Long-term Impact of Virus-Free Apple Seedlings on Fruit Quality and Yield in Commercial Orchards of Korea.

This study presents a comprehensive, long-term assessment of the performance and economic impact of virus-free (VF) apple seedlings distributed to commercial orchards in Korea. We compared VF and virus-infected (VI) 'Hongro' and 'Fuji' apple trees over five years, starting from four to five years after planting. VF trees maintained no reinfection for up to nine years, while VI trees showed a high infection rate (78.6%). VF trees consistently showed higher fruit set, greater yield, and superior fruit quality-including size, color, and soluble solids-than VI trees. VI trees produced more unmarketable fruit in both cultivars. Economic analysis showed that adopting VF seedlings increased net grower income by KRW 825,000 per 10 a. These results demonstrate that VF apple trees provide sustained improvements in productivity, fruit quality, and profitability in orchard conditions, supporting the continued expansion of VF seedling programs for sustainable apple production in Korea.