Evaluation of Foramsulfuron + Idosulfuron (MaisTer OD) Herbicide Efficacy on Weed Control, Growth and Yield of Maize

 Maize (Zea mays L.) is the third most important cereal after rice and wheat, which is widely grown in the world and used as a primary staple food in many developing countries.  The area and production under maize in the world in 2020 was 202 M ha with 1162352997 tonnes production and contributed almost 5% of the world’s dietary energy supply. Recent projection indicates that by 2020 the demand of maize in all developing countries will overtake the demand of wheat and rice, with Asia accounting for nearly 60% of the global demand for maize.  Chemical control can be very important because of the low efficiency and cost effectiveness of mechanical or other methods of weed control. Hence, it is necessary to provide information about the sulfonylurea herbicides and suitable doses. Sulfonylureas such as iodosulfuron, nicosulfuron, rimsulfuron, and foramsulfuron are effective group of herbicides for annual and perennial weed control in maize. These herbicides provide a new chance for weed management in maize. Their mode of action occurs through inhibiting acetolactate synthase (ALS), thereby interfering with the production of branched-chain amino acids, leucine, isoleucine, and valine The objectives of this experiment were to evaluate the effect of different doses of MaisTer OD herbicide in comparison to the other herbicides on weeds control and growth and yield of corn.

 In order to evaluate the effect of different herbicides on weeds control and growth and yield of corn, a field study carried out during 2015 growing seasons at Seydan, Marvdasht, Fars province, Iran. The experiment was conducted in a randomized complete block design with 3 replications. Treatments included different rates of MaisTer OD (1, 1.5 and 2 l ha-1), Acetochlor (4.5, 5 and 6 l ha-1), Cruz (1.5, 2 and 2.5 l ha-1), Ultima (1, 2 and 3 l ha-1) and 2,4-D+MCPA (1.5, 2 and 2.5 l ha-1) herbicides and weed free and weedy control. The number and biomass of aboveground weeds parts were harvested within three fixed 1 × 1 m quadrats in every plot, separated by species, enumerated, oven-dried at 75 °C for 48 h, and then weighed. Then, percent weed density and biomass reductions were measured. The traits included ear length, row number per ear, grain number per ear, grain number per row, 1000 grain weight, grain yield, biological yield and yield loss percentage. Data were analyzed using SAS v. 9.1 software (SAS Institute 2003). When significant differences were observed among treatments, mean comparisons were made using Duncan's multiple range tests (P < 0.05). Correlation coefficients between different traits were also calculated.

 Results showed that the application of herbicide could reduce density and biomass of weed. The lowest biomass of redroot pigweed (Amaranthus retroflexus), lambsquarters (Chenopodium album), bindweed (Convolvulus arvensis), purple nutsedge (Cyperus rotundus) and foxtail millet (Setaria italica) was obtained, so that applying of MaisTer OD herbicide at 1.5 l ha-1 could be cause 47.10 and 27.36%, 69.38 and 56.22%, 66.79 and 70.94%, 66.85 and 74.26% and 66.85 and 80.15% reduction in density and total biomass of weeds in comparison with weedy control treatment, and grain yield increased by using MaisTer OD  herbicide at 1.5 l ha-1 in comparison to the other herbicides including Acetochlor (5 l ha-1), Cruz (2 l ha-1), Ultima (2 l ha-1) and 2,4-D+MCPA (2 l ha-1) by 53.3, 36.7, 5.7, and 56.7%, respectively. Grain yield and grain number per ear were reduced by weeds up to 60 and 50%, respectively. Highest row number per ear (16 and 15.30), grain number per row (41 and 41), grain number per ear (656 and 628.70), 1000 grain weight (286.33 and 276.33 g), grain yield (9.41 and 8.68 t ha-1) and biological yield (20.12 and 18.74 t ha-1) were obtained in weed free and MaisTer OD (1.5 l ha-1) treatments. Applying MaisTer OD herbicide showed lowest yield loss percentage (6.63%) and highest grain yield as compared to the other herbicides for weed suppression. 

 It can conclude that MaisTer OD herbicide at 1.5 l ha-1 showed the best performance for weed control, especially broadleaf weeds and were associated with the maximum corn grain yield. Therefore, due to the restricted use of herbicide in corn, the herbicide used in this experiment is not created serious injury in corn at the recommended rate while effectively controlling weeds. Hence, utilization of this herbicide could be a favorable option in contemporary weed control programs for local or regional corn growers.