Data collection and analysis
Data was collected on daily rainfall, sprouting rate at 15 days after planting while stand count was taken at harvest. Plant height (base to the tallest apical leaf) was recorded at 6, 16 and 40 weeks after planting (WAP) as a means of monitoring treatments effects on early and final growth. Five plants were randomly selected from the net plot for plant height for measurements using a ruler (100 cm). Canopy diameter was measured from the same plants at 6 and 16 WAP. At harvest, number of branches and number of stems were determined by counting branches and the stems of the same 5 plants from each net plot. Tuber diameter and tuber length were taken by measuring the cross section of cassava tubers of 5 randomly selected of the representative plants immediately after harvesting. Yield of the cassava was determined by fresh weight, which was done by weighing all the tubers from the net plot and expressed as kg/ha. Harvest index was determined by dividing economic yield (cassava tubers) by total biological yield comprising of both the above ground parts and cassava tubers. After determining yield data, a random sample of tubers were taken from the 5 plants from the net plot and chopped into smaller pieces. These pieces were mixed and 400 g taken and oven dried at 72°C for 72 h (Koide et al., 2000). The weight after constant value was recorded and dry matter content calculated as
percentage. All data were subjected to the analysis of variance procedure using Genstat Release 16. Regression analysis yield and yield components and plant height were also done.