The effect of strong microwave electric field radiation on: (2) wheat (Triticum aestivum L.) seed germination and sanitation

Abstract The seeds of the winter and spring wheat (Triticum aestivum L.) were subjected to a strong microwave electric field (SMEF) generated in a high power magnetron generator, working in a pulsed mode. Seed samples with different moisture contents (12, 15 and 18 %) were treated at the band 2.6, 5.7 and 9.3 GHz at 5, 10 and 20-minute exposures. Seed germination energy (GE), germination (G), abnormally germinated seeds (AG), germination index (GI) and seedling vigour index (SVI) were tested. The effect of SMEF on Tilletia caries infestation, plant productivity and seed sanitation was also explored. Seed treatment with SMEF did not sufficiently effect on winter wheat seed GE and G; however, the increase in AG and reduction in GI and SVI were observed. The negative effect on GI and SVI increased when seeds with higher humidity were treated. Treatment of winter wheat cv. 'Kovas' seeds, artificially inoculated with Tilletia caries, with SMEF showed a trend towards reduction of bunt infected ears. Seed treatment with SMEF stimulated grain yield increase and the bands 2.6 GHz for 20 min, 5.7 GHz for 10 min and 9.3 GHz for 5 and 10 min induced an increase in grain number and grain weight per ear. The efficacy of the chosen SMEF bands and exposition time on winter and spring wheat seed sanitation were contradictory. The SMEF treatment against wheat seed borne pathogens such as Phaeosphaeria nodorum (causal agent of Stagonospora glume blotch), Pyrenophora tritici-repentis (causal agent of tan spot) and Fusarium spp. (causal agents of seedling and adult plant foot and root rots and Fusarium head blight) gave conflicting and inconsistent efficacy results. The composition of most frequently isolated Fusarium species on SMEF treated winter wheat seeds was pertained to SMEF bands and exposition time

The infestation of winter rye and triticale grain with Fusarium fungi as affected by fungicide use

Experiments conducted at the Lithuanian Institute of Agriculture in 2004–2005 were designed to investigate the contamination of winter rye cv. ‘Duoniai’ and triticale cv. ‘Tornado’ grain with fungi of genus Fusarium and mycotoxins produced by them as affected by the spray-applications of the crops with the fungicides propiconazole, tebuconazole, and azoxystrobin at the beginning of anthesis (BBCH 63). Having analysed winter rye and triticale grain samples for Fusarium species composition ( Fusarium avenaceum (Fr.) Sacc, F. sporotrichioides Sherb., F. poae (Peck) Wollenw, F. culmorum (W. G. Sm.) Sacc., F. graminearum Schwabe, F. solani (Mart.) Sacc., F. incarnatum (Desm.) Sacc . F. sambucinum Fuckel) were identified in rye grain — ( F. culmorum (W. G. Sm.) Sacc., F. poae (Peck) Wollenw., F. heterosporum Nees) — in triticale grain. The grain samples from winter rye plots sprayed with azoxystrobin were the most heavily affected by Fusarium (42.5%) and the highest contents of DON (691 μg kg −1 ) and T-2 toxin (153.6 μg kg −1 ) were identified in them. Tebuconazole reduced the amount of Fusarium -affected grain in rye and triticale, but did not have any effect on mycotoxin production in rye. The grain of triticale not sprayed with fungicides was more heavily contaminated with DON (427 μg kg −1 )

Pseudomonas syringae patogeninės bakterijos Lietuvoje auginamuose javuose

Pseudomonas syringae pathovars cause bacterial diseases of cereals in nearly all temperate and subtropical cerealgrowing regions. As being of low importance compared to fungal diseases, P. syringae has not been studied in cereal crops in Lithuania. However, leaf blights and glume discolorations, uncharacteristic of fungal diseases, were found relatively frequently in the fields. Therefore, the study aimed to identify the occurrence of P. syringae in cereals grown in Lithuania. In this study, cereal crops were tested for the presence of plant pathogen P. syringae. In total, 452 symptomatic plant samples of winter wheat, winter triticale, spring wheat and spring barley were collected in 2013–2015. Symptoms of leaf blight and basal glume blotch on grain were more frequently detected in spring and winter wheat crops than in winter triticale and spring barley. Symptomatic leaves and grain yielded 113 P. syringae strains (51 from leaves and 62 from grain), but only 13 strains (10 from wheat, 2 from triticale and 1 from barley) were pathogenic to host plants when tested by spray method (SM). These strains were isolated from grain (10 strains) and leaves (3 strains) of all sampled plant species originating from different districts of the country. Based on 16S rRNA gene sequence analysis, leaf injection method (LIM) and origin of pathogenic strain, it can be assumed that P. syringae pv. atrofaciens is the dominat causal agent of bacterial diseases of cereals, particularly basal glume blotch of wheat

Evaluation of eyespot incidence and structure of Oculimacula spp. population in winter rye in Lithuania

Abstract Eyespot of rye, caused by two fungal pathogens Oculimacula yallundae and O. acuformis, is widespread throughout many cool and wet cereal growing regions. The study was aimed to estimate eyespot incidence in winter rye crops in three agro-ecological zones of Lithuania, and to quantify eyespot disease causal agents O. yallundae and O. acuformis in the population using the real-time polymerase chain reaction (RT PCR) method. During the 2008-2012 periods, 69 winter rye fields were surveyed and eyespot-affected stems were identified in 92.7% of the crops surveyed. The incidence of eyespot in winter rye crops varied from 8.0% to 82.7% depending on the year and location. The average disease incidence in the reviewed crops was 26.0%. The highest incidence of eyespot averaging 34.0% was identified in the winter rye crops of the Middle Lowland zone. Both eyespot causal agents O. yallundae and O. acuformis were often found to co-exist on the winter rye stems. In the majority of the winter rye crops tested, O. acuformis was predominant in the Oculimacula spp. population. In most cases, O. yallundae was identified only at trace-level concentrations

Pathogenicity of Asymptomatically Residing Fusarium Species in Non-Gramineous Plants and Weeds to Spring Wheat under Greenhouse Conditions

Despite significant efforts in recent decades to combat Fusarium head blight (FHB), this disease remains one of the most important and widely studied diseases of wheat and other cereal plants. To date, studies have focused on small grain cereals as hostplants for these pathogens, but it was recently discovered that asymptomatic non-gramineous plants and weeds can serve as alternative sources of fungi associated with FHB. The aim of this study was to evaluate the pathogenicity of Fusarium avenaceum, F. culmorum, F. graminearum and F. sporotrichioides isolated from non-gramineous plants and weed species to spring wheat under greenhouse conditions. A total of 91 Fusarium isolates, including 45 from weeds and 46 from non-gramineous plants were floret inoculated at mid anthesis. The FHB incidence and severity (%) of inoculated heads and the area under the disease progress curve (AUDPC) were calculated. To determine yield losses, the weight of 1000 grains (TGW) was evaluated. Results of the research showed that FHB severity (%) values in Fusarium spp.-inoculated heads from non-gramineous plants varied from 9.3% to 69.6% and AUDPC values ranged from 161.5% to 1044.6%. TGW was most significantly reduced by the F. culmorum isolates BN26r and BN39fl from Brassica napus and isolates BV15.1l and BV142.1pe from Beta vulgaris (37%, 30%, 28.8% and 31.8% respectively, compared to the water control). In Fusarium-inoculated heads from weeds, FHB severity values ranged from 6.2% to 81.0% and AUDPC values varied from 134.2% to 1206.6%. TGW was most significantly decreased by CBP1401r isolate from Capsella bursa-pastoris (52%). The study results suggest that the pathogenicity of Fusarium species isolated from different hosts to wheat more strongly depends on the Fusarium species and strain than the hostplant. Under greenhouse conditions, F. culmorum strain groups obtained from weeds, non-gramineous plants and Triticum were more pathogenic to wheat than the water control and other Fusarium species

In Vitro Sensitivity Test of <i>Fusarium</i> Species from Weeds and Non-Gramineous Plants to Triazole Fungicides

Fusarium species are common plant pathogens that cause serious crop losses worldwide. Fusarium spp. colonize not only the main host plants, crops, but also alternative hosts. The effectiveness of fungicide use in disease management ranges from very successful to possibly promoting the growth of the pathogen. Triazole fungicides are widely used to control these pathogens due to their broad-spectrum activity and systemic nature. This paper reviews the sensitivity of 40 Fusarium strains isolated from weeds, non-gramineous plants, and spring wheat to metconazole, prothioconazole, and tebuconazole. The effect of fungicides was determined by the percentage inhibition of F. graminearum, F. culmorum, F. sporotrichioides, and F. avenaceum fungal mycelial growth. The 50% effective concentration (EC50) values of all isolates on metconazole were lower than 2.9 mg L−1, prothioconazole EC50 ranged from 0.12 to 23.6 mg L−1, and tebuconazole ranged from 0.09 to 15.6 mg L−1. At 0.00025–0.025 mg L−1, the fungicides were ineffective, except for the growth of the F. avenaceum species. It was observed that isolates from weeds were more sensitive to low concentrations of fungicide than isolates from crop plants. In general, information is scarce regarding the comparison of fungicide resistance in Fusarium isolates from weed and crop plants, making this study an additional contribution to the existing knowledge base

The effects of moistening water on the quality of the sprouted cereal seeds for food

Seed germination is a simple, inexpensive and environmentally friendly method for producing plant-derived foods with functional properties for human's nutrition. One of the most important factors influencing quality of germinated seeds is water used for seeds soaking and moistening during the germination. Therefore, during the germination of wheat cv. 'Skagen', oat cv. 'Jaugila' and rye cv. 'Matador' for watering was used water with different chemical composition and properties. The research was carried out at Aleksandras Stulginskis University the Faculty of Agronomy in the Institute of Agricultural and Food Science in 2017 - 2018. The research aim was to determine the influence of water with different properties used in germination process on the quality of germinated seeds. Standard methods were used to determine the amount of dry matter, ash content, fats, proteins, fibres, carotenoids, chlorophyll a and b, colour parameters and microbiological contamination of the four days at 21 °C temperature germinated seeds. Seeds were moistened with drinking, filtered and nano-water. Statistical analyses were performed using two-way analysis of variance. It has been determined that, among the assessed germinated cereal seeds, the greatest amount of the dry matter (33.29%), proteins (9.67%) and chlorophyll a (0.28 mg 100g"') was found in germinated wheat seeds, the highest amount of fibre (16.77%), ashes (3.19%) and fats (2.66%) were recorded in germinated oat seeds, and the greatest amount carotenoids (0.15 mg lOOg"1) and chlorophyll b (0.39 mg lOOg"1) was revealed in germinated rye seeds. Filtered water has affected the germinated cereal seeds positively, the highest amount of carotenoids (0.15 mg lOOg'1), fats (2.66%), ash (3.19%), fibre (16.77%), proteins (9.67%), dry matter (33.29%) and chlorophyll a (0.28 mg lOOg1) was determined in seeds moistened with filtered water. [...]Vytauto Didžiojo universitetasŽemės ūkio akademij

Soil Fungistasis against <i>Fusarium Graminearum</i> under Different tillage Systems

The establishment of the harmful pathogen Fusarium graminearum in different agroecosystems may strongly depend on the ability of the soils to suppress its development and survival. This study aimed to evaluate the influence of different soil tillage systems (i.e., conventional tillage, reduced tillage and no-tillage) on soil fungistasis against F. graminearum. Soil samples were collected three times during the plant growing season in 2016 and 2017 from a long-term, 20-year soil tillage experiment. The F. graminearum in the soil samples was quantified by real-time qPCR. The soil fungistasis was evaluated by the reduction in the radial growth of F. graminearum in an in vitro assay. The antagonistic activity of the soil bacteria was tested using the dual culture method. The F. graminearum DNA contents in the soils were negatively correlated with soil fungistasis (r = –0.649 *). F. graminearum growth on the unfumigated soil was reduced by 70–87% compared to the chloroform fumigated soil. After the plant vegetation renewal, the soil fungistasis intensity was higher in the conventionally tilled fields than in the no-tillage. However, no significant differences were obtained among the tillage treatments at the mid-plant growth stage and after harvesting. 23 out of 104 bacteria isolated from the soil had a moderate effect, and only 1 had a strong inhibitory effect on the growth of F. graminearum. This bacterium was assigned 100% similarity to the Bacillus amyloliquefaciens Hy7 strain (gene bank no: JN382250) according to the sequence of the 16S ribosome subunit coding gene. The results of our study suggest that the presence of F. graminearum in soil is suppressed by soil fungistasis; however, the role of tillage is influenced by other factors, such as soil biological activity, type and quantity of plant residues and environmental conditions

The response to crop health and productivity of field pea (Pisum sativum L.) at different growing conditions

With increasing the area of legumes one of the most possible risks for productivity limitation is diseases. The research on the response to diseases and productivity of field peas was carried out during 2018–2020. The six cultivars and breeding lines were grown at two different infection levels: at natural field infection and under disease control using seed treatment and foliar fungicides. The main disease in field peas during the research year was Ascochyta blight at different intensites depending on year, cultivar/breeding line and disease control efficacy. Dominating pathogenic fungus D. pisi on harvested grains prevailed. Pea grain yield was significantly affected by cultivar/breeding line, experiments year and growing conditions. The highest yield difference between growing conditions (natural field infection and under disease control) was recorded in 2020 when Ascochyta blight and Grey mould gave the most severe attack. This finding illustrates the importance to eliminate one of the most important limiting factors for productivity – severe diseases. Future research on the forecast system of Ascochyta blight and other field pea diseases infection risk is needed. The response of cultivar/breeding line to weather conditions was established in this research as well. Tested breeding lines showed higher drought stress tolerance compared with commercial cultivars. More focus on environment stress-resistant cultivars is needed