Evaluation of pigeonpea [ Cajanus cajan (L.) millsp.] genotypes for intercropping with tall sorghum ( Sorghum bicolor (L.) moench) in Southern Guinea Savanna of Nigeria

摘要

Improved pigeonpea [Cajanus cajan (L.) Millsp.] genotypes of short (≤ 150 days, usually erect, medium (151- 180 days) and long (≥ 181 days) duration with semi-spreading or spreading habits were intercropped with traditional red sorghum [Sorghum bicolor (L.) Moench]. The aim was to identify the suitable genotype (s) of pigeonpea for intercropping with the traditional red sorghum and to determine the productivity of pigeonpea/sorghum intercropping systems in Southern Guinea Savanna of Nigeria (SGS). The treatments consisted of three cropping systems {sole pigeonpea, sole sorghum and intercropping (pigeonpea and sorghum) }as main plot, combined with 15 pigeonpea genotypes [ICPL 85010, ICPL 84031, ICPL87, ICPL 161 (short duration), ICPL 8863, ICPL 85063, ICPL 87119, ICPL 7120, ICEAP 00068 (medium duration), ICPL 8094, ICPL 7035, ICPL 87051, ICPL 9145, ICEAP 00040 (long duration) and ‘Igbongbo’ (traditional cultivar-control)] as sub-plot, laid out as a split-plot in randomized complete block design with three replications. The experiments were established at the National Root Crops Research Institute Sub-station, Otobi, Benue State, Nigeria, in 2002 and 2003. Intercropped sorghum were taller (≥ 180 cm) than both intercropped and sole cropped pigeonpea (≤ 150 cm) at 12 weeks after planting (WAP), except ICPL 8094 and ICEAP 0068, which maintained similar heights with sorghum component. Intercropped pigeonpea produced significantly lower mean number of branches. Plant-1 (21.32) and mean dry pod weight (2.82 t.ha-1) and mean dry grain yield (1.59 t.ha-1), as compared to sole cropped pigeonpea with 25.09 (branches. plant-1), 4.58 t.ha-1 (dry pod weight) and 2.72 t.ha-1 (dry grain yield) in 2002 and 2003 combined. The high land equivalent ratio (LER) values (1.47-2.07) exhibited by the improved pigeonpea genotypes under intercropping with the traditional red sorghum clearly proved the suitability of these pigeonpea genotypes for intercropping with the traditional red sorghum.