Effect of Seed Biofertilizers Inoculation on Photosynthesis Rate, Yield, and Competitiveness Ability of Quinoa (Chenopodium quinoa Willd.) with Weeds

In order to investigate the effect of quinoa seed inoculation on photosynthesis rate, yield and competitive ability with weeds, an experiment was conducted as split-plot based on a randomized complete block design with three replications at experimental farm of School of Agriculture, Shiraz University, Shiraz, Iran during 2020 growing season. Treatments were three levels of weed management as main-plot (weedy, weed-free and weeding) and five levels of seeds inoculation with biofertilizers (humic acid, bioumic, seaumic, organic herbicide, and no biofertilizers) as subplots. The results showed that the highest rate of photosynthesis in all weed management levels was achieved in the presence of seeds inoculated with seaumic biofertilizer. The highest grain yield (259.63 g/m2) and grain yield components (1000-seed weight, number of seeds per panicle, and number of panicles per plant) and harvest index (48.73%) were also obtained in weed-free plots when seeds were inoculated with seaumic biofertilizer. Leaf area index and dry weight of the main weed species (wheat) was significantly reduced in inoculation of seeds with biofertilizers compared to the no biofertiliuzer condition. The highest crop’s competitive ability was achieved when the seeds were inoculated with seaumic treatment. The quinoa’s competitive ability was increased by 2.8 times and 94.11% at weedy and weed-free treatments, respectively, compared with control in seed inoculation with seaumic treatment. Thus, our finding suggests that seed inoculation with biofertilizers, especially seaumic treatment is an effective strategy that can be used to enhance germination rate, growth, yield and weed competitive ability in quinoa.