A decade has now elapsed since this Station issued the last formal report on plums in its Bulletin 46. During this period many varieties have been received for testing on the Station grounds and a good opportunity has been offered for studying their records together with the older varieties which were previously established at the Station. This bulletin is offered as a report of progress, in the testing of varieties at this Station. Since Bulletin 46 is no longer available for distribution, somewhat fuller treatment has been given than would otherwise be necessary.
Varieties of plums which are generally cultivated in Iowa belong chiefly to American native species. Those of the Japanese type, Prunus triflora, together with those of the European species, Prunus domestica, are seldom grown here with any satisfactory degree of success, either on account of lack of hardiness or because the crop is very apt to be destroyed by fruit rot.