Efficiency of sulphate of potash (SOP) as an alternate source of potassium for black pepper (Piper nigrum L.)

Abstract

Field experiments were conducted at two locations, viz., Kannur (Kerala) and Chettalli (Kodagu, Karnataka) for evaluating the efficacy of sulphate of potash (SOP) as a source of potassium (K) on black pepper. There were nine treatment combinations viz., T1 -Control, T2 -Recommended (Rec.) K as muriate of potash (MOP), T3 -Rec. K as SOP, T4 -125% of Rec. K as SOP, T5 -T3 + SOP 2% foliar spray, T6 -50% of Rec. K as SOP + SOP 2% foliar spray, T7 -50% of Rec. K as SOP, T8 -T2 + Mg @ 25 kg ha-1 as MgSO4 and T9 - T3 + Mg @ 25 kg ha-1 as MgSO4 laid out in a randomized block design with three replications. The results showed that soil nutrient status in treatment with 25.0% higher recommended K as SOP recorded significantly higher concentrations of soil organic carbon, K, Ca, S, Zn and Cu. The study further revealed that for economic yield of high quality black pepper, 50% of recommended dose of K as SOP for soils of high K status and 100% recommended K as SOP + 2% foliar spray of SOP for soil of low K status can be recommended.