Abstract:

This study investigated the patterns of calcium absorption, accumulation, and distribution in potatoes, as well as the effects of exogenous calcium on potato calcium nutrition characteristics, with the aim of effectively increasing tuber calcium content. Using potato variety ‘Youjin’ as test material, a two-year field experiment was conducted in Suihua with five calcium application levels (CaO at 0, 20, 40, 60, and 80 kg/hm²). Calcium content in various organs of potatoes at different growth stages was measured to analyze the dynamic changes in calcium accumulation and distribution characteristics. The results showed that the calcium content in potato stems and leaves continued to increase throughout the growth period, while the calcium content in tubers peaked during the tuber bulking stage and subsequently declined. The calcium accumulation in leaves reached its peak during the starch accumulation stage and then decreased, whereas it continued to increase in stems and tubers until harvest. The calcium accumulation rate in all potato organs followed a "slow-fast-slow" trend during the growth period. The accumulation rates in leaves and tubers were highest during the tuber formation to bulking stages, while in stems, it was delayed until the bulking to starch accumulation stages. Calcium application significantly increased the calcium accumulation rate in tubers more than in stems and leaves, although tuber calcium content, accumulation, distribution proportion, and accumulation rate remained significantly lower than those in stems and leaves. Compared to the non-calcium treatment, calcium application significantly increased tuber calcium content (9.4%-46.7%), accumulation (12.6%-90.2%), accumulation rate (13.4%-97.4%), and distribution proportion (7.3%-46.5%). However, the calcium fertilizer utilization efficiency was only 2.0%-22.8%. Calcium application increased yield by 0.2%-14.0%, and the optimal calcium application rate. Based on yield evaluation, the optimal calcium application rate was 43-58 kg/hm². Correlation analysis revealed that tuber calcium content at harvest was significantly positively correlated (P<0.01) with calcium content in all organs during the tuber formation stage, while tuber yield was significantly positively correlated (P<0.05) with calcium accumulation rates in leaves and tubers during the tuber bulking stage. In conclusion, calcium application effectively improved calcium nutrition in potatoes and significantly increased tuber calcium content, and the tuber formation to bulking stage was identified as the critical period for enhancing tuber calcium nutrition.

Key words: potato, application of calcium fertilizer, calcium content, accumulation rate, accumulation and distribution, fertilizer utilization rate, nutritional characteristics