Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 1, 2013
Publication Date: October 15, 2013
Citation: Wood, B.W. 2013. Iron-induced nickel deficiency in pecan. HortScience. 48(9):1145-1153. Interpretive Summary: The magnitude of crop loss due to undiagnosed nickel (Ni) deficiency is unknown, but appears to be far greater than is generally recognized. There is increasing evidence that in certain situations Ni deficiency can be induced by excessive fertilization with other fertilizers or metals. This possibility merits research to better determine fertility situations that impact Ni nutrition of crops. Iron (Fe) was found to potentially trigger Ni deficiency of pecan trees and probably other crops as well, if the crop is exposed to excessive Fe during the period when foliage and shoots are rapidly growing, even if tissue Ni concentrations are considered sufficient. This information provides insight into factors that can cause Ni deficiency in crops and highlight the need to take special precautions whenever Fe fertilizers are being used on crops.
Technical Abstract: Economic loss due to nickel (Ni) deficiency can occur in horticultural and agronomic crops. This study assesses impact of excessive iron (Fe) on expression of Ni deficiency in pecan [Carya illinoinensis (Wangenh.) K. Koch]. Field and greenhouse experiments found Ni deficiency to be inducible by either excessive Fe or diethylenetriaminepentaacetic acid (DPTA; a commonly used Fe-chelant). Foliar sprays of Fe [Fe-DPTA (1.1995 g/L)] during early post-budbreak shoot growth can trigger, or enhance, Ni deficiency symptoms in emerging pecan shoots. Deficiency is also inducible via soil application of Fe-DPTA, or to a lesser extent with DPTA, to greenhouse grown ‘Desirable’ seedlings at budbreak. Endogenous Fe triggers Ni deficiency associated distortions in leaf growth and morphology in pecan just after budbreak when the Fe:Ni = ˜ 150, with severity of deficiency being proportional to the Fe:Ni ratio. Extreme dwarfing of canopy organs occur at Fe:Ni = ˜ 1,200. Timely foliar treatment of symptomatic canopy organs with foliar Ni-sulfate restores normal growth; whereas, treatment with other transition metals (i.e., V, Cr, Co, Cu, Zn, and Mo) is ineffective. Results indicate that excessive endogenous Fe, and DPTA to a lesser extent, in organs and tissues during early post-budbreak growth can trigger Ni deficiency. A similar Fe on Ni antagonism may also occur in other crops. These results are suggestive that Ni related nutritional physiology issues can occur when Fe-chelates are used in pecan and possibly other crops.