Evaluation of urea and ammonium sulfate on yield and yield components of sesame (Sesamum indicum L.) under high pH vertisol of Western Tigray, Northern Ethiopia

Abstract

Field experiment was conducted during 2012/13 and 2013/14 cropping season at Kafta Humera to evaluate sesame response to Urea and Ammonium sulfate. Treatments were: 0, 41 N from urea+20P, 20 N from Urea + 21 N from NH4SO4 [24 S] +20P and, 41 N from NH4SO4 [47 S] +20P were applied at five farmers' field with two replications. The initial soil analysis revealed that strong alkaline, low organic matter and Nitrogen while very low in available phosphorus and sulfur, high CEC with clay texture. The agronomic parameters like 50% Flowering, days to 50% Maturity, plant height, Length of pod-bearing zone, Number of capsule per plant, Number of seeds per Capsule and grain yield were significantly (P < 0.05) affected by treatments. treatments received 20 N from Urea + 21 N from NH4SO4 [24 S]+20P followed by 41 N from urea+20P obtained additional grain yield (148.1% & 85%), number of capsules per plant (79.5% & 56.5%), plant height (60.7% & 31.7%), Branch number (62.7% & 28.7%) over the control, respectively. While the length of pod-bearing zone was significantly affected due to only 20 N from Urea + 21 N from NH4SO4 [24 S] +20P. This study implies that sulfur, Nitrogen and phosphorus in the area are deficient nutrients that limit Sesame crop production. Hence, a combined application of urea and ammonium sulfate as the sources for nitrogen and sulfur with phosphorus is best to enhance sesame crop production on Vertisols of Kafta Humera.