Morphological and chemical changes in three cultivars of sorghum under dry conditions in Pakistan

A field study was carried out during 2010-11 to quantify fodder and yield qualityin three sorghum [Sorghum bicolor (L.) Moench] cultivars viz., JS-2002, Chakwal Sorghum and Local Cultivar at different growth stages i.e. 3rd leaf stage (GS1), prebooting (GS2) and 50% heading (GS3). Experiment was laid out in randomized complete block design with three replications. Cultivar JS-2002 showed the maximum plant height (196.1 cm), number of leaves per plant (11.3), leaf area per plant (535.9 cm^2), stem thickness (1.7 cm), green fodder yield (63.3 t ha^-1) and dry matter yield (18.9 t ha^-1) followed by Chakwal Sorghum and Local Cultivar. Cell wall components viz., acid detergent fiber (ADF), neutral detergent fiber (NDF), hemicellulose, cellulose and silica contents were higher (72.90%, 41.91%, 34.3%, 27.77% and 3.5) in local cultivar i than rest of two cultivars. Higher contents of cell wall components indicated the inferior quality and poor digestibility of the fodder. Overall, JS-2002 sorghum cultivar provides better yield and quality among the tested cultivars. Although at GS3, maximum fodder yield was observed but at this stage nutritional value decreased. So, GS2 is good stage for feeding to livestock with higher nutritional value and digestibility.