Effect of terminal high temperature imposed by late sowing on phenological traits of wheat (Triticum aestivum L.)

Abstract With a views to observe the effect of prevailing air temperature at irrigated late sowing (ILS) conditions on phenological traits of advanced wheat genotypes and to identify heat tolerant genotypes, the trial was carried out in the research field of Wheat Research Centre, Bangladesh Agricultural Research institute (BARI), Nashipur, Dinajpur in the season of 2011-12. The treatments were four dates of sowing viz. 30 Nov (D1), 15 Dec (D2), 30 Dec (D3), 14 Jan (D4) and four genotypes viz. BARI Gom 26 (V1), BAW 1051 (V2), BAW 1120 (V3), BAW 1141(V4) . The genotypes V2, V3, and V4 were taken as tested genotypes and V1 as check. The design was split-plot with three replications. In ILS conditions, the genotypes phased high temperature stress that significantly reduced the duration of booting, heading, anthesis and physiological maturity stages of all genotypes compared as irrigated timely sowing (ILS, D1) condition since those faced 21 to 25.8oC average mean temperature during booting to physiological maturity stages from 19 February to 09 April, 2012 (10 days interval minimum and maximum temperature was averaged). All genotypes sown on 30 Nov. and 15 Dec. produced yield more than 4 t ha-1 but produced less than 4 t ha-1 in other ILS conditions except BAW 1141 seeded on 30 December. Considering overall performance, BAW 1120 and BAW 1141 may be cultivated up to 15 December and 30 December to get yield 3.34 t ha-1 and 4.15 t ha-1, respectively as heat tolerant genotypes.