10.26165/JUELICH-DATA/FOQOFI Konche, Deepthi0009-0009-2644-6477(FZJ/IBG-2)Romero, Juan ManuelIspizua Yamati, Facundo Ramón0000-0001-5775-3554(IFZ, Goettingen)Boemer, Jonas0000-0003-0723-4224(IFZ, Goettingen)Askin, Ilgaz(FZJ/IBG -2)Jedmowski, Christoph0000-0003-4647-4896(FZJ/IBG-2)Mahlein, Anne-Katrin0000-0003-1091-3690(IFZ, Goettingen)Rascher, Uwe0000-0002-9993-4588(FZJ/IBG-2)Muller, Onno0000-0002-0473-5632(FZJIBG-2) Jülich DATA 2026 This dataset includes measurements in sugar beet crop collected during field experiments investogating the effects of Cercospors leaf spot infection. The dataset integrated measurements from both active and passive chlorophyll fluorescence techniques. Active fluorescence parameters, including PSII efficiency obtained using the light induced fluorescence transient (LIFT) system. Passive fluorescence measurements including red and far-red sun-induced fluorescence (SIF) and range of reflectance-based vegetation indices (VIs) using a fluorescence (FloX) box. The dataset further estimates SIF Yield using the escape fraction (fesc) derived from reflectance data and fraction of absorbed photosynthetically active radiation (fAPAR). Complementary agronomic and disease related observations like final yield measurements and disease severity scores (DSS) are also included. Konche, Deepthi(FZJ/IBG-2)