Spring Barley Cv Research Articles

Effect of TopDressing on Chlorophyll Content in Barley Leaves and Its Relation to Grain Quality Parameters

The effect of top-dressing at tillage phase by Polydon® Amino Start organomineral fertilizer and KAS-28 liquid mineral fertilizer on the state of the leaf pigment complex of spring barley cv. Novichok, Rodnik Prikamya and Pamyati Rodinoy and its relationship with grain quality parameters was studied under field conditions of the Kirov region of the Russian Federation in 2020–2022. Significant effect of top-dress treatments on pigment content in the flag and second leaves was revealed. The use of top-dressing with KAS-28 enhanced the association of grain quality parameters with the chlorophyll pigment content of the two upper leaves compared to the control variant. The effect of Amino Start was not uniform: some of the connections were somewhat weakened compared to the control, some intensified, and some became statistically significant. The total content of chlorophyll correlated with the content of cellulose and fat in the grain in all treatments. Compared to controls, the use of top-dress treatments altered the effectiveness of using of photoassimilates of both leaves for cellulose and fat synthesis. The obtained data indicate the possibility of predicting the content of the main parameters of spring barley’s grain quality by the content of chlorophyll pigments in flag or second leaves of plants during the flowering phase.

Superabsorbent Seed Coating and Its Impact on Fungicide Efficacy in a Combined Treatment of Barley Seeds

The technology of seed coating with superabsorbent polymer (SAP) has the potential to mitigate the negative impact of drought on seed germination and crop establishment. However, their application on the seed surface can affect the effectiveness of pesticides used for seed treatment in the protection against phytopathogens. In our work, the influence of the Aquaholder®Seed polymer coating on the effectiveness of fungicides in the protection of germinating seeds of spring barley cv. Bojos and Laudis against the fungal pathogen Bipolaris sorokiniana was studied. One-half of the seeds were first treated with fungicides, and then a polymer was applied. Fungicide efficacy was evaluated in a Petri dish test and pot test under the pathogen attack. Seed coating with SAP did not negatively affect fungicide efficacy. The percentage of germinated seeds, seedling emergence, plant height, and symptoms of the disease in the fungicide-treated variants were not significantly changed by the SAP application. Moreover, in cv. Laudis, the application of SAP alone partially protected germinating seeds against pathogen attack. The amount of pathogen DNA in plant tissues of cv. Laudis was not significantly different among seed treatments, while in cv. Bojos, the pathogen DNA increased in seeds coated with SAP alone but decreased in combined treatment with fungicides. These results demonstrated that SAP seed coating does not negatively affect the efficacy of fungicides used for seed protection against fungal pathogens.

The effect of inoculation with Azospirillum brasilense strain 410 on spring barley cv. nosivsky development and yield

Aim. To study the efficiency of inoculating spring barley with Azospirillum brasilense 410. Methods. 1) A field ex- periment on turfpodzolic sandy soil with different mineral fertilization regimes; 2) A greenhouse experiment on sand as substrate, with isotope dilution analysis using 15N; 3) A lysimetric experiment in a stationary lysimetric installation. Furthermore, chromatography to determine nitrogenase activity of bacteria in the root zone of plants, agrochemical, and statistical methods. Results. Under field conditions, the inoculation with A. brasilense 410 promoted a significant increase (37–103 %) in the nitrogenase activity in the “soil-plant” system without any mineral fertilization and (espe- cially) where N60P60K60 was used. A high fertilizer level (N120P120K120) lead to a long-term inhibition of the nitrogenase activity. In both cases (plants with and without inoculation with A. brasilense 410) this fertilization level showed an increase in the nitrogenase activity only at the end of the vegetation period. The highest increase in yield (0.7 t/ha, 27 %) in yield following A. brasilense strain 410 inoculation, occurred in plots with N60P60K60 fertilization; the least increase in yield (0.33 t/ha, 16.5 %) was observed in plots receiving no fertilizers. The pre-sowing inoculation led to an increase in the protein content of 0.3–1.0 % in the barley grain, especially when receiving high fertilization levels, enhancing its value for the use in cereals and feeds, but decreasing its value for its use in brewing. The green- house experiment with 15N established an increase 77.1 % in the nitrogen intake into the plants due to the activation of the nitrogen-fixation process and enhanced 29.5 % nitrogen consumption from fertilizers. The lysimetric studies demonstrated that inoculation of spring barley cv Nosivsky with A. brasilense 410 limited the vertical migration and leaching of nitrogen by 27–30 %, potassium by 13–30, calcium by 32–51 %, manganese by 33–100 %, and water-sol- uble organic matter by 46–75 %. Conclusions. The pre-sowing inoculation of spring barley cv. Nosivsky seeds with A. brasilense 410 intensifies nitrogen consumption by plants within 29.5 % due to active nitrogen-fixation and a better utilization of N from mineral fertilizers. The barley yield increase with 0.7 t/ha was in our limited experiment, using one cultivar roughly equivalent to the increase after mineral fertilization with N60P60K60. Thus, pre-sowing inoculation with A. brasilense 410 may lead to substantial reduction of the use of mineral fertilisers in practice.

Влияние депонированной формы комплексного пестицидного препарата на структуру урожая зерновых культур и заболеваемость корневыми гнилями

The use of chemical plant protection products is essential to obtain a quality crop, but entails the risks of spreading pesticides in the biosphere and causing damage to beneficial biota. Therefore, the development of new approaches to the delivery of pesticides, which reduce the negative impact on agroecosystems, is an important direction for sustainable agriculture development. The effect of a complex preparation containing the fungicide tebuconazole and the herbicide tribunuron-methyl, embedded in a biodegradable polymer base of poly(3-hydroxybutyrate) and birch sawdust, on the several indicators was studied: the number of rhizospheric micromycetes of spring wheat cv. Novosibirskaya 15 and spring barley cv. Biom, the effectiveness of root pathogens control, and the structure and quality of the crop. In field experiments, a prolonged fungicidal action of the complex embedded preparation was demonstrated, which was superior in duration and efficiency to the traditional pre-sowing seed dressing. During the growing season, there was a significant (p <0.05) decrease in the number of micromycetes in the rhizosphere of wheat and barley by 1.5-2 times in comparison with the control, as well as a decrease in the prevalence of root phytopathogenic fungi (Alternaria, Bipolaris, and Fusarium). A high level of biological efficiency of the embedded fungicide was demonstrated in different phases of plant development - from 73.4 to 100% on wheat and from 68 to 100% on barley. As a result, the use of a complex embedded preparation increased the yield of spring wheat and barley, respectively, by 10.8 and 4.4 c/ha compared to the control and contributed to the improvement of the grain quality of crops. Keywords: PESTICIDES, EMBEDDING, TEBUCONAZOL, TRIBUNURON-METHYL, POLY(3-HYDROXYBUTYRATE), ROOT ROTS, YIELD, WHEAT, BARLEY

Effect of biofertilizers and osmotic stress on morphological parameters of spring barley seedlings

One of ways to increase resistance of agricultural plants to abiotic stresses is the use of biofertilizers with anti-stress and growth-regulating properties. They improve absorption of nitrogen and phosphorus from organic fertilizers and soil. The purpose of the research was to study sowing qualities of seeds, morphological indicators of spring barley seedlings after presowing seed treatment with biofertilizers under conditions of sufficient humidification and osmotic stress. The laboratory experiment was carried out to study the effect of biofertilizers on seedlings of spring barley ( Hordeum vulgare L.) cv. Gubernatorsky under conditions of sufficient and insufficient humidification. The barley seeds were treated once according to the following scheme: 1. control (distilled water) 10 L/t; 2. Gumi 20 M potash (0.4 L/t); 3. Borogum-M complex (0.2 L/t); 4. PEG 6000 (100 g/L); 5. Gumi 20 M (0.4 L/t) + PEG 6000 (100 g/L); 6. Borogum-M complex (0.2 L/t) + PEG 6000 (100 g/L). Treatment of spring barley seeds with biofertilizers increased the germination rate and germination capacity by 35 and 2 %, respectively. When modeling drought using PEG-6000, the sowing qualities of seeds decreased by 4 %. Under conditions of sufficient humidification, the studied biofertilizers had a complex positive effect on shoot and root weight of barley seedlings. In addition, the average length of roots, shoots and the total root length increased. The number of roots did not change significantly. Lack of moisture decreased the effectiveness of Borogum-M complex biofertilizer, while Gumi 20 M potassium biofertilizer had a positive effect on the parameters of barley seedlings under water stress conditions.

Impact of Soil Fertilized with Biomass Ash on Depth-Related Variability of Culturable Bacterial Diversity and Selected Physicochemical Parameters in Spring Barley Cultivation.

This study investigated the effect of different doses of fertilization with biomass combustion ash (Salix viminalis L. willow) on changes in the biological, chemical, and physical properties of soil. The experiment was carried out on podzolic and chernozem soils in a one-way field experiment (fertilization dose: control (without fertilization), NPK (nitrogen (N), phosphorus (P) and potassium (K)), 100, 200, 300, 400, 500 kg K2O ha-1). The biomass ash was characterized by a pH value of 12.83 ± 0.68 and a high content of macronutrients. The samples were collected from 0-5, 10-15, and 20-25 cm soil layers under the cultivation of spring barley (Hordeum vulgare L) cv. Planet in April and August 2021. Mass spectrometry (MALDI-TOF MS) was used for microbiological analyses, which revealed the presence of 53 culturable species from 11 genera: Bacillus, Pseudomonas, Paenibacillus, Lysinibacillus, Pseudarthrobacter, Arthrobacter, Staphylococcus, Paenarthrobacter, Micrococcus, Rhodococcus, and Flavobacterium. The podzolic and chernozem soils exhibited the presence of 28 and 44 culturable species, respectively. The study showed an increase in the number of microorganisms in the top layer of the soil profile. However, the number of bacteria decreased at the depths of 10-15 cm and 20-25 cm. With depth, the bulk density (BD) and moisture increased.

The interplay between nitrogenated allelochemicals, mineral nutrition and metabolic profile in barley roots

AimsThe alkaloid hordenine is one of the major allelochemicals involved in the allelopathic ability of barley (Hordeum vulgare L.), whose biosynthesis and accumulation is preferentially located in roots. Hordenine appears to have been unintentionally favored during domestication in modern and cultivated barley cultivars at the expense of another alkaloid, gramine. In this study, we assessed the content of hordenine and its two precursors, N-methyltyramine (NMT) and tyramine, in roots and root exudates of the modern spring barley cv. Solist, and particularly how they are affected due to nutrient deficiencies.MethodsWe monitored the three metabolites during the early phases of barley growth i.e., up to 8 days, applying HPLC time-course and both target and untargeted metabolomic approaches. Barley plants were grown either in full nutrient solutions or in specific nutrient shortage conditions (N, S, P and Fe).ResultsResults confirmed a strong decrease of the allelochemical accumulation (hordenine and the two precursors) in roots and in root exudates during both 24 h and 8 days time-course experiments. Yet, the overall tyramine content was approximately tenfold lower compared to the other two compounds. In addition, plants subjected to nitrogen (-N), sulfur (-S), phosphorus (-P) and iron (-Fe) deprivation showed nutrient-dependent accumulation of hordenine, N-methyltyramine and tyramine, as well as of other secondary metabolites. Indeed, the synthesis of hordenine and N-methyltyramine was trigged under nutrient deficiencies.ConclusionsIn conclusion, this study highlighted the impact of nutrient availability on the growth-dependent accumulation patterns of all the three compounds investigated in modern barley roots.

The use of the data derived from the PlanetScope satellite and unmanned aerial vehicles to estimate crop yield as dependent on the amount of nitrogen fertilizer applied

The purpose of the present study is to show the usefulness of the satellite data and the data derived from unmanned aerial vehicles (UAVs) for estimating the relationship between cereal grain crop yield and the amount of nitrogen fertilizer applied. The study was conducted on the land of the Kuraginskoye Research Farm. The study material was spring barley cv. Biom. Three test plots were studied; mineral fertilizer, urea, was used in different quantities for foliar application in June; applications were performed at equal intervals. Multispectral images were based on PlanetScope satellite data, with the 3 m spatial resolution, and the data derived from the DJI Phantom 4 Multispectral UAV, with the 10 cm resolution. The satellite and UAV data were used to calculate spectral vegetation index (NDVI) (Normalized Difference Vegetation Index). A high correlation was obtained between the NDVI values calculated using satellite data and UAV data. The satellite data provided the basis for assessing barley crop yield as dependent on the amount of foliar-applied urea during the growing season. Maps of the spatial distribution of barley NDVI were constructed using the Phantom UAV data; they showed that the third foliar application of the fertilizer was not economically justified.

Transient Carbon Reserves in Barley: Malate, Sucrose and Starch Are the Main Players, Their Quantitative Involvement Being Light Intensity Dependant.

Under natural environment plants experience different light intensities which can affect photosynthesis and consequently the availability of carbohydrates for daytime growth and their transient storage to supply night growth. We grew a spring barley cultivar, Propino, under three different light intensities under warm days and nights, and evaluated the spatial and diurnal adjustments occurring in the transient carbon stores. Leaves under high light at the end of the day accumulated mainly sucrose (30%) and malate (35%), with lower content of hexoses (5%), starch (15%) and fructans (15%). Under low light, plants presented reduced photosynthesis, with lower metabolite contents at end of day. The malate represented 51% of the total carbon accumulated at end of the day, at the expense of sucrose (12%), other metabolite contributions remaining similar to high light. The percentage of metabolites consumed at night was similar for all light intensities with around 75% of the sucrose and starch being mobilized whilst malate and fructans were only partially mobilized with 56 and 44%, respectively. Altogether, sucrose and malate were the main contributors of the total carbon used at night by barley plants, sucrose being predominant under high light (35% vs. 27%), but malate being the major metabolite used under low light with 40% of the total carbon consumed. Interestingly, light intensity also influenced the location of the C transient stores, the plants under low light prioritizing the accumulation of the metabolites, mostly malate, in the youngest tissues. Therefore, light influences quantitatively, but also qualitatively and spatially the carbon stores in the spring barley cv. Propino, suggesting a tight regulation of the primary metabolism.

Application of widely used fungicides does not necessarily affect grain yield, and incidence of Fusarium spp. and mycotoxins DON, HT-2 and T-2 in spring barley in northern climates

Fungicides are widely used to reduce Fusarium infections and grain contamination by mycotoxins and increase the yield in cereals, but the efficacy of fungicide treatments in varying climates has not been systematically explored. Field experiments with Estonian spring barley (Hordeum vulgare L.) cv. ‘Maali’ were carried out in three successive years 2012–2014 with strongly varying weather conditions to study the effects of three fungicides, Folicur (active ingredient tebuconazole), Falcon Forte (prothioconazole, tebuconazole, spiroxamine) and Archer Top (fenpropidin, propiconazole), on the yield, incidence of Fusarium spp. and on the contamination of grain with mycotoxins DON, HT-2 and T-2. The fungicides were sprayed once a year at spring barley flowering time. The weather conditions during the three years of study were extremely different. The content of cycotoxin DON, HT2 and T2 was low. The spraying with fungicides had not a clear effect on the barley yield and 1 000 kernel weight, and the study year was primarily the main factor that affected barley yield (p<0.05) and 1 000 kernel weight (p<0.05). The impact of year together with fungicide treatment had a significant effect on the incidence of Fusarium spp. (p<0.05) and on the incidence of mycotoxin DON in barley kernels (p<0.001), but did not have a clear effect on the incidence of mycotoxins HT2 and T2.

Salt acclimation induced salt tolerance in wild-type and abscisic acid-deficient mutant barley

Salt acclimation is a process to enhance salt tolerance in plants. The salt acclimation induced salt tolerance was investigated in a spring barley (Hordeum vulgare L.) cv. Steptoe (wild type, WT) and its abscisic acid (ABA)-deficient mutant Az34. Endogenesis ABA concentration in leaf was significantly increased by salt stress in WT, while it was not affected in Az34. Under salt stress, the salt acclimated Az34 plants had 14.8% lower total soluble sugar concentration and 93.7% higher sodium (Na) concentration in leaf, compared with salt acclimated WT plants. The acclimated plants had significantly higher leaf water potential and osmotic potential than non-acclimated plants in both WT and Az34 under salt stress. The salt acclimation enhanced the net photosynthetic rate (by 22.9% and 12.3%) and the maximum quantum yield of PS II (22.7% and 22.0%) in WT and Az34 under salt stress. However, the stomatal conductance in salt acclimated Az34 plants was 28.9% lower than WT under salt stress. Besides, the guard cell pair width was significantly higher in salt acclimated Az34 plants than that in WT plants. The results indicated that the salt acclimated WT plants showed a higher salt tolerance than Az34 plants, suggesting that ABA deficiency has a negative effect on the salt acclimation induced salt tolerance in barley.

Two mutations in the truncated Rep gene RBR domain delayed the Wheat dwarf virus infection in transgenic barley plants

Wheat dwarf virus (WDV), an important cereal pathogen, is closely related to Maize streak virus (MSV), a model virus of the Mastrevirus genus. Based on its similarity to known MSV resistance strategies, a truncated part of the WDV replication-associated (RepA) gene (WDVRepA215) and the WDV RepA gene with a mutated retinoblastoma-related protein (RBR) interaction domain (WDVRepA215RBRmut) were cloned into the pIPKb002 expression vector and transformed into immature embryos of spring barley cv. Golden Promise plants through Agrobacterium-mediated transformation. A detailed study of T1-generation plants infected by leafhoppers (Psammotettix alienus) fed on infection sources of variable strength was performed over a 5-week period encompassing the initial stages of virus infection. A DNA WDV TaqMan qPCR assay normalized using the DNA puroindoline-b SYBR Green qPCR assay for samples on a per week basis revealed an approximately 2-week delay in WDVRepA215RBRmut plants to WDVRepA215 plants before significant increases in the WDV viral levels occurred. Both WDVRepA215 and WDVRepA215RBRmut plants showed similar levels of transgenic transcripts over the screened period; however, the transgenic plants also showed increased numbers of infected plants compared to the control plants.

First Report of Ramularia Leaf Spot Caused by Ramularia collo-cygni on Leaves and Seeds of Barley in Estonia.

Ramularia leaf spot (RLS) is a disease of barley (Hordeum vulgare) caused by the fungus Ramularia collo-cygni Sutton & Waller (Rcc). Rcc causes necrotic lesions, premature senescence of leaves, and yield reduction. Under Estonian conditions, there are usually no leaf spots on the upper leaves of barley prior to flowering. In 2009, 2010, and 2012, symptoms similar to those of RLS were observed on leaves of spring and winter barley in several Estonian agricultural regions. Approximately 30% of the plants in affected fields were symptomatic. Symptoms were not observed in 2011, which was a dry and hot year. Initial symptoms were small brown spots, beginning on the upper leaves (flag leaf, F-1 leaf) at the flowering growth stage (4). Later, the spots spread to the sheaths, stems, and awns and became necrotic. The lateral margins of the spots were delimited by the leaf veins and spots are surrounded by a chlorotic halo. During summer 2012, two samples of 15 F-1 leaves were collected from spring barley cv. Maali and line SJ111609 from the Estonian Crop Research Institute in eastern Estonia in late July at growth stage 71 (4). In addition, six grain samples, containing 200 seeds each of the cv. Maali, were collected from different agricultural regions in Estonia, along with one grain sample of SJ111609 from Jõgeva. All samples were collected from untreated plots and leaves were observed under a dissecting microscope, revealing white clusters of conidiophores in rows on the undersides of the leaves. Conidia and conidiophores were scraped aseptically from the leaf surface using a sterile needle under a dissecting microscope and transferred to potato dextrose agar (PDA) containing ampicillin sodium salt (50 mg l-1). Plates were incubated at 18°C in the dark for 20 days until fungal mycelia were produced. The fungus was initially identified as Rcc on the basis of morphological characteristics (3). Colorless, 0- to 3-septate conidiophores were 15 to 17 × 2 to 5 μm, with a strongly curved end. Conidia were 7 to 11 × 3 to 6 μm, solitary, subglobose, single-celled, and of a darkish color. To confirm the presence of Rcc, DNA was extracted from the original barley leaf material, milled seeds, and positive control mycelia of Rcc grown on PDA using DNeasy Plant Mini Kit (Qiagen Gmbh, D-40724 Hilden, Germany) following manufacturer's guides. Rcc specific primers RC3 and RC5 (1) were used. A positive control consisting of 1 ng of purified Rcc DNA was included in the PCR. Standard PCR was conducted in a SEE AMP Seegene cycler. PCR were carried out in 20 μl volumes, containing 2 μl of DNA, 10 μl PCR mix, 0.4 μl each of forward and reverse Rcc primers, and 7.2 μl H2O. Qualitative detection analyzed by standard PCR with primers RC3 and RC5 revealed the presence of Rcc in symptomatic leaves and seeds. To complete Koch's postulates, a pathogenicity test was performed. Twenty-five barley seedlings were grown under controlled conditions (15°C/48 h dark, 16 h light/8 h dark, 70% RH) and spray-inoculated with a suspension of Rcc mycelium fragments as described by Macepeace et al. (2). The pathogen was re-isolated from leaves with necrotic lesions similar to those observed in the field, thus fulfilling Koch's postulates. To our knowledge, this is the first confirmed report of Ramularia leaf spot caused by Ramularia collo-cygni on barley in Estonia.

Electrophoretic and chromatographic evaluation of transgenic barley expressing a bacterial dihydrodipicolinate synthase

Nutritional quality of human and animal foodstuffs is determined by the content of essential amino acids. Barley is the fourth most important cereal of the world and the second most important cereal grown in the Czech Republic. Cereal grains such as barley contain insufficient levels of some essential amino acids, especially lysine. Dihydrodipicolinate synthase is the key enzyme involved in the regulatory step for lysine biosynthesis. Two constructs pBract214::sTPdapA and pBract214::mdapA containing the dapA gene from Escherichia coli coding for the bacterial dihydrodipicolinate synthase were used for transformation of barley. An Agrobacterium-mediated technique was used for transformation of immature embryos of spring barley cv. Golden Promise. Transgenic barley plants of the T0 and T1 generations were evaluated by PCR, real-time PCR, gel electrophoresis, and Western blot. Amino acid content was analyzed by HPLC after HCl hydrolysis. The lysine content in leaves of the T1 generation plant no. 5/5 was 50% higher than in wild-type plants; the lysine content in seeds of T2 generation plant no. 5/16 was 30% higher than in wild-type seeds of spring barley cv. Golden Promise.

Weed infestation in canopy of spring barley in condition of different tillage systems and fertilization and plant protection levels

The purpose of this work was to determine the influence of conventional tillage (fall ploughing at 25 cm) and minimum tillage systems (chisel ploughing at 30 cm) and two differentiated fertilization and plant protection levels on number, species composition and air dry weed mass in spring barley cv. Rataj. This spring barley was cultivated in crop rotation potato - spring barley - winter rye. The analysis of field infestation was made prior to spring barley harvest with quantitative- weighting method. There was estimated number of weeds, weed species composition and air dry weight of weeds in two randomly chosen areas of each plot of 0.5 m<sup>2</sup>. The density of weeds and weed air dry weight was statistically analysed by means of variance analysis, and the mean values were estimated with Tukey's confidence intervals (p=0.05). Intensive level of fertilization and chemical crop protection decreased number of monocotyledonous weeds and total weeds in canopy of spring barley. Conventional system of soil cultivation decreased in a canopy of spring barley the following species of weeds: <i>Geranium pusillum</i>, <i>Galinsoga parviflora</i>, <i>Stellaria media</i>, <i>Apera spica</i>-<i>venti</i>, <i>Poa annua</i> and <i>Echinochloa crusgalli</i>. Conventional tillage increases number of <i>Chamomilla suaveolens</i> and <i>Fallopia convolvulus</i> in a canopy of spring barley. Intensive fertilization and plant protection levels decreased weed infestation first of all through <i>Echinochloa crusgalli</i>, <i>Apera spica</i>-<i>venti</i>, <i>Fallopia convolvulus</i>, <i>Galinsoga parviflora</i>, <i>Geranium pusillum</i>, <i>Chenopodium album</i> and <i>Setaria pumila</i>.

Health status of five spring barley cultivars cultivated under organic system

The objective of the study was to compare health status of harvested grain of spring barley cv. Rudzik, Rodos, Start and Maresi cultivated in organic system and cv. Damazy grown in an organic farm. Analyses showed that prevalent pathogen on grain was <i>Bipolaris sorokiniana</i> isolated from 48% of grains. Fungi from genus of <i>Fusarium</i> were obtained less numerously, from 27% of grains and were represented mainly by <i>F. poae</i> and <i>F. avenaceum</i>. Microscopic analysis of <i>F. poae</i> was confirmed by PCR analysis. All cultivars were intensively diseased by <i>B. sorokiniana</i>, thus it is impossible to show a cultivar especially recommended for this system, where <i>B. sorokiniana</i> can be serious problem. However cv. Damazy showed relatively the lowest infestation by <i>B. sorokiniana</i> and it also was not more intensively diseased by <i>Fusarium</i> spp. It is very important in nutrition aspect because these fungi can be dangerous for both human and animal health due to their abilities to produce mycotoxins.

Dehydrogenases, urease and phosphatases activities of soil contaminated with fungicides

A greenhouse experiment was performed to determine the effects of the fungicides containing cyprodinil as well as dimoxystrobin and epoxiconazole on the activity of soil enzymes: dehydrogenases, urease, acid phosphatase and alkaline phosphatase, depending on fungicide dose (0 − control, 1 − recommended dose, 10-fold dose and 100-fold dose), the method of soil management (soil cropped with spring barley cv. Start, and uncropped soil) and the time of fungicide action (14, 28, 42 and 56 days). The experiment was established on Eutric Cambisols with pH<sub>KCl</sub> = 6.7. It was found that the enzymatic activity of the soil was affected primarily by such factors as fungicide dose, method of soil management and time of fungicide action, and to a much lesser degree by the type of fungicide. Fungicide contamination of the soil significantly inhibited the activity of dehydrogenases and urease, and produced a significant negative effect (100-fold dose) on spring barley yield. A higher activity of dehydrogenases, urease, acid phosphatase and alkaline phosphatase was recorded in the soil cropped with spring barley cv. Start.

Light-Dependent Oxidative Stress Determines Physiological Leaf Spot Formation in Barley

ABSTRACT We reported previously that physiological leaf spot (PLS) formation in winter and spring barley is dependent on genotype-related oxidative stress under field conditions. In the present study, we searched for factors inducing PLS symptoms in the greenhouse similar to those observed in the field and investigated its relationship to reactive oxygen species (ROS) metabolism. We found that in the greenhouse, oxidative stress induced spring barley cv. Extract, which is sensitive to PLS, to express symptoms similar to those observed in the field. Leaves severely affected by PLS showed significantly lower activities of key enzymes in the Halliwell-Asada cycle such as ascorbate peroxidase, glutathione reductase, dehy-droascorbate reductase, and monodehydroascorbate reductase. The sensitive cultivar also showed lower levels of total superoxide dismutase (SOD) and Cu/Zn-SOD activity but a higher level of chloroplast-specific Fe-SOD activity than that of the insensitive cultivar. Thus, an unbalanced ROS metabolism in chloroplasts may trigger PLS incidence in sensitive cultivars, which is in agreement with the fact that light is essential for the induction of PLS expression under both field and greenhouse conditions. Accordingly, under greenhouse conditions, continuous light stress (7 days), but not light shock treatments, induced PLS similar to that of field conditions in sensitive cv. Extract, but not in resistant cv. Scarlett. Light with a high proportion of energy in the blue wavelength spectrum (350 to 560 nm) was significantly more PLS inductive than light with a pronounced red (photosynthetically active radiation) spectrum (580 to 650 nm). Exposure to ozone did not produce PLS-like symptoms. Furthermore, similar to earlier observations in the field, PLS symptom expression was closely correlated with the accumulation of superoxide (O(2) (-)) detected by both biochemical and histochemical assays. Taken together, these data suggest that PLS in barley is genotype-dependent but its expression appears to be induced by certain environmental stress factors, among which photosyn-thetically active radiation plays a major role.

Evidence for Oxidative Stress Involved in Physiological Leaf Spot Formation in Winter and Spring Barley

ABSTRACT A leaf spot disease with unknown etiology has become more pronounced in spring and winter barley in Germany in recent years. The symptoms are similar to net blotch and Ramularia leaf spots, but the causal agents of these diseases are not identified. The symptom expression varied much on cultivars. Cultivars most affected by the disease of both spring and winter barley showed a significantly higher level of superoxide (O(2) ) production and lipid peroxidation (malondialdehyde), but a lower level of antioxidant potential expressed as superoxide dismutase (SOD) activity, catalase activity, and integral water-soluble antioxidant capacity (ACW) than insensitive cultivars. A high positive correlation between O(2) production and leaf spot development between ear emergence and milk ripeness was established in the most sensitive winter barley cv. Anoa (r(2) = 0.9622) and spring barley cv. Barke (r(2) = 0.9434). Leaf H(2)O(2) levels increased with the severity of leaf spots. The histochemical localization of O(2) and H(2)O(2) in the tissues adjacent to leaf spots indicated that these two active oxygen species (AOS) are involved in the formation of leaf spots. Reduction of symptom severity by applying strobilurin and azole fungicides was always associated with elevated SOD activity and ACW content and suppressed O(2) production. However, peroxidase activities were significantly higher in sensitive cultivars and in more severely affected tissues and decreased by applying fungicides. Thus, it is assumed that a possible genetic mechanism based on the imbalanced AOS metabolism contributes to formation of physiological leaf spots.

Annual forage production from spring-planted winter cereal monocrops and mixtures with spring barley

Spring-planted winter cereals grown as monocrops or in mixture with spring cereals maintain yield and quality into late summer and fall, and can be used to replace or complement perennial pasture. Our objectives were to determine the response to clipping of spring-planted winter cereals, and to determine the effects of seeding rates and ratios of spring to winter cereals on this response. Monocrops of winter triticale (X Triticosecale Wittmack) cv. Pika and winter rye (Secale cereale L.) cv. Musketeer and mixtures of these cereals with the spring barley (Hordeum vulgare L.) cv. Noble were evaluated. Tests were conducted from 1991 to 1993 at Botha and Lacombe, AB. Mixtures of spring:winter cereals were 0:100, 25:25, 25:75, 50:50, 75:25, 75:75 and 100:100 (Lacombe only), where the ratio of components represented the percentage of the base seeding rate of 250 seeds m−2. Biomass yields for triticale treatments (5.5 t ha−1 at Botha and 6.3 t ha−1 at Lacombe for the May to October growing season) were generally as high as for the rye treatments (5.9 t ha−1 at Botha and Lacombe); however, at Lacombe, spring regrowth after overwintering for triticale treatments was only 0.6 t ha−1 compared with 1.0 t ha−1 for rye treatments (LSD0.05 = 0.17). As little as 25% spring barley in a mixture ensured good early-season biomass yields, but more than 50% reduced late-season biomass yields. All treatments produced good-quality forage with protein >20%, neutral detergent fibre (NDF) <45% and acid detergent fibre (ADF) <30%. Nitrate contents were frequently >0.5% at both sites in 1991 and 1992, especially for those treatments with spring barley. Key words: Winter triticale, winter rye, annual forage, biomass, forage quality