Significant differences in damage occurred between selections when shakes having a stroke of 3.8 cm were applied at 186 cycles/min over a period of 40 s using a mechanical devise designed to screen selections for resistance to bruising and to obtain data on shelf life after bruising. Varietal differences were in general agreement with those which followed transport by road and rail. Some Auchincruive selections of 65G, bred from US2650, were very resistant to mechanical damage and are under consideration for release as commercial varieties. Fruits of 61A1 possessed a skin which was resistant to infection by Botrytis cinerea, while fruits of 65G seedlings were resistant to B. cinerea because the skin was resistant to bruising.