1 soil in 2004 and 2005, respectively. The weed seed bank density in second sampling date (post harvesting of barley) for CMFs were 33 and 30.5 seeds kg-1 soil, and for NCMFs were 210 and 254 seeds kg-1 of soil in 2004 and 2005, respectively. Seed bank density decreased over sampling times (growing season) for CMFs in 2004 as compared with NCMFs. In 2005, the NCMFs variation trend of the seed bank densities for managed farms was constant between the two stages of sampling. But the trend of variation in NCMFs was similar to that of previous year. Shannon-Weiner diversity index in CMFs was higher than those of NCMFs. Herbicide application had reduced the seed production of weeds and the ultimate seed rain into the soil seed bank. Results of this study demonstrate the importance of weed control practices in reducing weed seed bank size.
Study of effectiveness of different combinations of selective herbicides for control of broadleaf weeds in Sugar beet (Beta vulgaris L.) fields
Received date: 20 Oct 2010 Accepted date: 08 Dec 20101- Iranian Research Institute of Plant Protection, Tehran, Iran.
2- Khorasan Razavi Agricultural and Natural Resources Research Center, Iran.
3- Western Azarbayejan Agricultural and Natural Resources Research Center, Iran*:Corresponding author's E-mail:
Field studies were conducted in 2005 to determine the effectiveness of different combinations of selective herbicides for control of broadleaf weeds in sugar beet fields in Tehran (Karaj), Khorasan Razavi (Mashhad) and Western Azarbayejan (Miandoab) provinces. Weed biomass and frequency and visual evaluation of weed injury and Sugar beet yield were those traits evaluated in this experiment. Weed biomass and frequency measurements in each province indicated that (phenmedipham + desmedipham + ethofumesate) + triflusulfuron methyl was the best composition. triflusulfuron methyl + desmedipham also was another composition that produced a good result. These treatments had no good effect on bindweed. The least herbicidal effect came from chloridazon + triflusulfuron methyl and chloridazon + (phenmedipham + desmedipham + ethofumesate) which had little effect on weed biomass and frequency.