In order to investigate the effect of mixing nicosulfuron HERBICIDE with salicylic acid and cocowet adjuvant on growth, yield and weeds control in corn, a field experiment was conducted as factorial based on randomized complete block design with three replications at the research field of Shahrood University of Technology. Factors were including weed control method (A) at four levels, control (a1), weeding (a2), consuming 1 liter of HERBICIDE (nicosulfuron) (a3) and consuming 2 liters of HERBICIDE (a4) and salicylic acid (B) in two levels, 0. 7 mM salicylic acid (b1) and the absence of salicylic acid (b2) and cocowet (C) in two levels, consumption of 2 liters per hectare cocowet (c1) and absence of cocowet (c2). The results showed that the maximum plant height (143. 2 cm) and leaf area index (7. 76) was obtained with combined use of salicylic acid and cocowet. Also the highest grain (7528 kg. ha ) yield was observed in weeding × salicylic acid consumption treatment. The results indicated that no significant difference was observed in grain yield and total weed density between the cocowet + REDUCED HERBICIDE DOSE (1 L. ha-1 ) and biological (20490 kg. ha-1 ) with recommended HERBICIDE DOSE (2 L. ha-1 ). Based on the results of present study, application of cocowet in combination with REDUCED DOSE of HERBICIDE can be an effective method of weeds control and increase growth and yield of crop and also reduce HERBICIDE consumption.

Introduction: Modeling fertilizer-HERBICIDE relationship is helpful to minimize the competition of weeds with crops. The goal of present study was to develop the empirical models for predicting crop yield, number and weight of common mallow seed using integrated DOSE-response curves of HERBICIDE and fertilizer application. Materials and Methods: An experiment was conducted in split plot design based on randomized complete block design with three replications in Agricultural Sciences and Natural Resources University of Khuzestan in 2017 growing season. Experimental factors were N-fertilizer as main plot at 5 levels (0, 75, 150, 225 and 300 kg ha-1 of urea) and DOSE of bromoxynil+2, 4-D as sub plot at 5 levels (0, 0. 25, 0. 50, 0. 75 and 100% rate of recommended DOSE (1. 5 L ha-1)). Common mallow density (50 plant m-2) was fixed in all plots and wheat sowing density was 350 plant m-2. The wheat cultivar was Chamran 2. Spraying was carried out using a 20-liter rechargeable Matabi back Sprayer equipped with a nozzle (11003) and a pressure of 2 bar (calibrated based on 200 to 300 liters of water per hectare) in the post-emergence stage at the middle of the wheat tillering stage (6-4 The leaf of the common mallow). Half of the nitrogen fertilizer was applied at sowing stage and the other half was distributed in the middle of the wheat tillage stage. The plants were then cut at surface and dried in oven (75 ° C) and weighted. The four parameters sigmoid model was used to assess wheat and common mallow yield response to HERBICIDE REDUCED DOSE and N fertilizer. The three parameters power model was also applied to explain the change of mallow number and weight in response to REDUCED HERBICIDE DOSE and different levels of N-fertilizer application. Results and Discussion: Wheat grain yield increased in response to increasing HERBICIDE DOSE and reducing the competitive ability of common mallow in different levels of urea fertilizer application. The grain yield was equal to 202, 277, 329, 408, 443 and 450 g m-2, when 300 kg of urea fertilizer ha-1 with 0. 375, 0. 60, 0. 75, 1. 05, 1. 35 and 1. 50 L ha-1 of the recommended DOSE of HERBICIDE was employed, respectively. Moreover, the DOSE required to reduce 50% of the weed competition effects on wheat grain yield was decreasing in urea fertilizer levels. The results showed that the higher levels of urea fertilizer decreased wheat grain yield, but increased the number and weight of the common mallow seeds. The number of common mallow seeds was maximum for the higher levels of urea fertilizer and lesser DOSEs of bromoxynil+2, 4-D, was minimum under low urea fertilizer consumption and the higher levels of bromoxynil+2, 4-D. The density of common mallow seeds under no-HERBICIDE conditions ranged from 4. 78 to 35. 87 g m-2 for each urea fertilizer level. The number of common mallow seeds produced under no-HERBICIDE application varied between 1915. 95 and 16540. 76 seeds per m-2 for each fertilizer level. However, in the case of higher DOSEs of bromoxynil+2, 4-D, weight and seed number of common mallow showed a decreasing trend. Thus, under no-HERBICIDE condition, common mallow produced much more seeds when higher N-fertilizer rates were applied. Application of 300 kg of urea ha-1 without HERBICIDE application led to the highest common mallow seed number and weight and the lowest wheat yield. The greatest wheat yield (i. e. 515. 40 g m-2) was obtained by consuming 225 kg of urea ha-1 along with 1 L ha-1 bromoxynil+2, 4-D. In addition, the higher urea fertilizer levels REDUCED wheat grain yield, but increased the common mallow seed number and weight. Conclusion: Increasing the competitive ability of weeds, application of high N-fertilizer rate results in a larger yield loss. However, HERBICIDE application with the application of high N-fertilizer is highly likely to control weed, causing an increase in wheat yield. The combined model helps to lessen the HERBICIDE and fertilizer application.

Field experiments were conducted to investigate the effect of HERBICIDE DOSEs on corn-multiple weed competition.Sixteen weed density combinations consisting of 4 densities of redroot pigweed × 4 densities of common cocklebur under five DOSEs of HERBICIDE were assessed. The two weed species responded differently to HERBICIDE DOSEs.Competitivity of redroot pigweed decreased with increasing HERBICIDE DOSE and was completely removed by applying HERBICIDE at 0.5 of full recommended DOSE, but for common cocklebur an initial increase occurred at 0.25 rate of full dosage. The relationship between weed competitivity and HERBICIDE DOSE was well-described by standard DOSE response curve and Brain & Cousens model for redroot pigweed and common cocklebur, respectively. A combined model incorporated standard DOSE response curve and Brain & Cousens function into the multivariate rectangular hyperbola competition model gave a good description of corn yield. When no HERBICIDE was applied, the competitivity of common cocklebur was approximately 1.7 times greater than that of redroot pigweed and 63% of yield loss occurred from the combination of 8 common cocklebur and 12 redroot pigweed plants m-2. Where the density of common cocklebur was low (0 to 4 plants m-2) applying HERBICIDE at half the full recommended DOSE could save the yield, but with increase in common cocklebur density, the HERBICIDE REDUCED DOSEs failed to prevent the yield loss. Even at full recommended DOSE of HERBICIDE, corn yield suffered loss of 6 to 10 percent from high density of common cocklebur.Nomenclature: Nicosulfuron; common cocklebur, Xanthium strumarium L.; redroot pigweed, Amaranthus retroflexus L.; corn, Zea mays L.

To evaluate the effect of different corn/redroot pigweed densities and REDUCED HERBICIDE DOSEs of 2, 4- D+ MCPA on corn growth and yield and control of redroot pigweed, a field experiment were conducted at the Agricultural Research Station, Ferdowsi University of Mashhad, in 2007. A strip block design on the basis of randomized complete block design with three replications was applied. The experiment consisted of three factors: weed density (3, 6, 9 and 12 plant/m2) as vertical factor, HERBICIDE DOSE (0, 50 and 100 % of recommended DOSEs) as horizontal factor and crop density (7, 9 and 11 plant/m2) which splitted on vertical factor. Results showed that HERBICIDE application REDUCED weed dry weight and leaf area index (LAI). In contrast, corn dry weight and LAI increased as HERBICIDE application DOSEs increased. Corn grain yield and yield components increased significantly by increasing corn density. The HERBICIDE efficiency increased, when HERBICIDE was applied to corn of upper crop density and corn yield losses decreased. The increase in HERBICIDE efficiency was significant in REDUCED DOSE treatment, but in recommended DOSE a little increase was observed. Corn grain and biological yield, grain numbers per row, 100 seed weight and harvest index decreased significantly by increasing pigweed density, but rows number per cob was not affected. The results of this research indicated that HERBICIDE DOSE could be decreased by using high corn density, without significant decrease in grain yield.

To determine the most appropriate method of weed management in conventional row and ultra narrow row spacings of cotton, a factorial experiment was based on a randomized complete block design with three replications was conducted in Sabzevar in 2015-2016. Factors under study were plant spacings in two levels, conventional (70 cm row spacing) and ultra-narrow row (20 cm row spacing) and weed management in six levels: without controlling of weeds (control), application of HERBICIDE at recommended DOSE of Ethalfluralin (Treflan 48% EC) at 1160 g/ai ha), application of HERBICIDE at 50% recommended DOSE + hand weeding at 45 days after emergence (DAE), application of HERBICIDE at 50% recommended DOSE + two times hand weeding at 30 and 60 DAE, three times hand weeding at 30, 45 and 60 DAE, and full weed free condition. The results showed that traits like weed density, by 33. 71 percent, lateral branches by 14. 77 percent, number of bolls per plant by 16. 88 percent, and boll weight by 12. 30 percent were lower in narrow row spacing, while seed cotton yield by 39. 85 percent and fiber yield by 23. 71 percent higher, as compared to, conventional row spacing. In the conventional cultivation system, if 50% of the HERBICIDE DOSE is REDUCED, it needs two hands weeding at 30 and 60 DAE,while in ultra-narrow row spacing condition, with a 50% reduction in the recommended HERBICIDE DOSE, one hand weeding at 45 DAE is needed to achieve suitable seed cotton yield. As a whole, the results showed that, under ultra-narrow row spacing, with a 50% reduction in HERBICIDE DOSE and REDUCED weed control times (only one hand weeding at 45 DAE) it can be obtained seed cotton yield similar to other control treatments.

A study was carried out over 2 years (2008/2009 and 2009/2010) in Greece, in order to evaluate the weed control using REDUCED rates of the HERBICIDE mesosulfuron-methyl+iodosulfuron-methyl-sodium of four major weeds (Avena sterilis, Phalaris minor, Papaver rhoeas and Sinapis arvensis), grain yield and yield components of five wheat cultivars (Bob, Cosmodur, Meridiano, Quadrato and Simeto). The results indicated a significant differentiation between the several wheat cultivars regarding their weed competitive ability, in terms of dry biomass and seed production. In the case of cultivars such as Simeto the efficacy of 50% reduction of the HERBICIDE recommended rate on wild oat remained high, since it resulted to a reduction of biomass and seed production up to 81 and 98% compared with the untreated plots. In most cultivars studied, the reduction of the HERBICIDE rates by 25 to 50% resulted to a no significant reduction of grain yield compared to the recommended rate. The study revealed that some wheat cultivars with enhancing weed competitiveness can improve the efficacy of REDUCED HERBICIDE rates. Consequently, sustainable cropping systems could be further developed through the integration of such agronomic practices, while in parallel, care on the threat of HERBICIDE resistance development should be also taken.

Introduction: Bean (Phaseolus vulgaris L. ) is so sensitive to intercompetition especially with weed species. Weed management is an essential factor for the success of an agricultural production system. The use of high competitiveness figures is one of these approaches. Another way to manage properly is just to reduce HERBICIDE DOSE using through the mixed HERBICIDEs in crops. By intercropping, filling the empty space prevents weed development in the area. Mixing or simultaneous cultivation of two or more species in one plot of land is one of the oldest agricultural systems in the world. Planting density is another important factor in determining plant yield. Planting density not only determines competition for light and nutrients, but also controls the distribution and allocation of dry matter between plant organs. The studies showed that by increasing bean planting density from 20 to 30 and 40 plants m2, yield increased by 15. 4% and 24. 7%, respectively, and the weed biomass also increased by a density of 20 to 40 by 30 percent. The use of high competitive cultivars and increasing planting density are the main strategies to increase the competitive ability of beans against weeds. This study was carried out to investigate the methods of pure and mixed cultivation of bean cultivars with different densities for their effect on reduction of bentazone HERBICIDE DOSE, weed control and crop yield. Materials and Methods: In order to investigate the effect of planting density and reducing HERBICIDE DOSEs on weeds biomass and crop yield in pure and mixed cultivation of red bean cultivars, a field experiment was carried out at Agronomy Research Field of Ferdowsi University of Mashhad during 2013-2014. A factorial experiment (with three factors) was conducted in a completely randomized block design with 4 replications. Experimental treatments including bean planting densities in three levels consisting of optimum density (Goli 40 and Akhtar 50 /m2), 20 and 40 % higher than the optimum density of both Akhtar and Goli cultivars, and Bentazone HERBICIDE concentrations (0, 50 and 100 %) based on the recommended DOSE (2. 5 liters per hectare), and separate and mixed cultivation of Akhtar (standing) and Goli (ascending) cultivars were performed in rows (1: 1). Weed biomass was evaluated every two weeks after spraying by 100*25 cm2 cadaver from two middle rows. At the end of the growing season, a 1*1 m2 staff was used to determine the performance. Data were analyzed by SAS 9. 1 software and averages were compared with the LSD test at 5% probability level and the graphs were analyzed using SigmaPlot 12. 0 software. Results and Discussion: The results showed that for the weed biomass, the mixed cultivation of Akhtar and Goli cultivars was more than pure cultivation due to its success in suppressing high competitive weeds through rapid space cover, which can be attributed to this feature. It was used to reduce the HERBICIDE DOSE. Also, the highest and lowest grain yield (respectively 463 and 132 g/m2) were found for the pure cultivation of Akhtar cultivar at concentration of 100 and 0 % HERBICIDE, respectively. However, in flowering and mixed cultivars, the highest grain yield was observed at 372. 2 and 341. 3 g/m2, at 50% HERBICIDE concentration, which was also observed in biological yield. Results of interaction effect showed that the highest biological yield in intercropping (1166 g/m2) was observed for 50% HERBICIDE concentration and 40% planting density. It can be, therefore, concluded that REDUCED DOSEs of HERBICIDEs can only be used if the crop has high competitive ability and planting density is increased, which can reduce the competitive ability of weeds. The use of high competitive crops and increased density of crops have the greatest potential in suppressing weeds and reducing HERBICIDE dosage. The previous studies also showed that limiting bean growth leads to a decrease in leaf area index and bean growth rate, which in turn reduces its competitiveness against weeds. Conclusion: The use of high-strength cultivars in mixed cultivation due to their overlap, space conquest, and ability to compete with weeds along with increased plant density has a high potential for weed suppression and can be used in other ways to reduce HERBICIDE DOSE. The results of this experiment showed that there was no significant difference between biological yield at 50% and 100% HERBICIDE concentrations in the mixed cultivation and the highest biological yield was observed in the mixed cultivation.

To evaluate the different DOSEs of mesosulfuron + iodosulfuron (Atlantis) and application time on two Kurdistan and Fars populations in crop year 2013-2014, a split spilt plot experiment was carried out in the field in Fars province. The different DOSEs of HERBICIDE (0, 6, 12, 18, 24 g ai/ha) as the main plot, two populations of wild oat (Kurdistan and Fars respectively) as sub-plot and application time at stages of 18 (8 leaves) and 23 zadoks (tillering) as sub-sub plot were considered. The regrowth percentage of wild oat Fars and Kurdistan populations in highest DOSE (24 g ai/ha) at two HERBICIDE application times in 8 leaves (16. 16 and 4. 5%) and tillernig (23 and 6%) were obtained respectively. It is remarkable that the regrowth percentage of wild oat at REDUCED dosage (12 g ai/ha) at tillernig time was more than 8 leaves in two Kurdistan and Fars populations. DOSE-response equations for dry weight of wild oat showed that the required level of DOSE for reaching a 50% decrease in two populations of wild oat and application times was different. DOSEs of 7. 93 and 8. 38 g ai/ha in order to achieve a 50% decrease in the dry weight of Kurdistan population in two application times of 8 leaves and tillering was required. These amounts for a 50% reduction in dry weight of Fars were 9. 89 and 9. 66 g ai/ha, respectively. In REDUCED DOSEs of HERBICIDE with delayed application time, regrowth and dry weight of wild oat increase and effect on grain yield and number of spike in wheat. The application of REDUCED DOSEs (12 g ai/ha) is recommended at stages of 18 zadoks (8 leaves).