J. W. Cha

Some modifications in trace metal toxicities and deficiencies in plants resulting from interactions with other elements and chelating agents‐‐the special case of iron

Abstract Whenever land becomes contaminated with trace metals, most always two or more of the trace metals are in excess simultaneously. Nearly all of the baseline studies of metal excesses, however, have been made with single metals, and such studies do not accurately reflect the critical response levels. Various critical points can shift due to interactions. Analytical data must be obtained for as many as 20 different elements and their differential distribution among various plant parts, including roots, must be known to gain even a partial understanding of the interactions. Positive and negative synergisms, competition, protection, and sequential additivity are observed among the interactions. The nature of interactions varies considerably with concentration levels, soil pH, soil texture, level of soluble Ca in soil, presence of salinity, differential distribution in soil of the metals present in toxic quantities, presence or absence of chelating agents, soil organic matter levels, and other factors. ...

Some effects of chromium toxicity on bush bean plants grown in soil

SummaryChromium applied to a noncalcareous soil at 50 ppm did not decrease yields of bush beans (Phaseolus vulgaris L. var Improved Tendergreen), but when EDTA (ethylenediamine tetraacetic acid) was added with it, it did. Very little Cr was present in leaves. In solution culture 10-5M Cr and higher were toxic. With solution culture the highest level of Cr in leaves was about 30 ppm and in general there was a decreasing gradient in Cr from roots to stems to leaves. EDTA had less effect in solution cultures on Cr toxicity because the Cr was already in solution. Chromium toxicity decreased cation levels in plants.

Nickel phytotoxicity in relationship to soil ph manipulation and chelating agents

Abstract The main objective of this study was to ascertain effects of some edaphic factors on the uptake and influence of Ni on plant growth sinee Ni is a common trace element contaminant as well as an important component of serpentine soils. Corn (Zea mays L. inbred Ys1/Ys1) was rown in Yolo loam soil amended to give soil pH values of 4.2, 5.6, 7.5, and 8.2. A level of 100 μg Ni/g soil was not toxic to the corn. Shoot concentrations of Ni increased as soil pH decreased for both application rates of Ni. A level of 250 μg Ni/g soil decreased yields more at soil pH below 7 than above 7. Iron, Zn, and Mn levels in shoots did not appear to be directly related to the Ni applications although Fe levels tended to increase as a result of smaller plant size. PI54619–5–1 soybeans (Glycine max L. ) were grown in soil at two different pH values (with and without CaCO3) and with and without a level of 1000 μg Ni/g added as the sulfate and thoroughly mixed with the soil and equilibrated for 1 month prior to transplanti...

Lithium toxicity in plants

Abstract The toxicity of Li to three plant species was studied to determine if there were interactions with other elements and to determine if a chelating agent modified Li toxicity. Bush beans (Phaseolus vulgarls L. C.V. Improved Tendergreen), grown in solution culture, were sensitive to 0.5 X10‐3Li which resulted in 10 μg/g in leaves, 48 in stems, and 24 in roots. Higher concentrations of Li produced marked reductions in plant yield accompanied by increased Li concentrations in leaf, stem, and root tissues. For most treatments, root concentrations of Li were lower than those in shoots, but those in stems were higher than those in leaves. Higher levels of Li decreased Zn in leaves, increased Ca in stems, and generally increased Fe and Mn in all plant tissues. Ethylenediamine tetraacetic acid (EDTA) resulted in slightly increased Ii levels in leaves, stems, and roots. Bush bean plants were injured slightly with 25 μg Li/g of Yolo loam soil applied as LiCl; 50 μg Li/g soil caused more severe injury. Leaf c...

Comparison of the effects of high levels of DTPA and EDDHA on microelement uptake in bush beans

Abstract Bush beans (Phascolus vulgaris L. var Improved Tendergreen) were grown for 21 days in noncalcareous Yolo loam soil with 0, 500, and 1000 ppm of DTPA (diethylene triamine pentaacetic acid) and also of EDDHA (ethylenediamine di(o‐hydroxyphenylacetic acid)) applied as the Na salts. The objective was to learn more of DTPA‐increased uptake of some heavy metals. The high levels of both agents tended to depress yields and result in leaf symptoms of excesses of metals. Both agents resulted in large increases of Fe in shoots. DTPA resulted in much larger increases in Zn, Cu, Mn, Co, Ni and Pb than did EDDHA. For Cu, Co, and Ni the proportional increases with DTPA were greater than that for Fe. Aluminum was increased more by EDDHA than by DTPA while Mo was increased almost equally by the two chelating agents. Chromium was increased slightly by each agent, but V was unaffected. Leaf/stem ratios were increased by DTPA for Co and Ni and to a lesser extent for Fe and Zn indicating some transport through the pl...

Effect of washing procedures on mineral analyses and their cluster analyses for orange leaves.

Abstract Fifty mature orange leaves were divided into groups of 10 and each group received a different washing procedure (control, wipe only with cloth, wipe plus detergent and acid (1/10N HC1) wash, acid wash, wiping and acid wash followed by deionized water). The objective was to determine if the so‐called dust elements (Fe, Al, Si, Ti) clustered together when dust was cleaned from leaves. The clustering was changed by washing procedures. Calcium, Na, Cu, and Mn concentrations were not changed by washing. Phosphorus, Mg, and K were lost from leaves by leaching with severe washing. Dust or contaminating Fe, Al, Si, Ti, and Pb were removed by all washing procedures but wiping with acid tended to decrease the coefficient of variation among samples.

Influence of washing of soybean leaves on identification of ikon deficiency by leaf analysis

Abstract Iron inefficient PI54619–5–1 soybean (Glycine max L.) plants were grown for 17 days in calcareous Hacienda loam soil with and without added FeEDDHA and with half in a glasshouse where plants would be reasonably free of dust, while the remainder were outside where plants were exposed to a normal amount of dust. Primary and trifoliate leaves were separated, half of each leaf washed with rubbing in 1/10N HC1 while the others were not washed. Large amounts of Fe, Ti, Si and Al were washed from leaves grown outside but relatively little from those grown in the glasshouse largely because the latter were initially cleaner. Iron deficient trifoliate leaves from plants grown outside had higher concentrations of these four elements after washing than did similar leaves grown in a glasshouse. Since iron deficiency was very pronounced for both locations it can be concluded that the Fe derived from dust was nonfunctional and that the washing technique removed foliar Fe from leaves but not sufficiently well to...

Nickel--iron interaction in bush beans

Abstract Bush beans (Phaseolus vulgaris L. C. V. Improved Tendergreen) plants were grown in solution culture and in soil with different levels of Fe and Ni to determine more precisely if Fe would overcome part of the phytotoxicity caused by Ni. In solution culture, a high level of Fe improved growth of plants in the presence of 2.5 × 10‐5 M Ni, but not with 5 × 10‐5 MNi. The 2.5 × 10‐5 M Ni decreased Fe concentrations in leaves, but not in other plant parts. The 5 × 10‐5 M Ni also decreased Fe concentrations in leaves relative to the controls although they were increased relative to those for 2.5 × 10‐5 MNi. The high Fe levels did not decrease Ni concentrations in plant parts. In soil Fe chelate improved plant growth at 50 and 100 μg Ni/g soil, but not at higher levels of Ni. The Fe did not depress Ni concentrations in leaves and Ni had no effect on Fe concentrations.

Effects of bicarbonate, phosphorus, iron EDDHA, and nitrogen sources on soybeans grown in calcareous soil

Abstract Hawkeye soybeans (Glycine max L.), an iron‐efficient cultivar when grown in calcareous Hacienda loam soil low in P and available Fe, did not respond to P, FeEDDHA, NH4+‐N or NO‐ 3‐N when applied singly nor to Fe + P together; but did give yield response for N + P + Fe applied together. Addition of HCO3 ‐ with N + P + Fe decreased yields by about 10% and decreased Fe in shoots also by 10%. The NH4+ source of N gave 12% higher leaf yield without HCO3 ‐ and 11% higher with HCO3 ‐ than did nitrate N. Bicarbonate alone caused severe damage to the Hawkeye soybeans, while P alone had little effect. In contrast, P was very damaging with less effect from HCO3 ‐ with iron‐inefficient PI‐54619–5–1 soybeans from a companion study. Addition of Fe decreased Zn and Mn concentrations in leaves, while addition of both Fe and P decreased Zn concentration even more. Bicarbonate contributed additionally to low Zn in leaves with treatments of Fe and Fe + P. These Fe‐efficient Hawk‐eye soybeans were less impaired by N...

Calcium deficiency and CaCO3 on micronutrient status of plants grown in solution culture

Abstract Plants were grown in solution culture with different levels of Ca to further evaluate Ca relationships to trace metal uptake and to toxicity of trace metals. When tomato plants (Lycopersicon esculentum L., Tropic) were grown at a low level of Ca, the Zn, Cu, Fe, Mn, Al, and Ti concentrations of leaves, stems, and roots were considerably increased. The use of an excess of CaCO3 which increased pH did not influence the trace metal concentrations of plants any more than did Ca++. In a factorial experiment with bush beans (Phaseolus vulgaris L. C.V. Improved Tendergreen) with Ca (10‐4,10‐2, 10‐2 N) and Ni (0, 2 × 10‐6 M, 2 X10‐5 M), Ni phytotoxicity and Ni uptake were decreased somewhat at the highest Ca level. High Ni tended to decrease the Ca concentration in leaves. High Ca and Ni both tended to decrease Fe, Cu, Zn, and Mn concentrations in leaves. The Ni had some interactions on the P concentrations of shoots.