Effect of ammonium sulfate,ammonium chloride and root‐zone acidity on inorganic ion content of tobacco     

J. Kevin Vessey  C. David Raper Jr.  Leslie T. Henry 《Journal of plant nutrition》2013,36(7):827-842

Tobacco plants (Nicotiana tabacum L. cv NC82) were supplied with (NH₄)₂SO₄, or NH₄Cl at root‐zone pH of 6.0 and 4.5 in hydroponic culture for 28 days. Dry matter accumulation, total N and C content, and leaf area and number were not affected by the NH₄ ⁺ source or root‐zone pH. Plants supplied with NH₄C1 accumulated up to 1.2 mM Cl g DW^‐1, but accumulated 37% less inorganic H₂PO₄ ^‐ and 47% less SO₄ ^2‐ than plants supplied with (NH)₂SO₄. The large Cl^‐ accumulation resulted in NH₄C1 –supplied plants having a 31% higher inorganic anion (NO₃ ^‐, H₂, PO₄ ^‐, SO₄ ^2‐, and Cl^‐) charge. This higher inorganic anion charge in the NH₄C1‐supplied plants was balanced by a similar increase in K⁺ charge. Plants supplied with NH₄Cl accumulated greater concentrations of Cl^‐ in leaves (up to 5.1% of DW) than plants supplied with (NH₄)₂SO₄ (less than ‐% DW). Despite the high Cl^‐ concentration of leaves in NH₄Cl supplied plants, these plants showed no symptoms of Cl^‐ toxicity. This demonstrates that toxicity symptoms are not due solely to an interaction between high Cl^‐ concentration in tissue and NH₄ ⁺ nutrition. The increase in root‐zone acidity to pH 4.5 from 6.0 did not induce toxicity symptoms.  相似文献   

Diurnal malate and citrate fluctuations as related to nitrate and potassium concentrations in tomato leaves     

Carl E. Niedziela Jr.  Paul V. Nelson  Mary M. Peet  William A. Jackson 《Journal of plant nutrition》2013,36(1):165-175

Abstract

Two experiments were conducted to determine if malate and citrate change diurnally, if these changes are light dependent, and how these changes relate to K⁺ and NO₃ ^?1 levels. Malate concentration in tomato leaves was shown to increase during the day and decrease at night. The inverse occurred with citrate. The dependency of the changes on light was demonstrated for malate, but not for citrate. A relationship with NO₃ ^? assimilation and K⁺ recirculation may explain the changes in malate concentration.  相似文献   

Response of Hibiscus Rosa‐Sinensis L. to varying levels of potassium fertilization: Growth,gas exchange and mineral element concentration     

Jonathan N. Egilla  Fred T. Davies Jr. 《Journal of plant nutrition》2013,36(9):1765-1783

Little is known about the effect of varying levels of potassium (K) on the mineral element concentration, growth, and gas exchange, characteristics of woody ornamental plants. The commercially important woody ornamental species Hibiscus rosa‐sinensis L. cv. Leprechaun was evaluated for K response in a series of three experiments with full strength Hoagland's nutrient solution, which supplied 0 to 10 mM K. Plants grown with 4 mM K in nutrient solution (2.4% leaf tissue K) had the greatest shoot growth and root extension. Gas exchange rates (net photosynthesis, transpiration, and stomatal conductance) were also highest at 4 mM K compared to the control (0 mM K /0.6% leaf tissue K), 0.2, 2.0 and 10 mM K treatments. The application of 4 mM K increased net photosynthesis and tranpiration by 2.1 fold and stomatal conductance by 4.5 fold over 0 mM K controls. Increasing K in nutrient solution correlated positively with tissue K, manganese (Mn), and zinc (Zn), but negatively with nitrogen (N), phosphorus (P), calcium (Ca), and magnesium (Mg). There was a stronger sink for K in yonger leaves (the first to fourth fully expanded leaf from the shoot apex) which had higher K concentration than older leaves (the eighth to twelfth fully expanded leaf from the shoot apex). However, with increasing K in nutrient solution, K concentration in leaf tissue increased regardless of leaf age, and the difference between the younger and older leaf was constant. Daily application of 10 mM K resulted in 6.9% leaf tissue K and caused a decrease in plant total dry matter, net photosynthesis, compared to 4 mM K treated plants. However, these parameters remained higher in 10 mM K plants, which retained high ornamental quality than in 0 mM controls. Plants fertilized with 10 mM K, had the highest leaf tissue K and Zn, but lowest P, Ca, Mg, iron (Fe), copper (Cu) and boron (B). Nevertheless, the 10 mM K treated plants exhibited no morphological differences or deficiency symptoms; rather those plants had similar vegetative vigor and flower bud formation rate as those at 4 mM K.  相似文献   

Nitrogen and fungicide effects on winter wheat produced in the Louisiana Gulf Coast region     

H. J. Mascagni Jr.  S. A. Harrison  J. S. Russin  H. M. Desta  P. D. Colyer  R. J. Habetz 《Journal of plant nutrition》2013,36(10):1375-1390

Management decisions affecting wheat (Triticum aestivum L.) yield include nitrogen (N) fertility rate, cultivar selection, and fungicide application. Since these cultural practices may interact with each other and the environment, often times affecting grain yield, test weight, and disease development, they need to be better defined for wheat production in for the Gulf Coast region. Field experiments were conducted to evaluate the effect of N rate, fungicide, and cultivar on grain yield, test weight, and disease development. Three N rates (67, 101, and 134 kg#lbha^‐1), two fungicide treatments (no‐fungicide control and fungicide), and four high‐yielding wheat cultivars with different levels of resistance to leaf rust (Puccinia recondite Rob. ex f. sp. tritici) were evaluated in 12 Louisiana field environments. Environment and interaction between environment and N rate, fungicide, and cultivar were significant for grain yield, leaf rust ratings, and test weight. Grain yield response to N rate was linear in five environments and quadratic in five environments. Although there was little evidence of a N x fungicide interaction for grain yield, increasing N rates increased leaf rust severity. Grain yields were increased by fungicide application in only four of twelve environments with a significant cultivar x fungicide interaction for grain yield. Grain yield increase from foliar fungicides was related to leaf rust severity and resistance of cultivars to leaf rust. Test weight was increased due to N in three environments and decreased in two environments. Test weight increased with fungicide application and varied among cultivars. The findings indicate that 101 kg N ha is probably adequate for maximum yield in most years. Although the higher N rates may increase yield in some years, disease pressure and the need for fungicides may also be increased.  相似文献   

Interseeded legumes with loblolly pine. II. Effect of phosphorus and legume variety on the growth of pine seedlings     

L.A. Redmon  F.M. Rouquette Jr.  C.L. Goad  G.R. Smith  M.J. Florence  J.W. Stuth 《Journal of plant nutrition》2013,36(12):1765-1772

A field study was initiated to quantify growth attributes of loblolly pine (Pinus taeda L.) when intercropped with warm‐season annual legumes. In addition to main treatments, subplots of phosphorus (P) and a cool‐season annual legume were also evaluated as factors contributing to growth of pine trees. After 3 years, pine seedlings grown with ‘Iron and Clay’ cowpea [Vigna unguiculata (L.) Walp.] had grown to a height of 315 cm and had a diameter of 63 mm which was a substantial increase when compared to plants receiving other treatments. Phosphorus application had no effect (P>.10) on pine growth parameters. The addition of ‘Tibbee’ crimson clover (Trifolium incarnatum L.) affected height (P<.10) of pine trees grown with ‘Comanche’ partridge pea (Cassia fasciculata Michx), and pine trees grown alone (control). Regression analyses indicated no correlation between rate of growth in height of pine trees and warm‐season legumes over a three‐year period. Growth rate in diameter during this period, however, was greatest for pine trees growing with cowpeas. Pine seedlings grown as a control or with alyceclover had similar diameter growth rate, but then grew slower than pines with cowpeas, and faster than pines grown with partridge peas.  相似文献   

Effects of root‐zone acidity on utilization of nitrate and ammonium in tobacco plants     

Leslie Tolley Henry  C. David Raper Jr. 《Journal of plant nutrition》2013,36(7):811-826

Abstract

Tobacco (Nicotiana tabacum L., cv. ‘Coker 319') plants were grown for 28 days in flowing nutrient culture containing either 1.0 mM NO₃ ^‐ or 1.0 mM NH₄ ⁺ as the nitrogen source in a complete nutrient solution. Acidities of the solutions were controlled at pH 6.0 or 4.0 for each nitrogen source. Plants were sampled at intervals of 6 to 8 days for determination of dry matter and nitrogen accumulation. Specific rates of NO₃ ^‐ or NH₄ ⁺ uptake (rate of uptake per unit root mass) were calculated from these data. Net photosynthetic rates per unit leaf area were measured on attached leaves by infrared gas analysis. When NO^‐ was the sole nitrogen source, root growth and nitrogen uptake rate were unaffected by pH of the solution, and photosynthetic activity of leaves and accumulation of dry matter and nitrogen in the whole plant were similar. When NH₄ ⁺ was the nitrogen source, photosynthetic rate of leaves and accumulation of dry matter and nitrogen in the whole plant were not statistically different from NO₃ ^‐ ‐fed plants when acidity of the solution was controlled at pH 6.0. When acidity for NH₄ ⁺ ‐fed plants was increased to pH 4.0, however, specific rate of NH₄ ⁺ uptake decreased by about 50% within the first 6 days of treatment. The effect of acidity on root function was associated with a decreased rate of accumulation of nitrogen in shoots that was accompanied by a rapid cessation of leaf development between days 6 and 13. The decline in leaf growth rate of NH₄ ⁺ ‐fed plants at pH 4.0 was followed by reductions in photosynthetic rate per unit leaf area. These responses of NH₄ ⁺ ‐fed plants to increased root‐zone acidity are characteristic of the sequence of responses that occur during onset of nitrogen stress.  相似文献   

Peach orchard studies utilizing fluidized bed material     

R. F. Korcak  J. J. Wrubel Jr.  N. F. Childers 《Journal of plant nutrition》2013,36(11):1597-1604

Abstract

Fluidized bed material (FBM, a coal/limestone combustion byproduct) was used as a lime substitute prior to establishment of a peach (Prunus persia L.) orchard. Growth and nutrition of the trees were generally unaffected by applied FBM, either broadcasted or incorporated, at rates up to three times the soil lime requirement. Leaf and fruit Ca concentration were not significantly effected by FBM additions when compared to limestone or a fertilized control. Minor differences between treatments were noted for some elements. The applied FBM was found to be a suitable substitute for limestone in establishing a peach orchard from the aspects of tree nutrition and expected effects in the soil; elevated pH and higher extractable Ca status.  相似文献   

Effects of combined applications of ammonium thiosulphate and fungicides on fruit load and blossom blight and their phytotoxicity to peach trees     

W. C. Olien  R. W. Miller Jr.  C. J. Graham  E. R. Taylor Jr.  M. E Hardin 《The Journal of Horticultural Science and Biotechnology》2013,88(5):847-854

Summary

Timing of bloom sprays of ammonium thiosulphate (ATS) for foliar fertilization and fruit thinning, and of fungicides for disease control, is critical in peach production. Initial observations in commercial orchards indicated that ATS and fungicides, when applied as tank mixes, could cause burn of blossoms and shoots, but not when applied separately. Nine fungicides, alone and in combination with ATS, were evaluated on single tree plots in 1993 and five representative treatments were repeated in 1994 under commercial orchard conditions. Treatments were applied by hand-gun from a 100 litre sprayer in 1993 and by air-blast sprayer in 1994. In 1993, fruit number per tree was affected only by ATS and the numbers of blossom blight cankers per tree only by fungicide, with no interaction between ATS and fungicides. There were however some ATS × fungicide interaction regarding phytotoxicity to blossom and one-year old shoots, but the damage to the latter was slight. In 1994 blossom blight did not occur and there was no evidence of phytotoxicity to shoots or blossoms. Fruit number was not affected by any treatment.  相似文献   

Long-term applications of untreated and alum-treated poultry litter drive soil nitrogen concentrations and associated microbial community dynamics     

Peter J. Tomlinson  Mary C. Savin  Philip A. Moore Jr. 《Biology and Fertility of Soils》2015,51(1):43-55

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Salmonella pathogenicity island 2-dependent evasion of the phagocyte NADPH oxidase     

Vazquez-Torres A  Xu Y  Jones-Carson J  Holden DW  Lucia SM  Dinauer MC  Mastroeni P  Fang FC 《Science (New York, N.Y.)》2000,287(5458):1655-1658

A type III protein secretion system encoded by Salmonella pathogenicity island 2 (SPI2) has been found to be required for virulence and survival within macrophages. Here, SPI2 was shown to allow Salmonella typhimurium to avoid NADPH oxidase-dependent killing by macrophages. The ability of SPI2-mutant bacteria to survive in macrophages and to cause lethal infection in mice was restored by abrogation of the NADPH oxidase-dependent respiratory burst. Ultrastructural and immunofluorescence microscopy demonstrated efficient localization of the NADPH oxidase in the proximity of vacuoles containing SPI2-mutant but not wild-type bacteria, suggesting that SPI2 interferes with trafficking of oxidase-containing vesicles to the phagosome.  相似文献