Effect of climate variability on some tuber crop yields in the federal capital territory (FCT), Nigeria

Abstract

Climate is the most important factor that determines crops distribution, cultivation, growth and yield in Nigeria. This study aimed at looking at the effect of climate variability on yam and cassava yields in the Federal Capital Territory (FCT), Nigeria. Rainfall and temperature data for 32 years as well as yam and cassava yields data for 15 years were collected from the Nigerian Meteorological Agency (NiMet), Abuja and Agricultural Development Programme (ADP), Gwagwalada, Abuja and used for the study. Results were presented in both figures and tables. The data were subjected to various statistical analysis such as mean, kurtosis, skewness, coefficient of variation, time series, correlation, regression analysis, standard deviation and percentage change. Findings revealed that the study area observes two (2) seasons namely, rainy and dry with April (mean rainfall of about 79.5 mm) as the onset and October (mean rainfall of about 187.6 mm) as the cessation of rains. August has the highest mean rainfall of about 355.6 mm, while January has the least mean monthly rainfall of about 3.0 mm. the inter-annual temperatures range between 32oC-34oC. Also, a significant positive change in yam yield of 6.33Mt/Ha and 3.17 Mt/Ha for cassava occurred between year 2000 and 2014. Further findings revealed weak positive relationship of 0.3 each between rainfall and temperature with yam yield as well as weak negative relationship of -0.2 and -0.3 between rainfall and temperature with cassava yield. The R2 for both yam and cassava are 84.2% and 73%, while the p-value is <0,001 which is less than the significant level of 0.05. The study recommends the use of hybrid varieties by farmers so as to help in sustaining and improving the yields of yam and cassava, continuous weather monitoring as well as irrigation.