Variation in plant growth, tiller dynamics and yield components of wheat (Triticum aestivum L.) due to high temperature stress

To observe the effect of high temperature stress on the growth and development of five wheatvarieties (Sourav, Pradip, Sufi, Shatabdi and Bijoy) an experiment was conducted at the research field ofSher-e-Bangla Agricultural University, Dhaka, Bangladesh (23°77 N and 90°37 E) from November, 2008to April, 2009. There were two growing conditions viz. normal sowing (November 30) and another waslate sowing (30 December). The late sown wheat plants phased a significant heat stress, especially at thereproductive period that influenced their growth and development pattern. Plant height, tiller number,yield components and yield were compared of all varieties under two environmental conditions. All thevarieties performed negatively for all parameters under heat stress condition. Due to heat stress plantheight, no. of total tillers, fertile tillers decreased and no. of sterile tillers increases. In the sameenvironment the ear length, no. of spikelet main stem-1, fertile floret main stem-1 decreased and no. ofsterile floret main stem-1 increased. The 1000 grain weight and yield also decreased due to hightemperature stress. The performance of Bijoy was the best in respect of yield as the yield reduction wasthe least (53.42%), whereas Sufi showed worst performance (73.01% yield reduction). Therefore, fromthis study it may be concluded that under high temperature stress the performance of the variety Bijoywas the best especially regarding the yield components and yield.