[Effects of different application amounts of potassium fulvic acid on yield and quality of Fritillaria thunbergii].

Fritillaria thunbergii is a commonly used traditional Chinese medicine, which has the effects of clearing heat and resolving stagnation, eliminating phlegm and relieving cough. At present, it is mostly produced by cultivation, and the cultivation process requires application of base fertilizer, winter fertilizer, seedling fertilizer and late top dressing. Now farmyard manure or organic fertilizer can be used to replace the base fertilizer and winter fertilizer, but the research on the replacement of organic fertilizer has not been completed for the late top dressing. Potassium fulvate is a kind of fulvate fertilizer, which can not only regulate the growth of crops but also supplement potassium necessary for the growth of crops. In this paper, using F. thunbergii as a model plant with mature cultivation techniques, the effect of potassium fulvate on the quality and yield of rhizome traditional Chinese medicine F. thunbergii was systematically studied for the first time. HPLC-ELSD was used to determine the contents of peimine A and peimine B, hot dip method was used to determine the content of alcohol extract, and the SPAD-502 Plus chlorophyll meter was used to detect SPAD value. The results showed that applying 1.5 to 2.25 kg·hm~(-2) of potassium fulvic acid per hectare could effectively improve the yield of F. thunbergii and there was significantly difference between potassium phosphate monobasic and potassium fulvic acid in terms of quality. After the application of range 1.5 to 2.25 kg·hm~(-2) of potassium fulvic acid per hectare, the content of alcohol soluble extract of F. thunbergii was ranged 21.61% to 22.27%, the total amount of peimine A and peimine B were ranged 0.09% to 0.10%. Applying 1.5 to 2.25 kg·hm~(-2) of potassium fulvic acid per hectare could replace the conventional pure chemical fertilizer potassium phosphate monobasic, which could be used as top dressing fertilizer for the cultivation of F. thunbergii.