The microclimate and productivity of a groundnut/millet intercrop during the rainy season uri icon

abstract

  • The microclimate of a Pennisetum americanum/groundnut intercrop (1:3 row arrangement) was monitored for three successive rainy seasons, 1985-1987, at ICRISAT, Hyderabad, India. Major changes in microclimate of the intercrop were in the wind speed and the relative duration of leaf wetness. Reduction in wind speed just above the groundnut crop depended on the height of the P. americanum canopy. Wind speed was reduced by 50% at 35 d after sowing (DAS) in 1985 and by 70% at 60 DAS in 1987. Leaf wetness duration of the groundnuts was increased by intercropping but this appeared to have little effect on defoliation. Calculating thermal time showed that the intercropped groundnuts developed 2.5-2.8 d earlier than pure stand groundnuts. The effect of saturation deficit on crop growth was small. Intercropping increased the radiation use efficiency of groundnuts by 21-35%. Yield loss from foliar diseases of groundnuts was 37-40% in 1985, negligible in 1986 and 33-35% in 1987. Intercropping appeared to have no significant effect on the severity of foliar disease in groundnuts, largely because defoliation occurred after P. americanum was harvested. Therefore the grain yield of intercrop sprayed with fungicide was similar to that of the unsprayed control. The land equivalent ratio of the intercrop ranged from 1.67 in 1985 to 0.94 in 1987. The discussion highlights differences between observations made during the rainy and post-rainy seasons

publication date

  • 1991
  • 1991