Abstract Summer pak choi ( Brassica chinensis L.) farming is difficult due to insect pressure. The preventive and physiological benefits of insect‐proof netting with mesh sizes 20, 40, and 80 on pak choi cultivation were investigated in summer. We found that 20, 40, and 80 mesh nets significantly reduced insect activity ( p < 0.05). Aphid populations decreased by 50.84% (20‐mesh) and up to 80% (40/80‐mesh), whereas Pieris rapae and Plutella xylostella infestations were completely eliminated (100% reduction) in 40‐ and 80‐mesh nets. The net treatments increased shoot weight by 63.94%–67.91%, root weight by 52.63%–52.94%, and total biomass by 63.11%–66.67% over the uncovered control. The nets increased chlorophyll content (65.29%–67.25%) and improved antioxidant enzyme activity (superoxide dismutase, glutathione peroxidase: 85.51–104.38 µmol/min/mg protein; catalase: 41.16–55.62 µmol/min/mg protein) ( p < 0.05). Magnesium and potassium concentrations increased by 117%–118% and 106%–121% over the uncovered control, respectively. The statistics show that insect‐proof nets provide effective protection against key monitored pests and improve physiological performance in summer pak choi cultivation, with the 40‐mesh net providing the best overall pest exclusion and growth promotion.
Wang et al. (Thu,) studied this question.