The greenhouse equipped with 29-mesh insect-proof nets and a zipper door enhances insect pest control and yield of bok choy

Abstract The use of insect-proof nets (IPNs) are an environmentally friendly physical method for preventing insect pests from entering the greenhouse and damaging the vegetables. Bok choy Brassica rapa L. subs. chinensis Brassicaceae, a widely cultivated vegetable in China, is commonly planted in the conventional greenhouses built with plastic films (PFs), IPNs and sliding doors (SDs), and named as PF-SD. However, the effectiveness of controlling agricultural insect pests in PF-SD greenhouse is low due to improper mesh sizes of IPNs and easily-deformative SDs. In this study, the rainproof performance of IPN-ZD greenhouse was compared with that of the open field, and the effects of pest damage, temperature and relative humidity as well as the growth and metabolites of bok choy in the novel greenhouse (IPN-ZD) equipped with 29-mesh IPNs and zipper doors (ZDs) were compared with those of the PF-SD greenhouse at Nanjing, China (31.5°N, 119.0°E) in autumn. The results indicated that the IPN-ZD greenhouse was able to reduce rainfall infiltration compared to that of the open field and increased the yield by 44.9%, reduced internal temperatures, significantly reduced the leaf damage rate from 15.93% to 5.94% and metabolite contents (chlorophyll a and chlorophyll b ) in bok choy compared with those in the PF-SD greenhouse. In conclusion, the IPN-ZD greenhouse could reduce the leaf damage rate, improve the integrity, yield and quality of bok choy and is potentially beneficial to the environment and ecology compared with the PF-SD greenhouse. Significance of the study What was already known about this subject? Insect-proof nets (IPNs) are widely used in greenhouse vegetable cultivation as a physical pest control measure. However, their effectiveness can be affected by inappropriate mesh sizes, inadequate sealing and ventilation conditions. What are the new findings? This study developed a novel greenhouse structure equipped with 29-mesh IPNs and zipper doors (IPN-ZD). Compared with the conventional PF-SD greenhouse, the IPN-ZD greenhouse significantly reduced the leaf damage rate from 15.93% to 5.94% and increased bok choy yield by 44.9% without pesticide application. It also reduced rainfall infiltration and internal temperature. What are the expected impacts on horticulture? The IPN-ZD greenhouse provides a practical physical pest-management approach for protected vegetable production, with the potential to reduce leaf damage and improve crop yield while supporting environmentally sustainable horticultural production.