Different Cropping Year's Atractylodes Ovta's Allelopathy And Its Influence On The Growth And Yield And Quality

It can greatly help us make appropriate plans and take reasonable measures based on regular sampling and systematic study on the growth process of the parts both under the ground and above?the dry matter's accumulation and distribution,as well as the changes and growth stages of medicine quality.Atractylodes Ovta(A.O.),which belongs to perennial plant,is quite sensitive to planting soil,so there exist serious problems in its continuous cropping system.The experiments on how continuous cultivation influence the growth and quality of A.O.can be conducted by comparing non-continuous cultivation with one-year ? two-year and three-year continuous cultivation.The result shows that allelopathy autotoxicity is one of the main factors hindering the continuous cultivation of A.O..The allelopathy material is used to get the bioassay of Chinese cabbage and green bristlegrass,and we are able to analyze different period continuous cultivation of A.O.and gain allelopathy concentration of leaching liquor of the above-ground and under-ground parts of A.O.as well as the rhizosphere soil's leaching liquor.Meanwhile through applying organic extractant with different polarities,researchers can separate and purify allelopathy material,and thus can discuss the location of allelopahty material in A.O..(1)The growth process of A.O.is divided into four stages,which are seedling stage,the flourishing growth stage of above-ground part,rhizome's expansion stage and sprout tumble stage.And the single plant obtains maximum accumulation of lactones need different length of time.For example,the maximum accumulation of lactone I is about 150 days wnearlhile lactone II and III are in 175 days.According to comprehensive analysis,the best harvest time of A.O.in Guizhou Province is about 200 days after its growth,nearly in late October.(2)Result shows that the stem height and diameter of sprouting and the amount of leaves of A.O.through/in continuous cultivation are clearly smaller than that of uncontinuous cultivation.Because A.O.is shade plant,which has distinct photosynthetic and midday depression phenomenon,so the second photosynthesis crest value of continuous cultivation is inferior to uncontinuous ones.What's more,continuous cultivation also affects the height,diameter and the root length,volume as well as the yield of A.O.,which are smaller uncontinuous ones.Researches manifest that the Atractylodes Ovta's yield of uncontinuous cultivation is3.99 times,11.32 time and 17.28 times compared with continuous cultivation in1 year,2years and 3years respectivel.In addition,continuous cultivation has an influence on A.O.'s moisture and ash content.It says that the moisture of A.O.through one-year and two-year continuous cultivation,the ash content of A.O.through three-year continuous cultivation are higher than the standard of Chinese Pharmacopeia while lactone I,II and III declines.To sum up,not only the growth of A.O.will get restrained,but also the yield and its quality of A.O.will get reduced through continuous cultivation.(3)Different period of continuous cultivation of A.O.'s different parts plays a role in allelopathic inhibitory effect on Chinese cabbage and green bristlegrass.When the above-ground part has been though 3years(0.5g/ml)of continuous cultivation,the influence on the allelopathic inhibitory of Chinese cabbage and green bristlegrass reaches the strongest position and the allelopathy's critical year is uncontinuous and the concentration is 2g/ml.When the under-ground part has been continuous cropped through 2years(0.5g/ml)it has the strongest influence on the allelopathic inhibitory of Chinese cabbage and the allelopathy's critical continuous year is 1year with the concentration of 0.3g/ml.The effect on the allelopathic inhibitory of green bristlegrass gets to its strongest point at the continuous cultivation year of 3years(0.5g/ml)and the allelopathy's critical year is 2years with the concentration is 0.2g/ml.The rhizosphere soil gets its strongest point on the influence on the allelopathic inhibitory of Chinese cabbage when its concentration is 0.20g/ml at uncontinuous condition.Under the condition of uncontinuous condition with the concentration of 0.10 g/ml can reach the strongest point for the allelopathic inhibitory on green bristlegrass and the allelopathy's critical year is 1 year(0.20g/ml)at this time.(4)In order to Explore further different continuous year's influence on allelopathic effect of different parts of A.O.,researchers separate the allepathic inhibitory critical year 's concentration by extraction which turns out that the allelopathy material of different parts of A.O.is mainly concentrated on the n-butyl alcohol extract phase.