a1 University of Reading, Department of Agriculture and Horticulture, Plant Environment Laboratory, Shinfield, Reading RG2 9AD, England
Plants of two genotypes of chickpea (Cicer arietinum), classified as early or late-maturing in the field, and relying either on dinitrogen fixation by nodules or on nitrate-N, were grown in various simulated tropical environments in growth cabinets. Plants were transferred between cabinets at various times so that they experienced either warm (30°C) or hot (35°C) days (both in combination with a typical night temperature of 10°C) for different durations of reproductive growth, after growing in average (30°C day - 10°C night) or warmer than average (30° - 18°C) temperatures for the first 28 days from sowing and then average temperatures until transferred into the hot regime. Diurnal vapour pressure deficits were adjusted so that plants experienced a constant atmospheric relative himidity (70%) in all thermal regimes. The greater the proportion of the reproductive period spent in hot days the smaller the seed yields produced; plants transferred at 50% flowering were almost barren. The implications of these data for breeding chickpeas well adapted to hot environments are discussed.
(Accepted August 30 1983)
p1 Present address: Sub-Department of Horticulture, University of Reading
p2 Present address: Plant and Crop Physiology Department, Grassland Research Institute, Hurley, Maidenhead SL6 5LR, England.
† One of a series of papers resulting from a collaborative project with the International Crops Research Institute for the Semi-Arid Tropics, India; sponsored by the UK Overseas Development Administration.