African Journal of Biotechnology Vol. 5 (17), pp. 1545-1550, 4 September 2006   

ISSN 1684–5315 © 2006 Academic Journals        

Full Length Research Paper

Effect of different rates and methods of benomyl and mancozeb application on delay in senescence and grain yield of cowpea (Vigna unguiculata (L) Walp) under different cropping season

O. Akinbo¹*, S. A. Ogunbayo², K. A. Sanni² and A.O. Ojo¹

¹Department of Agronomy, Ladoke Akintola University of Technology, Ogbomoso, Nigeria.

²Africa Rice Center (WARDA), 01 BP 2031, Cotonou, Benin.

*Corresponding authors E-mail: akinbooa@yahoo.co.uk

Present address: International centre for Tropical Agriculture, Km 17 Recta Cali – Palmira.  Cali, Colombia.

Accepted 22 July, 2006

Field assessment of different rates and methods of three fungicide applications on delay in senescence (DS) and grain yield of cowpea during the early and late cropping season of 1999 respectively was conducted. The benomyl treatment applied via the combination of seed and foliar methods at the highest rate of 0.75 + 0.75kg a.i/ha gave the highest percentage delay in senescence (100%) as well as highest grain yield of (2.1 t/ha) which were significantly different (p<0.05) from the untreated control plots and mancozeb plots. Application via the seed gave the lowest percentage delay in senescence (20.3%) and the lowest grain yield of (0.24 t/ha), respectively, for early cropping season. Similar trends were recorded during late season for all these parameters, though they were lower than that of early cropping season.

Key words: Benomyl, mancozeb, cowpea, delay in senescence, grain yield