DOI: 10.36347/sjavs.2021.v08i02.004

Pages: 20-32

Studies to ascertain the effect of organic and mineral sources of N, P and K on growth and yield attributes of Bankyehemaa and Nkabom varieties were undertaken in Offinso, Ghana, from June, 2014 to May, 2015. The cassava varieties and 2 t/ha of poultry manure (PM), 600 kg/ha each of NPK 15-15-15 and NPK 23-10-10, and a combination of the mineral fertilizers with PM at their half rates and a negative control were laid out in a factorial combination in a Randomized Complete Block Design with three replications. Plant height, number of roots per plant, mean root weight and root length were measured over the period, whereas height at first branching, shoot weight, stem girth and number of stems per hill were evaluated at final harvest at 11 months after planting (MAP). The data collected were subjected to analysis of variance using the 12th Edition of GenStat Statistical package. Variety, fertilizer and treatment interaction effects for all the parameters measured were significant, except varietal effect on number of stems per plant, stem girth, mean root weight and root length. Growth and mean root number were increased in Bankyehemaa variety. NPK 23-10-10 alone increased number of roots per plant, while its combination with PM improved mean root weight and root length. This fertilizer combination increased root length in Nkabom variety. At final harvest, PM alone significantly improved mean root number in Bankyehemaa and also increased mean root weight in Nkabom. Cassava farmers should be encouraged to apply PM, NPK 23-10-10 and their combinations to improve the performance of Bankyehemaa and Nkabom varieties grown in sandy loams in a semi-deciduous forest ecology. In future studies, the impact of these fertilizers on soil physico-chemical properties and nutrient use efficiency of the test cassava varieties should be evaluated in multi-locations over many years.