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The paper presents a synthesis of investigations with 30 inbred lines of maize from different germplasm groups (BSSS, Iodent, Lacaune, Lancaster) and different ma-turity groups as parental forms. The research was carried out at the Institute of Crop Science „Porumbeni”, in the pedoclimatic conditions of 2022. As a result of topcross pollinations, hybrids from 6 maturity groups were obtained, which differ in morphologi-cal characters, productivity and the rate of water loss from the grains. Hybrids from the middle maturity group resulted in a higher productivity, compared to the hybrids from the other maturity groups. The rate of grain moisture loss for the hybrids from middle maturity group is more pronounced compared to early hybrids and is at the same level as late maturity group hybrids.

The purpose of this presented paper is determining the main indicators of soil fertility of typical chernozems in the Northern part of Moldova, by the Near Infrared Reflectance Spectroscopy method, used as a rapid and cost-effective analytical tool for the assessment and monitoring of their quality over time. The study was carried out in the fields of 10 districts in the northern area of Republic of Moldova. For the analysis of the agrophysical and agrochemical soil properties, a total of 16 soil pro-files cultivated with different agricultural crops (winter wheat, corn, winter barley, sunflower, soybean, peas, sugar beet) and a soil profile from a fallow land were taken. Data on soil texture (clay, silt and sand fractions) do not show large differences between the sampling regions and the depth of the soil layer. On average, physical clay content is 53-64%, and fine clay content is 35-44%. The humus content varies between 3.48-4.85% in the arable soil layer and between 2.69-4.80% in the 25-50 cm sub-arable layer. The total nitrogen content in the investigated soils correlates with the humus content. The higher the humus content, the higher the total nitrogen content. Total N content ranges from 0.28% (chernozem under fallow) to 0.13% (chernozem grown with maize) in the 0-50 cm soil layer. The C:N ratio is equal to 10-11 in the 0-50 cm soil layer and 8-11 in the 50-100 cm layer. The pH values vary between 5.9-7.2 in the 0-50 cm layer and 6.8-8.1 in the 50-100 cm soil layer. Carbonates are accumulated throughout the soil profile. Comparing the results previously obtained on the typical chernozems under fallow land with the results obtained on the arable chernozems investigated in this study, showed that there is a tendency of the humus content decrease by about 2%, especially in the 0-50 cm soil layer, as a result of applied agricultural practices. Simultaneously, degradation processes are amplified, especially through erosion. In this context, the main issue is the need to monitor soil fertility to assess the impact of agricultural management applied by farmers.

This paper studies the profitability issue of raising pigs for meat in the Republic of Moldova. The research was basedon the financial information fromover 195 enterprises that have as their basic or complementary branch raising pigs for meat. For this study, we determined the profitability level and selected only those enterprises (140) that recorded the profitability level higher than 0. In order to process statistically the received information, the enterprises have been systematized according to 4 criteria: average daily gain, average number of feed days, average weight of a pig at slaughter, and the profitability level. Based on this information, it was determined the impact of each criterion on the profitability of pork production and it also served as a basis to establish their forecasted indicators. Our calculations have shown that together with increased levels of profitability the profit of production increases too, the production cost reduces, but there is an increased share of expenses for feed in the production cost. The cost of meat production is highly influenced by the labour remuneration costs and costs for veterinary medicines. This paper proposes to establish a profitability level of 25 % as it can be considered optimal for the sustainable development of pig breeding branch in the Republic of Moldova. Also, this study could be useful for institutional decision makers form the Republic of Moldova, as well as for producers specialized in this field in order to assess the profitability level of their production.

Wine is one of the most ancient commodities in the world. The critical residues from the wine industry are grape leaves, stems, grape pomace, grape seeds, yeast lees, tartrate, and wastewater. The indiscriminate disposal of produced wastewater has adverse environmental and health consequences. Nevertheless, winery effluent has substantial prospects as an energy source. Hence, this paper aims to briefly showcase the potential of energy generation from wastewater in the wine industry through anaerobic digestion. From literature and statistical records, in 2018, the cultivation of grapes in Moldova covered about 126,873 ha of land and produced 730,171 t of grapes, with over 24% pressed for wine production. Consequently, the industry released over 6 billion litres of wastewater. Therefore, by anaerobic digestion of this effluent, there is a potential for the wine industry to produce 459,166 MWh of electricity annually to satisfy nearly 287,000 people. This potential represents a very important step towards energy self-sufficiency of the wine industry and a contribution to the sustainable development goals concerning wastewater, energy and sanitation.

The paper is focused on streamlining the seed drying process using the method of suspended layer treatment. The research was carried out with three types of oilseeds (grape, sea buckthorn seeds and linseeds), based on an experimental drying plant using convection and SHF as treatment agents. The results demonstrated that seed treatment process in a suspended layer ensures the increase of the speed and reduces the drying time. Moreover, the application of the developed installation allows to reduce the consumption of electricity and to re-duce the costs of technological processing.

The paper is dedicated to streamlining the process of fruit dehydration, by microwave treatment in the tunnel, mainly by reducing electricity consumption. To address this issue, an experimental system for fruit dehydration was developed, thus the research being conducted applying a tunnel-type dehydrator. The experiments were performed on the example of apricots, peaches and plums. The results obtained with the application of the experimental system were compared with those obtained based on the classical dehydration technology. Fruit de-hydration based on the developed system reduces the consumption of electricity by about 1.37 times, compared to the application of classical technology.

The organization of complete feed rations for cattle meeting the needs of animals in energy, protein, amino acids, minerals and vitamins in terms of basic nutrients and biologically active substances represents the main condition to achieve the genetic potential of productivity. The purpose of the paper was to optimize the pro-tein utilization in the body of young cattle by synchronizing the processes of fermentation of nitrogen-containing substances and carbohydrates in feed. Barothermal treatment of concentrated feed mixtures with high protein degradability and a high content of non-structural carbohydrates causes a more uniform fermentation of nutrients, intensification of microbial protein synthesis processes and an increase in the efficiency of energy use of carbo-hydrates and protein nitrogen by rumen microflora. This is evidenced by an increase in the number of ciliates by 4.4–8.1% and a decrease in the concentration of ammonia and volatile fatty acids in the rumen fluid by 5.2–9.2 % and 3.4–4.3 %, respectively. A decrease in nitrogen losses is indicated by a decrease in the content of urea in animals’ blood by 2.0–9.0%. Extrusion of concentrated feeds with high protein degradability and high content of non-structural carbohydrates improves animal productivity and feed efficiency. The average daily gain in live weight increases by 4.8-6.0% in the experimental group. As a result, feed consumption is reduced by 2.7-6.9%, while protein consumption is reduced by 2.6-5.7%.

The scientific researches presented in this paper aimed to study the aspects of the bacterial micro-flora in some assortments of cheese in their fresh state and in various refrigeration periods, sold in the industrial network, according to the scheme of classical microbiological laboratory procedure. Bacterioscopic and bacteriological investigations evaluated the number of Streptococcus and Lactobacillus colonies, yeast cells and condition-ally pathogenic species in hard and soft cheeses. Obtained data confirmed the presence of a normal bacterial microflora resulted from the lactic fermentation mechanism. Potential pathogenic microorganisms like Salmonella, Staphylococcus and coliform bacteria were not identified. These researches are of public interest as evidenced by the fact that dairy products sold in markets are of high quality and meet food safety and marketing requirements.

Staphylinids (Coleoptera, Staphylinidae) are insects playing an important role in nature. They serve as indicators for various habitat types and are actively involved in regulating the density of some invertebrate species. The research aimed to inventory the staphylinid species in the State Nature Reserve „Plaiul Fagului”. In order to determine the Staphylinidae fauna framework, the author used the material collected in the period 2020-2021 and analysed literature data on staphylinids collected in previous periods (2005-2018). The paper presents a list of 46 species, highlighting the most important aspects characterizing this group as a whole. The list includes 3 staphylinids with the status of new species for the fauna of „Plaiul fagului” Reserve and for the Republic of Moldova, namely: Phloeopora concolor (Kraatz, 1856), Acylophorus glaberrimus (Herbst, 1784) and Xantholinus sublinearis (Coiffait, 1970).

It is known that the growth rate of a tree, respectively, a stand, during its life differs from one period of life to another. Thus, the growth rate is more accelerated at the beginning of life, so that, achieving the peak of growth in volume, this rate gradually decreases, becoming more and more weak in old age, until the tree stand passes into a state of decrepitude. This variation in the process of accumulation of wood biomass makes the eco-nomic efficiency of the tree, respectively, the stand, which varies depending on the development phase, i.e. its age. This increase in volume, usually expressed by the current annual growth of the tree, respectively, the stand at the level of measurement unit and transferred to total yield, ultimately defines its economic efficiency, which in turn varies according to the amplitude of the variation of the growth index. In this context, the purpose of this paper was to evaluate the diameter increments of sessile oak stands (Quercus petraea Liebl.) of vegetative origin from shoots in the Republic of Moldova in relation to the yield class, age and generation originating from shoots, as well as in relation to the composition and consistency of the stand at the level of physical-geographical areas and phytoclimatic levels.

Globally, the most used waste treatment method is landfilling, although (improper) landfilling, which is typical for developing countries, has no material or energy recovery possibility compared with other treatment methods. In Indonesia, open dumping on final disposal sites covers most of the treated waste, which is an even worse method than landfilling in terms of environmental issues. The main objective of this article is to evalu-ate the feasibility of the waste-to-energy solution/waste incineration approach for proper and sustainable waste management in Bandung. A big issue of municipal solid waste is the organic portion of waste, as most emissions and pollution come from organic waste and improper handling. A specific objective is to conduct the risk analysis of an incineration plant model and to compare the environmental impact of incineration vs landfilling. The input data for the assessment will be obtained from the laboratory analyses of solid waste samples collected from the Sarimukti disposal site. The lab analyses will comprise the determination of fractional composition (biodegrad-able and non-biodegradable compounds like food waste, paper, textiles, plastics) and physico-chemical properties (such as moisture content, calorific values, trace elements). The research will also include general calculations of energy balance and economic costs of the incineration plant. Thus, the selected criteria will assess the following aspects of the incineration plant model: technical, environmental, social, energy, and economic.

The paper presents the synthesis of multiannual investigations concerning the development of inbred lines and early maize hybrids. 2874 sources were used over the period 1981-2020 for inbreeding and phenotypical selection, out of which 532 constant families were selected and were subject to preliminary assessment in terms of their production capacity, then transferred to the operational collection. The consequent testing resulted in the selection of 36 original lines used as parents of registered hybrids. At present, the related crosses – 56,7%, single cross hybrids – 31,6%, backcrosses – 11,4% and foreign hybrids – 0,3% are used as sources of initial material. The germplasm of alternative heterotic groups Reid Iodent – 40,1%, Euroflint – 28,9%, BSSS-B37 – 12,6%, Lancaster – 11,6%, Dent mixt – 4,0% and Dent canadian – 2,8% predominates in the lines’ pedigree. The heterotic patterns Reid Iodent x Euroflint and Reid Iodent x BSSS-B37 are mostly used for hybrid development. The production of commercial seeds for export is assured by 9 registered hybrids FAO 160-240 registered in Belarus. The hybrids Porumbeni 310, Porumbeni 305 and Alimentar 325 are used for cultivation in the Republic of Moldova.

The paper presents an analysis of the level of contingency and the contribution of each of the main yield components to the overall yield of winter wheat and their functional relationships in Balti steppe, Republic of Moldova. For the correlation analysis, the authors used the level of productivity of winter wheat and its main yield components obtained in the competitive variety trials during 2016-2020 in the Research Institute for Field Crops “Selectia”. In the experiment 6 morpho-biological indices for 15 typical varieties of 2 different ecotypes were analyzed. The coefficients of variation and correlation were determined according to the methodical guidance of Dospehov B.A. and Sedlovschi A.I. In the ecological conditions of the Republic of Moldova a strong direct cor-relation was established between the level of overall wheat productivity and its yield components - grain weight per ear and plant height, while an average correlation was revealed between overall productivity and the mass of 1000 grains and the amount of productive ears on the unit area (productive tillering).

The paper presents data on the response of F2 hybrid combinations and parental forms of tomato at different temperatures (optimal 25 C and stressful 40, 42 C), tested in laboratory conditions. It was established that stressful temperatures significantly affect the early ontogenesis of tomato varieties and hybrids by suppressing the growth of the embryonic root, stem and seedling (sometimes by stimulating them). Cluster analysis by the k-media method demonstrated that stressful temperatures manifested a higher discriminating ability of tomato clusters for seedling length and embryonic root length characters, which reveals a more pronounced specificity of interaction at these temperatures. Florina, Wake, Prestij and Rome varieties and F2 hybrid combinations Mary Gratefullt x Pontina, Prestij x Pontina, Rome x Wake have the highest complex resistance in terms of the reaction of the embryonic root, stem and seedling at 42 C temperature. They are of interest in the further process of breeding.

The paper presents the results of studying the dynamics of seed quality parameters (germination energy and seed germinability) during the storage of wheat (variety Polesskaya 90), cultivated after perennial grasses, peas and maize for silage, under industrial, ecological and biological cropping systems. Research program included the assessment of quality parameters before storage (control), and also after one, three, six, nine and twelve months of storage. The results of the study revealed a low initial level of germination energy and germination rate, as well as a prolonged period of post-harvest ripening (6 months) of seeds of the studied variety. Only after six months of storage,the germination index attained a high percent (on average 96-98%) and the seeds were characterized as conditioned. Preceding crops had no significant effect on the studied parameters, which was confirmed by the analysis of variance. However, a significant impact on the dynamics of germination rate was due to cropping systems, and especially to the storage period. The germinability of wheat seeds cultivated under industrial and ecological cropping systems was almost the same during 6-12 months of storage (within the limits of experimental error), which allowed to use these grains for the production of malt and for sowing. The paper presents the results of studying the dynamics of seed quality parameters (germination energy and seed germinability) during the storage of wheat (variety Polesskaya 90), cultivated after perennial grasses, peas and maize for silage, under industrial, ecological and biological cropping systems. Research program included the assessment of quality parameters before storage (control), and also after one, three, six, nine and twelve months of storage. The results of the study revealed a low initial level of germination energy and germination rate, as well as a prolonged period of post-harvest ripening (6 months) of seeds of the studied variety. Only after six months of storage,the germination index attaineda high percent (onaverage 96-98%) and theseeds were characterized as conditioned. Preceding crops had no significant effect on the studied parameters, which was confirmed by the analysis of variance. However, a significant impact on the dynamics of germination rate was due to cropping systems, and especially to the storage period. The germinability of wheat seeds cultivated under industrial and ecological cropping systems was almost the same during 6-12 months of storage (within the limits of experimental error), which allowed to use these grains for the production of malt and for sowing.

The paper presents the testing results concerning the operation of agricultural tractors which were divided into two groups: those operating on diesel fuel and others on biofuel B20. The use of biofuel led to obtain performance characteristics in the case of Diesel engines during a seasonal year beginning with the plowing and ending with the harvesting works. The data presented in this paper, such as: oil consumption when combustion takes place, gases escaped into the crankcase, compression in cylinders etc., proved a good functioning as in the case of tractors operating on diesel fuel.

The agriculture is indisputably the basis of the economy of the Republic of Moldova. Philosophically, it would maintain the society, people, and country on the whole. There are few countries in our region having an agrarian potential as high as that of Moldova. In this paper the authors presented a point of view, but a very important one form odern and current world economies to which Moldova tends – the information of the domain. It is obviously that the agricultural information is sought by the authors using the Agricultural Information System and by the content of the agricultural cadastre. The paper tries to answer to the following questions: What does the Agricultural Cadastre represent as an Information System for Moldova? What are the problems and achievements in this important area?

The paper presents the traceability of the stages of control, research and diagnosis of the pathogen Plum pox virus that causes diseases on foliage and fruits by manifesting typical symptoms on host plants of the genus Prunus. The researches were carried out in the plum plantation of “Star Agro Grup” Ltd from Ustia village, Dubasari District, extended on an area of 10 ha and structured in 5 sectors. From each sector 10 samples were analyzed, a total of 50 samples. At the diagnostic stage DAS-ELISA method was used. This is a technique often practiced in the phytosanitary field based on the use of polyclonal antibodies, antigen-antibody reaction related to the enzyme-substrate reaction, performed on a solid support (microtiter plate). The final results obtained are presented in a structured way with the exposure of the samples according to the researched sector.

The aim of this paper was to test the Rotfinder® device which use the method of measuring electrical resistances of the wood. Research was conducted in the north of the Eastern Carpathians, in four Norway spruce plots. A total of 1046 healthy standing trees (according with visual inspection) were analyzed. Between 5% and 16% of trees were affected by root rot, the highest values being recorded in the first 5 classes indicated by the Rot-finder® device. The relationship between the value indicated by the Rotfinder® device and the proportion occupied by the root rot in the cross-section of the Norway spruce trees is given by a logarithmic equation. The correlation is very strong and very significant (r = 0.956***). The correlation between the value indicated by the Rotfinder® and the proportion occupied by the root rot in the cross-section have a considerable practical importance because it is possible to estimate the proportion of root rot in the cross-sectional area for different forest areas.

In the context of the concerns regarding the better management of the fundamental natural oaks grove forests of the Republic of Moldova in the future, this paper tries a fundamental approach on assessing the growth in diameter of pedunculate oak stands originating from vegetative regeneration by shoots in the Republic of Moldova. The stands under study are between 65-100 years old, belong to I-V generation of shoot origin, are lo-cated on three phytoclimatic levels and fall into yield classes 3-5. By their composition the stands are both pure and mixed and have a normal consistency (over 0.6). The maximum current growth index, the average growth index and the age at which the curve of the current growth index intersects with the average growth index, which means the peak of growth and economic efficiency of the stand, were evaluated and analyzed. The data did not show a significant difference between growth indices in pure and mixed stands, nor was there a significant variation at the level of physicogeographical areas or phytoclimatic levels. On the other hand, there is a correlation of the growth indices with the yield class of the stand and with the generation of shoot origin The research was carried out in the context of the implementation of the provisions of the development strategy for the forestry sector regarding the improvement, restoration, conservation and ensuring the sustainable development of the national forest estate

The paper is focused on the tree crown formation and the choice of rootstock for modern cherry plantations. The investigations regarding the establishment of cherry cultivation systems for high level produc-tivity varieties were carried out in the southern and central fruit growing areas of the Republic of Moldova, in 6 stationary experiments located on common chernozem. The authors studied the influence of the rootstocks Gisela 6, Maxima 14 and Mahaleb on the growth and fructification of cherry varieties Valerii Cikalov, Record, Ferrovia, Kordia, Regina, Stella, Skeena, Bigarreau Burlat, Lapins, Early Star, Samba and Black Star in various combina-tions and analyzed the interaction between the planting distance and crown shape as basic factors that determine the bearing age of fruit trees, the yield and the fruit quality. All the variety-rootstock associations analyzed and tested in the conditions of the Republic of Moldova find in the respective areas favorable pedoclimatic conditions for cultivation. Their share in the new plantations should be chosen according to the main objective pursued, the cultivation system and the technology applied.

The paper presents the results of the laboratory testing of the response of some tomato varieties and lines from the collection of the Institute of Genetics, Physiology and Plant Protection to the pathogens Fusarium spp. and Alternaria alternata. Using the k-mean clustering method it was found that all fungi species manifested a high discriminating capacity of tomato cluster in the seed germination trait. The specificity of more pronounced interaction with Fusarium oxysporum and Fusarium solani pathogens was revealed for the stem and root length traits. A significant influence of fungi Fusarium and Alternaria on the genotypic and phenotypic variability of growth and development of tomato, on coefficients of heritability, genotypic and phenotypic variation and genetic progress was established.

The aim of the study is to reduce electricity consumption in rural milk collection points from the popu-lation. The paper presented a study on milk cooling refrigeration installations used at milk collection points in the Republic of Moldova. The design of the installation and the ratio of its electricity consumption nodes were analyzed. In order to reduce energy consumption, solutions have been proposed to improve the constructive-technological parameters of the electric motors in the refrigeration installations for milk cooling. It was proposed to modernize the asynchronous motors by placing permanent magnets on the rotors, which will increase the efficiency and the power factor of the motor, therefore reducing the consumption of active and reactive energy in the electrical network.

The paper presents the results of the study on the use of the peat-based immunomodulator and the nutritional additive “Stimulcom” for stimulating feeding of bees in the spring. It was found that feeding bees sugar syrup with immunomodulator in doses of 2-6 ml/l stimulates a 0,5-21,51% increase of bee colony power, 1,73-33,02%increase in the number of capped brood and 0.69 -29.9% increase of honey production against the control group. The optimal dose of the immunomodulator is 2 ml/l of sugar syrup, and its use is recommended from the first days of April to the beginning of the main honey flow, one liter per colony once every 6 days. The application of the elaborated procedure ensures the increase of productivity of bee colonies by 29.9%. The use of the nutri-tional additive “Stimulcom” in feeding bees in the spring until the beginning of black locust honey flow ensures an increase in productivity by 4.13%.

The paper includes new data on the distribution of the Western Corn Rootworm – Diabrotica virgifera virgifera Le Conte, 1868 in the Republic of Moldova. The research was carried out in August, 2020 around the Municipality of Chisinau, the Central and Southern Regions of the country. For the Northern Region, the presence of the pest was confirmed in 2016. In total, 20 corn fields from 15 localities were investigated and 117 specimens of dangerous insects were collected. The pest was present in 11 corn fields from 8 localities, while in the other fields, adults were not observed, but some plants showed traces of the pest’s visit.

This paper deals with the possibility of using agricultural residues for the production of densified solid biofuels. The aim of the study is to evaluate energetic characteristics of plant residues that come from sea buckthorn production chain in the conditions of the Republic of Moldova. The biomass for investigations (branches obtained as a result of pruning sea buckthorn trees of the Cora variety) was collected from an experimental plantation established in 2014. The analyses carried out in the Laboratory of Solid Biofuels of the State Agrarian University of Moldova show that moisture content of the studied samples, estimated immediately after pruning, does not exceed 46%. Ash content varies within the limits of 0,49-1,94%, and the net calorific value is from 16,92 to 17,21 MJ/kg when the humidity equals to 10%. Based on the gained results, it has been proven that plant residues from sea buckthorn pruning can be used as a raw material for the production of densified solid biofuels with the qualitative characteristics that comply with European standards ENPlus 3.

The paper refers to a process for forming the crown of the apple tree in the form of a slender spindle with a vertical central axis, weakly curved and well branched, with a single level of semiskeletal branches and fruiting branches. The Granny Smith variety was used, grafted onto the M9 rootstock and planted at a distance of 3.2 x 0.8 m. Before planting, a trellis was installed and 5 wires spaced 50, 80, 160, 240, 320 cm from the ground were fixed. The process of training the central axis includes: the bending of the vigorous axis and its fixation in horizontal position in spring in the first year after planting at the onset of the bud opening; the selection of an extension shoot of the central axis and pruning of vertical shoots at the collar when they reach a length of 20-25 cm; the fixation of the extension shoot in vertical position, in July.

The paper presents the results of the analysis of relationship between genetic distance and geographical distance in different broomrape populations (Orobanche cumana) - a rhizopathogen specific for sunflower that essentially affects the production of this important oil crop. Thirty-nine broomrape populations collected from different regions of the Republic of Moldova and belonging to different races (≤ E, F, G and H) have been included in the study. Correlative analysis of the data with reference to the genetic distance calculated based on the results of fingerprinting with SSR (Simple Sequence Repeats) and ISSR (Inter Simple Sequence Repeats) markers and to the geographical distance suggested that no correlation exists between these two parameters. The matrix of genetic distances was used as input for a principal coordinate analysis (PCoA). The PCoA revealed a more clear grouping of populations from the same region in the case of ISSR analysis, the main part of populations from central and southern part of the country being grouped into two clusters, regardless of their race.

The purpose of this study is to improve the methods used to calculate the accuracy of interference fits made of reconditioned parts by means of different wear compensation materials. The given purpose has been achieved by application of Green’s functions in order to calculate the minimum permitted interference, highlighting all the possi-ble influencing factors that may occur during the functioning of agricultural machinery. Based on the results presented in this paper, there has been developed an algorithm to determine tolerance fields for interference fits by calculating the minimum clearance depending on the mechanical stress, centrifugal forces and the thermal action, having consid-ered deformations caused by the destruction of microrelief and the number of repeated mountings.

The paper discusses the research results on the influence of forest types on the wood specific gravity of Scots pine as an integral indicator of wood quality. For the study, pine stands were selected in the forest conditions of the Precarpathian region (Ukraine). In the forest type of wet pine broadleaves biotope, wood density at the moisture content of 8% varied in the range from 356 to 735 kg∙m-3 with an average value of 511 kg∙m-3 and exceeded the similar indicator in fresh pine broadleaves biotope by 11%. A linear relationship between the wood specific gravity and the number of annual tree rings in 1 cm was established, which was described by the equation of the first level. A multiple comparison of the obtained research results allowed to distinguish four groups of wood samples in relation to wood density and the number of growth rings in 1 cm. The average value of the wood density for the first group of samples with the number of annual rings less than 5 pcs.∙cm-1 is equal to 385 kg∙m-3, and for the fourth with the number of annual rings more than 16 pcs.∙cm-1 - 601 kg∙m-3. The last one was characterized by the largest range of changes of the wood density, which varied from 445 to 735 kg∙m-3. The obtained results are of practical importance for the selection of stemwood for its desired purpose.

The synonyms of cucurbitaceous crops powdery mildew causative agents are presented in the paper. The criteria used for species identification according the anamorphic stage are given and their taxonomic value is characterized. The authors analyzed 6 samples of powdery mildew pathogens isolated from zucchini, cucumbers and melons. It is shown that 5 isolates belong to the species Golovinomyces cichroacearum, and one is Podosphaera xanthii. A perfect stage has not been detected in any of the isolates. None of the G. cichroacearum isolates was able to infect cucumbers (cv. Konkurent) in the field. The detection of the pathogen species should be taken into consideration by plant protection specialists and by breeders when breeding cucurbitaceous crops for plant resistance against the certain species of pathogens or their complex.

This paper is devoted to research on the determination of parameters and regimes of operation of the electro-hydraulic system for primary processing of agricultural products. The electro-hydraulic system, developed at the State Agrarian University of Moldova, consists of a discharge chamber with electrodes, a spark gap discharger, a condensator, a step-up transformer 100/30 000, a step-down transformer 220/100 and a self-regulating transformer. The system under study was tested for various applications: for oil extraction from sunflower seeds and walnut kernels as well as for high voltage pulse treatment of milk and fruit and vegetable juice. It showed the following advantages: energy expenditure reduction, easiness in utilization and enhanced reliability.

The paper refers to a process for forming the cup-shaped crown of the cherry tree. The cup-training system was applied to the varieties Lappins, Skeena and Big Star, grafted on the medium vigor rootstock MaxMa 14 planted at a distance of 5 x 3 m, and to the variety Ferrovia, grafted on Gisela 6 rootstock and planted at a distance of 4 x 2 m. The process includes: shortening of the tree after planting and removal of the buds from the trunk at the height of 40-50 cm with blanding of 2-3 axial buds located under two terminal buds; removal of the extension shoot; selection of a vertical branch for the future central axis and 3…4 branches for the future scaffold branches from the base of the tree crown; the future scaffold branches are pruned at 60 cm from their base, and the central axis − at 20 cm higher than the top of the scaffold branches; pruning of the central axis at 30…40 cm from the base of the upper scaffold branch above a lateral branch.

The paper presents a generalization of the results of multiannual investigations concerning the reaction of early maize lines to M-type and C-type cytoplasmic male sterility (cms) and the development of male sterile analogues and pollen fertility restorers. 308 inbred lines belonging to the main groups of germplasm useful for early maize breeding were studied. The classification of the lines by their reaction to male sterility was preponderantly performed at the stage of combining ability evaluation in systemic crosses with male sterile testers. A high percentage of inbred lines (85,7%) maintaining M-type cms was established, while for C-type cms there was an approximately equal proportion of sterility maintainers (41,2%) and pollen fertility restorers (44.5%). The germplasm groups Euroflint, Early Batler, Northwester Dent and subgroups A654, CG-12 manifested similar reaction in both types of cytoplasmic male sterility. In specific cases deviations of male sterility expression were observed in relation to the genetic background. 9 male sterile analogues and 4 pollen fertility restorers were created as parental components for 14 registered maize hybrids.

The objective of this paper was to analyze the crop yield of the common winter wheat variety „Blagodarka Odesskaya” in relation to three factors: sowing date, sowing rates and forerunner crops (pea for seeds, sunflower and maize for grain). Under the conditions of the agricultural year 2017/2018 the forerunner pea crop (grown for split peas) was found to be more beneficial than sunflower and maize for grain and it ensured the highest wheat yield (6178.8 kg/ha) due to more favorable conditions for plant growth and development. The yield of wheat kernels after the forerunner sunflower crop constituted 3511.9 kg/ha and after maize for grain – 3780.8 kg/ha or respectively by 2666.9 kg/ha and 2398.0 kg/ha less. By its protein and gluten content the obtained wheat grain belongs to class B (precious wheat). Strong wheat with a protein content of over 14% was obtained after pea for seeds at the sowing rates of 6.0 million viable seeds per hectare when sowing was done at admissible time.

In this paper the control algorithms were developed for natural cold storage of fruits and vegetables when air or water is used as a coolant. The control algorithms are based on automaton graphs. The algorithm for the formation of an electrical equipment system of natural cold installations for the storage of fruits and vegetables consists of two stages: study of natural cold settings as a control object and the development of electrical equipment for natural cold installations.

This paper presents the results of assessing a tomato collection (18 genotypes) on the basis of precocity, productivity and some fruit characters. Cluster analysis has shown that genotypes, separated into three clusters, are distinguished based on the fruit mass, fruit length, fruit diameter, mesocarp thickness, pericarp thickness, and number of seed beds. The analysis of the valuable characters of the studied forms revealed a wide variability regarding the duration of the interphase period, the shape of the bush and fruit, the whole yield, the proportion of marketable fruits. This allowed to select the most valuable forms and recommend them for hybridization and to obtain new varieties and hybrids for various uses.

The paper presents the results of the laboratory investigations of the inhibition effect of the liquid biofungicide Glio-cladin-SC, prepared on the base of live cells of the antagonistic fungus Trichoderma-based Miller, Gidden аnd Foster strain 3Х, against the pathogen fungi, causative agents of the agricultural crops diseases. The influence of the biopreparation was determined by the method of difusion in agar. The metabolites contained in the biopreparation suppress the pathogens development and create sterile zones of growth inhibition. The preparation can have wide application spectrum for the agricultural crops protection against a wide range of dangerous plant disease agents – fungi from the genus Fusarium and the species Botrytis cinerea, Rhizoctonia solani, Sclerotinia sclerotiorum, Monilia cinerea, М.fructigena etc.

In this paper the parameters of the process of fruits and vegetables storage using the natural cold were determined and evaluated. These parameters: atmospheric air temperature and speed, the duration of cold and warm seasons and design parameters of cold units were determined experimentally in the north, center and south of the Republic of Moldova. The sum of temperatures inside and outside of the ice store are practically identical within 24 hours. Because of this, for the calculation of natural cold units parameters the exterior air temperature may be taken as equal to the inside temperature. Within the same climatic zone the duration of warm season and the sum of exterior air temperatures also depend on the site relief (altitude) and slope angle and vary within the limits of 10-13%. These parameters must be taken into account for more exact calculations of the length of use of natural cold units. Air speed inside of the ice store is approximately 2-2,5 times lower than the exterior air speed for different climatic zones of the Republic of Moldova and varies from 1,2 to 2,0 m/s.

The paper presents the results of studies of the effect of nano aqua citrate of microelements (Se + Ge) with biologically active components on the combined changes in the body of Aphidoletes aphidimyza Rond. When supplemental nutrition is used, the optimum concentration of nano aqua citrate of microelements (Se–0.0005 + Ge–0.0003) – 0.0008 mg/dm3 with the biologically active components – 65 mg /dm3, the survival increases to 89%, the fertility to 98%, the reproductive capacity(Rp ) of females to 64.5%. It has been established that during the modification of trophism, positive changes occur in the biology of the aphidophage, and the competitive capabilities of Aphidoletes aphidimyza Rond. are improved as a biological agent of limiting the harm of the members of the Aphidoidea superfamily. The proposed elements of the technology of reproduction and practical application of Aphidoletes aphidimyza Rond. are characterized by high economic efficiency (25%) in the conditions of the protected soil. The aim of the research was to study the possibility of using nano aqua citrate of microelements (Se + Ge) with biologically active components for the correction of the life cycle of Aphidoletes aphidimyza Rond. To achieve this goal, the following tasks were solved: on the basis of trophic relationships in the phytophage – host – aphidophagus system, to carry out the analysis of the functioning of resistant adaptive systems Aphidoletes aphidimyza Rond. in the conditions of agrobiocenosis.

Abstract. The factors influencing on the quantity and stability of fuel delivered to gas-diesel engine are considered in this paper. As a result of researches the factors having significant effects on the reduction of ignition dose size of diesel fuel and on the optimization of combustion of two-fuel mix have been established. Реферат. В статье рассмотрены факторы влияющие на количество и стабильность подаваемого топлива в газодизельный двигатель. В результате исследований установлены факторы оказывающие существенное влияние на уменьшения величины запальной дозы дизельного топлива и оптимизацию сгорания двухтопливной смеси.

Abstract. This paper aims to quantify from the technical, economical and sustainable point of view the theoretical and feasible potential of agricultural residues to generate heat through the production of solid biofuels in the form of briquettes. To this end, a methodology has been developed based on a statistical and geographical system of information on the quality and quantity of agricultural residues specific to the Northern Development Region of the Republic of Moldova. Results reveal that only 9% of the total residues can be used directly for the production of densified biofuels with a calorific value in accordance with ENPlus international standards.

Abstract. Soil has an important role in sustaining life on earth and represents the support for the practice of agriculture, which provides the population’s food security and safety. Preserving the land production potential and ensuring a durable development is a key factor in the present times. In this context the researches presented in the paper analyze the effects of soil compaction and of the type of tillage machinery over some soil properties for autumn wheat crop set up. Twelve experimental variants were considered, based on two influencing factors: factor A = soil compaction, with 3 variants; factor B = tillage machinery system, with 4 variants. The following indices were taken into account for each experimental variant: apparent volumetric mass, penetration resistance and stability of the soil structural elements, expressed by the means of two indices: weighted average diameter and water stability of the aggregates. The results of the experiments regarding the effect of soil compaction and tillage machinery system led to the conclusion that the technological variants that create favorable conservation conditions were the ones leading to minimum soil compaction, obtained through direct seeding into the stubble and no plowing.

Abstract. The paper presents and analyzes the grain yield of the common winter wheat variety „Meleag” created at the Research Institute of Field Crops „Selectia” (Republic of Moldova) in polyfactorial field experiments under the effect of the forerunner crops: pea for seeds, sunflower and corn for grains. Wheat was drilled on recommended, admissible and late planting dates at various seeding rates. On average over two years 2017/2018, the experimental results proved the priority of pea for seeds as preceding crop that ensured a wheat yield of 5879.0 kg/ ha due to more favorable conditions for plant growth and development created as a result of earlier harvesting and biological nitrogen presence in the vegetable residues of peas. The yield of wheat kernels after the preceding corn crop constituted 3161.2 kg/ ha, and after sunflower – 3328.3 kg/ha or less by 2717.8 and 2550.7 kg/ha respectively. The admissible and late planting dates taken into study did not positively affect the wheat yield in comparison with the recommended planting date, the first decade of October. The common winter wheat variety „Meleag” recorded a statistically significant positive increase after pea for seeds on the recommended and admissible planting dates at the seeding rate of 6.0 million viable seeds/ha and on the late planting date - at the seeding rate of 8.0 million seeds/ha. After the preceding sunflower crop, a statistically significant positive increase was obtained on the admissible and late planting dates at the seeding rate of 6.0 million seeds/ha and after corn for grains – at the seeding rate of 6.0 million seeds/ha on the admissible planting date. Yield quality was superior after the preceding sunflower crop. Rezumat. În lucrare se prezintă şi se analizează nivelul producţiei de boabe a soiului de grâu comun de toamnă „Meleag”, creat la Institutul de Cercetări pentru Culturile de Câmp „Selecţia”, în experienţe polifactoriale, sub acţiunea premergătorilor mazăre pentru seminţe, floarea-soarelui şi porumb pentru boabe, semănat în termen recomandat, admisibil şi tardiv, cu diferite desimi. În medie pe anii de studiu 2017–2018 s-a confirmat prioritatea premergătorului mazăre pentru seminţe, aceasta asigurând 5879,0 kg/ha de grâu datorită condiţiilor create de recoltarea timpurie şi azotului biologic prezent în resturile vegetale ale mazării. Producţia de cariopse după premergătorul porumb pentru boabe a constituit 3161,2 kg/ha, iar după floarea-soarelui – 3328,3 kg/ha sau cu 2717,8 şi, respectiv, 2550,7 kg/ha mai puţin. Epocile de semănat admisibilă şi tardivă luate în studiu nu au influenţat pozitiv producţia în comparaţie cu termenul recomandat, adică prima decadă a lunii octombrie. Soiul de grâu comun de toamnă „Meleag” a înregistrat un spor de producţie pozitiv statistic semnificativ după premergătorul mazăre pentru seminţe în cazul semănatului în termenele recomandat şi admisibil la desimea de 6,0 mil. seminţe viabile, iar în termenul tardiv – la desimea 8 mil/ha. După premergătorul floarea-soarelui, spor de producţie pozitiv statistic semnificativ s-a obţinut în cazul semănatului în termenele admisibil şi tardiv la desimea de 6,0 mil/ha, iar după porumb pentru boabe – la desimea de 6 mil/ha, semănate în termenul admisibil. Calitatea producţiei a fost mai înaltă după premergătorul floarea-soarelui.

Abstract. The paper includes the results of evaluation of 20 sunflower hybrids for some biometric and productivity parameters under different climatic conditions in the experimental fields of Agricultural Research and Development Station Braila, Romania and AMG-Agroselect Comert, Soroca, Moldova. Some differences in the behavior of sunflower plants cultivated under conditions varying in water availability and thermal regime were established. In Soroca fields the parameters: plant height and thousand-seed weight had less values (by 23% and 12,3% respectively) compared to the plants cultivated in Braila where the weather conditions over the experimental period (2016-2017 agricultural year) were more favorable. The diminished values of the mentioned indicators recorded in Soroca can be caused by the small amounts of precipitation during June-July, critical for the development of the sunflower, as well as by the lack of soil water created due to the low amount of precipitation in September-April. As regards calathidium diameter no significant differences in dimensions related to precipitation amount and thermal regime were found in the majority of hybrids cultivated in both Republic of Moldova and Romania. There were 6 hybrids that showed stable values of the analyzed parameters with insignificant diminution of the productivity indices (H2, H5, H6, H8, H9 and H11). Rezumat. Lucrarea include rezultatele unui studiu destinat evaluării a mai multor parametri biometrici şi de productivitate la 20 de hibrizi de floarea-soarelui cultivaţi în condiţii climaterice diferite pe câmpurile experimentale ale Staţiunii de Cercetare-Dezvoltare Agricolă Brăila, România şi ale companiei AMG-Agroselect Comerţ, Soroca, Republica Moldova. Au fost puse în evidenţă unele deosebiri ale comportamentului plantelor de floarea-soarelui cultivate în condiţii variate ale aprovizionării cu apă şi regimului termic. La plantele cultivate pe câmpurile din Soroca indicatorii: talia plantei şi masa a 1000 de boabe au prezentat valori diminuate (respectiv cu 23% şi 12,3%) faţă de plantele cultivate la Brăila, unde condiţiile meteorologice pe parcursul perioadei experimentale (anul agricol 2016-2017) au fost mai favorabile. Valorile diminuate ale indicatorilor menţionaţi înregistrate la Soroca pot fi cauzate atât de cantităţile reduse de precipitaţii în perioada iunie-iulie, perioadă critică pentru dezvoltarea florii-soarelui, cât şi de deficitul de apă din sol specific pentru lunile septembrie-aprilie. În cazul diametrului calatidiilor, la majoritatea hibrizilor cultivaţi atât în R. Moldova, cât şi în România, nu s-a evidenţiat o diferenţă esenţială a dimensiunilor în funcţie de cantitatea de precipitaţii şi regimul termic. S-au remarcat 6 hibrizi de floarea-soarelui ce au prezentat stabilitate a parametrilor analizaţi, cu diminuare nesemnificativă a indicilor de productivitate (H2, H5, H6, H8, H9 şi H11).

Abstract. A new mineral concentrate made by a special method from bone tissues of farm animals is presented in this paper. Mineral concentrate constitutes a concentrated source of calcium and phosphorus and is an alternative to tricalcium phosphate. Samples collected from seventeen experimental batches of mineral concentrate were tested to study the chemical composition and the degree of variation of the parameters of calcium and phosphorus content. Laboratory studies showed that more than 70% of the analyzed samples contain calcium in the range of 380 to 420 g/kg and phosphorus – in the range of 120 to 163 g/ kg. It was established that the average calcium content in the mineral concentarate is 39.6% and phosphorus content is 14.5%. Comparative studies indicate a higher solubility of phosphorus in 2% citric acid in the mineral concentrate when compared with tricalcium phosphate.

Abstract. The major factors that influence the traction resistance of seed drills are: specific resistance of different soil types, seeding depth, shape of work organs, etc. The paper presents a comparative analysis of the traction resistance of the rotary seed drill and coulter seed drill (standard). The data reveal a linear dependence between traction resistance and the length (4, 6, 8, 10 and 12 cm) of the seed embedding device. With an increase of 2 cm in the seed embedding device length, traction resistance increases by 11,5 … 8,5%. Traction resistance of both coulter and rotary seed drills increases as working speed is raised (1,85; 2,19; 2,55; 3,09 and 3,63 m/s), but the traction resistance of the rotary drill is by 1,4 … 2,11% less, because the coulter meets a greater friction force than the seed embedding device of the rotary drill.

Abstract. The results on the productivity and grain quality of winter wheat of intensive and semi-intensive ecotypes which were created in the Research Institute of Field Crops “Selectia”, Balti (Republic of Moldova) are presented in this paper. The data were obtained during 2014-2016 years contrasting by their hydrothermal characteristics. It was established that the productivity level and quality indicators as sedimentation, thousand-seed weight, flour strength and protein quantity in the analyzed ecotypes directly depend on precipitation amount per year, as well as in the critical periods of vegetation. An inverse dependence was found between the hydrothermal regime and the content of gluten, its quality according to GDI (gluten deformation index) and total baking score. A higher productivity and better quality was obtained by homologated and perspective varieties as: Phenix, Rod, Accord, Capriana, Lautar, Vestitor, Savant, Meleag.

Abstract. The paper presents the results of researches with legume-grass mixtures, which consisted of alfalfa (Medicago sativa L.), birdsfoot trefoil (Lotus corniculatus L.), tall fescue (Festuca arundinacea), smooth brome (Bromus inermis) and perennial ryegrass (Lolium perenne). The experiment was designed to study sward mowing stages (branching stage of legumes and booting stage of grasses; budding-early flowering stage of legumes and earing stage of grasses) and different types of nitrogen fertilizers (ammonium nitrate, limestone-ammonium nitrate, urea) which were introduced on phosphorus-potassium background. The purpose of the research was to investigate the effect of the studied factors on the quality indices of the forage of legume-grass mixtures and to conduct its evaluation in accordance with the current standard. General scientific and special scientific methods were used: field, laboratory and calculation methods. The evaluation of experimental swards by some forage quality parameters (the content of crude protein, crude fiber, fodder units, metabolizable energy and leaf proportion) allowed to reveal the optimal variants of fertilizers and mowing regimes. It is expedient to use ammonium- and limestone-ammonium nitrate as nitrogen fertilizers in the conditions of natural moisture of Western-Forest-Steppe of Ukraine on dark gray podzolic soils for the effective use of sown legume-grass agrophytocenoses. The mowing of plants in the early stages of vegetation contributes to the improvement of forage nutritive value and to increased forage quality category.

Abstract. The paper presents the results of a study on growth particularities of the sea buckthorn (Hippophae rhamnoides L.) varieties ‘Cora’, ‘Clara’, ‘Mara’ and ‘Dora’ depending on the tree training system: 1) bush; 2. tree with the trunk height of 45-50 cm, with annually pruning of fruit branches; 3. improved vase-training system; 4. mixed-pyramid-training system (control). Experimental data on trunk diameter and total length of annual branches have been obtained during the first three years after planting, depending on the variety and plant training system. As a result, it has been established that according to the studied indicators, the growth vigor of ‘Dora’ variety plants is lower compared to that of ‘Cora’, ‘Clara’, and ‘Mara’ varieties. The highest values of these indicators have been recorded by the bush-shaped plants.