Shining Light on Eggplant Production
Citation
Terlizzese, D., Lanoue, J., Hao, X. and Zheng, Y. 2023. Shining Light on Eggplant Production, Ontario Fruit and Vegetable Convention, Feb. 22-23, 2023, Niagara Falls, ON, Canada.
Résumé en langage clair
Canada imports more than 26,000 metric tons of eggplant yearly, most of which occurs during the winter months. While the use of supplemental lighting has become popular for year-round greenhouse cucumber and tomato production, lit cultivation of eggplant is uncommon, likely due to the lack of research and knowledge surrounding the crop. Therefore, we investigated the effects of supplemental lighting on plant growth and fruit yield in eggplant winter production. Using long photoperiod of low intensity lighting to meet the crop’s daily light requirement (daily light integral, DLI) can reduce light fixture costs and electricity costs through lighting during off-peak hours, especially during the night. In our previous research on tomatoes and peppers, we have discovered that dynamic (change in light intensity and spectrum during a day) will allow up to 24 hours of lighting per day without compromising crop production when monochromatic blue light is used at the night. Therefore, we also evaluated the effects of different durations of photoperiod including the 24 h lighting with monochromatic blue light during the night. Four light treatments comprised of a natural light control and 3 different supplemental light photoperiods with the same DLI were implemented in the study: 16h white light, 20h white light, and dynamic 24 h lighting (16h white light followed by 8h blue light). Overall, photoperiods did not alter individual leaf photosynthetic performance, but did impact the generative/vegetative balance of eggplants. Total yield was doubled in all supplemental light treatments relative to the natural light control, and the dynamic 24 h lighting has a high potential to reduce electricity costs while maintaining good crop production.
Résumé
Canada imports more than 26,000 metric tons of eggplant yearly, most of which occurs during the winter months. While the use of supplemental lighting has become popular for year-round greenhouse cucumber and tomato production, lit cultivation of eggplant is uncommon, likely due to the lack of research and knowledge surrounding the crop. Therefore, we investigated the effects of supplemental lighting on plant growth and fruit yield in eggplant winter production. Using long photoperiod of low intensity lighting to meet the crop’s daily light requirement (daily light integral, DLI) can reduce light fixture costs and electricity costs through lighting during off-peak hours, especially during the night. In our previous research on tomatoes and peppers, we have discovered that dynamic (change in light intensity and spectrum during a day) will allow up to 24 hours of lighting per day without compromising crop production when monochromatic blue light is used at the night. Therefore, we also evaluated the effects of different durations of photoperiod including the 24 h lighting with monochromatic blue light during the night. Four light treatments comprised of a natural light control and 3 different supplemental light photoperiods with the same DLI were implemented in the study: 16h white light, 20h white light, and dynamic 24 h lighting (16h white light followed by 8h blue light). Overall, photoperiods did not alter individual leaf photosynthetic performance, but did impact the generative/vegetative balance of eggplants. Total yield was doubled in all supplemental light treatments relative to the natural light control, and the dynamic 24 h lighting has a high potential to reduce electricity costs while maintaining good crop production.