In connection with the processing of potatoes grown at Tarland, Aberdeenshire, certain field data were obtained over a period of eight years. It was found that the yield per acre was inversely correlated with rainfall and positively correlated with sunshine for the period May to September; the indications were that the period May to July was more important in this respect, high rainfall and low sunshine during this period depressing the crop more than high rainfall in the August to September period. It has been possible, statistically, to separate the effect of rainfall from that of sunshine (and temperature), and an analysis shows that sunshine (or temperature) is die dominant factor. The number of tubers produced was greatest in those years when sunshine was high and rainfall low. The dry matter content of die tubers was also highest when the sunshine was high and the rainfall low, the closest inverse correlation being with the rainfall for the month of August. The combination of high yield of potatoes and high dry matter content meant that the actual food produced was highest in the drier, more sunny, years.