In order to study efficacy of prosulfuron+DICAMBA for control of wheat broadleaf weeds, an experiment was conducted in randomized complete block design with four replications at Zarghan, Dezful, Karaj and Mashhad regions during 2018-2019 cropping season. The treatments were included of bromoxynil+MCPA (1.5 l ha-1 of Bromicide-MA® 40%), bromoxynil + 2,4-D (1.25 l ha-1 Buctril Universal 56%), bazagran+dicloprop ( 2 l ha-1 Basagaran-DP® 6.56%), triasulfuron+DICAMBA (165 g ha-1 Lintur® 70%), and the new herbicide prosulfuron+DICAMBA (300, 400 and 500 g ha-1 alone or mixed with adjuvants). The results showed that prosulfuron+DICAMBA in all doses, alone or mixed with adjuvants, caused a decrease in the dry weight of the dominant weeds in Karaj (75 to 100%), Zarghan (85 to 93%), Dezful (70 to 100%) and Mashhad (42 to 97 percent), but compared to other herbicides, there was no significant difference in saving wheat yield in most areas. Lintur® was the most inefficient (50%-75%) and Buctril Universal® was the most efficient (more than 85%) herbicide in our experiment. The most important weeds include Descuriania sophia, Fumaria vailantii, Galium tricornutum, Centaurea depressa, Carduus sp., Rapistrum rugosum, Veronica persica, Malva neglecta and Sinapis arvensis. As a recommendation, prosulfuron+DICAMBA can be used in the dose of 300 g ha-1, alone or mixed with adjuvants (0.5% v/v of Cytogate). No visual damages were observed from prosulfuron+DICAMBA application on wheat.

An experiment was conducted on clay soil at Lods Agronomy Research Center, McGill University to study the response of weeds communities and corn plants to nitrogen and herbicide application. The experiment was arranged as split plots design with 6 replications, in which application of herbicide (at 4 levels) and nitrogen (at 3 levels) were respectively the main- and sub-treatments. The herbicide Nicosulfuron (9 g ha-1) mixed with mineral oil (Agral 90, 25% v/v) was used to control grass weeds. The herbicide DICAMBA (590 g ha-1) was used for broadleaf control. Nicosulfuron mixed with Agral at the above mentioned rates, and DICAMBA at 295 g ha-1 were used to control both grass and broadleaf weeds. Weedy check also was considered as control. Nitrogen (ammonium nitrate) at 60, 120, and 250 kg ha-1 was applied twice; once at planting time and again 54 days after planting. The results indicated that the density of grass weeds was higher than that of broadleaf weeds. However, broadleaf weeds could grow vigorously and by the end of the season they showed strong growth in most weedy check. Nitrogen had a pronounced effect on corn growth and yield. Reducing the nitrogen supply resulted in pale green leaves in the corn. Increasing nitrogen application increased the corn biomass mainly during the rapid vegetative growth stage.

Yield variability of selected winter wheat cultivars under different sowing rate and selected application, was investigated during 2006-2008, in the Lower Silesia region (South-West Poland). Experiments with two varieties, two levels of sowing rate and seven herbicides, including untreated object were set up on the same field, using split-plot method. For evaluation of yield stability Kang's yieldstability statistic (YS) was applied. Examined herbicides did not influence grain yield of both cultivars, at standard wheat density (450 seeds/m2). Under low density, Kobra Plus variety showed variable reaction to herbicides. Iodosulfuron methyl sodium+diflufenican+mezosulfuron methyl, mecoprop+MCPA+DICAMBA and iodosulfuron methyl sodium+amidosulfuron resulted in yield increment in comparison with untreated object, whilst DICAMBA+triasulfuron gave opposing effect. Yield stability at different herbicide objects during 3-years period was considerably variable and dependent on cultivar and sowing rate. Yield of both cultivars, obtained from plots treated with iodosulfuron methyl sodium+diflufenican+mezosulfuron methyl, iodosulfuron methyl sodium+amidosulfuron and mecoprop+MCPA+DICAMBA, under low density was comparable with standard sowing.

In order to introduce new chemical weed management program in maize weed control in Iran, a study was conducted during 2014 and 2015. Experiment were carried out in a randomized complete block design with three replications. 15 treatments of the common maize herbicides, including nicosulfuron, foramsulforon, eradicane and 2, 4-D + MCPA were applied in their recommended doses, moreover the treatments related to cycloxydim with DICAMBA + tritosulfuron were used with different doses and in different times along with two control treatments (weedy and weed-free). Treatments contained 75-150 g a. i. ha-1 of cycloxydim, showed similar results with the common treatments including nicosulfuron, foramsulforon, eradicane and 2, 4D + MCPA. However, treatments with high doses of cycloxydim, had a significant reduction in weed density and weed biomass. There were no significant differences between the effects of treatments on maize grain yield and biomass. Despite the acceptable weed control of the combined treatment of cycloxydim with DICAMBA plus tritosulfuron, maize canopy could overcome weed growth. Based on the results and by considering cycloxydim efficacy in controlling perennial grassy weeds in maize plantation, this chemical is a suitable option during different growing stages of weeds and maize. Finally, the application of 200-300 g a. i. ha-1 of cycloxydim combined with DICAMBA plus tritosulfuron was the best option from an economic and environmental safety points of view.

An experiment was conducted to evaluate individual application efficiency and mixing herbicides of broad leaf killer on control of European bishop (Bifora testiculata) as well as traits of growth, yield and components yield of wheat (Triticum aestivum) based on the Randomized Complete Block Design (RCBD) in four replications in research farm of Gonbad Kavous University in 2014-2015 growing season. Treatments included Tribenuron methyl (Granstar), Bromoxynil+MCPA (Bromicide MA ), 2, 4, D + DICAMBA (Dialen super), mecoprop-p + dichloprop-p + MCPA (Duplesan super), 2, 4, D, mixing of the Tribenuron methyl with other herbicides and control (without application of herbicides and hand weeding). Results showed that effect of the various treatments of control (without application of weeds and hand weeding) and herbicides on dry matter, plant desity and total chlorophyll content of Bifora testiculata and whole measured traits of wheat were significant (p<0. 01). In the Overall, mixing herbicides had a more decrease effect on the plant desity, dry matter and total chlorophyll content of Bifora testiculata in comparison with individual application. In this study, the hieghest yield were obtained in the treatment of Tribenuron methyl along hand weeding about 3527 and 3720 Kg/h respectively. In return, the lowest yield were found in the treatment of without application of herbicides (1864 Kg/h). The mixing of Tribenuron methyl with mecoprop-p + dichloprop-p + MCPA and 2, 4, D + DICAMBA caused highest negative effect on Bifora testiculata, while these treatments had a lower negative impact on seed number in spike and seed yield over individual application of them. Regarding to more efficiency effect of Tribenuron methyl in mixing with new herbicided in Bifora testiculata control and low negative effect on seed yield of wheat, to prevent herbicide resistance using individual application, it is recommended to apply Tribenuron methyl with other herbicides specialy mecoprop-p + dichloprop-p + MCPA and 2, 4, D + DICAMBA in wheat field.

Although, weed control in saffron farms is critical, no herbicide is registered for saffron fields. This experiment was carried out in a randomized complete block design with three replicates during 2016-2017. Treatments included application of trifluralin, pendimethalin, metribuzin, bentazon, ioxynil, oxadiazon, oxyfluorfen, haloxyfop-r-methyl, sethoxydim, clethodim, cycloxydim, nicosulfuron, rimsulfuron, tribenuron methyl, foramsulfuron, paraquat, DICAMBA + triasulfuron, and DICAMBA + tritosulfuron herbicides at recommended and reduced doses. Mother corms were planted on 10th of September 2016 at 5 × 10 cm corms distance and planting depth of 15 cm. Measured indices included: number of flowers, fresh and dry weights of flower and stigma, number of replacement corms and total corms weight. Results showed that visual phytotoxic symptoms were not observed in pre emergence herbicides. Post emergence herbicides showed different levels of phytotoxicity from slight to severe. The application of paraquat, oxyfluorfen and oxadiazon, caused higher levels of phytotoxicity compared to other herbicides. Acetyl CoA carboxylase inhibitor herbicides caused the least injury to saffron, while acetolactate synthase inhibitor herbicides damaged saffron severely. The highest and the lowest dried stigma yield was obtained from control treatment (0. 54 g. m-2) and post application of tribenuron methyl (0. 003 g. m-2) respectively. Among pre emergence herbicides, the highest dried stigma yield was recorded for pendimethalin herbicide. The post application of metribuzin, oxadiazone and oxyfluorfen resulted in greater dried stigma yield than other broadleaf herbicides. By reducing herbicide dose saffron yield increased and phytotoxic levels were reduced significantly. Among the studied herbicides, trifluralin, oxyfluorfen, pendimethalin and metribuzin can be used as selected herbicides in saffron.

Introduction: Plant Protection Organization (PPO) has registered 22 commercial herbicides formulations for weed control of wheat, barley and triticale in Iran. Among these herbicides, sixtheen herbicides introduced act as two proposed or only for broadleaved weeds. Their active ingredients including acetolactate synthase (ALS) enzyme inhibiting groups, synthetic-auxin groups, a photosynthetic inhibitor of photosystem II, and pigment synthesis inhibitor groups (Tomlin, 2009). Previous studies show that existing weed species do not similarly respond to herbicides and therefore the percentage control of some of the weed species is lower than the other species (Ohadi, 2010). These hard-to-control weeds are naturally tolerant to herbicides or may be developing resistant to one mode of action. Thus, we need new herbicides to suppress such weeds. The aim of this work was to find the best chemical treatments against weeds in wheat production based on using the new herbicide fluroxypyr and comparing their efficacy with commonly registered herbicides in the major wheat growing areas of Iran. Material and Method: A field study was conducted in four regions of Iran, including Karaj, Shahryar, Ahwaz, Shiraz, and Gonbad during 2017-2018 growing season. The statistical layout was a completely randomized block design with four replicates. Ten herbicides in 12 treatments were 2, 4-D+MCPA (U46-Cambi fluid®,67. 5%SL, 1. 5 1 L ha-1), Mecoprop-p + Dichloprop-p + MCPA (Duplosan super®,60% SL, 1 L ha-1), Bromoxynil + MCPA (Bromicide®,40% EC, 1. 5 L ha-1), Tribenuron-methyl (Granstar®,75% DF, 20 gr ha-1), Mesosulfuron-methyl + Iodosulfuronmethyl sodium+ Diflufenican+Mefenpyre-diethyl (Othello®,75% WG, 1. 6 L ha-1), 2, 4-D + DICAMBA (Dialant super®,46. 4 SL, 0. 8 L ha-1), Triasulfuron + DICAMBA (Lintur®,70% WG, 165 gr ha-1), Bromoxynil + 2, 4-D (Buctrile Univeral®,56% EC 1. 5 L ha-1), Dichloprop+bentazone (Basagran DP 56. 6% SL, 2 L ha-1) and the new herbicide Fluroxypyr with th recommended doses (Kavin Flurox®,20% EC 1. 5, 2 and 2. 5 L ha-1). An unweeded treatment served as controls. Weed density and weed dry weight for each plot were measured four weeks after the last application the herbicides. Wheat was harvested from six m2 of each plot after removing border plots. Wheat grain yield was determined after adjusting the moisture level of grain to 14 %. Data from each region were subjected to statistical analysis using SAS/STAT®,statistical software and the means were separated by Duncan (α, =5%). Results and Discussion: The results showed a diverse spectrum of weeds (14 species) at the experimental locations. Descuriania Sophia was dominant in two tested locations Karaj and Shiraz. The next dominant weed species were Galium aparine L., Conringia orientali and Centaurea depressa M. B. were present dominantly in Shiraz. Polygonum aviculare, Fumaria vailantii and Veronica persica were present in Karaj. Lepyrodiclis holosteoides as a noxious weeds, were dominant only in Shahryar. Malva neglecta and Scorpiurus muricatus were in Ahwaz and Bifora testiculata was dominat in Gnbad. Across the experimental locations, fluroxypyr was efficient at 2-2. 5 L ha-1 concentrations for weed control (85. 77 to 90. 68%). However, when applied at dosage of 1. 5 L ha-1, total weed control efficiency was lower (80. 75%). Bromoxynil + 2, 4-D (85. 43%), Dichloprop-p + Bentazon (83. 98%) were the most efficient after fluroxypyr. Mecoprop-p + Dichloprop-p + MCPA and Bromoxynil + MCPA with 80% average efficiency controled weeds in all the locations. Triasulfuron + DICAMBA and 2, 4-D + DICAMBA were inefficient in weed control (67. 75 and 68. 22%, respectively) across all locations. These findings were in agreement with the results of some previous studies (Minbashi and Saeedi, 2019, Minbashi et al. 2020). Lepyrodiclis holosteoides with average control of 63. 68% and CV= 23. 98% was the most difficult-to-control weed in this experiment. Other weeds beside that were Scorpiurus muricatus, Polygonum aviculare, Malva neglecta and Bifora testiculata identified as difficult-to-control weeds. None of herbicides showed visual injury symptoms on wheat. Conclusion: According to these experiments, we found that the Fluroxypyr (2-2. 5 L ha-1) as new candidate herbicide showed good to excellent (85%-100%) weed control efficiency averaged in the all experimental locations and it could be recommended to be used in wheat field after registration process. Due to environmental concern, it should be applied at lower doses for non-difficult-to-control weeds. We found that Bromoxynil + 2, 4-D was the most efficient next herbicide after fluroxypyr and Triasulfuron + DICAMBA as an unefficient herbicide overall. L. holosteoides as the most hard-to-control weed was controlled only by upper dose (2. 5 L ha-1) of new herbicide. Other difficult-to-control weed species were Scorpiurus muricatus, Polygonum aviculare, Malva neglecta and Bifora testiculata.

A field study with 3 replications based on RCBD was conducted in order to improve the efficacy of some herbicides using adjuvants in the control of broadleaf weeds of saffron. Oxadiazone, oxyfluorfen, rimsulfuron and DICAMBA+ tritosulfuron herbicides at recommended rates of 500, 700, 10 and 150 a. i. ha-1, respectively without adjuvants and in reduced rates 375, 480, 8. 75 and 112, respectively were used when they were tankmixed with and without citogate (0. 2% v. v-1) and humix 99 (0. 25% v. v-1) as well as a control plot with no herbicide application and hand weeding. Weed species of Polygonum aviculare and Cardaria draba with relative density of 26% and 20. 5%, respectively were the dominant weeds in the experimental field. The results showed that hand weeding significantly increased the yield of saffron flower and corm. Application of oxyflurfen and oxadiazone in reduced rates decreased saffron damage while addition of citogate to these herbicides increased the phytotoxicity damage in saffron. Addition of humix to these herbicides had no effect on phytotoxicity damage. Although application of rimsulfuron and DICAMBA+ tritosulfuron in reduced rates reduced phytotoxicity damage and increased yield of saffron, these herbicides have the potential to damage saffron even at reduced rates. Adding citogate to these herbicides can increase the efficacy of these herbicides in weeds control but considering the potential of these herbicides in damage to saffron, application of these herbicides in saffron fields is not recommended even at reduced doses. Application of oxyflurfen at 480 a. i. ha-1 without adjuvant and tank-mixed with humix were best treatments for use in saffron fields. However, it is also possible to use oxadiazone at 375 a. i. ha-1 to control saffron broadleaf weeds.