Evaluation of different salinity stress and plant densities effects on quantitative and qualitative forage and grain yields of Kochia in Arak region

In order to investigate the effects of different salinity stress and plant densities on quantitative and qualitative forage and grain yields of Kochia, a randomized complete blocks design used in factorial arrangement with three replications. A field study was conducted in 2011 cropping season in Agriculture Experiment Satiation, College of Agriculture, Islamic Azad University, Arak Branch. Treatment consisted of three levels of salinity stress (4.1, 18 and 32 dS/m) and four plant densities (10, 20, 30 and 40 plant m-2). The analysis of variance showed that the effects of salinity on grain yield, 1000 grain weight, plant height, stem diameter, forage yield, forage protein, protein yield, dry matter digestibility percent, acid detergent fiber (ADF) and ash amount were significant. With increasing salinity stress levels, the grain yield, 1000 grain weight, plant height, stem diameter, forage yield, forage protein, protein yield, dry matter digestibility percent and ash decreased, while ADF increased. Maximum grain and forage yield were obtained with irrigation of 4.1 dS/m with an average yield of 2677.9 and 33907 kg ha-1 and the minimum were obtained with irrigation of 32 dS/m with an average yield of 932.4 and 10911 kg ha-1 respectively. Effects of plant densities on grain and forage yield and stem diameter were significant. Maximum grain yield were obtained with plant densities of 20 plant m-2 with an average yield of 2262.9 kg ha-1 and the minimum were obtained with plant densities of 10 plant m-2 with an average 1459.3 kg ha-1. The results obtained from this study showed that, the best Kochia forage production were obtained with 18 dS/m irrigation water and plant densities of 30 plant m-2 and 20 plant m-2 for grain production. These results can be used for Arak region and areas that are similar climate.