Project „Light4Seeds“

Acorns, as recalcitrant forest seeds, can generally only be stored for relatively short periods of time. Fructification with sufficient quantities of seed only takes place every 6 – 12 years. Fungal pathogens such as the black rot pathogen Ciboria batschiana can destroy entire harvests. In a time of climate change and the associated need to restructure forests, stocks of sufficient quantities of suitable seed are urgently required. The aim was therefore to develop a fungicide-free process for treating acorns based on irradiation with blue light in the wavelength range 400 – 430 nm.
The basic prerequisite was a thorough examination of the properties of the recalcitrant fruits and the effects of blue light irradiation on their vitality and the pathogens to be inactivated.
The result was a demonstrator on a laboratory scale. Various non-contact spectral methods have been tested for feedback sensing. This demonstrated a reduction of acorn-damaging fungal pathogens by more than one log₁₀ in 60 min at an applied dose of 160 J cm^-2, which may lead to a significant extension of the possible storage time.The measurement of tryptophan fluorescence and color parameters in the LAB color space proved particularly remarkable.

INNO-KOM MF, FKZ 49MF220005