Cultivars and Their Developmental Phases Interact with Temperature Fluctuations to Modulate Growth, Productivity and Seed Tuber Physiology of Potatoes (Solanum tuberosum L.)

In view of raising concerns of climate change, the impact of temperature on potato (<i>Solanum tuberosum</i> L.) growth and productivity was investigated by planting at different times to expose plants to natural variations in air and soil temperatures. Over two seasons with differing temperature patterns, emergence, stem and tuber numbers, tuber size distribution, yield, processing quality, and seed tuber behavior were analyzed. Postharvest, tubers from each planting were stored and replanted to assess temperature carryover effects. Generally, delayed plantings increased the average number of stems per plant (37%) but did not alter the tuber numbers per plant. Early (18 April) and mid-season (9 May) plantings produced higher yields, while late planting (30 May) reduced total yield (42%), US No. 1 yield (48%), and tuber numbers (34%). Moreover, the storage period influenced subsequent stems per plant more than the prior-year temperature conditions. Optimal productivity was achieved by planting during cooler establishment temperatures, followed by warmer tuberization and relatively cooler bulking temperatures. Diurnal temperature variations and growing degree days had minimal effects on stems per plant, whereas storage duration (chronological age) and temperature significantly impacted physiological aging. These findings help growers optimize planting times to enhance tuber storability and yield to improve end use.