EFFECT OF PLANTING DATES ON THE GROWTH AND MATURITY OF COWPEA IN THE GUINEA SAVANNAH AGROECOLOGY OF NIGERIA

The study determined the effect of planting dates on the growth and maturity of siximproved cowpea varieties in three locations (Makurdi, Abuja and Zaria) and threecropping seasons (2016-2018) within Nigeria's Guinea Savanna agro-ecological zone.The experiment was laid in a split plot design with planting dates as the main plot andvarieties as subplots, with three replications per treatment. Data were analyzed using SAS(SAS Institute, 2003) software. Planting dates affected the growth and maturity ofcowpeas in the three seasons. The variety IT89KD-288 expressed higher growth andfodder yields in the early season. Photoperiod sensitive and late maturing varieties likeIT89KD-288 should be planted around 22nd August in any of the locations while dayneutraland early to medium maturing varieties like UAM09-1055-6, IT99K- 573-1-1,IT99K-573-2-1, UAM09-1051-1 and UAM09-1046-6-1 varieties can be planted between15th-29th August for maximum productivity. A significant variety-by-environmentinteraction effect was detected for early-maturity varieties. UAM09-1046-6, UAM09-1051-1 and IT99K-573-2-1 varieties were identified as ideal for early maturity in alllocations. The selected varieties are recommended for production in Guinea Savannah orin similar agro-ecologies and for incorporation in future production and breedingprograms targeting genetic improvement for grain yield.