Influence of growth temperature on development and yields in a medium late and late Scandinavian cultivar of potato

With more available meteorological field-sensors for agriculture, there is an increasing need for local-adapted growth models. Especially for cultivation of crop cultivars in areas with marginal temperatures and varying light conditions. The temperature response was therefore studied in climate-controlled growth chambers under constant temperatures from 9 to 21°C under a natural 24 h photoperiod in greenhouse in Tromsø (69.7°N, 18.9°E), Norway, for the potato cultivars Gullauge (medium late) and Mandel (late). There was a strong response in both cultivars to temperature, with reduced developmental time from emergence and leaf formation to visible flower buds at increasing temperature intervals. Developmental rates were higher for Gullauge than for Mandel. Shoot dry matter weight per plant was highest at 12°C and 15°C for both cultivars, though with higher shoot biomass at harvest in Mandel than Gullauge. Tuber yields and tuber dry-matter percentages for both cultivars was higher for Gullauge than for Mandel. Fresh weight yields and dry matter percentage for both cultivars were highest at 15°C. Optimum temperature for above-ground vegetative development-rate was estimated to be 24.0°C and 22.6°C, for Gullauge and Mandel respectively. In contrast, the respective temperature optimums for developing tuber dry matter content were 16.6°C and 15.6°C. Lower temperature optimums for below-ground development makes potato a suitable crop for temperate and boreal climates with cooler autumn temperatures. Different temperature optimums for above- than below-ground development needs to be considered when developing temperature-based growth models for potato cultivars from emergence to tuber yields.