Increasing frequency of high-temperature episodes in potato growing regions of Western Australia and its impacts on plant and tuber growth

Abstract

ABSTRACT Little is known about actual temperature regimes experienced by potato during the critical period of tuber bulking and their impact on plant and tuber growth outside the cool temperate production regions. We analysed the temperature data of potato growing regions in Western Australia (WA) and six other non-traditional potato growing regions for the number of days with maximum temperatures above 25, 30 or 35°C and their occurrence during tuber bulking. As anticipated, days with 25°C increased between 1985 and 2014 in all locations in WA. Surprisingly, across the other six locations, only Beersheba (Israel) showed a significant trend of increasing temperatures. Then, in a greenhouse experiment, we investigated how 1, 3, 6 and 9 days of 30°C applied shortly after tuber initiation influenced plant and tuber growth of potato cv. Royal Blue. Tuber mass and leaf area decreased linearly with increased duration of 30°C. In conclusion, potato grown in WA and other locations already experience growth limiting temperatures during tuber bulking and the frequency of hot days is increasing. Considering climate change and the expansion of potato production into non-traditional areas, more detailed examination of temperature regimes in other warm growing regions could be important for industry planning.