Effect of Humic Acid on Grain Filling Characteristics of Longzi Black Highland Barley

FU Tiantian; HUANG Huiyun; QI Wenjing; FENG Xibo

doi:10.14069/j.cnki.32-1769/s.2025.04.007

Abstract：To investigate the effect of humic acid application rate on post-flowering grain filling of Longzi black highland barley,Longzi hexagonal black highland barley was used as the test material,and humic acid treatments(CK,T1,T2,T3 and T4)were set at 0,150,300,450 and 600 kg/hm2 to analyze the differences in humic acid application rate on the phenotype,filling characteristic constants and correlation of Longzi black highland barley grains.The results showed that:(1)Applying humic acid can significantly increase the grain area,grain circumference,grain length,grain width,and actual thousand-grain weight of Longzi black highland barley,with T2>T3>T1>T4>CK.Compared with CK treatment,the theoretical thousand-grain weight of T1-T4 treatment increased by 2.01%～8.94%,and T2 treatment had the best effect.(2)The application of humic acid can significantly improve the grain filling rate(v),theoretical thousand grain weight and maximum grain filling rate occurrence time(tmax)of Longzi black highland barley.The maximum grain filling rate occurrence time(tmax)of T1 to T4 treatments was from 16.85 to 17.44 days after flowering,which was 3.10%,3.38%,2.47%and 1.55%earlier than that of the CK treatment,respectively.(3)The application of humic acid can significantly increase the maximum grain filling rate(vmax)of Longzi black highland barley,and the actual thousand-grain weight is positively correlated with vmax,t3,tb,tc,v2 and v3.Humic acid improves the grain filling ability and thousand-grain weight of black highland barley.It is recommended to use 300 kg/hm2 humic acid(T2)as the optimal fertilization scheme for Longzi black highland barley in production.