Improving yield, yield components and some qualitative traits of soybeans with priming and foliar application of micronutrients under weed stress

Background and objectives: Weed competition for resources is one of the most important limiting factors in soybean production, Today, one of the solutions to deal with these unwanted plants on farms is the use of stress alleviator and micronutrient fertilizers, which have a significant effect on the ability of crops to compete with weeds, The effect of seed priming and Foliar application of micronutrients was investigated on yield, yield attributes and some qualitative traits of soybean under weed stress.

Materials and methods: In this research, seed priming and foliar application of micronutrients affect yield, yield attributes and some qualitative traits of soybean cv. Kowsar under weed stress as a factorial experiment based on completely randomized blocks was performed during 2020-2021 at Qorveh (Kurdistan province) in three replications. salicylic acid prime with a concentration of 0.5 mM, hydroprime and non-prime, hand weeding in three levels no-weeding, once weeding, twice weeding and foliar application of micronutrients in four levels include foliar application with water (control), zinc sulfate with a concentration of 0.03%, manganese sulfate with a concentration of 0.03% and iron chelate with 9% was investigated.

Results: The parameters of the yield attributes such as the number of pods per plant, number of seeds in the pod, number of seeds per plant and the harvest index showed the yield stability in the pretreatment of seeds with salicylic acid under stress/non-stress conditions. The components of plant height, seed yield, biological yield, percentage and yield of protein and percentage and yield of oil were affected by the interaction of seed pretreatment, weeding and foliar application, so that with the application of seed pretreatment, with and without weeding conditions and foliar application with micronutrient elements, plant height, seed and biological yield, oil percentage and oil yield showed a significant increase than foliar application with water. The research findings show that the highest number of pods per plant was obtained in the twice-weeding and foliar application with iron so the number of pods per plant increased by 39.77% compared to the treatment of no-weeding and foliar spraying with water. Unlike seed oil, seed protein decreased under the pretreatment of seeds with salicylic acid and foliar application of micronutrients. In the non-prime conditions, the once-weeding treatment with the foliar application of micronutrient elements was able to increase soybean protein compared to the no-weeding treatment. The yield protein in seed pretreatment with salicylic acid and foliar application of iron with twice weeding had its highest value in soybean. Weeding increased protein yield and foliar application of micronutrient elements improved these conditions in prime and non-prime conditions. Pretreatment of seeds and foliar application of micronutrient elements at all levels of weeding increased the percentage of soybean oil compared to the control treatment so that in the treatment non-prime and foliar application with water, weeding increased 10.17% of soybean oil. In most of the studied traits, the pretreatment of seeds with salicylic acid compared to the pretreatment of seeds with water, was able to create more favourable conditions in the presence of weeds and without the presence of weeds, so that soybean seed yield with the application of salicylic acid with once weeding and iron foliar spraying was improved to the extent of pretreatment with salicylic acid with manganese and zinc foliar spraying with two times of weeding.

Conclusion: It can be done by applying salicylic acid priming and iron foliar application, at least one time reducing the field hand weeding, which result can reduce the time and cost of hand weeding saving or lack of chemical herbicides application to conserve soil resources and to avoid contamination of the environment.