20.500.12556/RUL-175240 Impact of polysorbate 20 and 80 emulsifiers on apple fruitlet thinning and their biochemical profile research data underlying the article Chemical thinning is an important practise in apple production, yet current thinning agents face limitations in environmental safety and efficacy under variable conditions. This study investigates the thinning potential and physiological effects of two food-grade emulsifiers, polysorbate 20 (P20) and polysorbate 80 (P80), compared to a standard ethephon-based as well as a metamitron-based thinner on ‘Gala’ apple trees. Fruitlet drop, sugar content and phenolic profiles were monitored in relation to fruitlet position and developmental stage. Both P20 and P80 induced significant fruitlet abscission, with P20 showing a comparable thinning effect to commercial thinners. The P20 and P80 treatments altered the natural cluster hierarchy, and fruitlets with reduced growth (reduced diameter and weight) showed increased abscission, indicating lower sink strength. Sucrose content was significantly reduced in P20 treated king fruitlets, which correlated with increased fruit drop. Fructose and sorbitol content varied over time, but not between treatments, while glucose levels remained stable. Phenolic profiling revealed a significant increase in dihydrochalcones and anthocyanins after treatment with P20, suggesting a stress-induced response. These results support the carbohydrate theory of fruitlet abscission and emphasise the potential of polysorbates as alternative late-acting thinning agents with additional insights into the physiological mechanisms behind fruit drop. Further research is needed to clarify the exact mode of action of polysorbates in apple fruitlet thinning. emulsifiers polysorbate 20/80 apple fruitlet thinning shedding dynamic hierarchy sugars and phenolic content emulgatorji polisorbat 20/80 redčenje jabolk dinamika odpadanja hierarhija vsebnost sladkorjev in fenolov true false false Angleški jezik Slovenski jezik Research data measured and sampled in the experimental orchard Brdo pri Lukovici, Slovenia (46° 10’ 04.8” N, 14° 40’ 55.2” E). Research data measured and sampled in 2023 and 2024. Neznano 2025-10-22 15:11:38 2025-10-24 15:33:19 2025-12-07 04:05:13 0000-00-00 00:00:00 2025 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 Methodology.docx Methodology.docx Methodology 1 2F43EC51E885B08143338F6F5027D2C1 1d2fc6595ced3ede8394de21c0753960d340ee64d78e64511f368bbdb9aedfdb 8d9d2be1-af48-11f0-9328-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=220584 Data.xlsx Data.xlsx Data 1 BE767E280FB75FA7F7AF92BC073CE34E fae2d49fe27f5b03c2257244e2214f8419712b9cdcc423c7e590f82e615b4c0e 8a05827e-af48-11f0-9328-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=220582 Biotehniška fakulteta Poskus Poskus: Laboratorij Poskus: Teren/Intervencija Meritve in testi: Fizično 0 0 0