Varietal Performance of Groundnut (Arachis hypogea) under two Phosphorus Levels on an Alfisol in Minna, Southern Guinea Savanna of Nigeria.

Abstract

Growth, nodulation and yield responses of groundnut varieties to phosphorus application was evaluated in a field experiment at the Teaching and Research Farm of the Federal University of Technology, Minna during the 2010 cropping season. The aim of the study was to select lines of groundnut varieties that exhibit good growth and yield characteristics with minimal input requirement. The experiment consisted of five groundnut varieties (Samnut 22, RMP 12, Samnut 23, Ex Dakar and a local variety) at 2 phosphorus levels(0 Kg P ha-1 and 30Kg P ha-1) in a 2 x 5 factorial experiment arranged in a randomized complete block design with three replicates. Results revealed that phosphorus significantly (p<0.05) increased plant height, leaf number, days to 50 % flowering and yield. With the exception of percent germination and nodule weight, varietal difference significantly(p<0.05) affected the measured parameters. On the average, 30 kg ha-1 gave higher percentage germination than 0 kg ha. Similarly, plants receiving 30 kg P ha-1 were taller than those supplied with 0 kg ha-1. Regardless of P application, Samnut 22 and RMP 12 recorded the best heights followed by Samnut 23, Ex Dakar and local variety in that order. Application of 0 kg ha-1 gave a higher shoot biomass but plants supplied with P flowered earlier by one day, produced heavier pods and nodules per plant, and had greater grain yield than those plants without fertilizer P. Results showed that Samnut 22 and Samnut 23 had the earliest flowering dates and highest grain yields regardless of P treatment, thus suggesting better adaptation by these varieties than the others.