Influence of Seed Source on the Date of Ear Emergence in Bread Wheat

Abstract

THE growth of grain crops may in some cases be influenced by the conditions under which the crop which produced the seed was grown. Among the characters affected have been yield¹ and winter hardiness² of winter wheat, and yield of spring wheat³, while similar differences have been reported in oats^4,5, maize^6–8 and rice⁹. In other cases and for some additional characters considered in these investigations no consistent differences in performance were found^5,9–11. Some of these effects have been attributed to differences in seed size³, condition and age of the seed^5,6, mechanical damage² or the presence of seed-borne pathogens⁶, while the level of soil fertility of the parental environment as reflected in the quality of the seed has also been implicated⁸. However, there are some instances in which it was considered that much of the variation remained unexplained^1,2. It has previously been noted that the time of ear emergence of wheat can be modified in this way¹², but the differences recorded were ascribed to the effects of selection for earliness in a mixed population. Small changes in heading date were also found in the investigation of the influence of seed source on winter wheat¹.