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United States Department of Agriculture

Agricultural Research Service

Title: Fedtpa Photodegradation in Nutrient Solution Ii. Effects on Root Physiology and Foliar Fe and MN Levels in Marigold

Authors
item ALBANO, JOSEPH
item Miller, William - CORNELL UNIVERSITY

Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 19, 2000
Publication Date: April 1, 2001
Citation: Albano,J.P.,Miller,W.B. 2001. FEDTPA Photodegradation in nutrient solution II.effects on root physiology and foliar FE and MN levels in Marigold.Hortscience.13:317-320.

Interpretive Summary: Iron-diethylenetriaminepentaacetic acid (FeDTPA) is vulnerable to photodegradation. The objective of this research was to determine the consequence of FeDTPA photodegradation on plant growth and physiology. Marigold (Tagetes erecta L.) grown hydroponically in an irradiated nutrient solution containing FeDTPA had root ferric reductase activity 120% greater, foliar Fe level 33% less, and foliar Mn level 90% greater than did plants grown in an identical, non-irradiated solution, indicating that the plants growing in the irradiated solution were responding to Fe-deficiency stress with physiological reactions associated with Fe-efficiency. The youngest leaves of plants grown in the irradiated solution had symptoms of Mn toxicity (interveinal chlorosis, shiny-bronze necrotic spots, and leaf deformation). Plants grown in irradiated solution in which the precipitated Fe was replaced with fresh Fe-chelate were, in general, no different from those grown in the non-irradiated solution. The results of this research are important to plant nutrition researchers, producers of water-soluble fertilizers, and to growers as we have demonstrated that FeDTPA photodegradation in nutrient solutions can cause Fe deficiency and excess Mn uptake when such solutions are used in plant production.

Technical Abstract: Marigold (Tagetes erecta L.) grown hydroponically in an irradiated nutrient solution containing FeDTPA had root ferric reductase activity 120% greater, foliar Fe level 33% less, and foliar Mn level 90% greater than did plants grown in an identical, non-irradiated solution, indicating that the plants growing in the irradiated solution were responding to Fe-deficiency stress with physiological reactions associated with Fe-efficiency. The youngest leaves of plants grown in the irradiated solution had symptoms of Mn toxicity (interveinal chlorosis, shiny-bronze necrotic spots, and leaf deformation). Plants grown in irradiated solution in which the precipitated Fe was replaced with fresh Fe-chelate were, in general, no different from those grown in the non-irradiated solution. Chemical names used: ferric diethylenetriaminepentaacetic acid.

Last Modified: 9/29/2014
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