Yield of commercial garlic (Allium sativum L.) varieties at three locations in Slovenia over two growing seasons

Garlic is an important crop for domestic consumption in Slovenia, used fresh or cooked in traditional and modern cuisine. However, there is little data available on the yield performance of commercial garlic varieties grown under different climatic conditions, which could help farmers to select the best-performing variety for cultivation. Field trials were conducted at three locations (Jablje, Ivanci, Šempeter) in Slovenia during two consecutive growing seasons (2020/21 and 2021/22) to evaluate the response of different garlic varieties. Ten commercial garlic varieties were used as experimental material: Ptujski jesenski, Garcua, Sabagold, Garpek, Gardacho, Germidour, Messidrome, Arno, Messidor, and Ptujski spomladanski. The same cultivation method and fertilisation regimes were applied in three replicates at each trial site. At Jablje, an unheated tunnel was used, while the trials at the other two sites were conducted under open field conditions. Marketable and non-marketable yields were determined five days after harvest. The total yield varied considerably from 3.13 t/ha for the Ptujski jesenski variety to 20.49 t/ha for Sabagold. The non-marketable yield was significantly higher (up to 40%) for the Slovenian varieties Ptujski jesenski and Ptujski spomladanski, due to their susceptibility to virus diseases and the lack of quality seed material. The best-performing marketable yields were recorded for the Sabagold, Messidrome, and Gardacho varieties with an average of over 11.5 t/ha. Among the different locations, the sub-Mediterranean climate proved to be less favourable for the production of market garlic, especially for late varieties. Results of statistical analysis have shown that the year, location, and variety all had a significant effect on marketable yield. Each factor contributes independently to yield variation, with year having the strongest effect, followed by location and variety. The data clearly show that the choice of garlic variety is the key to achieving high marketable yields.