Abstract
The present studies were carried cut to make clear the varietal differences of frost resistance in barley, using two varieties, Kogenmugi and Misuzuomugi, the fcrmer being cold resistant and the latter cold susceptible. They were treated with artificial low temperature of -5°C for 6 hours in several plots at different stages of growth. The results obtained were follows : ( 1 ) The low temperature injury was severe in both varieties and the damaged plants wer6 delayed in their growth. The yield was greatly affected by a low temperature treatment given at the vigorous elongation stage to the shooting stage. ( 2 ) The low temperature injury of leaf was severe in Kogenmugi, but it was slight in Misuzuomugi. ( 3 ) Death of young ear by low temperature was frequently observed when the ear grew longer than 6 mm, while it was rare when the ear was. shorter than 5mm. Also, there was a high correlation between the death of young ear and the stenl However, varietal differences regarding height. death of young ear were not observed. ( 4 ) It was found that staining of young ear with Luyet's solution was good to discriminate whether the ear was dead or alive. The test showed that there were three cases in the death of young ear by low temperature. ( i ) Only young ear is frozen. ( ii ) Upper internodes are frozen and young ear is not. (iii) Both young ear and upper internodes are frozen.
