Hazelnut tree belonging to the Betulaceae family and Corylus genus, is one of the most important horticultural crops in Iran and has always played an important economical and social role for orchardists. Iran's potential to become one of the world's major producers of this product. Gilan province has 13809 hectares of hazelnut orchards, which constitute 74.5% of the cultivated area of hazelnut orchards in the country. The production in Iran relies almost entirely on local cultivar that characterized by low quality and yield. Therefore it seems imperative to replace them with suitable commercial varieties that could boost crop yield and productivity resulting in higher sale and income for the farmers. Identifying imported varieties compatible with desired performance and quality directly and indirectly affects the livelihoods of farmers. Cultivation of many cultivars in different areas is of fundamental importance to test their adaptability to different environmental conditions.

Materials and Methods

Thus, a study was conducted to evaluate hazelnut cultivars imported from Russia in an area of Rudsar County, Gilan Province, at an altitude of 1750 masl, in Samadabad village, since 2023, in a randomized complete block design with five replications (each replication three uniform and same-aged suckers of each cultivar). Fifteen cultivars Bakhamerensky, Vartashen, Khettuvy, Chelsea, Volgras, Proones, Sochi, Koban, Morfineski, Trabzon, Kalib, Atrak, Qafqaz, Izdab, Prehistorica were planted without a local control cultivar at 4x4 m spacing. Adaptation to the environment and vegetative and reproductive traits such as the length of the current season's shoot, the number of buds per shoot, the height of the seedling, the number of male flowers (catkins), the number of fruits, nut weight, the shell weight, kernel weight and weight of the woody shell were studied in the years 2023 and 2025. Statistical analysis of the data was performed using a combined analysis. The data were analyzed using SAS software (Version 9.1), and treatment means were compared using the Least Significant Difference (LSD) test at the 5% probability level.

Results and Discussion

The results of the study of leaf and catkin emergence phenology showed, during both years 2024-2025, the Bakhamarensky and Vartashan cultivars were recorded as early-leafing cultivars, and the Prostorika cultivar was recorded as late-leafing cultivars. In addition, in both years, the emergence of catkin occurred earlier in the Bakhamarensky cultivar and later in the Khettuvy cultivar. Among the cultivars studied, the Qafqaz cultivar showed the highest shoot length and number of buds per shoot. The seedling length in the Atrak cultivar (179.28 cm) was higher than other cultivars and the lowest value was observed in the Koban cultivar (47.45 cm). The Morfineski cultivar showed the highest number of sucker, and the Qafqaz and Proones cultivars showed the lowest number of sucker. The highest number of catkin in the studied cultivars was observed in the Vartashan cultivar and the lowest number was observed in the Koban cultivar. The Bakhamerensky cultivar had the catkin length with an average of 2.11 cm, and the Koban cultivar had the lowest value of this index with an average of 0.28 cm. In addition, the Sochi, Prostorika, Chelsea, Vartashan, Qafqaz, and Kalib cultivars fruit set earlier than the other cultivars studied. The Vartashan cultivar (3.70) had the highest number of nuts per cluster. The highest fruit weight and kernel weight were observed in the Chelsea and Prehistorica cultivars.

Conclusion

This study highlights the potential of imported hazelnut cultivars for further evaluation as possible alternatives to low-yielding local cultivars in Iran. By selecting the right cultivars, farmers can significantly improve productivity and profitability. Increasing production per unit area has significant social and economic impacts in the region in terms of family and local employment, reducing rural migration, and stabilizing the livelihood of gardeners. In addition to playing an effective role in economic development and employment in the region, this issue is also effective in ensuring food security. Despite the high number of hazelnuts per cluster, the Vartashen cultivar does not have the necessary marketability due to the small size of the nut weight, but due to the higher number of catkin, it can be considered in the pollination management of orchards. According to the results, Sochi, Prehistorica, Chelsea and Qafqaz cultivars are recommended as initial options with good potential for further evaluation as possible alternatives to local cultivars due to their earlier fruiting and suitable pomological traits. Despite the limitation due to the lack of local cultivars in the preliminary phase, the findings of this study provide a first and necessary step for initial screening and selection of susceptible genotypes for more accurate multi-year evaluations and comparisons with local cultivars in future studies and provide practical recommendations for hazelnut cultivation in Iran.