Regulation of fruit set by light quality: a case study on pepper

ISHS Secretariat
Regulation of fruit set by light quality: a case study on pepper

Sijia Chen is a PhD student at Horticulture and Product Physiology, Wageningen University, the Netherlands, supervised by Dr. Ep Heuvelink, Professor Leo Marcelis as well as Professor Remko Offringa (Leiden University). Her research focuses on the effect of the light spectrum on fruit set in sweet pepper (Capsicum annuum L.). Fruit set is a crucial plant developmental process, determining yield in many crops. Pepper, as one of the most important and commonly consumed vegetables, is a crop with poor fruit set as typically about two-third of all flowers abort. Weeks with good fruit set are alternated with weeks with poor fruit set, resulting in a flushing pattern in fruit set and yield. Abortion of flowers and fruit in peppers is an active process involving the formation of an abscission layer, which could relate to the endogenous hormonal signaling. A higher light integral improves fruit set. However, the role of light spectrum has hardly been investigated. Opportunities for detailed investigations of light quality effects on fruit set have strongly increased because of the development of narrow band LED lighting. This research aims to improve the understanding on how fruit set can be manipulated by light spectrum, by studying the physiological and molecular mechanisms. For this purpose, Sijia has conducted a series of climate chamber experiments. She found that far-red radiation increased the fruit abortion in sweet pepper, and this effect was missing when the tops of the plants were removed. The underlying mechanism of this effect awaits further investigation.

Sijia Chen won the ISHS Young Minds Award for the best oral presentation at the IX International Symposium on Light in Horticulture, which was held virtually in Sweden in May-June 2021.

Sijia Chen, Horticulture and Product Physiology, Wageningen University, Droevendaalsesteeg 1, 6708PB wageningen, The Netherlands, e-mail:

The article is available in Chronica Horticulturae

light in horticulture
Young Minds Award Winners