Inbred Maize Performance Following Tassel and Leaf Removal1

Mechanical detasseling in hybrid seed production fields of corn (Zea mays L.) frequently is accompanied by loss of some leaf material. Little is known about the effect of this practice on seed production in those instances where the seed parent is an inbred line. We investigated the effects of tassel removal and tassel plus leaf removal on 5 short season inbred lines grown at Guelph, Ontario and 5 later maturing lines grown at Harrow, Ontario. Treatments at both locations consisted of a check, and the removal just prior to anthesis of the tassel, tassel plus one leaf, tassel plus two leaves, and tassel plus three leaves. When tassels alone were removed, there was an average increase "of 6.9%g rain yield. When 1, 2, and 3 leaves were removed with the tassel, yield reductions for the 10 inbreds averaged 1.5, 4.9, and 13.5% relative to the yield for tassel removal only. Yield differences were the result of a reduction in both kernel weight and number of kernels per row. However, yield responses to leaf removal varied greatly between inbreds, and therefore, it is impossible to generalize on the effects on grain yield of leaf removal during detasseling. For some inbreds, particularly shorter season ones, the reduction in yield due to removal of 2 and 3 leaves with the tassel is large enough to warrant consideration in seed production. On the other hand, yield of some of the later inbreds was reduced only slightly when 3 leaves were removed with the tassel. This probably reflects the higher percentages of leaf area removed in earlier inbreds as compared to the later inbreds.