Evaluation of seed vigor tests for determinig alfalfa seed quality

In order to determine the best seed vigor test in laboratory which may provide high correlation between alfalfa seedling stablishment in the field, two experiment were conducted in field as well as in laboratory. Four alfalfa cultivars Bami, Ghareyonjeh, Hamadani and Yazdi were used. Different seed vigor tests including standard germination, germination in low tempretaure (5c), germination rate, osmotic stress, accelerated ageing and electrical conductivity tests were laid out in a randomized completely design (RCD) with four replications in laboratory experiment‌. The second experiment was carried out in a randomized completely block design (RCBD) and each treatment replicated four times‌. Results revealed significant differences (p≤ 0.01) among different cultivars for establishment percentage and rate. Results also showed that there were significant correlations between electrical conductivity test and establishment percentage (r= -0.65, p ≤ 0.01) as well as establishment rate (r= -0.80, p ≤ 0.01). Correlation coefficients for rate and emergence percentage were significant and positive (r= 0.91, p ≤ 0.01). Stepwise method disclosed that the regression model (y=165.23 – 0.15 x r2=0.64), (p ≤ 0.01) for predicting rate of emergence could be recommended. In this model x (dependent variable) is value of electrical conductivity and y (independent variable) is rate of emergence.