2015 Volume 84 Issue 2 Pages 209-212
In sweet sorghum (Sorghum bicolor Moench), the starting time of stem elongation is the time when the stem can be recognized from external appearance and is also the time when the basal internodes, which are closely related to the stem volume, are formed. However, it is difficult to define the starting time of stem elongation because the internode is enclosed by leaf sheaths. The starting time of stem elongation can be estimated by measurements during the rapid elongation period of basal internode which became about 10 cm in length at harvest and the number of expanded leaves. In this study, we developed a new method for estimating the starting time of stem elongation based on the internode length pattern shown by arranging the internode length from the base to the top and the number of expanded leaves. Comparison of the two estimation methods suggested that the new method allows us to presume the starting time of stem elongation like the previous method, but is more useful than the previous method which requires confirmation of the data on all individuals.