Mohammad Bitarafan,; Hasan MohammadAlizadeh,; Eskandar Zand; Bejan Yaghobi; Fatemeh Bena Kashani
Volume 9, Issue 2 , January 2012
Abstract
The probability of Barnyardgrass resistance to some common rice herbicides used in the rice fields of Gilan, Mazandaran and Fars Provinces was investigated by conducting a series of greenhouse and Petri dish bioassay tests on 37 biotypes collected in 2005-2006. Greenhouse experiments involved screening ...
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The probability of Barnyardgrass resistance to some common rice herbicides used in the rice fields of Gilan, Mazandaran and Fars Provinces was investigated by conducting a series of greenhouse and Petri dish bioassay tests on 37 biotypes collected in 2005-2006. Greenhouse experiments involved screening tests with Petri dish tests implementing dose response assays to determine doses of herbicides inhibiting root and stem length growth by 50% (ID50) as well as to determine the sensitivity of the biotype to herbicides. Screening tests were carried out for each province separately for a given herbicide using a randomized complete blocks design with four replications. Minimum recommended doses of Butachlor, Molinate, and Thiobencarb were added to pots of 8cm water height before 2-leaf growth stage of Barnyard grass. Propanil was sprayed at the 3-4 leaf stage. Measurement of dry weight, number of surviving plants and visual rating (based on the EWRC rating scale) were conducted 4 weeks after treatments. A completely randomized design with four replications was also used in the Petri dish tests. This sensitive biotype was subjected to a range of herbicide doses resulting in 50% inhibition of root and stem growth and the response of biotypes to the ID50 of the sensitive biotype was further studied. Root (for Propanil) and stem length (for Butachlor, Molinate, and Thiobencarb) were measured 7 days after treatments. According to results obtained from greenhouse and Petri dish assays, it was revealed that Barnyardgrass biotypes collected from Gilan, Mazandaran and Fars Provinces were not resistant to the tested herbicides (Propanil, Butachlor, Molinate, and Thiobencarb). The results from Petri dish tests were correlated to those of greenhouse experiments.
Eskandar Zand; Fatemeh Bena Kashani; Saeid Soufizadeh; Meysam Ebrahimi; Mohammad Minbashi; Fatemeh Dastaran; Maryam Poorbayge; Mohammd Jamali; Azar Maknali; Masoumeh Younesabadi; Reza Deihimfard; Somayyeh Forouzesh
Volume 6, Issue 4 , July 2009
Abstract
To evaluate the resistance of wild oat (Avena ludoviciana), annual ryegrass (Lolium rigidum) and littleseed canarygrass (Phalaris spp.) in wheat fields of Fars, Khouzestan, Golestan and Ilam Provinces of Iran to clodinafop-propargyl herbicide from ACCase inhibitors of aryloxyphenoxy propionate classes, ...
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To evaluate the resistance of wild oat (Avena ludoviciana), annual ryegrass (Lolium rigidum) and littleseed canarygrass (Phalaris spp.) in wheat fields of Fars, Khouzestan, Golestan and Ilam Provinces of Iran to clodinafop-propargyl herbicide from ACCase inhibitors of aryloxyphenoxy propionate classes, 6 separate indoor experiments were conducted in the greenhouses of the Department of Weed Research in the Iranian Research Institute for Plant Protection. The experiments were conducted by using 19 populations of wild oat (including 15 questionably resistant populations and 4 susceptible populations), 14 littleseed canarygrass populations (including 10 suspected-resistant populations and 4 susceptible populations) and 9 annual ryegrass populations (including 8 questionably resistant populations and 1 susceptible mass) from Fars Province, 4 populations of wild oat (including 3 questionably resistant populations and 1 susceptible mass) from Lorestan Province, 17 littleseed canarygrass populations (including 16 probably resistant populations and 1 susceptible mass) from Khouzestan Province, and 12 littleseed canarygrass populations (including 11 questionably resistant populations and 1 susceptible mass) from Golestan Province. All the experiments were conducted separately in the form of a Randomized Complete Block Design (RCBD). A pot under no-herbicide application was also included as control. The remaining weeds number and dry weight percentage were calculated 30 days after herbicide application, and were then compared with their relative figures before herbicide application. A mass was recognized resistant only if it retained 80% of its number and 50% of its dry weight, in comparisonto the control. On this basis, 4 resistant and 2 questionably resistant littleseed canarygrass populations, 6 resistant and 3 questionably resistant wild oat populations and 5 resistant and 3 questionably resistant Annual Ryegrass populations were identified in Fars Province. In Ilam Province, 2 resistant wild oat populations were identified. Overall, in this experiment 75 populations including 63 questionably resistant and 12 susceptible populations were evaluated. Amongst the 63 questionably resistant populations (including 37 littleseed canarygrass, 18 wild oat and 8 annual ryegrass populations), 28 totally resistant populations (including 12 littleseed canarygrass, 11 wild oat and 8 annual ryegrass populations) and 10 probably resistant (consisting of 4 littleseed canarygrass populations, 3 wild oat populations and 3 annual ryegrass populations) were detected. In other words, approximately 60% (44% resistant and 16% probably resistant) of all evaluated questionably resistant populations were identified as resistant and probably resistant.
Eskandar Zand; Fatemeh Bena Kashani; Mohammad Ali Baghestani; Azar Maknali; Mehdi Minbashi; Saeid Soufizadeh; Reza Deihimfard
Volume 4, Issue 3 , April 2007
