Some effects of temperature regime during grain filling on wheat quality

Abstract

Dough quality from grain samples from the Interstate Wheat Variety Trials for 3 cultivars at Wongan Hills and Narrabri in 6 seasons and 4 cultivars at Narrabri, Wagga Wagga and Dooen in 4 seasons was studied in relation to av. daily min. and max. temp. from anthesis to harvest. In greenhouse experiments, wheat cv. Olympic, Hartog and Skua seedlings were raised at day/night temp. of 21/16degreesC and then transferred to 33/28degrees at 14 or 32 d after anthesis. Air temp. influenced wheat baking quality, particularly dough strength, loaf score and volume in both field and greenhouse trials. Dough strength increased with av. daily temp. up to 30degrees and tended to decrease at higher temp. Field data indicated that protein concn was most dependent on max. temp. The cultivars differed in inherent dough strengths but for all cultivars dough strength increased with protein concn, and a strong positive correlation with max. temp. was observed. In the greenhouse, high temp. increased grain moisture loss and shortened the time to maturity. Grain from the higher temp. regime was smaller and the dough particularly resistant to deformation. Loaf volume was very similar for all 3 cultivars but for other quality characteristics responses differed between cultivars.