Chemical Composition Of Plant Tissues Research Articles

Experimental modeling of the influence of mineral nutrition conditions on the plants of spring double

The purpose of the study: to identify the in uence of mineral nutrition conditions on morphogenesis and absorption of macronutrients by spring barley plants of two varieties in the period from germination to earing under controlled conditions of light culture. The objects of the study were plants of double-row barley of the Takmak variety and the Salome variety. The plants were grown by hydroponics on expanded clay under controlled environmental conditions. Four variants of nutrient solutions were prepared for watering plants: variant l (the control) - Knop solution of standard concentration; variant 2 - Knop solution was prepared with 50 % concentration from its standard concentration; variant 3 - solution was prepared on the basis of Knop solution, but with 50 % of N concentration from its standard concentration; variant 4 - solution was prepared on the basis of Knop solution, but with 25 % of P concentration from its standard concentration. As a result, variants 2 and 3 showed a decrease in total bushiness by more than 30 % compared to the control. The mass of plants in variants 2 and 3 turned out to be 50 % and 35 %, respectively, less than in the control. The decrease in plant mass was mainly due to a decrease in the mass of lateral shoots. The level of consumption of mineral elements, closely related to the composition of solutions, affected not so much the chemical composition of plant tissues as the amount of plant biomass, which manifested itself in high correlations between the consumption of mineral elements and the gross content of these elements in plants with rather weak links between consumption and the content of mineral elements in plants.

Identification of Plant Compounds Involved in the Microbe-Plant Communication During the Coinoculation of Soybean with Bradyrhizobium elkanii and Delftia sp. strain JD2.

Delftia sp. strain JD2 is a betaproteobacterium characterized as a plant growth-promoting bacterium with a 'helper' function, enhancing the performance of rhizobial inoculant strains during the coinoculation of alfalfa and clover. In this work we analyzed i) the effect of the coinoculation with Bradyrhizobium elkanii and Delftia sp. strain JD2 strains on the performance of soybean plants and ii) the production of a few secondary plant metabolites that would explain the positive effect of coinoculation on the growth and development of soybean plants. The results showed a beneficial effect of coinoculation on soybean growth, nodulation rate, and pulse yield, with the concomitant benefit for the agricultural economy. In addition, based on a metabolomics approach, we demonstrated that a different pattern of plant metabolites is being produced at different stages of plant growth. The new information suggests that the coinoculation of soybean changes the primary and secondary metabolism of the plant, including changes in the metabolic status of main and secondary nodules within the plant. The relevance of producing a different pattern of photosynthetic and photoprotective pigments, flavonoids, organic acids, and carbohydrates are discussed. Finally, we propose that JD2 could be used together with bradyrhizobia to manipulate the chemical composition of plant tissues, promoting the nutritional benefits and health of soybean.

Raman Imaging of Plant Cell Walls in Sections of Cucumis sativus.

Raman microspectra combine information on chemical composition of plant tissues with spatial information. The contributions from the building blocks of the cell walls in the Raman spectra of plant tissues can vary in the microscopic sub-structures of the tissue. Here, we discuss the analysis of 55 Raman maps of root, stem, and leaf tissues of Cucumis sativus, using different spectral contributions from cellulose and lignin in both univariate and multivariate imaging methods. Imaging based on hierarchical cluster analysis (HCA) and principal component analysis (PCA) indicates different substructures in the xylem cell walls of the different tissues. Using specific signals from the cell wall spectra, analysis of the whole set of different tissue sections based on the Raman images reveals differences in xylem tissue morphology. Due to the specifics of excitation of the Raman spectra in the visible wavelength range (532 nm), which is, e.g., in resonance with carotenoid species, effects of photobleaching and the possibility of exploiting depletion difference spectra for molecular characterization in Raman imaging of plants are discussed. The reported results provide both, specific information on the molecular composition of cucumber tissue Raman spectra, and general directions for future imaging studies in plant tissues.

Shrub-encroachment induced alterations in input chemistry and soil microbial community affect topsoil organic carbon in an Inner Mongolian grassland

Shrub encroachment frequently occurs in arid and semi-arid grasslands worldwide and affects the regional carbon balance. Many previous studies have revealed the effects of shrub encroachment on bulk carbon content of grasslands, but molecular evidence is surprisingly lacking. In this study, we examined the chemical composition of plant tissues and soil organic carbon (SOC), and soil microbial communities to identify the effects of shrub (Caragana microphylla) encroachment on SOC storage in the top layer (0–10 cm) along a gradient of natural shrub cover in the grasslands of Inner Mongolia. We found that SOC in the shrub patches was derived mainly from leaves, whereas SOC in the grassy matrix was composed of a mixture of fresh root- and leaf-derived compounds. Compared with pure grassland, the SOC decreased by 29% in the shrub-encroached grasslands (SEGs), and this decrease was enhanced by increasing shrub cover. We also found that free lipids and lignin-derived phenols increased while the ratios of ω-C18/∑C18 and suberin/cutin decreased with increasing shrub cover. In addition, the ratios of fungal to bacterial phospholipid fatty acids (PLFAs) and gram-negative to gram-positive bacterial PLFAs decreased with increasing shrub cover. These results indicate that the encroachment of nitrogen-rich legume shrubs can lead to carbon loss by altering the chemical composition of plant inputs as well as the soil microbial community in grassland ecosystems.

Primary Soil Formation And Dynamics Of The Evolutional Transformation Of Minerals Under Action Of Living Matter

We present the results of a comprehensive study of soil-forming processes under the influence of a long-term and end to end (7.5 years; twenty three vegetations) cultivating of the plants on initially lifeless mineral substrates (crushed granite, zeolite) under controlled conditions. The data were obtained under regulated conditions. It was shown that the higher plants (tomato, spring wheat) can actively participate in the pedogenesis process. We analyzed the evolutionary dynamics of the accumulation of organic matter and the dynamics of the biotic community. The result of the biogenic weathering minerals is decomposition of the rock, washing-out of the mineral elements, transformation of the minerals, formation of a secondary minerals and melkozem. We give consideration of the evolutionary dynamics of the chemical composition of plant tissues (roots, stems, leaves and reproductive organs). It was analyzed the percentage of the plant tissues the following chemical elements: P, S, Cl, Ca, Mg, Na, K, Fe, Si, Al, Mn, Zn. It was used the information approach for a quantitative analysis of the interrelation dynamics of changes in the chemical composition of the mineral substrates and chemical composition of plant tissues. The chemical composition of the mineral substrate evolutionary changes so that it is close to the information content of the plant root system. Studies processes of accumulation and transformation of the organic matter in the mineral substrate have shown that in a very short period of time under conditions of intense year-round cultivation of plants in the mineral substrates occur an intensive their enrichment by organic substance.

The structure and chemical composition of plant tissues revealed by high resolution attenuated total internal reflectance imaging.

The structure and chemical composition of plant tissues revealed by high resolution attenuated total internal reflectance imaging.

Edaphic factors and plant–insect interactions: direct and indirect effects of serpentine soil on florivores and pollinators

Edaphic factors can lead to differences in plant morphology and tissue chemistry. However, whether these differences result in altered plant-insect interactions for soil-generalist plants is less understood. We present evidence that soil chemistry can alter plant-insect interactions both directly, through chemical composition of plant tissue, and indirectly, through plant morphology, for serpentine-tolerant Mimulus guttatus (Phrymaceae). First, we scored floral display (corolla width, number of open flowers per inflorescence, and inflorescence height), flower chemistry, pollinator visitation and florivory of M. guttatus growing on natural serpentine and non-serpentine soil over 2 years. Second, we conducted a common garden reciprocal soil transplant experiment to isolate the effect of serpentine soil on floral display traits and flower chemistry. And last, we observed arrays of field-collected inflorescences and potted plants to determine the effect of soil environment in the field on pollinator visitation and florivore damage, respectively. For both natural and experimental plants, serpentine soil caused reductions in floral display and directly altered flower tissue chemistry. Plants in natural serpentine populations received fewer pollinator visits and less damage by florivores relative to non-serpentine plants. In experimental arrays, soil environment did not influence pollinator visitation (though larger flowers were visited more frequently), but did alter florivore damage, with serpentine-grown plants receiving less damage. Our results demonstrate that the soil environment can directly and indirectly affect plant-mutualist and plant-antagonist interactions of serpentine-tolerant plants by altering flower chemistry and floral display.

Comparison of soil organic matter composition after incubation with maize leaves, roots, and stems

As plants are major contributors to soil organic matter (OM), the chemical composition of plant tissues entering the soil should be related to the soil OM composition. We examined the OM composition of maize leaves, stems, and roots, to determine if differences in plant tissue composition altered the soil OM composition during a 36-week degradation experiment. Lignin phenols were measured by gas chromatography/mass spectrometry (GC/MS), and soil OM and humic substances were characterized using solid-state 13C and solution-state 1H nuclear magnetic resonance (NMR) spectroscopy respectively. Lignin phenol composition, oxidation, and depletion relative to cutin-derived OH-acids changed less in leaf- compared to stem- and root-amended soils over time, and may be due to greater vanillyl concentrations in leaves. Soil amended with stems had higher concentrations of carbohydrates in soil OM. Humic substances from leaf-amended soils had higher concentrations of aliphatic components, likely due to higher concentrations of aliphatic compounds in leaf tissues, which suggests that compounds derived from leaves are potential contributors to the stable pool of soil OM. After 36-weeks of incubation, the contribution of microbial-derived OM was greatest in humic extracts from root-amended soils, and increased contribution from these compounds was detected earlier in these soils than stem- and leaf-amended soils. This indicates that root amendment may enhance contributions from microbial-derived OM. Our study suggests that changes in soil OM composition over time was related to the chemical composition of the plant tissue, and demonstrates the important link between plant chemistry and soil OM turnover.

Reciprocal interactions between the bark beetle-associated yeast Ogataea pini and host plant phytochemistry

Here we report the first experiments testing reciprocal effects between the bark beetle-associated yeast, Ogataea pini, and phytochemicals present in tree tissues (Pinus ponderosa). We tested two hypotheses: (i) tree phytochemicals mediate O. pini growth and (ii) O. pini affects chemical composition of plant tissues. We tested six monoterpenes on O. pini biomass growth in vitro and found that most monoterpenes inhibited O. pini growth; however mean O. pini biomass increased 21.5% when treated with myrcene and 75.5% when treated with terpinolene, relative to control. Ogataea pini was grown on phloem tissue ex vivo to determine whether O. pini affected phloem chemistry. Monoterpene concentrations declined in phloem over time, but phloem colonized by O. pini had significantly different concentrations of monoterpenes at two periods than phloem with no yeast. After 7 d, when O. pini was present, concentrations of the monoterpene Δ-3-carene was 42.9% lower than uncolonized phloem and concentrations of the monoterpene terpinolene was 345.0% higher than uncolonized phloem. After 15 d phloem colonized by O. pini had 505.4% higher concentrations of α-pinene than uncolonized phloem. These experiments suggest that O. pini responds to phytochemicals present in host tissues and the presence of O. pini might alter the chemical environment of phloem tissues during the early stages of beetle development. The interactions between O. pini and phytochemicals in pine vascular tissues might have consequences for the bark beetle that vectors O. pini, Dendroctonus brevicomis.

Information flows between organic matter of the root environment and elemental chemical composition of plants under primary pedogenic conditions

The results of a comprehensive multiple growth-period experiment on intensive year-round cultivation of wheat and tomato plants on an originally abiogenic mineral substrate under controlled conditions are given. An interrelation is established between the ash content of plant roots and reproductive organs and the dynamics of the forming multicomponent organic matter of the root environment. It is shown that the effect of crop rotations leads to an intermittent change in the dynamics of the ash composition of plant tissues. A cause-and-effect relation between the composition of organic matter of the root environment and the elemental chemical composition of plant tissues is established by information theory methods.

O alto teor de silício no solo inibe o crescimento radicular de cafeeiros sem afetar as trocas gasosas foliares

O benefício do silício (Si) no crescimento de plantas cultivadas tem sido observado em vários trabalhos. O objetivo deste estudo foi avaliar os efeitos de Si no crescimento de mudas de cafeeiro cv. Catuaí Vermelho. O experimento foi conduzido em vasos, e as plantas crescidas em casa de vegetação, sem restrição hídrica. A partição de matéria seca entre raízes, caule e folhas, os teores de nutrientes e Si nos tecidos vegetais e no solo e as trocas gasosas foliares foram avaliados em plantas submetidas a doses de silicato de cálcio correspondentes a 0 (controle), 1,5 e 6 Mg ha-1. O delineamento experimental foi em blocos casualizados, com três tratamentos e 3, 4 ou 18 repetições, dependendo da variável considerada. Cada parcela experimental era composta por uma planta. Em relação à altura e matéria seca total, as plantas de todos os tratamentos apresentaram desenvolvimento satisfatório, com incrementos diários compatíveis com o esperado em cafeeiros bem nutridos. Os tratamentos com silicato de cálcio causaram aumento nos teores de Ca no solo e na planta e de Si no solo. Considerando que o único nutriente alterado pelos tratamentos foi o Ca e que os teores observados na planta podem ser considerados não prejudiciais, as respostas descritas a seguir são consequência do alto teor de Si no solo. Após 130 dias do início do experimento, as plantas tratadas com 6 Mg ha-1 de silicato de cálcio apresentaram menor acúmulo de matéria seca nas raízes e aumento da relação entre a matéria seca da parte aérea e a do sistema radicular. Embora as plantas tenham apresentado menor crescimento radicular na maior dose de silicato de cálcio, a assimilação de CO2 e a condutância estomática não foram alteradas. Cafeeiros arábica cv. Catuaí Vermelho submetidos a alta dose de silicato de cálcio apresentam redução do crescimento radicular, porém sem comprometimento da funcionalidade e do desenvolvimento da parte aérea das plantas cultivadas sob boa disponibilidade hídrica e nutricional.

Growth and survival of Tillandsia flexuosa on electrical cables in Panama

Almost 50% of the estimated 2500 species in the Bromeliaceae grow epiphytically in a remarkably wide range of habitats from inhospitable deserts to tropical rain forests (Benzing 2000). The degree of dependence on the host varies (Benzing 1990, Laube & Zotz 2006), and in some cases, epiphytic bromeliads may dispense completely with living hosts, and may thrive on artificial substrates such as electrical cables. This is not entirely surprising because this family provides examples of particularly remarkable adaptations to the epiphytic habitat like water-impounding leaf bases and water- and nutrient-absorbing scales (Benzing 2000). The so-called atmospheric forms in this family (e.g. Tillandsia recurvata) possess a dense covering of these scales, and use roots entirely as holdfasts, while leaves perform photosynthesis and take up water and nutrients. Although quite regularly mentioned in the literature (Benzing 1990, 2000; Brighigna et al. 1997, Lüttge 1989), we are not aware of any study investigating the vigour of plants growing on cables compared with plants growing on trees. The only functional aspects that have already been studied are related to nutrients, i.e. presence of nitrogen-fixing endophytes in Tillandsia recurvata plants from natural hosts and from electrical cables in Mexico (Puente & Bashan 1994) and differences in chemical composition of plant tissues and nutrient retention by leaves in Tillandsia capillaris growing on cables and trees in Argentina (Abril & Bucher 2009). Intermittent water supply, but also low nutrient supply, play an important role in epiphyte ecology (Zotz & Hietz 2001), which leads to the following alternative hypotheses: (1) Plants on electrical cables are usually close to roads.

Decomposition and element concentrations of silver birch leaf litter as affected by boron status of litter and soil

Inadequate boron (B) nutrition can affect the structural integrity and chemical composition of plant tissues. The changes in mass and element concentrations were studied using silver birch (Betula pendula Roth) leaf litter from seedlings grown with or without added B (Blitter+ or Blitter−). The litter was produced in a growth room, and it was incubated in either B fertilised or control forest plots (Bsoil+ or Bsoil−) between the moss and humus layers in two Norway spruce stands for 13 months. Additionally, the field decomposition experiment included long-term N and P application treatments (Nsoil and Psoil). Blitter+ somewhat reduced the remaining litter mass. In contrast, Bsoil+ increased it, possibly because of lower soil pH. The +Nsoil treatment reduced the remaining mass. Blitter+ increased the remaining P, S, Cu, Cd, Ni and Zn but reduced Pb. Remaining B was high in the Blitter– which also accumulated B from soil. Bsoil increased remaining Ca, Cd, Mg, Na, Pb, and slightly reduced N (in N fertilised plots). These changes in decomposition and element release have a potential to affect nutrient, carbon, and heavy-metal cycles in areas where B deficiencies are common, and where B fertilisation is practised.

A comparison of nutrient sources of the epiphyte Tillandsia capillaris attached to trees and cables in Cordoba, Argentina

Tillandsia capillaris Ruiz and Pav is an atmospheric epiphytic bromeliad able to grow attached to both trees and power lines in the arid–semiarid regions. We evaluated the influence of support type on nutrient sources of atmospheric bromeliads through of: a) quantity and chemical composition of material retained in the leaf surface (MRL) (dry weight, pH, nitrate, ammonium, phosphate and sulfate contents); b) chemical composition of plant tissues (nitrogen, phosphorous, carbon and chlorophyll contents); and c) nitrogenase activity and abundance of microbial functional groups involved in N cycling in leaf surface (phyllosphere). In the cable situation, MRL was lighter, more acidic, with a higher nitrate and sulfate content and lower phosphate content than in the tree situation. T. capillaris plant tissues on trees had lower N (89%) and higher C (6%) content than plants on cables. Phyllosphere micro-organisms' abundance and nitrogenase activity were similar in both situations. Our results indicate that T. capillaris has similar nutrient sources in both supports, and in consequence atmospheric bromeliads do not need plant host for their nutrition.

Heavy metal accumulation of Danube river aquatic plants — indication of chemical contamination

Abstract In this paper, the ecological status of a section of the Danube River flowing through Serbia from Bezdan to Djerdap was evalutated. Using the chemical composition of water, sediment samples from the littoral zone and dominant aquatic macrophytes, the level of chemical pollution was ascertained. Chemical analyses of the water and sediment indicated that the tributaries flowing into the Danube significantly influenced the chemical load of the water and as a direct consequence, the sediment. The concentration of heavy metals including Cu, Mn and Cd found in plants of the Potamogeton genus, further indicated significant chemical pollution, establishing a clear link between the chemical composition of plant tissues and the chemical composition of water and sediment. This paper therefore describes how the chemical composition of aquatic plants can be used as a reliable indicator for heavy metal pollution of aquatic ecosystems.

Uptake of nutrients and heavy metals by pine trees under atmospheric pollution

Pollution-induced changes in concentrations of elements in pine needles, branches, stem bark, and wood were investigated on 12 plots along the pollution gradient at distances of 5 to 77 km from the Pechenganikel copper-nickel smelter on the Kola Peninsula (northwestern Russia), the largest emitter of sulfur and heavy metals in northern Europe. Close to the pollution source, concentrations of S, Ni, Cu, Pb, and Cd in all the pine compartments were higher as compared to their background levels, while the Zn concentrations were lower. The concentrations of Ni and Cd—the main metals emitted—were the highest in all the pine compartments. Age-related variations in the needle composition were comparable to those at the background plots. Branches and, especially, stem bark, were richer in heavy metals than other tissues and, in addition to wood, contributed significantly to the accumulation of metals in the biomass of the polluted pine forests. Changes in the chemical composition of plant tissues could be explained by changes in element concentrations in the soils and by direct element uptake from the air, as well as by the antagonistic relationships between the elements.

Long-term experimental warming, shading and nutrient addition affect the concentration of phenolic compounds in arctic-alpine deciduous and evergreen dwarf shrubs

Environmental changes are likely to alter the chemical composition of plant tissues, including content and concentrations of secondary compounds, and thereby affect the food sources of herbivores. After 10 years of experimental increase of temperature, nutrient levels and light attenuation in a sub-arctic, alpine ecosystem, we investigated the effects on carbon based secondary compounds (CBSC) and nitrogen in one dominant deciduous dwarf shrub, Salix herbacea x polaris and two dominant evergreen dwarf shrubs, Cassiope tetragona and Vaccinium vitis-idaea throughout one growing season. The main aims were to compare the seasonal course and treatment effects on CBSC among the species, life forms and leaf cohorts and to examine whether the responses in different CBSC were consistent across compounds. The changes in leaf chemistry both during the season and in response to the treatments were higher in S. herbacea x polaris than in the corresponding current year's leaf cohort of the evergreen C. tetragona. The changes were also much higher than in the 1-year-old leaves of the two evergreens probably due to differences in dilution and turnover of CBSC in growing and mature leaves paired with different rates of allocation. Most low molecular weight phenolics in the current year's leaves decreased in all treatments. Condensed tannins and the tannin-to-N ratio, however, either increased or decreased, and the strength and even direction of the responses varied among the species and leaf cohorts, supporting views of influential factors additional to resource-based or developmental controls, as e.g. species specific or genetic controls of CBSC. The results indicate that there is no common response to environmental changes across species and substances. However, the pronounced treatment responses imply that the quality of the herbivore forage is likely to be strongly affected in a changing arctic environment, although both the direction and strength of the responses will be different among plant species, tissue types and substances.

Insect herbivory in an intact forest understory under experimental CO 2 enrichment

Human-induced increases in atmospheric CO(2) concentration have the potential to alter the chemical composition of plant tissue, and thereby affect the amount of tissue consumed by herbivorous arthropods. At the Duke Forest free-air concentration enrichment (FACE) facility in North Carolina (FACTS-1 research facility), we measured the amount of leaf tissue damaged by insects and other herbivorous arthropods during two growing seasons in a deciduous forest understory continuously exposed to ambient (360 microl l(-1)) and elevated (approximately 560 microl l(-1)) CO(2) conditions. In 1999, there was a significant interaction between CO(2) and species such that winged elm ( Ulmus alata) showed lower herbivory in elevated CO(2) plots, whereas red maple (Acer rubra) and sweetgum (Liquidambar styraciflua) did not. In 2000, our results did not achieve statistical significance but the magnitude of the result was consistent with the 1999 results. In 1999 and 2000, we found a decline (10-46%) in community-level herbivory in elevated CO(2) plots driven primarily by reductions in herbivory on elm. The major contribution to total leaf damage was from missing tissue (66% of the damaged tissue), with galls, skeletonized, and discolored tissue making smaller contributions. It is unclear whether the decline in leaf damage is a result of altered insect populations, altered feeding, or a combination. We were not able to quantify insect populations, and our measurements did not resolve an effect of elevated CO(2) on leaf chemical composition (total nitrogen, carbon, C/N, sugars, phenolics, starch). Despite predictions from a large number of single-species studies that herbivory may increase under elevated CO(2), we have found a decrease in herbivory in a naturally established forest understory exposed to a full suite of insect herbivores and their predators.

Implications of Rising Atmospheric Carbon Dioxide Concentration for Rangelands

Extensive rangelands and other vegetation types that we know today formed while atmospheric carbon dioxide (CO2) concentration was low (50 to 75% of today's concentration). Fossil fuel burning and deforestation and other land use changes during the last 200 years have increased CO2 concentration by about 30%, to the present 360 parts per million (ppm). Atmospheric CO2 will continue to rise during the next century, possibly to concentrations that are unprecedented for the last several million years. Much of the potential importance of CO2 concentration to vegetation derives from its influence on plant carbon balance and water relations. Plants grow by assimilating CO2 that diffuses into leaves through stomatal pores. Inevitably associated with CO2 uptake is transpirational loss of water vapor through stomata. Transpiration rates usually decline as CO2 increases, while, in many plants, photosynthesis and growth increase. Theseprimary responses to CO2 can lead to a multitude of changes at the plant and ecosystem levels, ranging from alteration of the chemical composition of plant tissues to changes in ecosystem function and the species composition of plant communities. The direct physiological responses of plants to CO2 and expression of these responses at higher scales differ among species and growing condition. Growth response to CO2 is usually highest in rapidly-growing plants that quickly export the carbohydrates formed in leaves and use them for storage or new growth and allocate a high proportion of fixed carbon to produce leaves. Growth is also more responsive to CO2 in plants with the C3 (most woody plants and 'cool-season' grasses) than C4 photosynthetic pathway (most 'warm-season' grasses). These and other differences among species could lead to changes in the composition of rangeland vegetation, but generalizations are difficult. On many rangelands, species abundances are determined more by morphological and phenological attributes that influence plant access to essential resources like nitrogen and light and reaction to fire, grazing, and other disturbances than by physiological traits that are sensitive to CO2 concentration. Species composition probably will be most responsive to CO2 on moderately water-limited and disturbed rangelands where multiple positive effects of CO2 on plant water relations can be expressed and competition for light is minimized. Greatest initial changes in species composition likely will occur on C3/C4 grasslands and at the transition between grasslands and woodlands. Plant production should also increase on water-limited rangelands, but CO2 may have little influence on production when nutrient elements like nitrogen are severely limiting.

EFFECT OF POTASSIUM CHLORIDE FERTILIZATION ON TWO BARLEY CULTIVARS DIFFERING IN COMMON ROOT ROT REACTION

The effects of potassium chloride (KCl) fertilization on common root rot severity (CRR, incited primarily by Cochliobulus sativus), chemical composition of plant tissue, and the grain yield of two barley cultivars (Hordeum vulgare L.) were studied at three locations in northern North Dakota in 1984. KCl was applied at 0, 46 and 188 kg KCl ha−1. Barley cultivars sown were Morex and Azure, with the former being the more susceptible to CRR at all sites. All sites tested ’’high’’ in available soil potassium (greater than 500 kg ha−1). Fertilization with KCl significantly reduced CRR severity of both cultivars at all sites. KCl fertilization dramatically decreased nitrate concentrations and increased chloride concentrations in the plant tissues of both cultivars. Morex accumulated more tissue nitrate than Azure at all levels of KCl fertilization. Thus, increased nitrate concentrations of the plant tissue were correlated with increased CRR severity on both cultivars. Grain yields were significantly increased by KCl fertilization at one site. Increased residual soil chloride was present after harvest at those plots receiving the high rate of KCl. The role of plant nitrate in CRR severity deserves more attention.Key words: Root rot (common), barley, fertilization (chloride), chloride-nitrate interaction, Cochliobulus sativus, Hordeum vulgare L.