Growth and resource utilization of perennial pigeonpea (Cajanus cajan (L) Millsp.) at the tree-crop interface uri icon

abstract

  • Perennial pigeon peas were grown as a multipurpose tree species in strips or blocks with annual crops (sorghum, Sorghum bicolor; sunflowers, Helianthus annuus; and chickpeas, Cicer arietinum) on a shallow Vertisol at ICRISAT (Andhra Pradesh) from 1987 to 1989. In the block planting, pigeon peas and annual crops were spatially separated with a single interface between them. The strip planting had 4 pigeon pea strips 4 m wide alternating with annual crop strips 8 m wide, providing 7 interfaces. Spacing was the same in both planting patterns, i.e. 1×1 m for pigeon peas and 45×15 cm for annual crops. Crops were planted (and harvested) in the order sorghum (planted with the pigeon peas), chickpeas (first cropping), sunflowers, chickpeas (second cropping). Growth of the perennial pigeon peas was compared at the tree-crop interface (TCI) and in the middle of the block planting. Perennial pigeon pea plants at the interface had significantly more branches and larger stems than those in the middle of the block planting at the onset of the following rainy season. The greater number of flowers and grains in interface pigeon pea plants was partly due to a better lateral light level and partly due to better access to water. There was a negative effect on growth of annual crops at the TCI, which extended to 1.5 m during the rainy season and to 2.5 m during the post-rainy season. Significant reduction in the growth of annual crops occurred 30-40 days after sowing and was associated with shading by the taller pigeon pea plants. Measurements of the root profile of pigeon pea at the interface indicated that competition for moisture was the major cause of yield reduction of chickpeas during the post-rainy season, but an allelopathic effect may also have been involved. The results are compared with other TCI studies (especially with Leucaena leucocephala) and the possible mechanisms for moisture interaction at the TCI are discussed

publication date

  • 1991
  • 1991