Abstract:
This study aims to evaluate the introduction adaptability of 10 American walnut (Carya illinoinensis) varieties (clones) in the dry-hot valley of Southwest Sichuan, providing a scientific basis for regional variety selection and configuration. By systematically observing the post-planting growth, phenological periods, and fruit yields of each variety, this study also attempts to analyze performance differences in the context of their origin bac kgrounds. The results showed that variety 35 exhibited the best growth performance, with average annual height increases of 70.7 cm at 1-year-old and 58.9 cm at 3-year-old trees. The annual ground diameter growth of Boni reached its peak at 3 years post-planting, measuring 1.3 cm. In terms of phenology, six varieties were protandrous, while four were protogynous, with peak flowering periods coinciding to enable cross-pollination. The average fruit yield was highest in Mahan (2.7 kg) and lowest in Boni (0.9 kg). Under the conditions of this experiment, the dry-hot valley climate in southwestern Sichuan is suitable for American walnut growth. It is recommended to prioritize varieties 35 and Boni, supplemented by high-yield varieties such as Mahan, 29, and 21 to establish a pollination combination, which can provide a reference for the development of regional specialty forestry industries.