EFFECT OF SOIL TEMPERATURES AT HARVEST ON BRUISE RESISTANCE OF POTATOES

The effect of soil temperature at harvest time on the bruise resistance of potatoes was determined by dropping a weight onto tubers, by dropping tubers, and by sampling commercially harvested potatoes. The results show that a positive linear relationship exists with bruise resistance increasing as soil temperature increases. Shifts in the regression function during the one season studied suggest that some factor or factors which were influenced by time also affected the bruise resistance rating. However temperature of the tubers (and hence, of the soil) at harvest remains the major determinant of the resistance of potato tubers to bruising. Correlation between the bruise rating and soil temperature, as found in the commercial operation, indicates that the relationship is of a magnitude to be of economic importance. An average of 20% of the Katahdin tubers sampled were bruised in the harvesting process and were a potential loss from marketing channels. © 1969 Springer.