Malt

Chen et al. / J Zhejiang Univ SCIENCE B 2006 7(1):79-84

79

Journal of Zhejiang University SCIENCE B
ISSN 1673-1581 http://www.zju.edu.cn/jzus E-mail: [e-mail]

Relationship between malt qualities and β-amylase activity and protein content as affected by timing of nitrogen fertilizer application*
CHEN Jin-xin (陈锦新), DAI Fei (戴 飞), WEI Kang (韦 康), ZHANG Guo-ping (张国平)†‡
(Department of Agronomy, Zhejiang University, Hangzhou 310029, China)
†

E-mail: [e-mail]

Received Aug. 25, 2005; revision accepted Oct. 5, 2005

Abstract: The effects of different timing of N fertilizer application at the same rate on grain β-amylase activity, protein concentration, weight and malt quality of barley were studied. Grain β-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 β-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 β-amylase activity.
Key words: Barley, Nitrogen fertilizer, β-amylase, Malt quality doi:10.1631/jzus.2006.B0079 Document code: A

INTRODUCTION
Barley β-amylase is synthesized during grain development and stored in mature grains. It plays an important role in determining good malting quality
(Ziegler, 1999; Evans et al., 2003). Georg-Kraemer et al.(2001) found that β-amylase activity was a better

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