PLANT-BENEFICIAL MICROBIAL INOCULANTS AND THEIR FORMULATION – A REVIEW

" Agriculture plays a crucial role in the society and global economy and has a huge impact on the environment. Human overpopulation require higher amounts of food, and due to the overwhelming increase of health disorder it is a consumer demand for high quality food products. However, intensive agricultural practices involve the use of synthetic substances, with negative effects on human health and environmental safety. These triggered the concern of global regulatory agencies for new strategies and harsh regulations regarding agricultural inputs. Sustainable agriculture practices, including the use of renewable resources are now promoted. Biofertilizers, biopesticides and biostimulants contribute to agricultural yield and quality improvement, having a low detrimental impact on the environment. Microbial inoculants based on selected microorganisms are promising products that can improve plant growth and productivity and prevent crops from pest and diseases attack, being an environmental friendly approach. Plant beneficial microorganisms trigger various mechanisms for soil improvement, nitrogen fixation, nutrients solubilization and uptake in plants. Some beneficial microorganisms can release active biomolecule involved in plant protection, or suppress biotic and abiotic stress factors, revealing plant or environmental benefits. This study aims to review plant beneficial microbial agro-inoculants, successful formulations and application methods."

OPTIMIZATION OF CONVENTIONAL AGRICULTURE (TILLAGE X FERTILIZATION X PLANT PROTECTION) FOR SOYBEAN IN THE TRANSYLVANIAN PLAIN

"The purpose of this study was to improve conventional agricultural technologies in soybean crop to ensure a higher yield and reduced environmental impact under climate conditions specific for the Transylvanian Plain. For the experimental design a three-factorial experiment was set up (tillage x fertilization x plant protection products). Factor interaction was evaluated using formula AxBxC-R:4x4x4-3 to highlight the benefits of the practices. This study examined yield crops and size of the soybean plants in an effort to identify best practices. Yield was highly increased in conventional soil tillage system (3420 kg/ha), whereas for the minimum soil tillage system and for direct sowing there were no significant difference 2755-2995 kg/ha and 2605 kg/ha, respectively. Crop performance in terms of yield was highly influenced by the soil tillage system (57.5%), followed by plant protection treatments (22.9%) and fertilization (11.8%). Fertilization with N40P40 + gulle + green fertilizer ensured the highest soybean production (3132 kg/ha). Plant protection treatments during vegetation determined significant yield increases, with high influence of insecticides and a cummulative effect when both fungicides and insecticides were used (3193 kg/ha). Highest size of plants was registered in conventional soil tillage system. Overall crop protection treatments during vegetation (insecticide + fungicide) triggered not significant increases in plant size, except Teo TD soybean cultivar."

PRELIMINARY STUDY ON EPIGEAL INVERTEBRATES FAUNA IN EXPERIMENTAL PEPPER CROPS AT SCDL BUZĂU, ROMANIA

" This paper presents the species composition and abundance of epigeal invertebrate fauna collected from experimental pepper crops at the Vegetable Research and Development Station Buzău, Romania during 219-2020. The open field bell pepper Buzau 10 (2019) and Cantemir (2020) varieties were used in the experiment in five variants with two factors, diatomite (three doses) and bioinoculant Trichoderma asperellum Td85 strain. Diatomite was local from the Pătârlagele deposit (Buzău County) and antagonistic fungus was from the collection of microorganisms of Research and Development Institute for Plant Protection Bucharest. The fauna on the soil surface was collected using Barber traps, replaced every two weeks from June to October. The ecological parameters of abundance, dominance, constancy and ecological significance have been calculated using specific formulas. Specific attributes of the two products, diatomite and bioinoculant Trichoderma, reflected on the ecological and structural characteristics of invertebrate communities."

IN VITRO THERMAL REQUIREMENTS OF TWO ISOLATES OF METARHIZIUM ANISOPLIAE METCH.) SOROK. UNDER CONSTANT CONDITIONS

"The effect of temperature on the mycelial growth of two isolates of Metarhizium anisopliae (Metch.) Sorok. (Hypocreales, Clavicipitaceae) was evaluated in vitro on PDA growth medium, by measuring the diameter of the fungal colonies, at the following temperature values: 5, 10, 15, 20, 25, 30, 35 and 40 °C, over 14 days under constant conditions. The data obtained were used for the calculation of the growth rate (mm/day) using linear regression. The representation of the values corresponding to the minimum, optimal and maximum temperature of vegetative growth was made by a curve described by a mathematical function, a modified beta (ß) function. The lowest temperatures at which growth occurs are 7 and 10°C, the highest is 35.7°C; temperature at which the most growth occurs, as indicated by the measurements, was distributed over a range of temperatures from 22.9 to 31°C."

INTEGRATED PATHOGENS AND PESTS MANAGEMENT IN SUSTAINABLE AGRICULTURE

Attack pathogens and increasing abundance of some insect pests were favored by the climate changes, culture technologies practiced and increasing of cultivated areas with soybeans. The aim of this paper was to evaluate the attack of pathogens in soybean crop and to monitor some pest Lepidoptera species in order to identify technological measures to ensure their control by methods with minimal impact on the environment. The experiment was performed at the Research and Development Station for Agriculture Turda during 2018-2020 period. The best technological option is plowing, balanced fertilization and fungicides application, either alone, or in combination with an insecticide.

RESEARCH REGARDING THE EFFICIENCY OF SOYBEAN CULTIVATION IN DIFFERENT TILLAGE SYSTEMS AND THEIR INFLUENCE ON SOIL COMPACTION, ACCUMULATION AND WATER STORAGE

In the last years there has been a slight increase in average annual temperatures, as well as a high fluctuation in the distribution of rainfall, thus the reduction of the effects of atmospheric and pedological drought is part of the reasons that determine the orientation towards new variants of soil tillage. The experiment conceived and performed at ARDS Turda includes four variants of soil tillage: plow with the turn of the furrow (CS), chisel (MT), disk (MD) and no tillage (NT), in a 3-year crop rotation of soybean - winter wheat - maize. The momentary water reserve was higher in the MD and NT system compared to the CS, MT. The specific resistance of the soil to penetration (Rp) in NT, MD are higher compared to the CS and MT systems. Soybeans can be cultivated in a MT, the yield difference compared to the CS is 107 kg/ha. Compared to CS (66.5 L/ha) significant reductions of diesel consumption are made in the MD system (21 L/ha) and in the NT (31.7 L/ha).

EFFECT OF DIFFERENT CARBON AND NITROGEN SOURCES ON SPORULATION OF BEAUVERIA BASSIANA ROMANIAN STRAINS

A requirement for industrial-scale production of mycoinsecticides is the capacity of fungal strains to produce infective and stable propagules on inexpensive artificial substrates, with either solid-state or submerged liquid fermentation methods. The ability of entomopathogenic fungi to use different nutritive substrates is one of the factors influencing their effectiveness.Vegetative growth and sporulation yield depend on the composition of the culture medium and are specific to each fungal isolate. Our study has focused on fungal inoculum produced in artificial media. Native Beauveria bassiana strains was cultivated in liquid medium involving variations in carbon and nitrogen sources and the production of spores was evaluated. The results revealed that among the carbon and nitrogen sources tested, zaharose and ammonium nitrate were most efficiently used for the production of B.bassiana spores in submerged liquid fermentation.

INFLUENCE OF SOIL TILLAGE SYSTEM, FERTILIZER AND TREATMENT APPLIED TO SEEDS ON SOYBEAN CHEMICAL COMPOSITION

"In order to evaluate the effect of soil tillage system, fertilization and also different treatments applied to seeds on chemical composition in soybean crop, a field experiment was conducted at Research and Development Station for Agriculture Turda in 2020. Teo TD, an early soybean variety developed at RDSA Turda and registered in 2017 was used as a biological material. The compared tillage systems were: conventional tillage (plowing), reduced tillage (chisel or disk) and also no-tillage system. Four different mineral and organic fertilizers (N40P40, N40P40 + gulle, N40P40 + green fertilizer, N40P40 + gulle + green fertilizer) and various treatments applied to seeds (fungicide, insecticide, fungicide + insecticide, untreated) were also studied. All data were subjected to ANOVA using Polifact. Chemical composition (protein content, oil content, stearic acid (18:0), oleic acid (18:1), linoleic acid (18:2), and linolenic acid (18:3)) of Teo TD seeds was analyzed using NIR spectroscopy. Significant differences between some tillage systems and fertilizers were recorded in protein content, fat content and also stearic, oleic and linolenic acids content. The treatments applied to seeds influenced very significant the stearic acid and oleic acid, distinct significant the linoleic acid and significant the protein content."

A 2019 STUDY ON TOTAL AFLATOXINS IN ROMANIAN MAIZE (ZEA MAYS L.) SAMPLES

Mycotoxin contamination represents a clear public health concern. In this context, a maize survey was conducted in Romania, to monitor the occurrence of total aflatoxins in maize samples collected during the 2019 growing season from fields located in all counties. A total of 95 maize samples were collected along with information regarding the specific location of fields, the applied agronomic practices and cropping systems. ELISA method was used for the quantification of AFs. The results showed 88 contaminated samples. Only one sample registered aflatoxin levels higher than the limit of 10.00 μg/kg, settled by the Commission Regulation (EC) No 1881/2006 for maize to be subjected to soring or other physical treatment before human consumption or use as an ingredient in foodstuffs. The highest AFs level was 77.59 μg/kg, noted by a maize sample from Argeș County (the South-Muntenia development region, macro region 3). When referring to the analysed samples, the total aflatoxin contamination was independent of the type of hybrid, but strongly influenced by the pedo-climatic differences between counties. The southern counties proved to represent critical risk areas for aflatoxin contamination when referring to maize crops. These results highlight the importance of an effective and sustainable mycotoxin management along the food and feed chain, as well as the need of mapping the mycotoxin risk areas.

STUDY REGARDING THE APHIDOFAGOUS FAUNA STRUCTURE IN THE PEACH ORCHARDS FROM CONSTANTA COUNTY IN 2020

"The cosmopolitan aphid species Myzus persicae is a key pest of peach orchards in south and southeastern Romania. The phenomenon of resistance induced by the intensive use of insecticides is a matter of concern for farmers and protectionists, making necessary integrated measure for the control of this pest. Conservation of natural enemy’s populations is an essential component of any management system proposed for pest aphids. The aim of the study was to determine the structure of predatory insects associated with Myzus persicae populations in peach orchards. The research was carried out in three orchards from two localities from Constanta County, in peach plantations with Springcrest variety aged 7, 11 and 12 years. As a result of this study, there were determined a total of 15 predatory insect species belonging to eight systematic families: Coccinellidae, Chrysopidae, Hemerobiidae, Syrphydae, Cecidomyiidae, Panorpidae, Nabidae and Forficulidae, which naturally contribute to the reduction of the green peach aphid populations. "