Effect of Potassium and Zinc on Yields and Nutritients Uptake by Castor

A field experiment was conducted in kharif during 2005 to 2007 with castor (Var.GCH 6) on medium black calcareous clayey (Typic Ustrocrepts) soils at Oilseed Research Station, Junagadh Agricultural University, Junagadh with three levels, each of Zn (0,25 and 50kg ZnSO₄ ha^-1), and K (0,50 and 75 kg K₂O ha^-1) in factorial RBD having four replications reveled that the highest (2763 kg ha^-1) seed yields of castor was recorded with combined application of Zn₅₀ x K₇₅ , which was 48.5 per cent higher over (Zn₀ x K₀). Individual application of each levels of Zn and K had significant effect on seed and stalk yield of castor in individual year and as well as in pooled results. Simultaneously, individual application of Zn and K increased their respective concentration and uptake by seed and stalk of wheat and soil nutrient availability.