G. V. Alexander

Multiple trace element toxicities in plants

Abstract A 2 × 2 × 2 factorial experiment was conducted with bush beans (Phaseolus vulgaris L. cv. Improved Tendergreen) in solution culture in which elements Cu, Ni and Co were applied at levels high enough to cause stress on the plants. Plants were grown in a Hoagland type solution in 3700 ml containers for 15 days. Solution pH values were near 4.5. Plant parts were washed in 1/10N HCl and deionized water and assayed for minerals by optical emission spectrometry. A concentration of 89 μg Cu/g dry weight for trifoliate leaves resulted in 42% yield reduction and 54 μg Co/g dry weight resulted in 68% yield reduction. The Colby (1968) technique of multiplication of relative yields was used to determine the nature of the multiple trace metal toxicities (additive, synergistic or protective). The combination of excess Cu and Ni resulted in a relative yield of trifoliate leaves of 7% of control. The relative yields of the two trace metals applied separately were 28 and 58% and when multiplied they are 16% which...

Single and multiple trace metal excess effects on three different plant species

Abstract Three crops of plants (corn (Zea mays L. cv. Golden Cross N.C.). barley (Hordeum vulgare L. cv. Atlas), soybeans (Glycine max L. cv. Hawkeye and PI54619–5–1) were grown in succession in flats of Yolo loam soil which had received in μg/g soil 0, 13 Li, 200 Zn, 200 Cu, 75 Co, 100 Ni, and 100 Cd both singly and in various combinations. The three plant species with two cultivars of soybeans reacted differently to the trace metals. Protective (competitive), additive and synergistic effects were all present. The treatments slightly modified soil pH but this did not explain all effects. Barley was most tolerant of the trace metals and yield depression occurred only when all six trace metals were applied simultaneously and this probably because of metal induced P deficiency.

Iron, nitrogen and phosphorus interactions in two cultivars of soybeans grown in a calcareous soil

Abstract Hawkeye (resistant to iron chlorosis) and PI54619–5–1 (susceptible to iron chlorosis) soybeans (Glycine max L.) were grown in calcareous Hacienda loam soil (fine‐loam, mixed, thermic Aquic Natrargid) for 26 days in a glasshouse. Objectives of the study included an evaluation of iron chlorosis as phosphorus and nitrogen were varied. The 2×2×2 factorial study with Fe, P and N (with and without each) provided the possibility for a look at three deficiencies simultaneously with some assessment of the use of the Colby (1968) technique for multiple stresses acting simultaneously. Iron addition (2 μg/g soil as FeEDDHA) overcame iron deficiency and increased yields. Nitrogen (200 μg N/g soil as NH4NO3) increased yields only when both iron and phosphorus were also applied with one cultivar (Hawkeye); nitrogen increased yield in combination with iron or with iron plus phosphorus with the second cultivar (PI54619–5–1). Phosphorus (100 μg P/g soil as CaH2PO4), on the average, had no effect on yields of eithe...

Calcium-trace metal interactions in soybean plants.

Abstract Hawkeye soybeans (Glyclne max L.) were grown for 13 days in nutrient solutions in a glasshouse with differential Ca and trace metal concentrations. Yields were little affected by low Ca levels without excesses of trace metals but yield depressions for excesses of Ni, Cd, Al, Ma, and Cu generally were greater at low Ca levels than at a high level. Ca, Mg and K levels in plants were all depressed by the trace metals. Some of the effects were expressed also in roots. The 10–3M level of Al resulted in virtually no Ca in roots and in diminished transport to shoots. The trace metal concentrations in leaves generally decreased with increasing Ca.

Effect of excess chelating agent in nutrient solution at low levels of iron, zinc, copper and manganese

Abstract When iron was supplied as FeEDDHA at 10‐6 M or 10‐7 M, Mn and Zn as sulfates variously at 10‐5to 10‐7 M and Cu at 10‐6 M, the copper concentrations of trifoliate leaves of bush beans (Phaseolus vulgaris L.) was in the toxic range (30–77 mg/kg)/ when iron was at 10‐5 M with the same concentrations of zinc, manganese and copper as above, the copper was in the adequate range (7.5–14 mg/kg) but when 10‐4 M Na2EDTA was applied to each of the above solutions, copper in the leaves was in the deficient range (2–4 mgAg) • The results point to the need for extreme care when chelating agents are used in hydroponic nutrient solutions especially where copper, manganese and/or zinc as well as iron are applied in che— lated form. As iron becomes depleted in a nutrient solution, copper toxicity can result, but deficiency can also result if there is excess free chelate even with the same copper level in the nutrient solution. The multielement stresses were shown to be mostly additive in nature, although in some c...

Micronutrient supplying power of pyrite and fly ash

Abstract Bush bean plants (Phaseolus vulgaris L. cv Improved Tendergreen) were grown in nutrient solution with added waste mine tailings pyrite and also coal fly ash to test their ability to supply micronutrients to plants. The ability of fly ash to supply K was also tested. The pyrite was a satisfactory source of Fe, Mn, Zn, B and Cu to the solution cultures. The pyrite also supplied Ca. The fly ash supplied inadequate Fe and Mn but adequate quantities of Zn, B and Cu. It supplied adequate Ca and inadequate K. Both pyrite and fly ash supplied some Cd (when solution was acid), Cr and Pb to roots but not in detectable amounts to shoots. In another experiment, fly ash also failed to supply K to bush bean plants and failed to supply Zn. Iron, B, Si, Cu, Mo, Sr, Ba and some Ni and Cr were supplied to leaves; Si, Sr, Ba, Ni and Cr were supplied to roots by the fly ash. None of these elements seemed to result in phytotoxicity. A suggestion is made that fly ash and pyrite could be blended for soil application of...

X-Ray Fluorescence Analysis of Biological Tissues

The application of conventional x-ray fluorescence equipment to the analysis of biological tissues is discussed. Several examples are given to indicate the type of procedure which is involved The integration of x-ray fluorescence and optical emission methods for a rather efficient analysis of biological tissues is outlined.

Influence of potassium on uptake and distribution op cesium in bush beans

Abstract Bush beans, Phaseolus vulgaris L. cv. Improved Tendergreen, were grown for 18 days in 3700 ml. nutrient solutions in a factorial experiment involving 3 levels of K (10‐2, 10‐3, 10‐4N) and 3 levels of Cs (10‐4, 5 x 10‐5, 10‐5N). Mild K deficiency was observed for the low K level but no yield differences were due to Cs. Increasing K markedly decreased the Cs concentrations in all plant parts. The relative uptake of K vs Cs was not influenced by Cs but was by K. The concentration ratio (C.R.) for K in trifoliate leaves varied from 99 (high K) to 7315 (low K). The C.R, for Cs in trifoliate leaves varied from 8,67 (high K) to,0.96 (low K). Potassium was translocated to trifoliate leaves from 89 to 843 times that of Cs. The “Y”; values for Cs in plant parts was consistently near 1 meaning that Cs uptake was directly proportional to its concentration in the nutrient solution. The “Y”; values for K in plant parts were around 0.5 for 10‐3/10‐4N K but only about 0,2 for 10‐2/10‐3N K. Roots accumulated abou...

Transfer values to fruits of Li in tomato and Cd in bush beans

Abstract Different levels of Li (10‐5, 10‐4, 5 x 1‐4 M) and Cd (2 x 10‐6, 10‐5, 10‐4 M) were studied in solution culture in a glasshouse to evaluate the effects on growth and fruit transfer values in tomato (Lycopersicon esculentum mill, cv. Marglobe) and bushbeans (Phaseolus vulgaris L. cv. Improved Tendergreen). No effect on yield was observed for up to 10‐4 M Li levels; after that yields were significantly decreased. The yield of bush‐beans was significantly reduced by the Cd levels added. The Li in solution culture significantly increased the Li concentration in tomato roots, leaves, and fruits. The Cd had an increasing effect on Cd concentration only in bushbean roots and a nonsignificant effect was observed in leaves and pods. Considerable amounts of Li were translocated to leaves and fruits while very little Cd was found in fruit pods. The exact amount was unknown due to limits of method.

A collander‐type experiment in large tanks of solution culture

Abstract Several different plant species were grown together in large (400 1) tanks of solution culture in the pattern of the original Collander experiment (Plant Physiol. 16:691) except in the present one, plants were spaced far enough apart that roots could not become entangled so that root‐shoot partitioning could be studied. Two sets of plants were grown in the tanks. One set was with agricultural species and the other was with native desert plants. One tank contained a standard nutrient solution and the second contained the same solution with addition of several cations: Na, Cd, Li, Ni, Cr, Pb, Sr, Ba. Plant species behaved differentially to the mixture of cations with differential partitioning among plant parts. Exclusion phenomena discussed in the original Collander paper are mostly retention in roots with little transloca‐tion to shoots. The extra cations in some cases increased yields, in some cases decreased yields with no differences in others. Several‐nutrient element interactions were indicat...