EFFECTS OF RAINFALL AND TEMPERATURE VARIATION ON CASSAVA YIELD IN OWERRI NORTH LOCAL GOVERNMENT AREA, IMO STATE, NIGERIA

The agricultural sector plays a critical role in the economic growth of Nigeria; it contributes to about 30 percent of the country’s Gross Domestic Product (GDP) and employs over 40 percent of total population. The agricultural sector however depends largely on climatic variables and is highly sensitive to climatic variability such as a change in rainfall and temperature. These changes can potentially compromise agricultural production thereby have negative impact on rural economy, food security, trade balance and foreign exchange earnings. It is therefore imperative to understand the effects of the variation of rainfall and temperature on agricultural output in a given environment, to which this study has contributed by way of analyzing the effects of rainfall and temperature variation on cassava yield in Owerri-norlh Local Government area of Imo State. The study employed an expos facto research design and utilized secondary data on respective variables from the Evaluation Unit (PM. E.D) Planning Department; Imo A.D.P HORS Owerri for the period between 1995 and 2011. Both descriptive and inferential statistics were used in the analysis of data. The findings of the study show an increasing trend in average temperature with a level of variation at 46 percent, while rainfall had an almost constant trend with a 0.03 percent level of variation. Cassava yield had an increasing trend, with a 16 percent level of variation over the period under study. It was discovered that 27 percent (r2 = 0.269) of the variation in cassava yield is explained my variation in rainfall and temperature. Rainfall had a negative influence on cassava yield with a coefficient value of -0.002, while temperature has a positive influence on cassava yield with a coefficient value of 1.301. The correlation result indicate a significant moderate positive linear relation between temperature and cassava output (r = 0.508) and a weak negative linear relationship between rainfall and cassava yield in the study area (r — -0.036). The study thus recommends that climate change mitigation and adaptive measures should be adopted. These include use of resistant varieties, drought tolerant species, farmers should be trained and equipped with weather forecast information to forestall hunger and food insecurity situation in the slate.