Effect of Climatic and Non-Climatic Factors on Cassava Yields in Togo: Agricultural Policy Implications

Abstract

This paper examines the effects of climatic and non-climatic factors on cassava yields in Togo using an Autoregressive Distributed Lag (ARDL) modelling approach and pairwise Granger Causality tests. Secondary data on production statistics, rural population, climate variables, prices and nominal exchange rate for the period 1978-2009 are used. Results for estimated short-and long-run models indicate that cassava yield is affected by both 'normal' climate variables and within-season rainfall variability. An inverse relationship is found between area harvested and yield of cassava, but a significant positive and elastic effect of labour availability on yield in the long run. Increasing within-lean-season rainfall variability and high lean-season mean temperature are detrimental to cassava yields, while increasing main-season rainfall and mean-temperature enhance cassava yields. Through Granger Causality tests, a bilateral causality is found between area harvested and yield of cassava, and four unidirectional causalities from labour availability, real producer price ratio between yam and cassava, main-season rainfall and lean-season mean temperature to cassava yields. Based on the findings from this study, investment in low-cost irrigation facilities and water harvesting is recommended to enhance the practice of supplemental irrigation. Research efforts should as well be made to breed for drought, heat and flood tolerance in cassava. In addition, coupling area expansion with increasing availability of labour is advised, through the implementation of measures to minimize rural-urban migration.

Agro-Climato-Edaphic Zonation of Nigeria for a Cassava Cultivar using GIS-Based Analysis of Data from 1961 to 2017

“…Nigerian farmers also bear the mentality that fertilizer application to cassava farm is unnecessary and wasteful 2 . From our regression modeling, the relevance of other environmental variables that influence cassava yield in Nigeria was confirmed, i.e., aside from the climate, soil conditions are key to cassava yield 31,58 . Our field investigations showed that farmers are still cultivating the local varieties of cassava even in South-western Nigeria where IITA is located.…”

Nitrogen, phosphorus, and potassium fertilizer effects on cassava tuber yield in the coastal district of Dondo, Mozambique

“…Due to the impact of ACMD and CBSD (Boansi, 2017;Hillocks et al, 2002b), finding sufficient disease-free planting material was difficult at the study onset. Cassava transplant cuttings should be robust (Polthanee and Wongpichet, 2017) including only the middle brownskinned portions of the stem and approximately 20 to 25 cm long with 5 to 8 nodes (James et al, 2000).…”

“…Cassava provides edible leaves and tubers (Boansi, 2017;Li et al, 2010) and is produced almost *Corresponding author. E-mail: ibcuvaca@ksu.edu.…”

“…Due to the ability of cassava to produce reasonable yields in areas with poor soil fertility (Boansi, 2017) where other crops would not thrive (Fermont, 2009), most farmers in Africa under-fertilize or do not fertilize cassava (ElSharkawy, 2004). Cassava is rarely grown as a main crop, but instead fills the important niche of being a "hunger" crop or the crop of last resort.…”

“…Cassava Brown Streak Disease (CBSD) and African Cassava Mosaic Disease (ACMD) impact cassava production (Boansi, 2017;Hillocks et al, 2002b). It is estimated that the CBSD disease alone has affected more than 50% of the cassava production with more aggravation in the Northern provinces of Nampula and Zambezia.…”