Shading wheat plants during the booting and anthesis stages reduces grain yield by decreasing dry matter accumulation. Spraying 6-BA before shading at anthesis helps mitigate yield loss by delaying leaf aging, increasing grain filling rate, and enhancing grain weight. This treatment also boosts dry matter accumulation and assimilate translocation, ultimately leading to higher grain yield compared to shading alone. Shading at anthesis has a greater negative impact on grain yield than shading at booting stage. Overall, applying 6-BA before shading at anthesis can help protect wheat yield under low light conditions in the Jianghan Plain.