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Ed McWilliams and Derald A. Harp

Spanish moss (Tillandsia usneoides) samples were deployed at 36 locations in a 6 × 6-grid system in northeastern Texas during the summer months of 1989 and again in the winter months of 1990. Analytical methods, including inductively coupled plasma emission spectrometry (ICP) and neutron activation analysis (NAA), were used in analyzing samples for sulfur, selenium, arsenic, sodium, and aluminum. Concentrations of most elements in Spanish moss samples were much higher in summer than winter. The highest concentrations of sulfur were found in Van Zandt, Wood, Titus, and Bowie counties. These results suggest that on average sulfur stays in the region in which it was generated. Potassium and sodium were highly correlated with latitude and seem to originate from the Gulf of Mexico.

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Attila Hegedűs, Emőke Balogh, Rita Engel, Béla Zoltan Sipos, János Papp, Anna Blázovics and Éva Stefanovits-Bányai

USDA database. Table 1. Elemental content of apple and four berry species recorded on a fresh weight basis (mg/100 g −1 ) z . Trace elements are essential regulators of cell redox homeostasis because they are cofactors for several

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Carey Grable, Joshua Knight and Dewayne L. Ingram

the two species. Fertilizer 1 (ICL503034; ICL Specialty Fertilizers) and Fertilizer 2 (ICL503037; ICL Specialty Fertilizers) were prototype blends with different experimental polymer coatings. Fertilizer 1 was 16N–3.5P–8.3K–1.8Mg + trace elements with

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Douglas A. Cox

Six cultivars of poinsettia (Euphorbia pulcherrima Willd. ex Kl.) were grown in unlimed growth medium consisting of equal volumes of sphagnum peat and perlite. Plants received fertilizer solutions supplying Mo at either 0.0 mg·liter-1 (-Mo) or 1.0 mg·liter -1 (+Mo). In the –Mo treatment, moderate to severe symptoms of Mo deficiency (marginal and interveinal chlorosis, marginal necrosis, and downward curling of the margins) developed on the middle-aged and some recently matured leaves of `Annette Hegg Brilliant Diamond' and `Eckespoint Lilo', while some interveinal chlorosis occurred on the same leaves of `Gutbier V-17 Angelika'. No symptoms appeared on `Gross Supjibi', `Peace Regal Velvet', and `Peace Noel'. All cultivars were symptomless in the + Mo treatment. In the –Mo treatment, upper, recently matured leaves of the symptomatic cultivars and two of three symptomless cultivars had Mo concentrations at or near the critical level for deficiency; however, nitrate reductase enzyme activity was higher and NO3-N was lower in the leaves of symptomless cultivars than of symptomatic cultivars.

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Douglas A. Cox

`Annette Hegg Brilliant Diamond' poinsettia (Euphorbia pulcherrima Willd. ex Kl.) was grown in an unlimed growth medium consisting of equal volumes of sphagnum peat and perlite and received a fertilizer solution supplying all micronutrients except Mo. Plants were untreated or foliage was sprayed with solutions of 1, 10, or 100 mg Mo/liter 5, 8, or 11 weeks after pinching. Untreated plants developed foliar symptoms of Mo deficiency (marginal and interveinal chlorosis, marginal necrosis, and downward curling), and leaf tissue contained Mo below the critical level of 0.5 μg·g-1 and NO3-N > 1.0%. Treatment at 5 or 8 weeks largely prevented deficiency symptoms, increased tissue Mo, and reduced tissue NO3-N. Molybdenum deficiency symptoms were in the early stages of development on the day of treatment when plants were sprayed at 11 weeks. Molybdenum sprays at this time increased tissue Mo and reduced tissue NO3-N but did not eliminate the symptoms. However, when the experiment was completed 15 weeks after pinching, the number of leaves showing symptoms was about one-half that of untreated plants. Increasing the concentration of Mo in the spray solution increased the concentration of Mo in the leaves but had no effect on NO3-N.

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Mary Ann Rose and Hao Wang

Micronutrient supplements were applied to container rhododendron (Rhododendron L. × `Girards Scarlet' [Girard Evergreen Hybrid Group]) in three forms: uncoated micronutrient fertilizer; slow-release, NPK-plus-minors fertilizer; and biosolids compost (15% v/v). Control plants received no supplement. While all micronutrient treatments had significantly higher foliar Mn or Cu concentrations than controls 1 year after potting, they did not increase growth (dry weight) or plant quality. At 1, 3, and 12 months after potting, the compost treatment had significantly higher diethylenetriaminepentaacetic acid (DTPA)-extractable levels of Mn, Fe, and Zn in the medium. Only one micronutrient fertilizer treatment increased extractable micronutrient concentrations (Cu) on all testing dates. Correlations between medium-extractable and foliar micronutrient concentrations were low (r 2 < 0.30). Vigorous growth in the control treatment suggested that adequate levels of micronutrients were supplied by the pine bark-hardwood bark-peat-sand medium. September concentrations [ppm (mg·L-1)] as low as 2.0 Mn, 17.8 Fe, 0.3 Cu, 4.2 Zn, and 0.9 B in DTPA extracts produced acceptable growth in rhododendron through the following June.

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Ambani R. Mudau, Puffy Soundy, Hintsa T. Araya and Fhatuwani N. Mudau

recorded were gas composition, weight loss, sensory quality, minerals and trace elements (Mg, Fe, and Zn), flavonoids and antioxidant activity. Weight loss. Baby spinach leaves were weighed using a digital electronic balance [Model MK-500C, DENVER

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Ambani R. Mudau, Mpumelelo M. Nkomo, Puffy Soundy, Hintsa T. Araya, Wonder Ngezimana and Fhatuwani N. Mudau

weight loss. Mineral and trace elements. All mineral and trace elements were analyzed using a method described by Van der Walt et al. (2009) . A 100 mg freeze-dried sample was accurately weighed and heated in 1 mL of nitric acid (70%) until clarity was

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Douglas A. Cox

'Annette Hegg Brilliant Diamond' plants were cultured under Mo stress conditions by using an unlimed sphagnum peat and perlite potting medium and by supplying all trace elements but Mo in the fertilizer solution. Plants were untreated or sprayed with solutions of 1, 10, or 100 μg Mo·liter-1 5, 8, or 11 weeks after pinching. Untreated plants developed foliar symptoms of Mo deficiency (interveinal chlorosis, marginal necrosis, and marginal curling) and leaf tissue contained Mo below the critical level of 0.5 μg·g-1 and NO3-N above 1.0%. At 5 or 8 weeks all Mo spray concentrations prevented deficiency symptoms, increased tissue Mo, and reduced tissue NO3-N. Some symptoms were visible when plants were treated at 11 weeks. Mo sprays at this time did not eliminate the symptoms but reduced the number of leaves showing symptoms to about one-half that of untreated plants when the experiment was ended 15 weeks after pinching.

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Douglas A. Cox

Nine cultivars were grown in a 1:1 sphagnum peat and perlite medium with no limestone or trace element fertilizer. Fertilizer solutions of 300 ppm N and K (calcium nitrate and potassium nitrate) and 24 ppm Mg were applied at every watering. Solutions supplied all trace elements and either 0 or 1 ppm Mo. Moderate to severe foliar symptoms of Mo deficiency developed on `Annette Hegg Brilliant Diamond' and `Eckespoint Lilo' with 0 ppm Mo. Symptoms did not occur with 1 ppm Mo. No Mo deficiency symptoms developed on the other 7 cultivars which included `Supjibi', `Gutbier V-17 Angelika', `Peace Regal Velvet', and `Cheers!'. With 0 ppm Mo these cultivars generally maintained higher levels of nitrate reductase enzyme activity and lower tissue nitrate levels than the 2 showing symptoms.