Effects Of Uniconazole On Yied And Quality Of Rhizoma Chuanxiong Hort.

The effects of different concentrations(0,20,40,80,160mg/L) of uniconazole spraying at stooling stage and tuber expansion stage on the photosynthesis characteristic,accumulation of dry substances,yield and quality of Ligusticum Chuanxiong Hort.as the famous-region drug in Sichuan were studied.The principal results were as follows:1.Uniconazole treatment increased SPAD value in the upper leaves.At stooling stage,spraying uniconazole with lower concentration A₂ and A₃ treatment were higher than that of control.But at tuber stage,with higher concentration,A₄ and A₅ treatment were higher than that of control.In general,spraying uniconazole with lower concentration at stooling stage was more effective.2.Uniconazole treatment increased the green leaf area,the leaf area of A₂ and A₃ treatment at stooling stage were higher than that of control while A₄ and A₅ were lower than that of control.At tuber stage,the effect was same as stooling stage with lower concentration.And there were no significant difference among the higher concentration.Uniconazole treatment increased the net photosynthetic rate,which increased significantly at 1%level under A₄ treatment.3.Uniconazole treatment could increase the dry weight of tubers,stems and leaves of Ligusticum Chuanxiong Hort.especially treated at stooling stage.And the maximum dry weight of tuber,stem and leaf during this stage was 5%,31%,13%higher than that during tuber expansion stage,respectively.4.Uniconazole treatment could increase the yield of Ligusticum Chuanxiong Hort.. Yield was higher with A₂ uniconazole sprayed at stooling stage and A₃ sprayed at tuber expansion stage.Uniconazole treatment increased the tuber size might be a reason for the increase of yield.Among these treatment sprayed at stooling stage,A₄ treatment,as well as A₂,got the most remarkable effect,which was 53%higher than that of control.And among these treatment sprayed at tuber expansion stage,A₃ got the most remarkable effect,which was 53%higher than that of control,then A₂.5.Uniconazole treatment could improve the quality of Ligusticum Chuanxiong Hort.. The ferulic acid content of tuber increased,varying among concentrations and spraying stages.And spraying at stooling stage was significant higher than that of tuber stage at 1%level,that was 16.5%.The effect of different concentrations of uniconazole sprayed at the same stage on the ferulic acid content was different.Uniconazole treatment also changed the volatile oil content greatly.