272 Broschat and Doccola: Effects of Manganese on Manganese Content of Coconut Palm Arboriculture & Urban Forestry 2010. 36(6): 272-274 Effects of Soil-Applied and Trunk and Petiole-Injected Manganese on Manganese Content of Coconut Palm (Cocos nucifera) Timothy K. Broschat and Joseph J. Doccola with MnSO4 Abstract. Manganese deficiency is a common and potentially fatal disorder of palms growing in highly leached and calcareous soils. Soil ap- plications of MnSO4 wounds that could potentially serve as entry sites for the trunk pathogen Thielaviopsis paradoxa, especially on young palms with minimal trunks. Key Words. Fertilization; Palm; Manganese Deficiency; Manganese Sulfate; Micronutrients. may not always be effective in treating this disorder due to rapid oxidation of Mn to less available forms. Trunk injection (2.0 g Mn) was found to be more effective in increasing foliar Mn concentrations than soil application (192 g Mn) or petiole injec- tions with 0.1 g Mn in a single hole, or 0.5 g Mn divided among four holes. In contrast to trunk injection, neither petiole injections nor soil applica- tion of MnSO4 increased foliar Mn concentrations above that of the untreated control palms. Trunk injections, while effective, result in permanent Manganese deficiency is a common and potentially fatal disorder of palms growing in highly leached sand and calcareous soils (El- liott et al. 2004). Soil applications of manganese sulfate are usual- ly effective in correcting these deficiencies, but in the calcareous soils of southern Florida, U.S., massive amounts of this product are required due to their high pH and buffering capacity (Dickey 1977). While foliar sprays with manganese sulfate are an effec- tive means of increasing Mn concentrations within palm leaves (Dickey 1977; Broschat 1991), this method is impractical for large specimen palms and must be repeated several times per year. In dicot trees, trunk injections with soluble nutrients are of- ten employed to alleviate deficiencies of Mn or Fe in trees with impaired root systems or those growing in calcareous soils. The wounds caused by these injections are eventually walled off with callous tissue produced by the vascular cambium so that no per- manent visible damage is done to the trunk. Palms, however, do not have a vascular cambium and are incapable of walling off wounds in the trunk (Tomlinson 1990). Thus, wounds from trunk injections of palms are permanent, unsightly, and can become potential entry sites for trunk pathogens such as Thielaviopsis paradoxa which require trunk wounds for infection to occur (Elliott et al. 2004). Trunk injections are therefore normally re- served for treatment or prevention of lethal diseases or disorders where soil or foliar applications are ineffective or impractical. A possible alternative injection site for palms is the leaf petiole which can be quite large in many palm species. Mc- Coy (1977) demonstrated that oxytetracycline (OTC) injected into coconut palm (Cocos nucifera) petioles was translocated to other leaves within the canopy in sufficient concentrations to control lethal yellowing disease. Petiole injections have the advantage of causing wounds only to tissue that will eventu- ally be shed by the palm and thus no permanent wounds to the ©2010 International Society of Arboriculture trunk are created. On the other hand, petiole injection may re- quire multiple injection sites in order to introduce sufficient vol- umes of the solution, and in tall specimens, accessing the palm leaves for treatment requires special equipment. The purpose of this study was to compare the relative effectiveness of man- ganese sulfate in increasing foliar Mn concentrations when ap- plied to the soil or injected into the trunk or petioles of palms. MATERIALS AND METHODS A 29-year-old planting of Fiji Dwarf coconut palms with trunk heights of 3–4.5 m was used for this study. The plot was located in Davie, FL, U.S. (latitude 26°4’56”N, longitude 80°14’23”W) and had a Margate Fine Sand soil with a pH of 6.1 and cation exchange capacity of 3.1 meq/100g. The ground cover was a very sparse cover of weeds due to shading by the palms and thus com- petition by groundcovers for Mn was not likely to be a significant factor. None of the palms exhibited symptoms of Mn deficiency at any time during the experiment. Ten replicate trees spaced 5 m apart were randomly assigned to each of the following treatments: (1) Control—no Mn treatment; (2) 600 g of MnSO4 (=192 g Mn) U.S.) injected into the petiole bases of four older leaves by drill- ing holes 7 mm in diameter by 50 mm deep, tapping in #3 Arbor- plugs® cast to the soil surface under the canopy; (3) 10 mL of a 5% Mn solution from MnSO4 leaf using a Quick-jet® a 5% Mn solution from MnSO4 (=0.1g Mn) injected into a single (=2.0 g Mn) were injected into the trunk about 60 cm above the ground. The single 7 mm-diameter hole extended into older petiole as in treatment 3; and (5) 40 mL of a 5% Mn solution from MnSO4 (TecMangam®, Industrias Sulfamex, Tampico, Mexico) broad- (=0.5 g Mn) (Arborjet, Inc., Woburn, MA, (Arborjet, Inc.), and injecting 2.5 mL of the solution per microinjector (Arborjet, Inc.); (4) 2 mL of
November 2010
| Title Name |
Pages |
Delete |
Url |
| Empty |
Search Text Block
Page #page_num
#doc_title
Hi $receivername|$receiveremail,
$sendername|$senderemail wrote these comments for you:
$message
$sendername|$senderemail would like for you to view the following digital edition.
Please click on the page below to be directed to the digital edition:
$thumbnail$pagenum
$link$pagenum
Your form submission was a success. You will be contacted by Washington Gas with follow-up information regarding your request.
This process might take longer please wait
