Comparison and Evaluation of Quality Traits between Forage Sorghum Varieties Effects of Pb, Cd Stress on the Growth and Pb, Cd Uptake of Forage Sorghum Effects of Lead, Cadmium Pollution on Tested Physiological Indices of Forage Sorghum Analysis on the Yield, Quality and Stress Resistance of Brown Midrib Forage Sorghum Varieties