The Effect Of Two Agro-Ecological Zones In Nigeria And Yield On Cyanogenic Potential Of Cassava Tuberous Roots

  • C. M. Githunguri
  • K. Waithaka
  • I. J. Ekanayake
Keywords: Agriculture

Abstract

The widespread commercial use of cassava is hampered by the presence of cyanogenic glucosides in edible plant parts, which can be converted to the potentially lethal hydrocyanic acid. Studies show that various factors affect cassava production and culinary qualities, and as such agronomic and postharvest recommendations might need to be agro-ecological zone and age specific. However, it is not clear whether agro-ecological zones and plant age either do or do not influence growth performance and accumulation of cyanogenic potential in cassava. As such, studies were conducted to determine the effect of agro-ecological zones and plant age on cassava yield and cyanogenic potential. Five cassava genotypes were planted in two agro-ecological zones in Nigeria and analysed at 4, 6, 8, 10 and 12 months after planting (MAP) for tuberous root yield and cyanogenic potential over two cropping seasons at Ibadan, the wetter, and Minjibir, the drier agro-ecological zones in Nigeria. Cassava roots at Ibadan had higher yield and lower cyanogenic potential than at Minjibir. Results of correlation and regression analysis showed a close negative relationship between them suggesting that a positive change in root yield would result in a corresponding negative change in cyanogenic potential. The highest yield and lowest cyanogenic potential of cassava roots were obtained at 8 months and it is therefore recommended that they should be harvested at this time. Since our study demonstrated that a safe genotype can turn into a toxic one with changes in agro-ecological zone, agro-ecological zone specific genotypes would be recommended to avoid possible cassava toxicity. A negative relationship between cyanogenic potential and yield was demonstrated. Selecting for high yield is thus likely to result in low cyanogenic potential cassava genotypes. Cassava genotypes with high yield and low cyanogenic potential ought to be selected at the drier agro-ecological zones where they are likely to be subjected to highest selection pressure.

Published
2011-09-22
How to Cite
Githunguri, C. M., Waithaka, K., & Ekanayake, I. J. (2011). The Effect Of Two Agro-Ecological Zones In Nigeria And Yield On Cyanogenic Potential Of Cassava Tuberous Roots. East African Agricultural and Forestry Journal, 76(1&2). Retrieved from https://www.kalro.org/www.eaafj.or.ke/index.php/path/article/view/418