Microclimate Effects Of Light Transmission And Light-Rain Transmission Shed And Their Influences On The Growth Of American Ginseng

The study compared the performance,growth,physiology,American ginseng yield and quality of Light-Rain transmission and light transmission shed.Within trial base,in Tian tang zhai town.Study the change condition of microclimate,such as air temperature, ground temperature,humidity.At the same time,compared the growth,the characteristics of physiological,yield and quality of Light-Rain transmission and light transmission shed,the main results are as follows.1.Compared with controled shed,Light-Rain transmission and light transmission shed can be reducing the temperature and increaseing humidity effectively.During the observing period,the various indicator are the lowest in Light-Rain transmission shed, and temperatures in light transmission shed are in the centre.From the comer of seasonal change of temperature,the effect of temperature declineing is obviously,soil temperatures in different depth are highest in controled shed from may to september,but this characteristic change is weakened with soil layer depthing.Judging from the corner of daily mean relative humidity,Light-Rain transmission shed is highest,light transmission shed is following,the daily mean relative humidity is 79.3%,76.1%,72.8% respectively.From the corner of seasonal change of humidity,shed humidity are lowest in controled shed from may to september,is 72.8%,69.0%,63.8%respectively.2.The result of growth indicate that American ginseng growth are better in Light-Rain transmission and light transmission shed.Compared with controled shed, plant height increase 32.4%and 19.9%respectively,centre leaf width increase12.8% and 2.1%respectively,centre leaf Length increase30.0%and 14.3%respectively,and leaf area increase 44.9%and 14.1%respectively.The survey also shows that seedling rate and existing rate are all highest in Light-Rain transmission shed,it higher than controled shed obviously,but is Similar to light transmission shed.Compared with controled shed, seedling rate increase5.9%and 3.5%respectively.3.The study shows that the order of total contents of chlorophyll and chlorophyll a is light transmission shed,Light-Rain transmission shed and controled shed,total contents of chlorophyll is 18.7%and 25.0%higher than controled shed respectively,chlorophyll a is13.0%and 23.2%higher than controled shed respectively.Then,the order of contents of Chlorophyll b is Light-Rain transmission shed,light transmission shed and controled shed,is 29.3%and 27.3%higher than controled shed respectively.The order of contents of Chlorophyll a/Chlorophyll b is controled shed,light transmission shed and Light-Rain transmission shed.The effect of treatment on photosynthesis rate is obvious.Light-Rain transmission and light transmission shed is higher than controled shed.The daily mean photosynthesis rate of Light-Rain transmission shed is 42.7%higher than controled shed, light transmission shed is 25.7%higher than controled shed.The diurnal variation of photosynthesis rate is obvious.The diurnal variation of photosynthesis rate assume two peak in Light-Rain transmission shed,the former occur at 10:00,but midday depression of photosynthesis is not clearly,The diurnal variation of photosynthesis rate assume two peak in light transmission shed and controled shed,midday depression of photosynthesis is clearly.4.The effcet of two sheds on yield is comparatively obvious too,namely,they are higher than controled shed.The yield is highest in Light-Rain transmission shed,average fresh root weight each square metre is 1.643kg,is 17.0%higher than light transmission shed,and is 51.3%higher than controled shed.Biology output is also highest in Light-Rain transmission shed,which is 24.29g,is 10.2g heavier than controled shed,and 3.32g heavier than light transmission shed.5.Compared with controled shed,it is more beneficial to accumulate active constituent in two treatments,the order of total content of amino acid,indispensable amino acid and saponin are Light-Rain transmission shed,light transmission shed and controled shed.The root of American ginseng contains 16 kinds of amino acid,there are 13 kinds of amino acid is highest in Light-Rain transmission shed among this,and lowest in controled shed,especially Asp,Phe,Agr.The content of Agr is highest,Met and His is lowest in different treatments.4 kinds of saponin are highest in Light-Rain transmission shed among 6 kinds of saponin,and lowest in controled shed,especially R_bl,R_e,R_c.The content of Rb is highest,R_g is lowest in different treatments.By studying of the performance Light-Rain transmission and light transmission shed,and the comparation of growth,physiology,American ginseng yield and quality of this two sheds,we suggest that Light-Rain transmission shed can be used in trial base,but,consider that the rainwater is too much in the season of American ginseng growth in trial area,so we propose the concrete measure to deal with these promble,in order to provide a reference to use Light-Rain transmission shed in the trial area.