2024

Selle valdkonna püsiv URIhttp://hdl.handle.net/10492/9341

Sirvi

Nüüd näidatakse 1 - 20 104

In vitro Assessment of the Food Preference and Toxicity of Five Insecticides against The Land Snail Eobania vermiculata (Gastropoda; Helicidae)
(Estonian University of Life Sciences, 2024) Al-Harbi, R.K.; Ismail, A.M.; Bashandy, A.S.M.E.; Awwad, M.H.; Raddy, H.M.; Korrat, E.E.E.
The land snail Eobania vermiculata is one of the most cosmopolitan and harmful agricultural pests, causing economic devastation to many crops. For this purpose, the choice and non-choice methods was used to determine the palatability of certain plants for E. vermiculata. Moreover, the vulnerability of the snail was assessed via its exposure to five common insecticides (spirotetramat, sulfoxaflor, chlorantraniliprole, spinetoram and fipronil) using leaf-dipping technique under laboratory conditions. The median lethal dose was determined for each compound while biomarkers, such as enzymatic activity levels of AST, ALT, total protein TP, and lipid TL were used to evaluate sublethal effects. The findings of the no-choice feeding trial revealed that E. vermiculata significantly consumed a higher amount of Lactuca scariola var. sativa leaves compared to other tested plants. Cichorium cicorea leaves were found to be the least preferred by E. vermiculata, with an average of 1.71 g after 5 days. On the other hand, the results of the free choice feeding trial revealed that L. scariola var. sativa and Brassica oleracea leaves were the most frequently consumed by E. vermiculata. Conversely, E. vermiculata exhibited the lowest preference towards Brassica rapa leaves. The results of the molluscicidal activity indicated that the mortality rate is dose-dependent. After one month of exposure to a concentration of 1,000 ppm per 100 mL, chlorantraniliprole caused 46.4% mortality, followed by sulfoxaflor and fipronil, which exhibited equal mortality values of 42.9%. The latter insecticides revealed LC50 of 1,010.5, 2,501.9, and 1,444.7 ppm per 100 mL against E. vermiculata, respectively. Nevertheless, spinetoram and spirotetramat caused a lower mortality rate for E. vermiculata. The biochemical analysis results showed that the activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total proteins (LP), and the lipid profile of E. vermiculata have increased by 50% in response to the insecticides. Compared to the control and other compounds, spirotetramat increased total cholesterol by 33 mg dL-1. The activity of ALT, AST, and triglycerides decreased after the application of spinetoram and fipronil treatment, with values reaching 13 u L-1, 32 u L-1, and 4 mg dL-1 of TL, respectively. However, no substantial effects of insecticides were observed on TP, Total cholesterol, LDH, or LP levels after the exposure period. The study's findings indicate that chlorantraniliprole, a novel insecticide group, could be a promising approach for controlling the land snail E. vermiculata. Unlike other, more hazardous insecticides, chlorantraniliprole has not previously been used to control snails. Furthermore, it appears to be safe for non-target organisms and mammals, making it an excellent choice for snail management.
Spatial variability of chlorophyll and NDVI obtained by different sensors in an experimental coffee field
(Estonian University of Life Sciences, 2024) Silva, S.A.S.; Ferraz, G.A.S.; Figueiredo, V.C.; Volpato, M.M.L.; Machado, M.L.; Silva, V.A.; Matos, C.S.M.; Conti, L.; Bambi, G.
The objective of this research was to study the spatial variability of NDVI and chlorophyll sampled by different sensors, as well as to evaluate the correlation between them in a coffee field. The study was carried out on a coffee farm located in the municipality of Três Pontas, Minas Gerais. A sampling grid containing 30 points was created for the study area. Each sampling point was represented by one plant, which was georeferenced by a GNSS RTK. For each sample plant, NDVI and chlorophyll were obtained by the optical and active sensors GreenSeeker and ClorofiLOG, respectively. In addition, it was carried out a flight with an RPA equipped with a passive and multispectral sensor. Using the data obtained by active sensors, a geostatistical analysis was carried out to evaluate the spatial variability of NDVI and chlorophyll. The geostatistical analysis verified the existence of spatial dependence for the two attributes, and thus it was possible to generate spatialization maps through kriging. The images obtained by the passive sensor resulted in five multispectral orthomosaics, making it possible to calculate the NDVI, thus generating a spatialization map of this index. It was possible to observe in the generated maps, points that presented a certain similarity and for this purpose a correlation analysis was carried out for the values of each attribute, sampled directly in the maps, and in different sampling grids (30, 60, 90 and 120 points). By analyzing the Pearson coefficient (R) it was possible to quantify the level of correlation between the data obtained by the different sensors and through the t test it was possible to find significant correlations between them.
Fusarium head blight in winter wheat: development peculiarities and protective strategies
(Estonian University of Life Sciences, 2024) Avagyan, G.V.; Martirosyan, H.S.
Fusarium head blight (FHB, caused by the fungal plant pathogen Fusarium graminearum Schwabe) is a widespread fungal disease in the Republic of Armenia, affecting various cereal crops, including wheat, leading to a decrease in productivity and grain quality. However, comprehensive research aimed at selecting proper fungicides and determining the optimal application timing has not been conducted before. FHB can undergo epidemic development during years characterized by favorable weather conditions. Conversely, during periods of adverse weather conditions, the severity and incidence of FHB tend to decrease notably. Abundant rainfall and mild temperatures render plants more susceptible, facilitating the spread of infection not only during the flowering of winter wheat but also at the waxy ripening stage, thereby increasing the risk of an FHB epidemic. The experiments were carried out during the 2022 and 2023 growing seasons under rain-fed conditions, with the primary focus on treating winter wheat with triazole group fungicides. During years with adverse weather conditions for FHB development, a single application of Falcon (0.5 L ha-1 ) or Prosaro (1.0 L ha-1 ) at Feekes 10.5.1 proved to be an effective strategy for managing FHB, particularly when integrated with cultural practices. These treatments provided a biological efficacy of 80.6% to 83.3% at Feeks 11.2, and from 76.6% to 79.4% at harvest, respectively, increasing wheat yield by 37.62% to 42.9%. In the case of epidemic development of FHB during years with more favorable weather conditions, a double fungicide treatment (Falcon or at Feekes 10.3 and Prosaro at Feekes 10.5.1) was the most effective option, showing high biological efficacy (97.4% at Feeks 11.2 and 90.3% at harvest) against FHB of winter wheat, increasing wheat yield by 40.1%.
Importance of mosaic augmentation for agricultural image dataset
(Estonian University of Life Sciences, 2024) Kodors, S.; Sondors, M.; Apeinans, I.; Zarembo, I.; Lacis, G.; Rubauskis, E.; Karklina, K.
The yield estimation using artificial intelligence is based on object detection algorithms. Firstly, the object detection algorithms identify the number of fruits on images, then tree fruit load is predicted using regression algorithms. YOLO is a popular convolution neural network architecture for object detection tasks. It is sufficiently well studied for fruit yield estimation. However, the experiments are traditionally restricted to only one specific fruit category and growing season. This is a big shortcoming for the smart solutions like agro-drones, which must automatically complete yield monitoring of the most popular fruit species in commercial orchards. Therefore, the modern studies related to yield estimation increasingly raise attention to multi-stage, multi-state and multi-specie detection tasks. The multi-stage datasets can be described as a collection of multiple sub-datasets, e.g. flowers, fruitlets and fruits. The multi-state dataset can contain classes like mature, immature or damaged fruits. Meanwhile, the multi-specie dataset contains images with representatives of multiple cultures. However, if classic object-detection tasks like urban or indoor object detection have multiple classes presented in one image, then yield estimation datasets usually have images with only one class presented on them. Therefore, an image shuffle or mosaic augmentation are the intuitive training strategies of YOLO for object detection working with a collection of multiple single class datasets. We applied the YOLOv5m model to test both strategies, which were verified on three datasets: apple fruits (MinneApple), pear fruits (Pear640) and pear fruitlets (PFruitlet640). Our experiment showed that mosaic augmentation improves mAP@0.5:0.95 better than simple image shuffle. The mean difference between both strategies is equal to 0.0438.
Balance and coefficients of usage of nitrogen, phosphorus and potassium from the soil and fertilizers by tomatoes and peppers in the conditions of Ararat Plain of Armenia
(Estonian University of Life Sciences, 2024) Matevosyan, L.G.; Harutyunyan, S.S.; Galstyan, M.H.; Osipova, R.H.; Mkrtchyan, A.T.; Sargsyan, K.Sh.; Sadoyan, R.R.
The aim of the research is to reveal the biological removal, balance and coefficient rates of nitrogen, phosphorus and potassium use from soil, organo-mineral fertilizers and microbiological concentrates by tomato and sweet pepper in the conditions of Ararat Plain of Armenia. Field experiments were carried out in 2017–2019, on typical irrigated meadow brown soils in triplicate. It has been established that at tomato yields of 50–75 t ha-1, the biological removal of nitrogen ranges from 110 (without fertilizers) to 178 kg ha-1 (N150P80), P2O5: 61–89, K2O5: 166–289 kg ha-1, and at pepper yields of 23–32 t ha-1, respectively - 55–76, 38–49 and 77–106 kg ha-1. Tomato utilization rates from the soil (unfertilized version) are: N: 118, P2O5: 37, K2O: 8%, and the negative balances are respectively: 107, 67 and 109 kg ha-1, similar data for pepper were recorded at: N: 59, P2O5: 23, K2O: 4% and 52, 44, 20 kg ha-1. From fertilizers, tomato absorbs 27–45% nitrogen, 11–48% P2O5 and 48–72% K2O with negative balances (N: 15–55, P2O5: 14–76, K2O: 34–79 kg ha-1), in poultry litter the balance P2O5 = + 94.2 kg ha-1. For pepper, however, these data were respectively amounted to: N: 6–14, P2O5: 10–15, K2O: 9–20%, and the balances were positive. Microbiological concentrates (Azoto + phosphate Barvar) showed poor effectiveness as compared to organo-mineral fertilizers. It was also found that the lower the amount of a mobile element in the soil, or in the fertilizer dose, the higher its utilization rate and vice versa.
Wind power equipment for small farms and households
(Estonian University of Life Sciences, 2024) Beresnevich, V.; Cerpinska, M.; Irbe, M.; Viba, J.
This article deals with the development of small-sized wind power equipment as a viable solution for decentralized renewable energy production. To improve operational specifications of conventional turbine models with rotating blades, it is proposed to use a new design of wind power plant synthesized on the base of a closed loop conveyor equipped with flatshaped blades. In this design, blades are mounted on a belt with an opportunity to move together with it in one straight line direction. Air flow interaction with flat blade that performs translation motion is studied by computer simulation using a superposition principle. In accordance with this approach, a fast-chaotic motion of air particles (Brownian motion) is separated from the slow-directed air motion, with the given average velocity. Dynamic analysis of flat blade interaction with air flow is performed for the stationary air flow with constant speed and also for non-stationary flows with wind gusts. Optimization of the system parameters is made using the generated power as a criterion. Simulation results confirm the serviceability and efficient operation of the proposed conveyor type wind power equipment. It can be mounted on the roofs of buildings or rooftops of vehicles, also device is befriended to nature and people.
Diallel and generation analysis in F2 soybean populations
(Estonian University of Life Sciences, 2024) Ferreira, S.B.; Gomes, B.H.; Hamawaki, O.T.; Dias, P.A.S.; Hamawaki, C.D.L.; Hamawaki, R.L.; Nogueira, A.P.O.
The present study aimed to obtain estimates of the general (GCA) and specific (SCA) combining abilities of three soybean parents by means of the half table balanced diallel and to estimate genetic parameters of agronomic traits in F2 populations. The experiment was organized in complete randomized blocks with ten replications. The plants obtained from the combinations between the parents UFU 510, UFUS 7415 and MG/BR 46 Conquista were individually evaluated for thirteen agronomic traits. The results indicated that the parent UFUS 7415 had the highest and most positive GCA values for the production components. The best cross was UFU 510 × UFUS 7415, with the highest number of total pods and grain production. The three combinations showed a high coefficient of heritability for the number of productive nodes. At the crossing UFU 510 × UFUS 7415, greater selection gains and higher averages were observed for the number of pods with one, two and three grains and the number of total pods.
Digital marketing and communication strategies of agri-food enterprises on social media platforms
(Estonian University of Life Sciences, 2024) Konoplyannikova, M.; Radkevych, L.; Netreba, M.; Bilan, M.; Lorvi, I.; Nahorna, O.
This article explores the dynamic evolution of digital marketing and communication strategies within agricultural enterprises across diverse social media platforms amidst the industry's ongoing transformation. Employing a comprehensive approach, including detailed case studies and a mix of quantitative and qualitative analyses, the study investigates how these strategies enhance online presence, stakeholder engagement, and overarching marketing goals. Utilizing an advanced econometric model, the research uncovers statistical relationships, revealing the quantitative impact of digital marketing and social media on revenue generation for agricultural enterprises. The results highlight the effectiveness of a nuanced blend of content marketing, community building, and targeted advertising in boosting visibility and engagement. Beyond statistics, the study identifies key propositions for optimizing digital strategies in agriculture, emphasizing tailored content, data analytics, and the integration of emerging technologies. By scrutinizing the dynamic interplay between digital marketing and communication dynamics within the agricultural landscape, the research contributes theoretical insights and practical recommendations. Serving as a guiding compass for stakeholders, policymakers, and researchers, the study offers a roadmap for leveraging the transformative potential of digital strategies in the evolving agricultural industry. This research provides valuable guidance for stakeholders aiming to harness the synergies between digital marketing and communication strategies, ensuring a holistic approach to navigating the complexities of the digital landscape within the agricultural sector.
Use of geostatistical analyses for wheat production areas throung the variables NDVI, surface temperature and yield
(Estonian University of Life Sciences, 2024) Abreu, A.L.; Ferraz, G.A.S.; Morais, R.; Bento, N.L.; Conti, L.; Bambi, G.; Ferraz, P.F.P.
Geostatistics is a crucial tool for data analysis in the field of precision agriculture, allowing the characterization of spatial variability magnitude, optimizing profitability and yield in agricultural areas. In this context, the present study aimed to evaluate the spatial dependence of the variables yield, Normalized Difference Vegetation Index (NDVI), and surface temperature in winter wheat plants. This was achieved through fitting semivariograms with different statistical models and interpolating the study variables using Ordinary kriging. The experiment was conducted at Fazenda Santa Helena, located in the municipality of Lavras in the state of Minas Gerais, Brazil, with a 12-hectare winter wheat crop of the TBIO Calibre variety. Data were collected using a grid sampling method at different stages of wheat plant growth (tillering and elongation). The analyzed variables included yield, NDVI, and surface temperature. Statistical analyses were performed using the R software. Initially, the spatial dependence of the study variables was analyzed by fitting semivariograms using the Restricted Maximum Likelihood (REML) method and considering spherical, exponential, and gaussian models. The evaluation of errors was carried out through cross-validation, and subsequently, the data interpolation was performed using ordinary kriging with the best-fitted semivariogram model. The results demonstrated a proper fit of semivariograms for the study models, with the spherical model standing out for surface temperature variables (elongation and tillering), NDVI (tillering), and the exponential model for NDVI (elongation) and yield. Therefore, the use of geostatistics is emphasized as an important tool to assist in precision agriculture management in winter wheat crops.
Intercropping insect repellent plants (irps): a promising strategy for sustainable pest management
(Estonian University of Life Sciences, 2024) Gunaeni, N.; Setiawati, W.; Muharam, A.; Karjadi, A.K.; Murtiningsih, R.; Moekasan, T.K.; Korlina, E.; Hasyim, A.; Saadah, I.R.; Sulastrini, I.; Diningsih, E.; Udiarto, B.K.
In current intensive crop production, the utilization of natural biological control in pest management is not fully maximized, resulting in a significant dependency on the application of insecticides. Insect-repellent plants (IRPs) have become a prominent subject of research and a widely implemented strategy for reducing both pest damage and reliance on chemical insecticides. In this study, intercropping three IRP species, coriander (Coriandrum sativum L.; Apiaceae), celery (Apium graveolens L.; Apiaceae), and bunching onion (Allium fistulosum l.; Amaryllidaceae), in two intercropping systems were assessed for controlling insect pests in chilli pepper. The research was carried out in the experimental field of the Indonesian Vegetable Research Institute (IVegRI) in 2022. The results revealed that intercropping systems of chilli pepper with coriander, celery, and bunching onion significantly reduced plant damage over sole crops. Among the various intercrop combinations, chili pepper intercropped with coriander resulted in the lowest damage of three major pest species on chili pepper, Thrips parvispinus (51.77%), Helicoverpa armigera (47.67%), and Bactrocera dorsalis (40.35%). Furthermore, this effect enhanced the productivity of chili pepper yield (43.27%).
Adapting agriculture to climate shifts: managing crop water needs for environmental resilience in Sindh, Pakistan
(Estonian University of Life Sciences, 2024) Qureshi, H.U.; Abbas, I.; Shah, S.M.H.; Qureshi, Z.U.; Al-Qadami, E.H.H.; Mustaffa, Z.; Teo, F.Y.
Sindh is an important hub for the agricultural production in Pakistan. Therefore, this study was aimed to model the air temperature trend in Sindh and its impacts on the seasonal water requirement for Rice, Wheat, and Sugarcane under the Representative Concentration Pathways (RCP) 4.5 and 8.5 scenarios. In this study, RegCM4 with GFDL-ESM2M was used and the bias correction of RegCM4 simulations was done using Quantile Mapping. As per the analysis, the average annual temperature over the study area may rise by about 1.2 to 1.8 °C and 2.8 to 3.3 °C under RCP 4.5 and 8.5 scenarios respectively. Seasonally, warming is expected to be higher in spring and winter seasons, whereas, diurnally, the daytime temperature may increase by about 1.2 to 1.7 °C and 2.6 to 3.2 °C, while the nighttime temperature may rise by about 1.4 to 2.7 °C and 3.0 to 3.5 °C under the RCP 4.5 and 8.5 scenarios respectively. Consequentially, the seasonal water requirement for Rice in Sindh may increase by about 50–100 mm and 100–200 mm under RCP 4.5 and 8.5 scenarios respectively. For Wheat, the water requirement may rise by about 60 mm and 100 mm, whereas for Sugarcane, it may soar by about 100–150 mm and 150–200 mm under RCP 4.5 and 8.5 scenarios respectively. Conclusively, the rising crop water consumption may cause increased irrigation requirements, low crop water productivity and yield, and rising local water disputes thereby endangering the crop production and water security in the province.
Metabolite profiling, terpenoid and kaurenoic acid production of Adenostemma platyphyllum at different concentrations of hydroponic solutions in the wick system
(Estonian University of Life Sciences, 2024) Tamsin, A.H.N.; Nurfalah, R.; Trivadila; Batubara, I.; Rafi, M.; Ridwan, T.; Aziz, S.A.; Takemori, H.
Adenostemma platyphyllum, a medicinal plant belonging to the Asteraceae family, has gained increasing attention due to its potential as a source of bioactive compounds with diverse therapeutic properties but has not been widely cultivated. This work aims to obtain the optimum concentration of AB-mix solution to produce higher terpenoid and kaurenoic acid, as well as metabolite profiling in cultivating A. platyphyllum using a hydroponic wick system. This research uses a one-factor randomized block design of different concentrations of AB-mix nutrient solutions. Total terpenoids were quantified using the UV-Vis spectrophotometric method, total kaurenoic acid was determined using a high-performance liquid chromatography (HPLC) method, and the metabolite profiling was analyzed using a liquid chromatography-tandem mass spectrometry (LC-MS/MS) instrument. Several terpenoid compounds have been identified in A. platyphyllum, including Ent-17-Oxo-15-kauren-19-oic acid, andrographolide, cafestol, alphaFarnesene, curcumene, as well as ent-11α-hydroxy-15-oxo-kaur-16-en-19-oic acid (11αOH-KA) and 11α,15-dihydroxy-16-kauren-19-oic acid (11α,15OH-KA), which belong to the kaurenoic acid group. The plants had the highest total terpenoid and kaurenoic acid found in 1,300 mg L-1 nutrient concentrations. On the other hand, the highest terpenoid and kaurenoic acid productivity were found in plants with 900 and 1,300 mg L-1 AB-mix solution, respectively. Therefore, the optimum concentration of nutrient solution to produce optimum terpenoid and kaurenoic acid levels in A. platyphyllum cultivation by hydroponic wick system was 1,300 mg L-1.
Does the level of resistance to Acanthoscelides obtectus of bean genotypes (Phaseolus spp.) change according to the seed production environment?
(Estonian University of Life Sciences, 2024) Jiménez-Galindo, J.C.; Castellanos Pérez, G.; de la Fuente, M.; Malvar, R.A.; Ramírez-Cabral, N.; Padilla Chacón, D.
Bean weevil (Acanthoscelides obtectus) cause considerable losses in warehouses in dry bean (Phaseolus vulgaris L). Phaseolus acutifolius varieties could be used for genetic studies and genetic improvement of common beans. Tepary bean varieties resistance was studied produced with irrigation and under drought conditions to A. obtectus. Previously, we studied A. obtectus colony from Spain with some of these bean varieties. In the present research, we studied a different A. obtectus colony from México. The varieties T-amarillo, PS-AZH-15 and T-cafe beans showed a lower ovopositation. T-amarillo, T-negro and T-cafe increased the duration of the insect biological cycle. In the varieties T-cafe, T-negro and T-amarillo increased larvae mortality before burrowing the seed in percent and reduced the number of first generation adults. Little grain weight loss is caused by small number of emerged adults, in the varieties T-amarillo, PS-AZH-15, T-cafe and T-negro. According with adult’s number of first generation and grain weight loss in percent T-amarillo showed resistance and tolerance to A. obtectus infestation and it could be used as source of resistance for P. vulgaris breeding. No significant differences were found according to the seed production environment for any traits studied except for initial seed weight. Resistant varieties maintain their lethality regardless of the seed production environment. Probably A. obtectus is genetically different according to the area and is adapted to the varieties produced in each country or region.
Exogenous phytohormones and growth-promoting microorganisms in Basilisk grass cultivation
(Estonian University of Life Sciences, 2024) Andrade, E.B.; Teixeira, F.A.; Fries, D.D.; Cruz, N.T.; Jardim, R.R.; Da Silva, H.S.; Dos Santos, B.E.F.; Vieira, T.M.; Seixas, A.A.; Dos Santos, J.P.
The use of plant growth-promoting bio-inputs has been widely disseminated as a means to optimise pasture production processes. This study was conducted to evaluate the effects of applying exogenous phytohormones along with different microorganisms on the productive characteristics of Basilisk grass (Urochloa decumbens). The experiment was conducted in a 4×2 factorial design, in a completely randomised layout, evaluating four microorganism inoculations (no inoculation; Azospirillum brasilense + Pseudomonas fluorescens; Rhizophagus intraradices; A. brasilense + P. fluorescens + R. intraradices), combined or not with an exogenous phytohormone based on cytokinin, gibberellin and auxin. The results showed that inoculation with plant growth-promoting microorganisms stimulated an increase in root volume. In addition, the presence of the microorganisms increased the concentration of chlorophyll pigments, resulting in a 14% increase in the crude protein content of Basilisk grass compared with the control. The use of exogenous phytohormones also resulted in higher concentrations of total chlorophyll pigments and crude protein content, with increase in 25% and 9.7% respectively. The combined use of bacteria and mycorrhizal fungi, along with exogenous phytohormones, increased the accumulation of forage mass and leaf biomass. The combination enhanced carbohydrate accumulation in the leaves of Basilisk grass, thereby improving its nutritional quality. Therefore, considering the evidence found in this research, it becomes evident that the application of exogenous phytohormones, when combined with the inoculation of A. brasilense, P. fluorescens, and R. intraradices, represents a strategy to enhance the productivity of Basilisk grass.
Influence of coconut fiber incorporation on the mechanical behavior of adobe blocks
(Estonian University of Life Sciences, 2024) da Silva, N.A.; Cecchin, D.; Rocha, C.A.A.; Toledo Filho, R.D.; Pessin, J.; Rossi, G.; Bambi, G.; Conti, L.; Ferraz, P.F.P.
Adobe is an ancient construction technique, simple and low cost, still used in some parts of the world, mainly in rural areas. Normally, in these regions, a considerable amount of agricultural waste is generated that can be used for different purposes. An agricultural waste that has been increasingly studied in the construction sector is natural fibers. The addition of natural fibers in the soil matrix has been gaining prominence as it is a natural and easily accessible stabilizer. This work aimed to analyze and characterize adobe blocks reinforced with coconut fibers, with the addition of 1% and 2% compared to the reference block (without the addition of coconut fiber) through capillary absorption, fiber-soil adhesion, durability in the presence of water and mechanical, properties through of compression bending tests. The adobe blocks with the addition of fibers showed mechanical results above those required by the standard NBR 16814. The addition of fibers promoted higher capillary absorption results than the samples consisting only of soil and when exposed to drip erosion, no significant damage was observed in the adobe structure.
Management alternatives for sandy soils to overcome edaphic limitations in irrigated okra cultivation
(Estonian University of Life Sciences, 2024) Rodrigues, N.F.; Tavares, S.R.L.; Silva, F.C.; Hüther, C.M.; Corrêa, G.M.; Oliveira, J.R.; Hamacher, L.S.; Clemente, E.P.
Sandy soils are often unsuitable for agriculture due to their poor physical and chemical properties. However, using conditioners can improve these parameters, making these soils viable for cultivation. This study evaluated Red-Yellow Argisol (Clay), Biochar, and Ceramic residues as soil conditioners for Planosol. The experiments were conducted in pots in a greenhouse and the experimental design was completely randomized with three treatments and five replications, compared to a control (100% P). Treatments included Clay (50% P + 570.6 t ha-1 A), Biochar (50% P + 189.9 t ha-1 B), and Ceramic (50% P + 459.9 t ha-1 C). Okra (Abelmoschus esculentus L.) was used to assess the impact on development and productivity over 90 days from transplanting (DAT). Granulometry of conditioners, and the carbon, hydrogen, nitrogen, and ash content were analyzed. For constructed soils, granulometry, bulk density, particle density, and water retention capacity (CRA) were measured before planting. Chemical parameters, including Ca²⁺, Mg²⁺, K⁺, Na⁺, Al³⁺, H⁺, pH, and others, were measured at 0 and 90 DAT. Okra growth parameters, such as height, stem diameter, leaf number, leaf area, stomatal conductance, and chlorophyll a fluorescence dry biomass and leaf nutrient contents (N, P, K, Ca, Mg, Na) were assessed at 90 DAT. Results indicated that conditioners improved the physical and chemical properties of the Planosol and the physiological parameters of okra. Biochar increased phosphorus and potassium, while Clay enhanced nitrogen and sodium for okra cultivation.
Effect of fermented purple sweet potato flour on physiological conditions and intestinal conditions of broiler chickens
(Estonian University of Life Sciences, 2024) Widiastuti, E.; Febrianti, D.; Wahyuni, H.I.; Yudiarti, T.; Agusetyaningsih, I.; Murwani, R.; Sartono, T.A.; Sugiharto, S.
The study investigated the effect of fermented purple sweet potato flour (PSPF) on intestinal and physiological health of broilers. A 189-day-old broiler chicks were divided into T0 (diet based on corn and soybean meal), T1 (diet containing 15% unfermented PSPF), and T2 (diet containing 15% fermented PSPF). Samples collection and measurement were conducted at day 35. The T2 chicks had greater (p < 0.05) weight gain than T1, but did not differ from T0. Feed conversion ratio (FCR) was better (p < 0.05) in T2 than in T1. The mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC) were higher (P < 0.05) in T2 than in T0 and T1 groups. Haemoglobin tended (p = 0.08) to be lower in in T2 than in T0 and T1 groups. Heterophils were higher (p = 0.05) in T2 than in T0 and T1 groups. Total cholesterol and high-density lipoprotein (HDL) were higher (p < 0.05) in T0 than in T1. Low-density lipoprotein (LDL) tended (p = 0.06) to be lower in T1 than that in T0. Total protein and globulin were higher (p < 0.05) in T0 than that in T1 and T2. Lactic acid bacteria (LAB) to coliform ratio in the ileum was higher (p < 0.05) in T2 than in T0. LAB counts tended (p = 0.08) to be greater in T2 than in other chickens. T1 tended (p = 0.09) to have a smaller number of lactose negative Enterobacteriaceae (LNE) in caecum as compared to that of T0 chicks. T2 tended (p = 0.09) to have a lower crypt depth than T0. In conclusion, feeding fermented purple sweet potato flour contributes for the better growth, feed conversion, immune defence, bacterial population and morphology of the small intestine.
Innovative approach to real-time diagnostic of bolted joints and elastic couplings to prevent their fractures
(Estonian University of Life Sciences, 2024) Gorbacovs, D.; Gavrilovs, P.; Eiduks, J.; Gailis, M.
Failure of fasteners can lead to undesirable consequences. Fatigue failure of machine parts is difficult to predict and prevent. Vehicles and agricultural machinery include various systems such as engine, transmission, and many other systems that are fixed and connected using fasteners. Without a doubt, the performance of an individual system depends on the design of its kernel. But for the system to work, it must be properly fixed. Premature failure of bolts is subject of interest of engineers. The purpose of this study is to identify the causes of the failure of the fixing bolts and develop device and algorithm for early detection of conditions that might lead to bolt failure. The experimental data is collected analysing bolts and elastic couplings of electric passenger trains. Laboratory studies included the measurement of tensile strength, hardness, microanalysis of the metal structure and chemical analysis of failed old and new bolts. The authors present various visual and numerical results from this study. It also provides detailed conclusions about the causes of failure and recommendations for the selection of bolts for critical mechanical connections under dynamic loads and variable temperatures. The authors have developed a device that can be used in mechanical engineering, shipbuilding and other industries to control the deformation, vibration and shocks acting on a bolted joint. This device for monitoring the load and vibrations of bolted connections allows to constantly collect and analyse data during the operation of the vehicle in order to reduce the number of unscheduled repairs of vehicles due to its damage, as well as to reduce the number of accidents or other incidents. The authors also have developed a method and algorithm for calculating and evaluating the influence of external factors on the shell of a rubber-cord coupling. The study is based on statistical, material, and mathematical analysis of unexpected failures of rubber couplings. A numerical analysis of the operating conditions of the couplings before failure was performed. The results obtained are encouraging and prove that the use of an impact force measuring device and real-time data analysis can be cost-effective and can eliminate the problem of bolt and elastic coupling failure in one go, as well as reduce the cost of operating and repairing vehicles.
Assessment of salt resistance of some potato varieties by biochemical and RFLP markers
(Estonian University of Life Sciences, 2024) Badalyan, M.V.; Aloyan, T.V.; Dilanyan, V.T.; Kharatyan, S.A.; Martirosyan, H.S.; Sahakyan, A.J.; Sahakyan, N.A.; Melikyan, A.Sh.
Continuous changes in climate, desertification, reduction of arable land, increase in salted land, in the conditions of continuous growth of the population, the problem of providing food and food security to humanity arises, the solution of which is one of the challenges of the 21st century that requires universal efforts. At the same time, abiotic stresses, which are the cause of 50% of global yield losses, are the motivation for the creation of new stress-resistant varieties of crops using modern technologies. The salt resistance of that idea as a physiological manifestation with a polygenic component is characteristic in the modern processes of selection management. This work presents studies of salt tolerance of three valuable varieties of potatoes cultivated in Armenia, using biochemical and DNA-markers. Classical agronomic, molecular-biological, genetic-mathematical methods are used in the researches. In order to induce salt stress and provocation background in plants, 50, 100 and 150 mmol solutions of NaCl were used. The results have shown that 11S-globulin of all varieties are polymorphic, forming different electrophoresis spectra and protein formulas. It is also evident that plants with different spectra of the same varieties react differently to salt stress. The DNA restriction regions of the saltresistant variants are significantly longer than those of the non-salt-resistant forms. Thanks to the biochemical and RFLP markers, it has been possible to establish salt tolerance loci, to identify and list plants with a salt-tolerant spectrum of the same variety, which can be nominated as new salt-tolerant varieties for breeding stock producers.
Effect of genotype x external environment interaction on the number of the kernel per ear of barley
(Estonian University of Life Sciences, 2024) Radic, V.; Komljenovic, I.; Nastic, S.; Petkovic, B.
Genotype, external environment and their mutual interaction are determining or limiting a yield and barley tolerance to stressful conditions. This paper presents the results of a two-year study of nine selected genotypes at two localities. Aim of the investigation was determine which of the genotypes in the given production conditions gives the best results in the height and stability of yield. Based on the analysis of variance, Duncan 's test and interaction relations, a large variability between the examined genotypes was determined under the influence of different agroecological conditions of the locality, years of testing and their mutual interactions. All genotypes in this study achieved high yields. The highest total average yield from both localities and both years of testing was achieved by genotype 3 (8,767.99 kg ha-1), and the lowest genotype 7 (6,075.85 kg ha-1), which is significantly higher than the average yield in production in our country (3,150 kg ha-1). This showed that, with the selection of quality genotypes, the application of quality agrotechnics in appropriate agroecological conditions, a higher yield can be achieved.

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