| Bletilla striata,a perennial,shady herb of the genus Orchidaceae,is suitable for cultivation under the forest.The dry tuber of B.striata is an important traditional Chinese medicine of forest source.At present,most of the studies on fertilization of B.striata were focused on the quality and yield of B.striata by nitrogen,phosphorus and potassium.In this experiment,5 kinds of molybdenum and boron fertilization levels were studied under forest and open-field environment.and 9 treatments were used to study the effects on the ground diameter,biomass,photosynthesis,chlorophyll fluorescence and polysaccharide content of B.striata.The test results as followings:1.During the application of proper amount of boron fertilizer and molybdenum fertilizer,the absorption of nutrient element N、P could be promoted,and the content of boron and molybdenum in tuber would increase with the increase of fertilizer amount.The absorption and accumulation of N elements could be improved significantly when applied0.41 kg/667m~2of boron fertilizer and 0.04 kg/667m~2molybdenum fertilizer.The boron fertilizer during 2.40-2.80 kg/667m~2and molybdenum fertilizer was 0.04-0.14 kg/667m~2could significantly promoted the accumulation of P elements in forest environment.And2.40 kg/667m~2boron fertilizer and 0.04 kg/667m~2molybdenum fertilizer could increase the P content of B.striata in open environment.If the amount of fertilizer was too high,it would inhibit the absorption of N、P elements,and the content of boron and molybdenum in tuber would also be reduced.2.To some extent,the application of appropriate amount of boron and molybdenum fertilizer in the growth period of B.striata could increase the SPAD,Fv/Fm、ETR of B.striata leaves and the photosynthetic rate of B.striata.The boron fertilizer of 0.41kg/667m~2and molybdenum fertilizer combined treatment of 0.24 kg/667m~2could significantly improve the SPAD of B.striata in forest environment;and the SPAD value of B.striata in open environment was generally higher than that in open environment.Under the forest,and the open environment the net photosynthetic rate was the highest after treatment with 1.40 kg/667m~2boron fertilizer and 0.14 kg/667m~2molybdenum fertilizer.The Pn was significantly higher than that of the other treatments in June.3.Different combinations of boron fertilizer and molybdenum fertilizer could promote the increase of ground diameter and stem height.1.40 kg/667m~2of boron fertilizer and 0.14 kg/667m~2of molybdenum fertilizer were the largest ground diameter in the two environments.There were significant differences between them and other treatments.when we only add 1.40 kg/667m~2boron fertilizer,it could significantly increase the stem height of B.striata in the forest environment,and the difference between different fertilization treatments was small.The diameter and height of the stem in the forest environment were higher than those in the open environment.4.Different ratios of boron and molybdenum could increase the fresh weight and polysaccharide content of B.striata.The boron fertilizer of 1.40 kg/667m~2and molybdenum fertilizer of 0.14 kg/667m~2had the most significant effect on the increase of fresh weight in the two environments.When the fertilizer treatment was 2.40 kg/667m~2boron fertilizer and 0.04 kg/667m~2molybdenum fertilizer combination,the content of polysaccharide in both environments reached the highest value in this experiment,1.40kg/667m~2boron fertilizer,0.14 kg/667 m~2of molybdenum fertilizer was the second highest in polysaccharide content.The optimum fertilization amount was 1.40 kg/667m~2boron fertilizer and 0.14kg/667m~2molybdenum fertilizer.It was expected that this experiment would provide a scientific basis for fertilization theory for increasing yield,quality and economic income. |
