An eco-friendly way to protect wheat seeds from phytopathogens

Protecting wheat seed from phytopathogens is a popular topic for plant breeders. The objects requiring close attention and control on wheat are smut infections, pathogens of root rot. And if the pathogens of smut we have learned to fight quite effectively with, then microorganisms that infect underground parts of plants are controlled with less success and many questions in the system of protection against them remain controversial. The issue of reducing the pesticide load on agrocenoses, starting with the protection of seeds, also remains relevant. The article presents the results of field trials of means of protecting spring wheat seeds from root rot in 2019–2020, carried out within the framework of the state assignment at the Kurgan SRIA — branch of FSBSI UrFASRC, according to generally accepted methods. The aim of the research was to assess the biological, economic efficiency of the combined use of a chemical seed dressing agent and a biofungicide based on Bacillus subtilis in protecting wheat from soil-seed infections, to determine the competitiveness of an ecologized method of protecting seeds (reduced consumption rate of a chemical seed dressing agent in combination with biological fungicide). The obtained research results indicate that with a high level of damage to wheat by root rot (Fusarium, B. sorokiniana), the use of seed treatment with the studied preparations ensured the preservation of 10–12% of the yield, more efficiency was noted in the variants with the Oplot 0.5 l/t and the Oplot 0.3 l/t + Nodix Premium 0.3 l/t . The technical effectiveness of fungicides against wheat root rot ranged 44% for Nodix Premium to 85–86% for chemical protection and mixed use. An environmentally friendly method of protecting wheat seeds, which consists in using a 40% lower rate of a chemical dressing agent with a biopesticide, turned out to be competitive.

Prevalence and management of aphids (Hemiptera: Aphididae) in different wheat genotypes and their impact on yield and related traits

Wheat (Triticum aestivum L.) production is significantly altered by the infestation of sucking insects, particularly aphids. Chemical sprays are not recommended for the management of aphids as wheat grains are consumed soon after crop harvests. Therefore, determining the susceptibility of different wheat genotypes and selecting the most tolerant genotype could significantly lower aphid infestation. This study evaluated the susceptibility of six different wheat genotypes (‘Sehar-2006’, ‘Shafaq-2006’, ‘Faisalabad-2008’, ‘Lasani-2008’, ‘Millat-2011’ and ‘Punjab-2011’) to three aphid species (Rhopalosiphum padi Linnaeus, Schizaphis graminum Rondani, Sitobion avenae Fabricius) at various growth stages. Seed dressing with insecticides and plant extracts were also evaluated for their efficacy to reduce the incidence of these aphid species. Afterwards, an economic analysis was performed to compute cost-benefit ratio and assess the economic feasibility for the use of insecticides and plant extracts. Aphids’ infestation was recorded from the seedling stage and their population gradually increased as growth progressed towards tillering, stem elongation, heading, dough and ripening stages. The most susceptible growth stage was heading with 21.89 aphids/tiller followed by stem elongation (14.89 aphids/tiller) and dough stage (13.56 aphids/tiller). The genotype ‘Punjab-2011’ recorded the lower aphid infestation than ‘Faisalabad-2008’, ‘Sehar-2006’, ‘Lasani-2008’ and ‘Shafaq-2006’. Rhopalosiphum padi appeared during mid-February, whereas S. graminum and S. avenae appeared during first week of March. Significant differences were recorded for losses in number of grains/spike and 1000-grain weight among tested wheat genotypes. The aphid population had non-significant correlation with yield-related traits. Hicap proved the most effective for the management of aphid species followed by Hombre and Husk among tested seed dressers, while Citrullus colocynthis L. and Moringa oleifera Lam. plant extracts exhibited the highest efficacy among different plant extracts used in the study. Economic analysis depicted that use of Hombre and Hicap resulted in the highest income and benefit cost ratio. Therefore, use of genotype Punjab-2011’ and seed dressing with Hombre and Hicap can be successfully used to lower aphid infestation and get higher economic returns for wheat crop.

Effect of Seed Dressing and Soil Chemical Properties on Communities of Microorganisms Associated with Pre-Emergence Damping-Off of Broad Bean Seedlings

Combating soil pathogens that disable plant emergence is among the most difficult challenges of global agriculture. Legumes, preferred in sustainable cultivation systems, are particularly sensitive to pre-emergence damping-off of seedlings. Seed dressing is therefore a very important element in the cultivation technology. The aim of this study was to compare the impact of biological (Pythium oligandrum) and chemical (carboxin + thiuram) seed dressing on the quantitative and qualitative composition of microorganisms participating in the epidemiology of this disease, under specific hydrothermal conditions and chemical properties of the soil (pH, humus, macro-, and micronutrient). Microorganism identification was done using the MALDI-TOF MS (Matrix Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry) technique. Species were assigned to frequency groups, and populations of pathogens, saprophytes, and antagonists were identified. The biodiversity of these communities was expressed with Simpson’s Reciprocal, Shannon–Wiener, and Evenness (Shannon) indices. In individual variants of seed pre-treatment, the correlations between individual edaphic factors and the suppression of pre-emergence damping-off, the number of isolates obtained from infected seedlings, and the share of individual trophic groups of fungi were assessed. The main causes of pre-emergence damping-off of broad bean seedlings are Ilyonectria destructans, Globisporangium irregulare, Fusarium equiseti, Rhizoctonia solani, and Fusarium solani. Eliminating seed treatment results in a seedling mortality rate of 33.5%–42.5%. The effectiveness of the chemical protection product is 44.2% and 25.9%. Carboxin and thiuram reduce the diversity of microorganisms involved in the pathogenesis of pre-emergence damping-off and limit the presence of antagonistic fungi. Under the influence of P. oligandrum, there was a five-fold increase in the population of antagonists. An increase in humus in the soil reduces the percentage of diseased broad bean seedlings.

Seed dressing with mefenpyr-diethyl as a safener for mesosulfuron-methyl application in wheat: The evaluation and mechanisms

Mesosulfuron-methyl is always applied by foliar spraying in combination with the safener mefenpyr-diethyl to avoid phytotoxicity on wheat (Triticum aestivum L.) cultivars. However, it was observed that the tolerance of Tausch’s goatgrass (Aegilops tauschii Coss.) to mesosulfuron-methyl significantly increased in the presence of mefenpyr-diethyl by performing bioassay. This confirmed phenomenon may lead to overuse of mesosulfuron-methyl and weed resistance evolution in field conditions. Therefore, we tested the effect of wheat seed dressing with mefenpyr-diethyl as a possible alternative and disclosed the underlying mechanisms by herbicide dissipation study, enzymatic analysis and transcriptome profiling. The results suggest that increase of ALS activity, enhancement of metabolic processes, and other stress responses are crucial for the regulation of herbicide detoxification induced by mefenpyr-diethyl. Additionally, transcription factors such as AP2/ERF-ERF, bHLH, NAC, and MYB, and protein kinase such as RLK-Pelle_DLSV might play vital regulatory roles. The current study has important implications for mesosulfuron-methyl application in wheat field to control Tausch’s goatgrass and provides a comprehensive understanding of the protective effect of mefenpyr-diethyl.

New Preparations for Winter Wheat Seeds Protection

The research results into the different seed dressing agents effect on winter wheat seeds sowing qualities are presented. In the experiment, effective combination preparations with multilateral insectofungicidal activity were studied. The presence of several active substances in the preparation reduces the pesticide burden on the environment. Under field conditions close to production conditions the Sistiva, Kuinto Duo, Imidashans, Chansometox, Shansil Ultra, Shansil Trio, Vaibrans Integral, Celest Max, Celest Top effect at recommended doses were studied. At present, for winter wheat seed dressing it is best to use insectofungicide preparations containing different chemical classes several components. The best indicators for productivity (7.23 t/ha) and grain quality among the studied preparations were obtained by using a four-component insectofungicide for winter wheat seed disinfestation Vaibrans Integral, KS at the rate of 2l/t. Its use provides not only high yield but also particularly high protein content in the grain (16.07%) and gluten (36.8%) of the first quality group. If we take the winter wheat yield as a basis, in this indicator terms the worst performance was that of Celest Top. Nevertheless, all the studied preparations can be used to disinfect winter wheat seeds from seed and soil infections, as well as from harmful insects of the early period of plant development.

EFFECT OF BOTANICALS SEED PRIMING ON YIELD AND YIELD COMPONENTS OF MALT BARLEY (Hordeum vulgare L.)

Application of synthetic compounds seed dressing enhancing yield and yield components of crops but it is becoming very expensive for resource poor farmers beside this; these also have a negative effect on the natural environment. Thus, the current field and laboratory experiment was conducted during the 2018 main cropping season for testing the potential of locally available plant extracts; garlic (Allium sativum), ginger (Zingiber officinale), neem seed (Azadracta indica), varnonia leaf (Vernonia amygdalina) and crouton leaf (Crouton macrostachya) as seed priming materials on malt barley. Three levels of each priming material (5%, 10% and 15 % concentration) were prepared and full sized malt barley seeds were soaked for 12hrs in these priming materials. Seed dressing chemical (Dynamic 400 FS), distilled water soaked seeds, and dry seeds were used as a control for the field experiment. Primed seeds with all concentrations of botanicals, including distilled water and dynamic dressing chemical had a significant enhancing effect on agronomic parameters of malt barley under both laboratory and field conditions except for the effect of ginger extract priming which negatively affected the agronomic parameters as compared to dry planted (untreated) seeds. However, there was clear variation among botanical extracts and this is depending on their concentration and types of used botanicals. Among the tested botanicals, all three levels of garlic extracts have a significant enhancing effect on all agronomic parameters and this was followed by the neem. From the result of this study, seed priming with naturally available plant materials were found to improve yield and yield components of malt barley where for this particular experiment, all levels of garlic performed best as compared to other priming materials.