Variations of flavanoid contents in vine tips among different varieties, parts and time of topping of sweetpotato for vegetable-use A Study on Components and Compound Prescription of Huangqin Decoction Influence of daub exogenous ascorbic acid and glutathione on wounds after tobacco topping on redox equilibrium and nicotine content of tobacco Comparative study of effects of xuejie superfine ponders with different diameters and its drop on stopping bleeding Agronomic regulation on NR and POD activities,K and nicotine contents after topping in flue-cured tobacco leaf Effects of brassinolide and auxin on growth, carbon and nitrogen metabolism and tobacco quality of flue-cured tobacco leaves after topping Effects of nitrogen on metabolism and dry matter accumulation of flue-cured tobacco before and after topping Effect of topping and fruit thinning on translocation and distribution of foliar 15N-urea at fruit inflating stage of nectarine under greenhouse condition