Husk Development and the Cause of Underdevelopment of Husks in Malting Barley

[摘要] The objective of this study was to clarify the factors causing underdevelopment of husks in malting barley. In 1986-87 growing season, many malting barley cultivars in Fukuoka and Saga districts had high occurrence of husk underdevelopment, resulting in the exposure of caryopsis through lemma and palea, which caused poor germination and low inspection grade. Special attention was given to the husk development stage, environmental factors which affected husk size and, varietal difference of husk size. In this study mechanical husk peeling by threshing was not included. There were varietal and yearly differences in the degree of the occurrence of husk underdevelopment. The length, width and weight of lemma and palea of cvs. Nishino Gold, Nirasaki Nijo and Haruna Nijo, which had high occurrence of husk underdevelopment, were less than those of cvs. Amagi Nijo and Kinuyutaka, which had low occurrence of husk underdevelopment. The length and width of lemma and palea rapidly increased from the flag leaf stage to the heading stage. In both excess-soil-moisture plots and shading plots, during this period, the growth of lemma and palea was inhibited. In excess-soil-moisture treatment plots combined with shading treatment or low temparature treatment for this duration, the degree of occurrence of husk underdevelopment was very high. Therefore, it was concluded that the husk underdevelopment in malting barley was due to the adverse environmental conditions such as wet-injury, scarce sunshine and/or low temperature during the husk-size determination period, i.e., from flag leaf stage to heading stage, when the length and width of lemma and palea rapidly increased.

[学科分类] 农业科学（综合）

[关键词] Determination of husk size;外穎;Husk underdevelopment;湿害;Lemma;側面裂皮粒;Malting barley;内穎;Palea;ビール大麦;Wet-injury