ANA LELO1, ENDRIT KULLAJ2*, HAFUZ DOMI1, MEHMET PUPA1
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1ADAD MALORE Association, Albania
2Department of Horticulture and Landscape Architecture, Agricultural University of Tirana, Albania
Abstract A two-year (2024–2025) multi-location trial was conducted to assess ten plum cultivars across four Albanian sites (Shumbat–Dibra, Shamoll–Korça, Zemblak–Korça, and QTTB Vlora) representing contrasting environments. Tree phenology, yield, fruit quality and pest/disease tolerance traits were measured. Traits were oriented so that higher values indicate desirable performance, then converted to standard scores (z‐scores) to eliminate units. Site- and year-specific Quality, Tolerance/Resistance, and Agronomy indices were computed as the mean of the relevant z‐ scored traits (e.g. Quality index = average of standardized taste, sugar, firmness, color scores), and an Overall Index was calculated as the mean of available indices. Indices were averaged over both years for final ranking. Missing trait values (few cases) were imputed by the trait mean. Principal Component Analysis (PCA) was performed on the combined standardized trait data to explore multi-trait patterns. In general, the Serbian-origin cultivar Čačanska Lepotica excelled in fruit quality traits, while Mildora, Zlatka, and Valiefka showed strong pest/disease tolerance, and Krina had the best agronomic performance (yield, precocity) across sites. Overall, Krina and Nada achieved the highest two-year mean indices across locations, closely followed by TopTaste and Mildora. PCA revealed that PC1 (≈50% variance) was dominated by fruit quality and yield traits, whereas PC2 (≈38%) reflected resistance/tolerance traits (Figure not shown). These results provide a rigorous, quantitative basis for recommending site-specific and general-purpose plum cultivars in Albania. Keywords: Prunus domestica, plum cultivars, multi-site trial, fruit quality, tolerance index, principal component analysis. |