Effects of paclobutrazol spraying on the growth and nitrogen utilization characteristics of Capsella bursa-pastoris in greenhouse

YUAN Yujuan; ZHU Yuxue; LI Jin; XU Chenwei

doi:10.16861/j.cnki.zggc.2025.0558

Abstract：To clarify the regulatory effects of different concentrations of paclobutrazol on the growth,yield,nitrogen utili-zation characteristics,and quality of greenhouse-cultivated Capsella bursa-pastoris,and to provide technical support for its high-quality and high-yield cultivation,the large-leaf variety of Capsella bursa-pastoris was used as the test material.Five paclobutrazol spraying concentrations were applied(50,100,150,200,250 mg·L⁻¹),with control of no paclobutra-zol application(C0)and no application of both paclobutrazol and nitrogen fertilizer(CK).The results showed that spray-ing an appropriate concentration of paclobutrazol could significantly inhibit excessive growth,increase leaf number,and promote dry matter accumulation in both aboveground and underground parts of Capsella bursa-pastoris.Among them,the 100 mg·L⁻¹treatment(C2)significantly reduced plant height by 16.41%and increased leaf number by 7.14%com-pared to C0.It also resulted in the highest values for aboveground fresh mass,belowground fresh mass,aboveground dry mass,and belowground dry mass,which were significantly increased by 16.33%,28.81%,31.67%,and 36.83%,respec-tively,compared to C0.Yield exhibited a trend of initial increase followed by decrease with increasing paclobutrazol con-centration.The C2 treatment achieved the highest yield of 21645.19 kg·hm⁻²,which was a significant increase of 12.86%than C0.Nitrogen use efficiency was also optimal under the C2 treatment.Compared to C0,the total nitrogen uptake,ag-ronomic nitrogen use efficiency,partial factor productivity of nitrogen,and nitrogen fertilizer recovery efficiency were sig-nificantly increased by 109.33%,59.04%,12.86%,and 90.69%,respectively.Principal component analysis of the quality evaluation indices for Capsella bursa-pastoris under different treatments showed that the C2 treatment had the highest score,indicating the best overall quality.The degradation of paclobutrazol in Capsella bursa-pastoris across the five treat-ments followed a first-order kinetic equation,with a half-life ranging from 7.1 to 12.4 days,and the residue levels at har-vest did not exceed the maximum residue limits.In conclusion,foliar application of an appropriate concentration of pa-clobutrazol in greenhouse-cultivated Capsella bursa-pastoris can promote growth,increase yield,improve nitrogen use ef-ficiency,and enhance quality.The C2 treatment(100 mg·L-1)demonstrated the most favorable effects and can be safely used in production.