The response of short-duration pigeonpea lines to variation in temperature under field conditions in Kenya uri icon

abstract

  • Field studies with pigeonpea (Cajanus cajan (L.) Millsp.) were conducted at four locations in Kenya varying in altitude and where temperature decreased with increase in altitude. Warm temperatures (most inductive temperatures, mean 23.5°C) hastened the times from sowing to flowering (f) and maturity (m), and between flowering and maturity (fm). Cool temperatures (17.8°C) delayed f, m, and fm but the delay was most pronounced for fm. In the least inductive cool environment, variation in f, m and fm was greatest among 63 lines developed in India. Compared to the most inductive temperature, the delay in cool environment was 2.2 for f, 3.1 for m, and 5.5 for fm, which indicates that fm is the most sensitive phase to low (sub-optimal) temperatures.Equations that describe the rates of development (1/f, 1/m, and 1/fm) were used to determine progress to different stages of development. Results revealed that optimum temperature for fastest time to flowering varied from 23.1 to 26.1°C. The 1/f at mean temperature of 26.8°C was slower, indicating that the mean temperature experienced was supra-optimal. Since the mean temperature of 26.8°C was not very different from the range considered optimal, further analysis revealed that this was mainly due to the high night temperatures. The 1/fm was strong and positive in the range of temperature tested indicating that warm temperatures shortened the duration between flowering and maturity. The optimum temperature range for this effect varied from 24 to 32°C. Cool temperatures at Kabete retarded plant growth while warm temperatures enhanced it

publication date

  • 2001
  • 2001