تاثیر علف‌کش‌های خاک کاربرد بر علف های هرز و عملکرد دانه گندم دیم در مناطق سردسیر

Soil-applied herbicides can be used at sowing time (incorporated by sowing (IBS)) to control weeds. In this method, the herbicide is sprayed all over the field before planting and, during the planting, a herbicide-free bed is provided for seeds by throwing poisoned soil by the seeding furrow opener between the planting rows. To investigate the effects of two soil-applied herbicides, Trifloralin and Metribozin by IBS method on dryland wheat and weeds, an experiment was carried out in the strip plots arrangement on a randomized complete block design in four replications in 1401-1402 cropping season at Dryland Agricultural Research Institute (DARI), Maragheh. Vertical treatments included weed controls at seven levels, Trifloralin at doses of 1.5 and 2 l ha-1, Metribozin at doses of 500 and 700 gr ha-1, Clodinafop Propargyl (1 l ha-1) + 2,4-D + MCPA (1.5 l ha-1) at the tillering stage of wheat and two control treatments of weeding and no weeding. The horizontal treatments included two tractor-spraying speeds at 5 and 7 km h-1 levels. Results indicated that 30 days after applying the Clodinafop Propargyl + 2,4-D + MCPA, the main effect of tractor speed and tractor speed × herbicide interaction had no significant effect on density, biomass, and grain yield of wheat, while the main effects of herbicide and dose were statistically significant (P < 0.05). The highest spike density was recorded for weeding and 2,4-D + Clodinafop Propagyl treatments with 408 and 368 spike m-2, respectively, and the lowest for the Metribozin at doses of 700 and 500 gr ha-1 with 33 and 99 spike m-2, respectively. The highest grain yield was recorded for weeding, 2,4-D + Clodinafop Propagyl and Treflan (1.5 l ha-1) treatments, respectively, by 2402, 2297, and 2083 kg ha-1, The lowest grain yield of wheat was observed for the Metribozin herbicide doses of 700 and 500 gr ha-1, respectively, 703 and 1375 kg ha-1. It can be concluding that leaching of Metribozin herbicide at the planting time due to the autumn rains damaged the germinated seeds and reduced the number of plants and grain yield. The lowest density and biomass of weeds were recorded for the Metribozin at a dose of 700 gr ha-1 with 16 plants and 60 grams of biomass per square meter. Trifloralin herbicide at doses of 1.5 l ha-1with the highest yield of wheat after Clodinafop Propargyl + 2,4-D + MCPA treatment is the best soil treatment.