Relation between seeding times and stem yield of sorghum in cold region in Japan

Abstract

The seeding time is an important factor affecting the process of stem yield. Nevertheless, details related to the optimum seeding time to maximize the stem yield of sweet sorghum have not been studied. This study elucidated information necessary to ascertain the optimum seeding time to obtain the maximum stem yield. We conducted an examination with three seeding times at intervals of two weeks, ranging from late May to mid-June for four years during 2009-2012, and we analyzed the relation between seeding times and stem yield based on internode characteristics of stems using two sorghum cultivars with different maturity: 'Kazetachi' and 'Wray' . Differences were observed in the respective relations between the seeding times and the stem yields. For Kazetachi, the dry matter yield increased with the earlier seeding time. Thus, to expand the growing period, an earlier seeding time with good establishment is better. For Wray, a cultivar that can grow to heading in the Tohoku region, the stem dry weight was greater by seeding in early June. For cultivars such as Wray with a sufficient growing period in a given region, the optimum seeding time to obtain stable higher stem yield existed and the cultivars should be seeded when they could grow under good weather conditions at the critical time strongly influences growth.

Evaluation of performance of sorghum varieties grown in Tokyo for sugar accumulation and its correlation with vacuolar invertase genes SbInv1 and SbInv2

“…Growth of sweet sorghum in temperate climates Sweet sorghums are not adapted to temperate conditions; however, lately due to the development of photoperiod-insensitive lines, sorghums have been cultivated in temperate regions as well (Thurber et al, 2013). Sweet sorghums have been previously grown in the colder Northern regions of Japan, for stem biomass, with sowing in early to mid-June as ideal for maximum stem yield (Fujii et al, 2016;Nakamura et al, 2011). The period of growth from sowing to flowering in tropical regions is around 55-70 days, with an extension by 20-30 days in temperate conditions (Mocoeur et al, 2015;Rao et al, 2013), which was observed in the varieties grown in our study as well (Tables S1 and S2).…”