Compatibility and economic assessment of sweetpotato and garden egg intercrop in a humid ultisol of southeastern Nigeria
This study was conducted at Umudike in the tropical ultisol of rainforest agro-ecological zone of Nigeria, to determine the compatibility and economic viability of sweetpotato (Ipomoea batatas) and garden egg (Solanum gelio) intercrop during 2011 and 2012 cropping seasons. Two sweetpotato varieties; NR05/022 and TIS/87/0087 were planted at a spacing of 1m x 0.30m between and within rows. Each variety was intercropped with garden egg at three different plant spacing; 1mx 0.5m, 1m x 1m and 1m x1.5m.The experiment was laid out in a randomized complete block design. Yield and economic data were collected on sweetpotato root yield at harvest (16WAP) while garden egg fruits were harvested in piece meal from 8-14 WAP and the yield summed up. The yield data were subjected to analysis of variance to compare the means while Land Equivalent ratio was used to estimate productivity. Also Gross margin analysis and Benefit Cost Ratio were employed to determine the economic viability of the cropping systems. The result showed that the Sweetpotato variety NR05/022 out yielded TIS 87/0087 both in sole and intercrop. Intercropping Sweetpotato with garden egg did not affect garden fruit yield. The land equivalent ratio (LER) was greater when Sweetpotato/garden egg were intercropped than the sole crop which shows that Sweetpotato and garden egg were compatible. The economic evaluation showed that in the intercropping system, NR05/022 variety of sweet potato intercropped with garden egg at a plant population of 33,333 and 10,000 plants/ha respectively, gave the best gross margin value of .240,825. However, sole cropping of NR05/022 variety of Sweetpotato had the best Naira return on investment with a BCR of 3.25. It is therefore recommended that Sweetpotato and garden egg are compatible and intercropping them in a humid ultisol is economically viable. So farmers in the study area are encouraged to intercrop Sweetpotato and Garden egg.
Keywords: Sweetpotato, Garden egg, Intercropping, Compatibility, Growth and Yield