Technical Abstract: Potato tuber development follows a genetically programmed progression from tuber initiation to maturation. Most grower activities nurture this process, but vine kill and harvest are exceptions that have the potential to affect the quality of the crop. Experiments conducted for two years determined the effects of harvest date and vine-kill treatment on the physiology and processing quality of potato tubers stored for up to 12 weeks. Russet Burbank potatoes were grown in central Wisconsin using standard procedures for planting, fertilization, irrigation, and pest management. Tubers were harvested in late July before vines had begun to senescence, in mid-August when limited senescence was observed, and in September after complete natural senescence. Vines were either killed with diquat two weeks prior to the first two harvests or were left untreated. Data were collected at harvest and in storage for skin set, respiration rate, and tuber glucose, fructose and sucrose. Skin set at harvest increased with vine-kill treatment at the early harvest date, but not at the middle harvest date. Significant, persistent differences in respiration rates and sugar profiles were observed for tubers from the different treatments. In particular, the early harvest/vine killed treatment resulted in tubers with respiration rates that were elevated relative to those from the other treatments. Tubers harvested in July after vine kill had lower tuber bud-end glucose than tuber harvested without vine-kill treatment, but stem-end glucose values were comparable. Across treatments, tuber sucrose or glucose content six weeks after harvest was a poor predictor of tuber glucose content twelve weeks after harvest.