Effects of nitrogen nutrition on photosynthesis and fruit production in Japanese pear, apple and grape trees.

Research Project

Project/Area Number	60480037
Research Category	Grant-in-Aid for General Scientific Research (B)
Allocation Type	Single-year Grants
Research Field	園芸・造園学
Research Institution	Chiba University
Principal Investigator	HIRATA Naomi Faculty of Horticulture, Chiba University, Professor, 園芸学部, 教授 (30032080)
Co-Investigator(Kenkyū-buntansha)	OHARA Hitoshi Faculty of Horticulture, Chiba University, 園芸学部, 助手 (40160931) HIRATSUKA Shin Faculty of Horticulture, Chiba University, 園芸学部, 助手 (10143265) TAKAHASHI Eikichi Faculty of Horticulture, Chiba University, Associate professor, 園芸学部, 助教授 (60009321)
Project Period (FY)	1985 – 1986
Project Status	Completed (Fiscal Year 1986)
Budget Amount *help	¥5,900,000 (Direct Cost: ¥5,900,000) Fiscal Year 1986: ¥900,000 (Direct Cost: ¥900,000) Fiscal Year 1985: ¥5,000,000 (Direct Cost: ¥5,000,000)
Keywords	Nitrogen nutrition / Photosynthesis / Nitrogen metabolism / Productivity / 果樹の生産性 / 果実の品質
Research Abstract	The effects of nitrogen nutrition during the growth season on net photosynthesis, photosynthate accumulation, nitrogen absorption, yield and fruit quality in Japanese pear, apple and grapes were investigated. In this studies, <^(15)N> and <^(13)C> were used as tracer elements. Photosynthetic activities in the shoot growth period were higher at high N levels than that both medium N levels and none N levels. While, in the fruit growth period, it were highest at medium N levels. Most of the nitrogen which had been applied on early April, were absorbed and translocated into fine roots and buds. The nitrogen applied on mid June were mainly translocated into leves and shoots. On the other hand, the nitrogen absorbed on early September were mainly transelocated into older shoots and roots. In the fruit growth and mature periods, the amount of <^(13)C> translocated into fruit increased at both medium N levels and none N levels, and decreased at high N levels. The <^(13)C> incorporated into fruit increased mainly in the sugar fruction at medium N levels and none N levels, but did not increased in both organic acid and amino acid fructions. In high N levels, more <^(13)C> was found in the organic acid and amino acid fructions than in the sugar fruction.