End-of-day far-red lighting combined with blue-rich light environment to mitigate intumescence injury of two interspecific tomato rootstocks

Effects of end-of-day far-red (EOD-FR, 700-800 nm) light and high blue photon flux ratio during the photoperiod on intumescence injury were examined for ‘Beaufort’ and ‘Maxifort’ tomato rootstock seedlings (Solanum lycopersicum × Solanum habrochaites) grown with 13 mol m^-2 d^-1 daily light integral (199 µmol m^-2 s^-1 photosynthetic photon flux, 18 h photoperiod). The EOD-FR light treatment (1.1 mmol m^-2 d^-1 provided by 6.0 µmol m^-2 s^-1 FR photon flux for 3 min at EOD) significantly reduced intumescence injury.
For example, by the EOD-FR light treatment, the incidences of leaf abscission were reduced from 88 to 8% for ‘Beaufort’ and from 79 to 25% for ‘Maxifort’. However, EOD-FR light caused undesirable stem extension (41% greater than that without EOD-FR light). By combining relatively high B (blue, 400-500 nm) to R (red, 600-700 nm) photon flux ratio (50%B-50%R) during the photoperiod with EOD-FR light, intumescence injury was further decreased without causing undesirable stem extension.
For example, the incidences of leaf abscission were reduced from 88 to 0% for ‘Beaufort’ and from 79 to 0% for ‘Maxifort’, compared to those under 10%B-90%R without EOD-FR light.
Also, the percentages of leaves that exhibited intumescences were reduced from 68 to 30% for ‘Beaufort’ and from 55 to 19% for ‘Maxifort’. Our study demonstrated that blue-rich light quality combined with a small dose of EOD-FR lighting could be applied to mitigate the problematic intumescence injury of tomato seedlings grown under LEDs.

VIII International Symposium on Light in Horticulture

T. Eguchi, R. Hernández, C. Kubota

edema, LED, light quality, oedema, Solanum lycopersicum, transplants

https://doi.org/10.17660/ActaHortic.2016.1134.22