Yield and Nutrient Uptake by Sudangrass (Sorghum Vulgare var. Sudanense) as Influenced by Phosphorus and Zinc Application

The study was conducted at the Basrah University / Karmat Ali, Iraq during the fall season 2020, to investigate the effects of four rates of phosphorus,(P0 =0, P1=40, P2=80 and P4=120 kg P ha^-1) and spraying four concentrations of zinc (Zn0-control, Zn1= 25, Zn2=50, Zn=75mgL^-1 on growth and forage yield of Sudangrass. The randomized complete block design (RCBD) was carried out in three replicates using a split plot experiment, zinc concentrations were put in the main plots while, rates of phosphorus in subplots. Application with P₁₂₀ resulted to a significantly greater stem diameter (14.61mm) number of leaves (20.00 leaf plant^-1), leaf area (7420cm²), number of branches (14.967 branch plant^-1) green and dry forage yield (29.25,12.69 t ha^-1). Foliar application of Zn₇₅ resulted in greater plant height (251.2cm), stem diameter (14.21mm), number of leaves (19.42 leaf plant^-1), leaf area (6163cm²) and number of branches (13.450 branch plant^-1). The combination of P× Zn had no significant effect on green and forage yield. Both P and Zn application had significant effect on N and P percentage of forage Sudangrass, on the other hand, no significant effect of their application on K percentage.