Seeds of Chionanthus virginicus L. have a double dormancy associated with germination. Seeds are inhibited by a hard bony endocarp. Inhibition may also be due to the endosperm and possibly embryo dormancy. Experiments were performed on excised embryos in sterile culture. Little growth was noted on excised embryos, which possibly indicates dormancy within the embryo. In another experiment, whole seeds, seeds with endocarp removed, and acid scarified seeds were germinated in moist peat moss to observe inhibition by the endocarp. Seeds with endocarps removed, germinated quicker and in higher percentages than whole seed or scarified seed. Scarified seeds showed no improvement over whole seeds and radicles which were produced tended to be less vigorous. Whole seeds were also soaked for 24 hours in 1000 ppm GA and germinated in moist peat moss. Treatment with GA did improve radicle emergence.
Stephen Redcay and John J. Frett
John Frett, W. Edward Kee, and Stephen Redcay
Lima bean yields are lower in Delaware than in other lima-bean-producing states. One of the factors that contributes to the low production is the high temperatures that occur during production. Six commercial varieties of lima beans, both fordhook and baby lima bean types, were grown in a glass greenhouse at either 25C or 35C daytime temperatures to screen for heat tolerance. Plants grown at high temperature were typically shorter and more bushy than plants grown at 25C. Few, if any, buds, flowers, or early pods remained on plants at harvest if the plants were grown at 25C, while plants grown at 35C were still producing buds and flowers. Lima bean yields were generally reduced at 35C. The magnitude of the effect on yield ranged from `F1072', which had a 100-fold decrease in yield, to `Early Thorogreen', which demonstrated a slight increase in yield in response to increased temperatures.