title: Relationship between malt qualities and beta-amylase activity and protein content as affected by timing of nitrogen fertilizer application.
abstract: The effects of different timing of N fertilizer application at the same rate on grain beta-amylase activity, protein concentration, weight and malt quality of barley were studied. Grain beta-amylase activity and protein concentration were significantly higher in treatments where all top-dressed N fertilizer was applied at booting stage only or equally applied at two-leaf stage and booting stage than in the treatment where all top-dressed N fertilizer was applied at two-leaf age stage only. On the other hand, grain weight and malt extract decreased with increased N application at booting stage. There were obvious differences between barley varieties and experimental years in the grain and malt quality response to the timing of N fertilizer application. It was found that grain protein concentration was significantly and positively correlated with beta-amylase activity, but significantly and negatively correlated with malt extract and Kolbach index. The effect of grain protein concentration on malt quality was predominant over the effect of grain beta-amylase activity.
authors.affiliation: Department of Agronomy, Zhejiang University, Hangzhou 310029, China.
authors.forename: Jin-Xin
authors.initials: JX
authors.lastname: Chen
authors.forename: Fei
authors.initials: F
authors.lastname: Dai
authors.forename: Kang
authors.initials: K
authors.lastname: Wei
authors.forename: Guo-Ping
authors.initials: GP
authors.lastname: Zhang
mesh_terms: D000383:Agriculture / Q000379:methods; D002523:Edible Grain / Q000737:chemistry* / Q000187:drug effects / Q000378:metabolism*; D004789:Enzyme Activation; D005308:Fertilizers; D001467:Hordeum / Q000187:drug effects / Q000378:metabolism*; D009584:Nitrogen / Q000008:administration & dosage*; D010940:Plant Proteins / Q000378:metabolism*; D013223:Statistics as Topic; D013997:Time Factors; D001614:beta-Amylase / Q000737:chemistry / Q000378:metabolism*
chemical_list: D005308:Fertilizers; D010940:Plant Proteins; D001614:beta-Amylase; D009584:Nitrogen