ABSTRACT

Post-harvest physiological deterioration (PPD) has limited the production, storage and marketing of cassava. This research work is aimed at investigating the growth parameters (height, canopy and stem girth), yield parameters (harvest index and root biomass) and analyse their PPD performance. Their carotene, starch and dry matter contents were determined and then the PPD was correlated against other variables. Twenty cassava cultivars were planted at the western farm ofthe National Root Crop Research Institute (NRCRI), Umudike. The twenty (20) cultivars were replicated twice and the different cultivars served as the source of variation. The design of the experiment was Randomized Completely Block Design. The eighty cassava cultivars were allowed to grow for a duration oftwelve months (one year). During this period the plant height, canopy and stem girth were taken and recorded. The incidence and severity of some common cassava diseases like Cassava Mosaic Disease (CMD), Cassava Bacterial Blight (CBB) and Cassava Anthracnose Disease (CAD) for each cassava cultivar were scored and recorded. Their cassava cultivars were harvested at the twelfth month after planting and their root and shoot biomass taken. Their roots were taken to the laboratory to evaluate for delayed Post-harvest physiological deterioration (PPD), total carotenoids, starch content and dry matter. The results obtained were recorded and subjected to GENSTAT to obtain the Analysis ofVariance (ANOVA), Correlation Coefficient and the mean separated using Least Significant Differences (LSD). The result we got from the correlation analysis, showed that PPD is inversely correlated to total carotenoids, although the association was a weak one. Starch content and dry matter are however directly correlated to PPD. Total carotenoids were inversely correlated to starch and dry matter, although their correlation is a weak one. Starch and dry matter are directly correlated to each other, however the association has a strong correlation. The cultivars B2-37 (3.00 and 8.80) had the best delayed PPD performance for day ten and fifteen respectively and second best performance for day five (1.71). COB517 (0.71) had the best delayed PPD performance for day five and the second best delayed PPD (10.50) for day fifteen while it had the fourth best delayed PPD performance (6.07) for day ten. Bl-42 (47.43 and 62.70) and NR100216 (61.79 and 72.50) had the worst delayed PPD performance for day ten and fifteen respectively. However from our statistical analysis there were significant differences (P< 0.05) among the mean result ofthese cultivars. B2-37 and COB517 had the most promising delayed PPD, thus are recorded for consumption due to their high total carotenoids. We also recommend that cultivars like Bi-42 and NR100216 that have high starch content should be cultivated for industrial purposes.