Effects of fruit skin and water temperature during soaking before germination on the emergence rates of common buckwheat

The studies focused effects of the presence of fruit skin (hull or pericarp) and water temperature during water soaking before germination on the emergence rates of common buckwheat (Fagophyrum esculentum Moench) after seeding. We aimed to understand the mechanisms underlying the poor emergence rates that have been observed after water flooding before germination. Shinano No.1 was exposed to water soaking treatments at temperatures of 10,15,20, or 25℃ for 3 days. After soaking, the seeds were grown at 20℃, and the percentages of emerged seedlings were investigated 7 days after seeding. Dehulled seeds and normal seeds were soaked for 4 days at 25℃, and the contents of dissolved oxygen were measured in the water. The emergence rates of normal intact seeds (fruits)decreased significantly (p＜0.01)with an increase in soaking water temperature before germination. The emergence rates of dehulled seeds improved after removing the fruit skin, and it reached 70%,even at 25℃.Soaking treatment for 96 h at 25℃ decreased the emergence rates of normal seeds and dehulled seeds. The emergence rate of normal seeds was significantly lower than that of dehulled seeds (p＜0.001). Moreover, there was no difference in the emergence rates of dehulled seeds between plots with or without daily water replacement. The contents of dissolved oxygen in the water at 25℃ did not differ between normal seeds and dehulled seeds after 50h. These results suggested that high temperatures affected embryo viability and that the relative mechanical resistance of the fruit skin on the embryo directly affected the seed emergence rate.Article信州大学農学部AFC報告 13: 113-118 (2015)departmental bulletin pape

Influence of organic fertilizer on rhizome yield and α-tocopherol content of Codonopsis lanceolata

Codonopsis lanceolata (Sieb. et Zucc.) Trautv. is a valuable wild vegetable in East Asian countries, especially Korea. We investigated effects of organic fertilizer application on rhizome yield and quality under Andosol soil conditions in the AFC field of Shinshu University. Commercial barnyard manure, which was fermented with crushed bark and beef cattle dung, and Japanese oak leaf mold were applied at the rates of 0, 5, 10, 15, and 20 g m-2. Barnyard manure increased the fresh weight yield of rhizomes but decreased the DL-α-tocopherol (vitamin E) content. The rhizome yield was drastically influenced by the C/N ratio of the soil from the surface to 30 cm below ground level that was controlled by the application ratio of barnyard manure to leaf mold. Total N, soluble P, exchangeable K, Ca, and Mg did not significantly affect the rhizome yield. There was a significant negative correlation between the rhizome fresh weight and vitamin E content at harvest time. The highest vitamin E content of 9-10 mg 100 g-1 dry matter was obtained at a leaf mold application rate of 10 g m-1. Nitrogen supply from the soil to plants primarily influenced the yield and quality of rhizomes as vegetables or drugs. The vitamin E content under a higher soil C/N ratio was the highest among commercial vegetables available in common Japanese food markets.Article信州大学農学部AFC報告 10: 1-7(2012)departmental bulletin pape