assessment of planting season effects on vegetation parameters of astragalus effusus and astragalus brachyodontus accessions

this research aimed to evaluate the effect of planting seasons (autumn and spring) on 10 accessions of two species of astragalus effusus and astragalus brachyodontus in the field condition (homand absard station, damavand). after preparing the seedbed, the plant species were planted on two lines in 2 m, where the spacing between the lines of each accession was 0.5 m, and the spacing between the lines of different accessions was 0.75 m. the selected design for this study was a complete randomized block with three replications. evaluation parameters were: forage production, canopy cover, plant height, seed yield, and number of flowering stems. data were analyzed using split plot in time as year for each plot, and mean comparisons were made using duncan’s method.the results showed that planting seasons had a significant effect on most of the measured parameters in different accessions. autumn planting increased the forage production, height, canopy cover and number of flowering stems. the species a. brachyodontus (zereshk), a. brachyodontus (alamut) and a. effusus (dareh shohada) had high production and canopy cover in the autumn cultivation. thus, the mentioned accessions are recommended for the improvement and development of rangelands and abandoned dry land farming with the same weather conditions of homand absard station.