Effects of light conversion film on the regulation of temperature and light environment and the growth physiology of pepper in autumn-ex-tended greenhouse

LIU Yan; SUN Xincheng; KANG Jie; YANG Lianyong; JIANG Wan; SUN Fang; HUANG Lin; CHEN Weiping; PENG Yuanqun; LI Qi; ZHANG Zhongwu

doi:10.16861/j.cnki.zggc.2025.0379

Abstract：To investigate the regulatory effects of light conversion film on the temperature and light environment in green-house for late-autumn pepper production in the Dongting-Lake area,as well as its effect on pepper growth and physiology,and to evaluate its applicability during high-temperature seasons,this study used the pepper variety Changla 60 as the experimental material.Two treatments were applied:light conversion film(T)and ordinary PO film(CK).Comparative analyses were conducted on changes in greenhouse temperature and light conditions,pepper agronomic traits,and physio-logical indicators.The results showed that the light conversion film significantly increased the daily maximum tempera-ture inside the greenhouse(peak increase of 6.34 ℃),reduced the daily maximum light intensity by 53 733.7 lx,and de-creased the average daily humidity by 4.80％.However,there was no significant change in the average daily temperature,exhibiting a temperaure and light regulation characteristic of peak-temperature-increase without average-temperature-rise.Coverage with the light conversion film promoted longitudinal fruit development(fruit longitudinal diameter increased by 9.81％),but due to the offsetting effect of high-temperature stress,there was no significant improvement in single fruit mass and yield per plant.In terms of physiologyical mechanisms,light conversion film coverage cuased a dramatic in-crease of 179.07％in leaf malondialdehyde(MDA)content,indicating oxidative damage induced by high-temperature stress,while CAT acitvity did not change significantly,suggesting an inadequate response of the antioxidant defense sys-tem.This study reveals that light conversion films exacerbate heat stress inside the greenhouse during high-temperature seasons,limiting pepper yield formation.Therefore,it is not recommended to directly and solely apply such film that sig-nificantly elevate peak temperatures during high-temperature periods.Their application in high-temperature requires the integration of cooling technologies to mitigate heat damage risks,providing a theoretical basis for optimizing the green-house cultivation environment for peppers in the region.