Table of Contents
ISRN Agronomy
Volume 2014 (2014), Article ID 925450, 7 pages
Research Article

Varietal Trials and Physiological Components Determining Yield Differences among Cowpea Varieties in Semiarid Zone of Nigeria

Department of Crop Production, University of Maiduguri, Maiduguri 600001, Nigeria

Received 18 January 2014; Accepted 25 February 2014; Published 1 April 2014

Academic Editors: O. Ferrarese-Filho and Y. Ito

Copyright © 2014 Nkeki Kamai et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Field trials were conducted at the Teaching and Research Farm, Faculty of Agriculture, University of Maiduguri, Maiduguri (11°47.840′N; 13°12.021′E; elevation 319 m asl), in Borno State in semiarid zone of Nigeria during the 2010 and 2011 rainy seasons. The objectives of the study were to evaluate the agronomic performances of some improved cowpea varieties and to identify the physiological traits associated with high grain yield in the semiarid zone of Nigeria. The trial consisted of eight treatments, which included two local varieties, namely, Kannanado White and Borno Brown and six improved varieties, namely, IT90K-277-2, IT97K-568-18, IT89KD-288, IT97K-499-35, IT98K-131-2, and IT89KD-391. The treatments were laid out in a randomized complete block design replicated three times. The gross plot size was 5.0 m × 4.0 m (20 m2) while the net plot size was 3.6 m × 3.0 m (10.8 m2). The results showed that the improved varieties, namely, IT90K-277-2, IT97K-499-35, IT98K-131-2, and IT89KD-288, had significantly higher grain yield per hectare and matured earlier to escape drought in this agroecological zone. The local varieties also had significantly heavier grains, took more days to reach first and 50% flowering, and matured later than the improved varieties. Cowpea grain yield per hectare was highly positively correlated with harvest index, shell weight, soil moisture suction measurements, shelling percentage, and grain yield per plant and also significant negative correlation between cowpea grain yield per hectare and number of days to first and 50% flowering, 100-grain weight, number of days to physiological maturity, and pod development period. The results also indicated that fodder yield per hectare was highly positively correlated with photosynthetically active radiation thereby indicating that higher photosynthetically active radiation produced higher yield of fodder.