Assessment of physiological and quantitative and qualitative yield of two millet species under different irrigation levels and application of growth promoting bacteria

Introduction Water and fertilizers are the main determinants of the level of agricultural production in the world. Iran's climate is predominantly dry and semi-arid, and the availability of water is a major problem in these areas. Water stress significantly changes the metabolism of plants and reduces the growth and photosynthesis and ultimately the performance of plants. In such a situation, drought management is an urgent necessity. Plants and cultivars with less water requirements are one of the most effective ways to manage water. Millet can be considered as a cost-effective product (cereals, fodder and oilseed) in the context of water scarcity due to its significant adaptation to a wide range of climatic conditions. In addition, in order to efficiently manage water use in agriculture, the use of agronomic techniques, such as the application of bio-fertilizers or the strengthening of biological conditions in the soil, may reduce the effects of water stress and less use of chemical fertilizers for sustainable agriculture and human nutrition be effective. Materials and methods In order to investigate the effect of deficit water stress and application of growth promoting bacteria on morphological, physiological traits, quantitative and qualitative yield and oil compounds of two millet species, an experiment was conducted as split factorial based on complete randomized block design with four replications in research farm of Fereydunshahr, Esfahan province in 2016. In this experiment, deficit water stress were considered as the main plots with three levels (100, 75 and 50 percent of plant water requirement) while application of growth promoting bacteria (with three levels including control, using 1 or 0.5 L.ha-1 Azotobacter chroococcum and Azospirillum brasilenseas seed inoculation) and two millet species (including Golbaf and Bastan) were arranged as factorial sub plots. Findings In this experiment, water deficit stress significantly reduced stem diameter, biological yield and seed, protein and oil, and its quality in millet. The application of bio-fertilizers could reduce the adverse effects of water stress on the above characteristics in both millet varieties and improve the quality of the oil in such a way that the use of one and a half bio fertilizers, respectively, increased grain yields (6.66 and 19/19%) in irrigation treatments (12.29% and 28.76%) in mild stresses (31.73% and 45.77%) in severe dehydration treatments. In mild stress (75% water requirement), as well as application of one litter of bio-fertilizer in the ancient cultivar, produced the highest quality (oleic and linoleic) oil content while reducing water consumption Also, ancient cultivar had superiority in terms of biological yield and grain and unsaturated fatty acids in different irrigation regimes, with and without bio-fertilizer application. Conclusion Regarding the increase in the amount of oleic acid, indicating the stability to the temperature and quality of the oil for frying food, and the higher percentage of linoleic fatty acid, indicates the improvement in the value of oil in direct feeding, mild water stress treatment (75% water requirement) Along with the application of one liter of biofertilizer in the ancient cultivar, while reducing water use, the highest quality (oleic and linoleic) was produced.