RT Journal Article SR Electronic T1 Manganese Deficiency — Contributory to Maple Decline? JF Arboriculture & Urban Forestry (AUF) FD International Society of Arboriculture SP 27 OP 32 DO 10.48044/jauf.1976.007 VO 2 IS 2 A1 Kielbaso, J. James A1 Ottman, Kenneth YR 1976 UL http://auf.isa-arbor.com/content/2/2/27.abstract AB Studies of maple problems in Michigan beginning in 1970 have shown that the problem occurs on soils of high pH (7.1-8.0). Foliar treatment with various micronutrients initially showed the problem to be related to manganese deficiency. Spraying chlorotic trees can effect a significant, though not complete, positive color change. Treatment through systemic means shows promise, with MnSO4 implantation superior to other methods researched to date. Results are not as quickly and markedly effective as similar treatment reported for pin oak chlorosis with iron. Maple manganese deficiency is described.