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Earliness <i>per se</i> (<i>Eps</i>) genes are important to fine tune adaptation, and studying their probable pleiotropic effect on wheat yield traits is worthwhile. In addition, it has been shown that some <i>Eps</i> genes interact with temperature and therefore determining the likely <i>Eps</i> × temperature interaction is needed for each newly identified <i>Eps</i> gene. We studied two NILs differing in the newly identified <i>Eps-7D</i> (carrying insensitive <i>Ppd</i>-D1 in the background) under three temperature regimes (9, 15 and 18 °C) and two photoperiods (12 and 24 h). <i>Eps-7D</i> affected time to anthesis as expected and the <i>Eps-7D</i>-<i>late</i> allele extended both the period before and after terminal spikelet. The interaction effect of <i>Eps-7D</i> × temperature was significant but not cross-over: the magnitude and level of significance of the difference between NILs with the <i>late</i> or <i>early</i> allele was affected by the growing temperature (i.e., difference was least at 18 °C and largest at 9 °C), and the differences caused due to temperature sensitivity were influenced by photoperiod. The rate of leaf initiation was faster in NIL with <i>Eps-7D</i>-<i>early</i> than with the <i>late</i> allele which compensated for the shorter duration of leaf initiation resulting in similar final leaf number between two NILs. <i>Eps-7D</i>-<i>late</i> consistently increased spike fertility through improving floret primordia survival as a consequence of extending the late reproductive phase.