Influence of Sowing and Harvesting Dates on the Fatty Acid and Lignan Contents of Seeds of the Sesame Variety “Maruhime”

Abstract

This study was conducted on the experimental field of NARO in Tsukuba in 2014 and 2015 using the sesame variety “Maruhime” which has a high lignan content and is early maturing. Although the period from sowing to flowering was shorter in the plants sown in July than in June, the period from flowering to harvest was longer. It was concluded that the variety “Maruhime” should be harvested at 85 to 95 days after sowing, because the seed yield and thousand-seeds weight were the largest. The seeds harvested from the plants sown in July, had a lower oleic acid content and higher linoleic acid content than in those from the plants sown in June. The temperature during ripening of the plants sown in June was 3°C higher and a negative correlation was observed between the contents of oleic acid and linoleic acid. This suggested that the high temperature inhibited the conversion of oleic acid to linoleic acid. Sowing in June seemed to be appropriate for “Maruhime”, because the sesamin content was higher than in the seeds harvested from the plants sown in July. The sesamin and sesamolin contents decreased as the harvesting date was delayed, the sesamin content being decreased up to 78%. The sesamin content was higher in the seeds from the capsules near the shoot tip than the base, as in the general varieties.