The impacts of cultivar maturity and meteorological factors on main quality of potato

Meteorological factors and cultivar maturity are the two determining factors of potato tuber quality. Analyzing the relationship between meteorological factors during the potato growth period and potato quality is of great significance for ensuring food security and enriching people’s dietary structure. On the basis of 2 years × 3-planting dates × 3-cultivars field experiment conducted in Wuchuan, Inner Mongolia Autonomous Region, the relationships between meteorological factors during different potato growth periods and the main indices of potato quality were quantified. On the basis of hydrothermal requirements during different potato growth stages, we divided the entire growth period into two periods, namely the vegetative growth period (planting-tuberization) and the reproductive growth period (tuberization-maturity), and then divided the reproductive growth period into tuberization to tuber bulking, tuber bulking to maturity. With the addition of the whole growth period and the water critical period (10 days before to 15 days after tuberization), six growth periods were set as the study phases. Five meteorological factors, namely effective accumulative temperature, mean temperature, daily temperature range, precipitation, and sunshine hours during the six growth periods were used to assess the relationships with potato quality, using correlation analysis, variance analysis, and membership function. The results showed that the average contents of crude protein, vitamin C, soluble sugar, and starch were 100.1 g∙kg⁻¹, 19.64 mg∙(100g)⁻¹, 18.58 g∙(100g)⁻¹ and 31.48 g∙(100g)⁻¹, respectively. The coefficients of variation for the main potato quality indices were in the order of soluble sugar > starch > vitamin C > crude protein. On the basis of membership function, the early maturing cultivar (‘Favorita’) with early planting (April 27), the middle maturing cultivar (‘Connibeck’) with late planting (June 2), and the late maturing cultivar (‘Kexin_1’) with middle planting (May 15) achieved the best potato quality when compared with other combinations of planting date and cultivar maturity. Ultimately, the coupling of planting date and cultivar had a significant effect on potato quality. Furthermore, meteorological factors had significant effects on potato quality during different potato growth periods. The results showed that potato tuber quality was mainly determined by meteorological factors during the potato reproductive growth period (tuberization-maturity), especially during tuber bulking to maturity.