DA-6对不同施肥水平下大豆生长、抗倒伏特征和产量的影响OA

To investigate the effects of DA-6 on soybean growth,lodging resistance characteristics,and yield under different fertilization levels,a field experiment was conducted at Heshan Farm,Heilongjiang Province,China,during 2022-2023.The soybean cultivar Heihe 52,which has weak lodging resistance,was used as the test variety.Three fertilization levels of nitrogen,phosphorus,and potassium were set:F1(1/2 conventional fertilization rate),F2(conventional fertilization rate),and F3(3/2 conventional fertilization rate).DA-6 was sprayed twice at the beginning of flowering and the early podding stages at concentrations of 0,30,60,90,and 120 mg·L-1(D0,D30,D60,D90 and D120).The differences in morphological traits,dry matter accumulation,growth rate,lodging resistance characteristics,yield components,and yield were analyzed among treatments,and correlation analyses were performed.Results showed that soybean morphological traits and dry matter accumulation increased with fertilization levels.DA-6 application significantly increased plant height under F2 and F3 conditions,stem diameter,node number,and leaf area index under F1 and F2 conditions,and growth rate during the R1-R5 stages.Under F1 and F2 conditions,D30 and D60 treatments enhanced stem-breaking resistance(SR)and lodging resistance index(LRI),whereas D90 and D120 treatments reduced SR and LRI.Under F3 conditions,D60,D90,and D120 treatments significantly reduced SR,LRI,and most lodging resistance-related physiological indices,while increasing lodging rates to varying degrees.In 2022,lodging rates increased by 43.42%and 88.78%for D90 and D120 compared to D0,respectively,and by 26.06%and 85.35%in 2023.Both D90 and D120 significantly increased the number of soybean pods,seed count,and yield per unit area under F1 and F2 conditions,while D90 and D120 significantly decreased soybean yield under F3 conditions.Under F1,soybean yield increased by 9.91%and 8.61%in 2022,and by 9.81%and 9.54%in 2023.Under F2,yield increased by 11.59%and 9.87%in 2022,and by 11.17%and 9.82%in 2023.Under F3,yield decreased by 4.55%and 4.77%in 2022,and by 3.84%and 4.66%in 2023.Mantel analysis revealed a significant positive correlation between lodging resistance traits and yield under low and medium fertilization levels,which was further confirmed by random forest analysis.These findings demonstrate a close relationship between soybean lodging resistance traits and yield under the experimental conditions.In conclusion,DA-6 application under different fertilization levels regulated soybean morphological traits and dry matter accumulation to varying degrees,enhanced lodging resistance physiology and yield under low and medium fertilization levels,but reduced lodging resistance capacity and yield under high fertilization levels.