Effects of fertility amendments on oxalic accumulation in cocoyam

Abstract

The availability of cheaper food energy sources which compares favourably well with other high priced cereals is of utmost importance and should be encouraged. Cocoyam presents such an opportunity as it can compete with other contemporary root crops like cassava, yam and potatoes with respect to its proximate and mineral contents. It however contains anti-nutritive components which may limit its utilization. This study investigated the effect different soil fertility amendment options (Urea, NPK, Single phosphate and organic fertilizer) have on the oxalate content of cocoyam cormels. Oxalate contents (mg/Kg) of cocoyam tubers ranged between 63.30 – 79.27: Urea; 66.13 – 92.80: single phosphate; 66.53 – 99.83: NPK and 66.93 – 97.15: organic fertilizer. Application of the different types of fertilizers was observed not to have any influence on the total oxalate accumulation in cocoyam cormels. Similarly, varying the levels of each soil amendment used was also observed not to have a significant effect (P<0.05) on the potential of cocoyam to accumulate oxalates in the tubers indicating that oxalic acid accumulation in cocoyam may be an intrinsic property of the crop and not as a result of differences in the type of available nutrient ions present in the soil.