[Effects of different planting density, leaf position and leaf age on growth and quality of Artemisia argyi var. argyi 'Qiai'].

In order to guide the standardized planting and scientific harvesting of Artemisia argyi var. argyi 'Qiai', effects of diffe-rent planting density, leaf position and leaf age on the growth and quality of A. argyi var. argyi 'Qiai' were studied in this paper. The results showed that appropriate sparse planting could increase stem diameter, compact leaf spacing, increase the leaf size, reduce the rate of withered leaves and increase the number of effective leaves. Dense planting can significantly increase the yield of A. argyi var. argyi 'Qiai' per Mu(1 Mu≈667 m~2) and the output rate of moxa, but reduce the yield per plant and the number of effective leaves. With the decrease of leaf position and the increase of leaf age, the leaf size and the weight of one hundred leaves increased at first and then decreased, the density of non-glandular hair field of the lower epidermis and the output rate of moxa decreased. With the increase of planting density, the contents of eucalyptus oleoresin, camphor, α-platyclone, and cyanidin decreased gradually, the contents of chlorogenic acid, isochlorogenic acid B, isochlorogenic acid A and isochlorogenic acid C in the leaves of A. argyi var. argyi 'Qiai' increased gradually, while the contents of borneol, bornyl acetate and isozelanin increased at first and then decreased significantly. With the decrease of leaf position and the increase of leaf age, the contents of volatile oil, phenolic acid and flavonoid in A. argyi var. argyi 'Qiai' decreased gradually. PCA analysis can divide the leaf quality characteristics of A. argyi var. argyi 'Qiai' into two parts: the middle and upper 10-30 days leaf age, the middle and lower 40-50 days above leaf age. Based on the above factors, the planting density of 28 000 plants/Mu(row spacing of 10 cm×20 cm) can be selected for cultivation of A. argyi var. argyi 'Qiai' rhizome, and the effective plants in the field are about 142 800 plants/Mu. In terms of harvesting, it is suggested that the A. argyi var. argyi 'Qiai' should be harvested on "March 3 rd" and "May 5 th" of the lunar calendar. If it is the traditionally harvested at one time in May, the A. argyi var. argyi 'Qiai' should be divided into two parts: the middle and upper leaves, the middle and lower leaves, so as to achieve high quality and high price of A. argyi var. argyi 'Qiai' leaves and improve the economic benefits of A. argyi var. argyi 'Qiai' planting.

[Moxa nitrogen content determination and its application in moxa floss grade identification].

Artemisia argyi samples were collected from different areas in Hubei Qichun and medicinal botanical garden of Hubei University of Traditional Chinese Medicine, and samples were purchased from different areas in Qichun medicinal market. The same method was used to prepare A. argyi samples from different areas into moxa floss of different leaf velvet ratio. The nitrogen content of A. argyi was determined by Kjeldahl method. The results show that there was an inverse relationship between the content of nitrogen and the level of the leaf velvet ratio grades of moxa floss and nitrogen content. Therefore, six functional models were established to illustrate the relationship between the grades of leaf velvet ratio and nitrogen content. The accuracy of the functional models was evaluated by ■. The cubic function model and exponential function model are selected as the best models and the formula is: Y_(grades)=-4.26 N~3+26.09 N~2-61.09 N+55.84, Y_(grades)=63.68×10~(-1.374N), with R~2 values of 0.976 5 and 0.969 6, respectively. The accuracy reached above 95% of the two function models when verified by laboratory-made moxa floss, while the accuracy of the models was 85.44% when verifed by commercial moxa floss. These results indicate that the model could be applied to the identification of the grades of moxa floss.

[Effect of planting period and ridge pattern on yield and quality of Artemisia argyi var.argyi 'Qiai'].

To solve the problems of the unclear planting period and the traditional flat planting of Artemisia argyi var.argyi 'Qiai', such as the serious dead leaves in the middle and lower parts of the plant and the low yield and low quality in the field, the effects of different planting period and ridge pattern on yield and quality of A. argyi var.argyi 'Qiai' were studied. The results showed that the growth and development of A. argyi var.argyi 'Qiai' was better when planted in autumn and winter, and the ridge directions had little effect on the growth and yield of A. argyi var.argyi 'Qiai', while the ridge width had a significant effect. Compared the traditional wide ridge planting mode(the width of the ridge is 160 cm) with the ridge width of 80 cm, 60 cm and 40 cm, the results showed that the density per unit area, the number of effective plants, and the rate of dead leaves were decreased, while the number of productive leaves per plant, the number of lateral branches, and the total yield per plant were increased, the total yield was decreased. The output rates of moxa in the leaves of A. argyi var.argyi 'Qiai' decreased with the planting time postponed and the width of planting ridge increased. The contents of volatile oil, 1,8-oxido-p-menthane, camphor and borneol in A. argyi var.argyi 'Qiai' reach to the highest when planted in autumn and winter and the ridge width was 80 cm. In addition, the contents of total flavonoids, kaempferol, jeceosidin and eupatilin flavonoids in the leaves of A. argyi var.argyi 'Qiai' gradually decreased as the planting period postponed and the ridge width increased. The results show that the A. argyi var.argyi 'Qiai' should be planted in autumn and winter, and the double row ridge planting mode with width of 60-80 cm is more suitable for the cultivation and production of A. argyi var.argyi 'Qiai' in Qichun County of Hubei Province. This study will provide a theoretical basis and guidance for higher yield and quality in cultivation of A. argyi var.argyi 'Qiai' in Qichun county.