Influence of foliar fertilization on walnut foliar zinc levels and nut production in black walnut

Abstract

The impact of foliar zinc fertilizer application on nut-bearing black walnut (Juglans nigra L.) trees was studied. Foliar sprays were applied three times per season on two cultivars during four growing seasons by wetting the foliage of the entire crown using a tank mix containing 500 ppm zinc, starting at leaf burst and continuing at 2 week intervals. The fertilizer treatment increased leaf zinc levels but did not impact nut production. Results from this trial indicate that the zinc standard for black walnut foliar nutrient analysis may be similar to the zinc standard of 25 to 100 ppm established for Persian walnut (J. regia L.).

Parent Publication

• Managing fine hardwoods after a half century of research: Proceedings of the Seventh Walnut Council Research Symposium

Citation

Reid, William R.; Thomas, Andrew L. 2013. Influence of foliar fertilization on walnut foliar zinc levels and nut production in black walnut. In: Van Sambeek, J.W.; Jackson, Elizabeth A.; Coggeshall, Mark V.; Thomas, Andrew L.; Michler, Charles H. eds. 2013. Managing fine hardwoods after a half century of research: Proceedings of the Seventh Walnut Council Research Symposium; 2011 August 1-3; Madison, WI. Gen. Tech. Rep. NRS-P-115. Newtown Square, PA; U.S. Department of Agriculture, Forest Service, Northern Research Station: 101-105.