Primordia and leaf production in winter wheat, triticale, and rye under field conditions

摘要

Primordia production and leaf emergence were investigated in winter wheat (Triticum aestivumL. em Thell.) and two related species, winter rye (Secale cerealeL.) and winter triticale (times;TriticosecaleWittmack), under field conditions in Southern Ontario, a region with a humid continental climate. Primordia initiation could be adequately described by a linear regression of primordia number on accumulated degree-days in the 1st year of study, 1981 ndash; 1982. In the 2nd year, however, a linear relationship was noticed only in the late winter and early spring, with the rate of primordia production being distinctly lower earlier in the season. The rate of primordia initiation was faster in the ryes than in the wheats, a superiority which was associated with greater spikelet production. Triticale had an intermediate rate of primordia initiation but was closer to wheat in the timing of double ridge and terminal spikelet formation. Leaves emerged at a constant rate (degree-days base) which was similar in most of the cultivars.