The influence of cultivar, temperature and photoperiod on post-flowering development of wheat

The duration of post-anthesis development was studied in eight spring wheat cultivars under field conditions. Variation in post-anthesis environment was achieved by varying the date of anthesis through the use of seed vernalization, extended photoperiod, and serial sowing. Multiple correlation and regression analysis of phase duration on temperatures and photoperiod was able to account for 75–97% of the variation in duration of the post-anthesis phase. Differences in the rate of post-anthesis development between cultivars were not statistically significant: nor was the influence of photoperiod significant. Air temperature was the principal factor influencing the rate of development in this phase. Observations of the duration of post-anthesis development taken from field crops in three successive years agreed well (R2 = 75%) with those predicted from the regression relationships previously established. The data are discussed in relation to the implication of the rate of post-anthesis development in yield variation.