Abstract: In response to the need for synergistic optimization of water and fertilizer in the water-deficient areas during winter of the Yunnan Plateau, the effects of different irrigation amounts on the growth traits, marketable tuber rate and yield of winter potato (Solanum tuberosum L.) were systematically investigated based on the integrated water and fertilizer management under mulch drip irrigation. Using Zhaoshu No. 12 as the test material, treatments included a traditional management model (control, 100% irrigation amount) and five irrigation gradients (T5 to T1, 60% to 100% irrigation amount) under the integrated water and fertilizer management. The results showed that the irrigation amount had no significant effect on the emergence rate and marketable tuber rate of winter potato, but both showed a downward trend as the irrigation amount decreased. Plant height decreased with the reduction of irrigation amount, and the T4 (70% irrigation amount) and T5 (60% irrigation amount) treatments were significantly lower than the other treatments. The tuber number per plant was the highest in the T3 (80% irrigation amount) treatment and was significantly higher than that in the control treatment. The single tuber weight, yield, and aboveground biomass were the highest in the T1 (100% irrigation amount) treatment and showed a decreasing trend as the irrigation amount decreased. Correlation analysis indicated that yield was significantly positively correlated with aboveground biomass, single tuber weight, emergence rate, and irrigation amount. Under the integrated water and fertilizer management with mulch drip irrigation, maintaining a 100% irrigation amount could maximize the growth and yield potential of winter potato, representing an effective strategy for achieving high yield and quality production in the region.

Key words: integrated water and fertilizer management, irrigation amount, winter potato (Solanum tuberosum L.), growth, yield