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, ≈1.6 to 9.4 ppm iron, and ≈2.7 to 18.9 ppm zinc in sweetpotato accessions from the South Pacific. Courtney (2007) observed up to ≈10 ppm iron and ≈6.4 ppm zinc in fresh storage roots for North American breeding material. The provitamin A and

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Iron-deficiency (Fe-deficiency) stress, characterized by chlorosis of leaf tissue, is a major limiting factor in turfgrass production on calcareous soils. The objectives of this study were to: 1) evaluate ferrihydrite-amended growth media and the threshold amount of Fe initially added for use in a whole-plant screening procedure for selecting cultivars that are tolerant to Fe-deficiency stress conditions; 2) measure and evaluate whole-plant growth characteristics that could be an index of Fe deficiency stress; and 3) assess the potential of using a synthetically produced Fe oxide, ferrihydrite, as a slow-release Fe fertilizer source. Iron-stress sensitive `Raleigh' St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze] and Fe-stress tolerant `Tifway' bermudagrass [Cynodon dactylon (L.) Pers. × C. transvaalensis Davy] cultivars were grown under glasshouse conditions in a medium consisting of quartz sand, 5% (m/m) CaCO,, and a ferrihydrite amendment providing Fe in concentrations of 0, 15, 30, 46, or 120 mg·kg-1 media, (equivalent to 2, 3, 4, 5, or 10 mg DTPA-extractable Fe/kg media). There also was a nonlimiting iron control. St. Augustinegrass was first rated for iron chlorosis 83 days after planting (DAP) while bermudagrass was first rated at 294 DAP. Initial Fe levels equivalent to 5 mg DTPA-extractable Fe/kg media showed potential for screening genotypes. Visual estimates of iron chlorosis and chlorophyll contents of leaves were the best indicators of low soil Fe availability. A single ferrihydrite soil amendment at 10 mg DTPA-extractable Fe/kg media was adequate in preventing chlorosis for the duration of the study (174 and 509 days for St. Augustinegrass and bermudagrass, respectively). Chemical name used: Diethylenetriaminepentaacetic acid (DTPA).

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glyphosate ( Yamada et al., 2009 ). Iron fertilizers are typically “chelates” that bind Fe 3+ (ferric, or oxidized Fe). A common form is Fe-DPTA. Iron (Fe 3+ ) chelates bind to the cytoplasmic plasmalemma, where, in dicots, sequestered Fe 3+ is chemically

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Basin takes place in greenhouses under conditions of intensive production, using alkaline soils with high calcium carbonate content [Ministry of Agriculture, Fisheries and Food (MAPA), 2004]. Iron deficiency (Fe chlorosis) is one of the most serious

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Abstract

Rockwool is an inert medium for use in greenhouses. It is reported to contribute negligible nutrients to plants. However, Rosa multiflora ‘Burr’ rootstocks grown in Grodan rockwool exhibited no visible Fe chlorosis with an Fe-free nutrient solution. Leaf chlorophyll content was 2.65 mg·g-1 with Fe and 2.85 mg·g-1 without Fe. Available Fe concentrations of three commercial materials (Hortiwool, Grodan block, and Grodan loose), estimated by using diethylenetriaminepentaacetic acid (DTPA) extraction (2 DPTA : 1 rockwool, v/w), were 43.0, 0.33, and 3.95 mg Fe/liter, respectively. With long-term DTPA extractions (20:1), Fe extracted from Hortiwool and loose Grodan increased for ≈3 days before leveling off, while Fe extracted from Grodan block increased for 6 days. Measurable levels of Mn, Cu (348 mg·liter-1), and Zn were found in DTPA extracts of Hortiwool; measurable levels of Mn and Cu were extracted from loose Grodan and measurable levels only of Mn from Grodan block.

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Iron (Fe) plays an important role in several basic physiological functions and is an important factor involved in pear ( Pyrus spp.) tree growth and development. Iron deficiency chlorosis (IDC) is a worldwide problem that began in the 1930s

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Iron is an essential micronutrient for plant growth and development because of its importance in numerous cellular functions. Low iron bioavailability is mainly the result of its insolubility at higher pH values, especially in calcareous soils

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Iron, a micronutrient essential for vegetable production, is required in low quantities between 1 and 1.5 lb/acre ( Liu et al., 2012 ). Iron is the fourth most abundant element in the soil; however, Fe in the soil is in the form of ferric oxides [Fe

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Floriculture species differ in susceptibility to developing micronutrient disorders, particularly iron and manganese toxicity or deficiency, depending on the efficiency at which micronutrients are taken up by plant roots and the solubility of

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Iron is an essential element for plant growth but its uptake by plants can be limited by biotic and abiotic factors ( Kim and Guerinot, 2007 ). Dicots and nongraminaceous monocots respond to iron limitation through strategy I iron uptake. This

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