Productivity of Cassava-Sweet Potato Intercropping System as Influenced by Varying Lengths of Cassava Cutting at Makurdi, Nigeria

摘要

Field experiments were conducted from April to December, 2009 and 2010 cropping seasons, at the Research Farm, University of Agriculture, Makurdi, Nigeria, to evaluate the productivity of cassava-sweet potato intercropping system, as influenced by varying lengths of cassava cutting and to assess the advantage of the intercropping system. The trial consisted of five treatments, replicated four times in a randomized complete block design. Three of the treatments consisted of cassava cuttings sown at varied lengths of 20 cm, 30 cm and 40 cm into sweet potato plots. Monocropped sweet potato and cassava, respectively sown at their recommended stem cutting lengths of 20 cm and 25 cm constituted the fourth and fifth treatments, which also served as control plots. Results obtained showed that the greatest intercrop yields of cassava and sweet potato were obtained when cassava cutting length of 30 cm was planted in the mixture. Although the lowest competitive pressure was recorded for cassava cutting length of 20 cm sown into sweet potato plots, however, intercropping sweet potato with cassava at cutting length of 30 cm gave the highest land equivalent ratio (LER) value of 2.15 in years 2009 and 2010, indicating that greatest productivity per unit area was achieved by growing the two crops together than by growing them separately. With this LER value, 53.5 % of land was saved in years 2009 and 2010, which could be used for other agricultural purposes. Both crops were found to be highly complementary and most suitable in mixture when 30 cm cassava cutting length was used. The implication of study showed that to maximize intercrop yields of cassava and sweet potato, the optimal cassava cutting length is 30 cm. This should therefore be recommended for Makurdi location, Nigeria.