Determination of Planting Density and Row Arrangement of Basil (Ocimum basilicum L.) For Intercropping with Tomato (Solanum lycopersicum L.) at Wondo Genet, Southern Ethiopia

Abstract

Intensive crop cultivation through inter-cropping is a reasonable agronomic practice to fulfill and sustain food security in areas like Wondo Genet where there is shortage of arable land. An experiment was conducted at Wondo Genet Agricultural Research Center to determine the optimum planting density and row arrangement of basil for intercropping with tomato and to examine yield advantage and economic return of the system. The experiment was conducted with a 2 × 4 factorial arrangement in RCBD with three replications each consisting of ten treatments: two basil row arrangement (one tomato row alternating with one basil rows (1T:1B) or with two basil rows (1T:2B)) and four basil population densities (66666, 50000, 33333 and 16666 plants ha -1 ). Results of the study indicated that cropping system significantly (p<0.05) affected yield and yield components of tomato. Intercropped tomato with basil had the highest yield (36657.8 kg ha-1 ) as compared to sole cropped tomato (31004.3kg ha-1 ) and intercropping with basil increased its yield by 15.42%. On the other hand, row arrangement by planting density interaction significantly influenced yield of basil with the maximum dry herbal (341.49 kg ha-1 ) and essential oil (22.86 kg ha-1 ) yields recorded for 100% basil population density with a 1T:2B row arrangement. Cropping system also significantly influenced essential oil content and essential oil yield of basil. The highest essential oil content (1.26%) and essential oil yield (21.83 kg ha-1 ) of basil were obtained with sole planting, compared to that of intercropping (0.96%) and (15.36 kg ha-1 )with tomato showing, showing 23.81% and 29.64% reduction, respectively. In general, yields of tomato increased in intercropped plots while basil yield was best when planted alone as compared to intercropped with tomato. Additionally, intercropping of tomato with basil had total land equivalent ratio (LER) value greater than one, which showed the advantage of intercropping over sole cropping of each crop. Intercropping of tomato with basil at 100% population density gave total LER value of 1.9 and monetary advantage index (MAI) value of 194600 ETB ha -1 , respectively. Therefore, basil with a density of 33,333 plants ha-1 and intercropped with tomato with 1T:1B row arrangement could be recommended for the target area. However, the effect of tomato-basil intercropping on the incidence and severity of major tomato insects and diseases needs further study