Foliar Application Of Zn Research Articles

Critical Zinc+2 Activities for Sour Orange Determined with Chelator-buffered Nutrient Solutions

Chelator-buffered nutrient solutions were used to study the effect of different levels of Zn activity in the rhizosphere on growth and nutritive responses of various tissues of sour orange seedlings. The seedlings were grown for 3 months in a growth chamber in a hydroponic culture containing from 5 to 69 μm and 5 to 101 μm total Zn in Expts. 1 and 2, respectively. Zn+2 activities were calculated with a computerized chemical equilibrium model (Geochem-PC), and buffered by inclusion of a chelator, diethylenetriamine pentaacetate (DTPA), at 74 and 44 μm in excess of the sum of Fe, Mn, Zn, Cu, Ni, and Co in Expts. 1 and 2, respectively. The use of DTPA-buffered solutions proved successful in imposing varying degrees of Zn deficiency. The deficiency was confirmed by leaf symptomatology, leaf chemical analyses, i.e., <16 mg·kg-1 Zn, and responses to foliar sprays and application of Zn to the roots. Growth parameters varied in their sensitivity to Zn deficiency, i.e., root dry weight < leaf number and white root growth < stem dry weight < leaf dry weight < shoot elongation and leaf area. The critical activities, expressed as pZn = -log(Zn+2), were ≈10.2±0.2 for root dry weight, 10.1±0.2 for leaf number and white root growth, 10.0±0.2 for stem dry weight, 9.9±0.2 for leaf dry weight, and 9.8±0.2 for shoot growth and leaf area. Increases in growth were observed in response to Zn applications even in the absence of visible Zn-deficiency symptoms. Seedlings containing >23 mg·kg-1 Zn in leaves did not respond to further additions of Zn to the nutrient solution. Zinc foliar sprays were less effective than Zn applications to the roots in alleviating severe Zn deficiency because foliar-absorbed Zn was not translocated from the top to the roots and thus could not correct Zn deficiency in the roots.

The effect of seaweed concentrate on the uptake of foliar-applied Cu, Mn and Zn by tomato seedlings

The effect the seaweed concentrate Kelpak on the uptake of foliar-applied Cu, Mn and Zn by tomato seedlings grown with and without added macronutrients was investigated. Kelpak had little effect on the uptake of Cu and Mn, but significantly stimulated Zn uptake in plants receiving no macronutrients. However, Kelpak did not increase Zn uptake in plants receiving macronutrients. Results suggested that seaweed concentrates are unlikely to be useful in promoting the uptake of foliar-applied trace elements in tomatoes grown under normal commercial conditions.

COPPER AND ZINC NUTRITION OF RUSSET BURBANK POTATOES GROWN ON PRINCE EDWARD ISLAND

Field experiments were conducted on potatoes (Solanum tuberosum L.) at two locations in P.E.I. to determine the response to soil- and foliar-applied Cu and Zn on tuber yield and leaf tissue nutrient concentration over a period of 3 yr. Foliar applications of 0.5–2 kg Cu ha−1 applied 1–2 wk prebloom reduced total tuber yield, number of tubers over 55 mm in diameter, average tuber weight, and specific gravity. The mean potato yield of tubers over 55 mm from the foliar-applied Cu treatments was less than the soil applied Cu by 4.5, 0.74, and 7.5 t ha−1 for 1985, 1986, and 1987, respectively. The toxic concentrations of Cu in potato leaves ranged from 63 to 139 μg g−1. Soil-applied Cu increased tissue Cu in the first sampling but had no effect in the second sampling. Foliar applications of Zn at 1–2 kg ha−1 reduced total tuber yield, tuber yield and tuber count over 55 mm, and specific gravity. The toxic concentrations of Zn in potato leaves ranged from 97 to 224 μg g−1. For the first sampling, the leaf tissue Zn concentrations ranged from 21 to 30 μg g−1 for the control and 27 to 70 μg g−1 for soil-applied Zn treatment. There was no difference in the Zn concentration between these two treatments for the second sampling. Copper and Zn concentrations as low as 7 and 21 μg g−1, respectively, in potato leaves were not related to deficiency of these nutrients, based on tuber yields. Soil applications of Cu or Zn would appear preferable to foliar sprays, which may cause phytotoxicity, as a means of increasing plant Cu or Zn content where a deficiency is suspected.Key words: Solanum tuberosum L., tuber yield, leaf copper, leaf zinc, Podzolic soil, potato

EFFECT OF ZINC FERTILIZATION ON PLANT ZINC CONCENTRATION OF FORAGES AND CEREALS

Field experiments were conducted in Prince Edward Island (P.E.I.) to determine the effects of Zn (zinc sulfate) applied to the soil; applied as a foliar spray; and the effects of chelated Zn applied as a foliar spray on Zn concentration of alfalfa (Medicago sativa L.), ryegrass (Lolium multiflorum Lam.), wheat (Triticum aestivum L.), and barley (Hordeum vulgare L.). Plant tissue Zn levels as low as 12 mg kg−1 in forages, 14 mg kg−1 in cereal boot stage tissue and 19 mg kg−1 in cereal grain were not related to Zn deficiency. Tissue Zn levels as high as 123 mg kg−1 in barley boot stage tissue and 153 mg kg−1 in alfalfa did not result in yield reduction or any Zn toxicity symptoms. Cereal and forage yields were not affected by Zn treatments. In most cases, soil and foliar Zn applications were effective in increasing the Zn concentration in forages and cereals. Should a Zn deficiency be suspected (either from the crop or animal nutrition viewpoint) Zn could be applied to the soil at 20 kg ha−1 or as a foliar spray at 0.5 to 1.0 kg ha−1 to overcome the problem in this region (and in other areas with similar soil and climatic conditions). Key words: Plant Zn, soil and foliar applied Zn, Zn chelate and zinc sulfate, podzol soils

EFFECT OF ZINC APPLICATIONS ON CORN AT TWO SITES EXHIBITING LOW PLANT TISSUE ZINC CONCENTRATIONS IN PRINCE EDWARD ISLAND

No yield responses to applied Zn occurred on corn (Zea mays L.) at two Prince Edward Island sites where untreated leaf Zn concentrations were 11 to 14 μg g−1. Both soil- and foliar-applied Zn increased leaf and whole-plant Zn concentrations. Key words: Banded Zn, foliar-applied Zn, corn yield

Effect of foliar and soil applied zinc on soil test levels, herbage composition, and yields of alfalfa

Abstract Forages in the Northeast generally do not contain enough Zn to meet the National Research Council (NRC) recommended allowance for dairy cattle (40 mg/kg Zn). A study was undertaken to determine if foliar or soil application of Zn could increase Zn levels in alfalfa herbage to the NRC recommended allowance. Alfalfa was treated with Zn by foliar applications of 0.34 and 0.68 kg/ha and soil application of 4.07 kg/ha. An untreated check was also included in the study. Average herbage Zn levels were 33.1 and 50.1 mg/kg for the low and high foliar applications, respectively. These levels were significantly higher than that of the check, 18.9 kg/ha. Average herbage Zn levels for the soil applied Zn treatment was 23.4 mg/kg. This level was also significantly higher than that of the check. Although foliar Zn application significantly raised herbage Zn levels above those of the check, the results were erratic. The 40 mg/kg level was reached only one‐third of the time with the 0.34 kg/ha foliar application ...

Factors affecting nitrogen fixation and yield of faba bean (Vicia faba) under Egyptian field conditions: A review

Abstract Several field experiments were conducted at different locations in Egypt to study effects of certain agricultural practices on nodulation, N2 fixation and growth of faba bean (Vicia faba). Applications of 18–48 kg N ha−1 and 30–45 kg P ha−1 stimulate nodulation, enhance N2 fixation and produce highest yield. Response of faba bean to P fertilization is quadratic between zero and 75 kg P ha−1. Foliar application of Mo and Zn or pre‐soaking of faba bean seeds in solution of these trace elements is beneficial. Water stress causes marked reduction in nodulation, N2 fixation, and growth and yield of faba bean. High yields are obtained when irrigation is practiced at 50% depletion of available water. Soil salinity or irrigation with saline water EC > 5 mmhos cm−1 badly affects plant growth and yield but nodulation and N2 fixation are less affected. Seed inoculation has proved to be a practical means of increasing yield and improving quality of grains.

Foliar Fertilization of Dry Beans with Zn and NPKS1

AbstractIn response to increasing grower use of foliar fertilization, field experiments were conducted from 1977 through 1979 to evaluate the effects of Zn and NPKS foliar fertilization of dry beans (Phaseolus vulgaris L.) on nutrient concentrations in the tissue and on yield.Commercial Zn formulations of ZnSO4, ZnEDTA (Zn ethylenediamine tetraacetate), NZn and ZnPK were sprayed at growth stages ranging from early vegetative (V4) to early bloom (R1). Foliar NPKS was applied at growth stages ranging from full bloom (R2) to fully expanded seed (R7). Foliar Zn and NPKS were applied either separately or together in combination treatments.Throughout the study there was no yield increase from foliar‐applied Zn when soil Zn was adequate. There was a yield increase over the untreated check in 1978 but not in 1979. No consistent differences in bean yields were observed among ZnSO4, ZnEDTA, NZn, or ZnKP. Stage of growth at which the foliar fertilization was applied did not affect yield response.All foliar Zn treatments increased plant tissue Zn except at growth stage V4 which had insufficient foliage to intercept the spray. Similar tissue Zn cone resulted from foliar ZnSO4, ZnEDTA, and ZnKP. The NZn material, containing Zn dissolved in a solution of urea, ammonium, and nitrate N, consistently resulted in about twofold greater tissue Zn than the other Zn materials.Concentrations of N, P, K, and Zn in the bean seed were not consistently affected by foliar applications of Zn or NPKS. Even twofold to fourfold differences in whole plant Zn cone did not affect seed Zn cone.

Soil Or Foliar Applied Nutrient Effects On Mineral Concentrations And Germinability of Peanut Seed1

Abstract The mineral composition of peanut (Arachis hypogaea L.) seed is important to seed germinability, human dietary quality, and may indicate nutrients limiting peanut productivity. Low germinability of peanut seed is frequently a problem for seed producers. Little is known about nutrient effects on seed germination except for Ca. Experiments were conducted on two Aquic Hapludults, one in Southampton Co. and the other in Suffolk, Va. The effects of lime, N, P, K, Ca, Mg, Mn, Zn, Cu, B, S, or Fe applied to the soil and/or foliage on the elemental composition and germinability of peanut seed were studied. Average germination varied from 39 to 82% and was highest where 1,120 or 3,360 kg/ha of landplaster (LP) was applied alone. Germination was decreased by application of KCl or K2SO4 at 1,120 kg/ha, or urea or NH4NO3 each at 224 kg/ha of N. Percentage germination was correlated positively with seed Ca and negatively with seed K concentrations. Also, a low but significant negative correlation was obtained between Fe or Cu and seed germinability. All treatments which contained considerable Ca increased the Ca concentrations in seed, except lime at 2,240 kg/ha. Concentrations of K in the seed were increased by the K treatments only when LP was not applied. Treatments which included foliar-applied Zn or both Zn and Mn decreased seed K or seed Mg levels, respectively. None of the treatments decreased Fe, Cu, P, Mn, or Zn concentrations in seed. The concentrations of the nutrients in the seed varied relative to the method of application. Fertilization practices which increase Ca uptake by the seed relative to K should enhance peanut seed germinability.