Effects of biofertilizers on yield and some biochemical and physiological traits of Sahand barley cultivare under rainfed and supplementary irrigation

Introduction Drought is the most severe abiotic stress factor limiting plant growth and crop production. Many physiological processes in plants are impaired by drought stress. Also this stress can damage the photosynthesis of plants, pigments and plastids reduce chlorophyll a, chlorophyll b and other carotenoids, hydrolyze proteins and prevalent photochemical reactions in most plants. The response of plants to drought stress depends on several factors such as developmental stage, severity, duration of stress, and cultivar genetics. Several strategies have been developed in order to decrease the water limitation-induced toxic effects on plant growth, among them use of bio fertilizers and supplementary irrigation play a key role in yield improvement. The aim of this study was to investigate the effects of supplementary irrigation and biofertilizers on yield and some biochemical and physiological traits of barley under rain fed and supplementary irrigation condition. Materials and methods In order to study the effects of biofertilizers on yield and some biochemical and physiological traits of barley (Sahand cultivare) under rainfed and supplementary irrigation conditions, a factorial experiment was conducted based on randomized complete blocks design with three replications in the village of Khalkhoran viand of Ardabil province in 2016-2017 cropping season. Experimental factors were irrigation levels (no irrigation as rainfed, supplementary irrigation at 50% heading and booting stages) and biofertilizers application at four levels (without bio fertilizers as control, application of mycorrhiza, Azetobacter, and both application of mycorrhiza with Azetobacter). Results The results showed that the highest catalase, polyphenol oxidase and peroxidase enzymes activity (99.9, 66.9 and 78.2 OD µg Protein min-1 respectively), proline and soluble sugars content (10.25 µg/g FW and 105.7 mg g-1 FW) were obtained in both applications of mycorrhiza and Azetobacter under rain fed condition. The highest grain yield (2682 kg.ha-1) was obtained from supplementary irrigation at heading stage with both application of mycorrhiza and Azetobacter, and the lowest it (2065 kg.ha-1) was obtained in no application of bio fertilizers under rainfed condition. In conclustion, it seems that application of bio fertilizers and supplementary irrigation can be as a suitable method for increasing grain yield of Sahand barley cultivare under rainfed conditions. In conclustion, it seems that application of bio fertilizers and supplementary irrigation can be as a suitable method for increasing grain yield of Sahand barley cultivare under rainfed conditions.