Life Sciences Commons^™

Photons From Nir Leds Can Delay Flowering In Short-Day Soybean And Cannabis: Implications For Phytochrome Activity, Paul Kusuma, F. Mitchell Westmoreland, Shuyang Zhen, Bruce Bugbee

Plants, Soils and Climate Student Research

Photons during the dark period delay flowering in short-day plants (SDP). Red photons applied at night convert phytochromes to the active far-red absorbing form (P_fr), leading to inhibition of flowering. Far-red photons (greater than 700 nm) re-induce flowering when applied after a pulse of red photons during the dark period. However, far-red photons at sufficiently high intensity and duration delay flowering in sensitive species. Mechanistically, this response occurs because phytochrome-red (P_r) absorbance is not zero beyond 700 nm. We applied nighttime photons from near infrared (NIR) LEDs (peak 850 nm) over a 12 h dark period. …