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Agronomic and bromatological characteristics of Cassava cultivars
(Estonian University of Life Sciences, 2025) Silveira, R.B.; Pires, A.J.V.; Dutra, I.C.; Nogueira, M.S.; Andrade, W.R.; Jesus, M.R.; Oliveira, G.R.S.; Oliveira, E.J.; Silva, N.V.; Santos, B.E.F.; Sousa, M.P.; Públio, P.P.P.
The aim of this study was to evaluate the potential of the aerial part of cassava, analyzing its development and nutritional value, in addition to the production of biomass at different times and with different management. A randomized complete block design was used, with six cassava varieties (BRS Formosa, BRS Mulatinha, Eucalyptus, BRS White Pot, BRS Kiriris and BRS New Horizon) and five replicates, harvested six and twelve months after planting, with and without pruning. To evaluate the amount of biomass produced by the aerial part of cassava and the production of roots, a 6×2 factorial scheme in randomized complete blocks design was conducted. Six cassava varieties were tested, each with five replicates. The plants were harvested at two different times: with pruning (harvesting at six and twelve months after planting) and without pruning (single harvest at twelve months). There was an effect for the characteristics plant height, stem diameter, number of stems, number of leaves, lobe length, lobe width and petiole length, however when they were evaluated at twelve months, there was no effect, only for the characteristics lobe length and petiole length. It was found that there was an effect for dry matter, ether extract, hemicellulose and ADF. The BRS White Pot variety presented a higher concentration of non-fibrous carbohydrates. Differences were observed for neutral detergent fiber corrected for ash and protein and lignin. For the values of total digestible nutrients, the cultivars BRS White Pot, BRS New Horizon and BRS Formosa stood out in relation to the others. There was a difference in the protein fractionation of the different cassava cultivars for total nitrogen fraction, fraction A and fraction C when they were harvested six months after planting. However, when they were evaluated at twelve months, there was only an effect for fraction C. There was an effect for CT, fraction A+B1, fraction B2 and fraction C when they were evaluated six months after planting. However, when they were evaluated twelve months after planting there was no difference for total carbohydrates and fraction B2. The interaction was not significant between the different cultivars and pruning management for the production of green matter, dry matter, crude protein, total digestible nutrients of the aerial part and green matter and dry matter of the roots. In management without pruning, there was an increase in the variables PGMPA, PDMPA, PCPPA and PTDNPA. The cultivars BRS Mulatinha and BRS New Horizon are recommended as they present greater leaf retention and number of stems, providing greater biomass production when managed without pruning.
The role of ICT and animal welfare concerns in Estonian food purchasing channel preferences
(Estonian University of Life Sciences, 2025) Aleksandrova, Olha; Põder, Anne; Kukk, Martin; Viira, Ants-Hannes; Tamm, Hardi; Estonian University of Life Sciences. Institute of Agricultural and Environmental Sciences. Chair of Rural Economics
The modern consumer is now more attentive to animal welfare practices, and this is an important factor when making food purchasing decisions. Different levels of concern for animal welfare as well as the use of information and communication technology (ICT) affect consumer food consumption and purchasing decisions and information access. This study explored both consumer preferences for food purchasing channels by using principal component analysis and regression analysis as well as the interaction between ICT use and animal welfare concerns. To analyse consumer preferences for food purchasing channels, we utilised data from a survey on the use of various retail outlets, such as buying online, retail stores, local markets, directly from producers, and organic or specialised shops. We used the varimax rotation method in principal component analysis to find the main factors in consumer choices related to animal health and welfare. Results from five generalised linear models indicated that Estonian consumers are more willing to purchase products of animal origin directly from producers or in organic or specialised shops when they pay attention to animal health and welfare. Animal health and general welfare practices aimed at ensuring the safety of food in large-scale production and distribution are significant for retail shop users. More frequent ICT use does not translate to a preference for online food shopping over more traditional retail purchasing. Compared with other age-gender groups, younger women prefer to buy food directly from producers. Older individuals in particular favour purchasing food from traditional retail stores rather than online. Consumers who prefer to buy food online are more concerned about animal health and welfare.
Evaluation of salt tolerance in sugarcane mutant clone M4 through the application of a rhizobacterial consortium
(Estonian University of Life Sciences, 2025) Hartatik, S.; Wildana, F.; Gusti, A.A.H.; Aurela, R.D.; Setiyono; Avivi, S.; Kim, K.M.; Ubaidillah, M.
Sugarcane is one of the most important commodities in the world, with average global production reaching 1.9 billion tonnes in 2022. However, the availability of productive land does not meet the high production demand. This encourages farmers to utilize suboptimal land to meet global sugar cane needs. The aim of this study was to utilise a rhizobacterial consortium to identify the sugarcane mutant clone M4's salt tolerance, which was compared to the widely used Bululawang variety. The experiment was conducted using a hydroponic system with salt treatment (150 mM NaCl) and varying concentrations of the rhizobacterial consortium (2, 4, and 6 mL). Morphological and physiological parameters were measured to assess the response to salt stress. The findings showed that the M4 clone significantly improved plant height, root length, and total chlorophyll content compared to Bululawang. The application of the rhizobacterial consortium significantly enhanced salt tolerance in both genotypes, with the M4 clone showing a stronger response. Overall, the M4 clone displayed greater potential for cultivation in high-salinity soils, particularly when supported by the application of a rhizobacterial consortium. These findings provide valuable insights for the development of sugarcane varieties with enhanced tolerance to abiotic stress, potentially improving agricultural productivity in suboptimal lands.
Effect of shade treatment on the growth and vitality of cloudberry Rubus chamaemorus
(Estonian University of Life Sciences, 2025) Āboliņa, L.; Karlsons, A.; Osvalde, A.
Cloudberry Rubus chamaemorus is a promising new berry species for cultivation in Latvia. This study aimed to assess how different shade levels influence cloudberry growth and vitality in semi-controlled conditions. Cloudberries (variety ‘Nyby’) were planted in enclosed planting area and grown under four shading treatments, using shading nets: control (no shade), 30%, 50%, and 80% shade for two years. Non-destructive SPAD measurements were taken weekly during the growing season (from May to August) in both years. Leaf size was measured at the end of August in both years, while leaf density and leaf nutrient concentrations were determined at the end of August in 2024. The results revealed significant differences between treatments for all of the measurements, with the highest values observed in plants under the 80% shade in both years. In the second year, the 50% an 80% shade treatments had similar results. Overall, the highest plant vitality was observed under 50% and 80% shade, demonstrating that netting effectively protects cloudberries from excessive sunlight. While larger leaves might improve light capture, they also require additional energy, potentially reducing resources available for fruit production. Thus, we suggest the 50% shade to be the most effective for cloudberries in the Latvian climate, as it balances protection with optimal energy conservation. Additionally, optimal fertilizing in the field could improve plant health and yield, therefore further studies regarding the combined effects of shade and fertilization on cloudberry production are required.
Assessment of CO2 emission rate from extended area sources with WindTrax model in a dairy cattle farm
(Estonian University of Life Sciences, 2025) Mattia, A.; Merlini, M.; Squillace, F.; Rossi, G.; Conti, L.; Becciolini, V.
This paper aimed to evaluate the WindTrax model to quantify CO2 (carbon dioxide) emissions in a commercial dairy cattle farm in Central Italy with a low-cost measurement system. A field trial of 20 minutes was conducted in February 2023, using two G-eko 2.0 MSPs (multi-sensor platforms), an anemometer, and a GNSS receiver, in unstable atmospheric conditions. Then, 5-minute averaged data were used as input in the WindTrax software for applying the backward Lagrangian Stochastic model. The model was used for calculating four mean CO2 emission rates (0.20212 ± 0.04994 g m-2 s-1) with 50,000 particles and the horizontal dispersion of CO2 concentrations around the sources using different numbers of particles (5,000, 10,000, 30,0000, and 50,000). Atmospheric dispersion maps, confidence interval concentration maps, and vertical profile plots were obtained by increasing the number of particles. The model shows better performances, in terms of confidence intervals, with a high number of particles with a stabilization of modeled median values between 30,000 and 50,000 particles. Horizontally, the lowest confidence intervals (near to zero) were obtained at 100–150 m from the sources along the wind direction, suggesting that the downwind sensor could be placed at a greater distance. Similarly, a better-defined vertical trend in modeled concentrations is observed as the number of particles increases. Wind gusts could have a great effect on emission rate calculation with limited sampling periods, as in this case, but simultaneously unstable atmospheric conditions affect the increased dispersion and dilution of CO2.
Psychosocial work environment risks for museum workers in Latvia
(Estonian University of Life Sciences, 2025) Priede, I.; Roja, Z.; Kalkis, H.; Sloka, B.
In Latvia, as elsewhere in the world, psychosocial risks at work are considered to be a topical occupational risk in every sector of the economy, including the cultural sector. The aim of this study was to investigate the psychosocial risks of the working environment for museum workers in Latvia. The study involved 303 respondents from different museums in Latvia. A staff survey was conducted, and psychosocial risks at work were assessed using the short version of The Copenhagen Psychosocial Questionnaire - COPSOQ III. The survey found that 73–77% of museum employees are women, with about a quarter of respondents reporting working more than 40 hours per week. Work is often performed in a forced posture, 28.1% of respondents complain of overwork, 70.3% of respondents report an unsuitable working environment, almost half of respondents indicate that they are exposed to harmful chemicals at work, and almost all employees report low pay. The results of the COPSOQ survey show that the main reasons why the majority of respondents have chosen to work in the existing museum are: the support of colleagues, a good atmosphere, the opportunity to use knowledge and skills, as well as the meaning of work. Future research will focus on using cognitive tests to better understand the psychosocial risks faced by museum workers.
Construction, calibration and evaluation of mini-lysimeters in the management of irrigation in a protected environment
(Estonian University of Life Sciences, 2025) Matos, M.L.; Lyra, G.B.; Cecchin, D.; Hüther, C.M.; Francisco, J.P.; Jorge, M.F.; Pereira, C.R.; Hamacher, L.S.; da Silva, L.D.B.
The production of forest seedlings requires controlled environments and specific practices, highlighting the need for rational irrigation management. Historically, excessive irrigation has compromised seedling quality, underscoring the importance of developing technologies and research focused on water use efficiency in nurseries. Thus, technologies that are more financially accessible to producers contribute not only to cultivation but also to the social inclusion of these producers in broader markets. Mini-lysimeters can be effectively used to monitor the water balance in potted and tray-grown plant production, thereby reducing water waste in forest nurseries. In this study, portable electronic weighing mini-lysimeters were constructed for greenhouse evapotranspiration research using load cells (capacity: 20 kg), as sensor elements, and dataloggers for data acquisition. Calibration curves were established by correlationg standard weights and voltage readings, and were analyzed using regression analysis. The coefficient of determination (𝑟𝑟2) and the standard error of estimation (SEE) were used to evaluate model accuracy. Under field conditions, the lysimeters’ performance was assessed using the correlation coefficient (r); Willmott's index (d); performance index (c) and SEE, with pine and eucalyptus seedlings. The calibration curves were well described by linear models, with 𝑟𝑟2 values exceeding 0.994. The highest SEE (2.44 g), observedin mini-lysimeter III, remained below the 4 g detection threshold of the load cell. All performance indicators (r, d, and c) were above 0.999, with SEE values ranging from 6.2 to 36.2 g (less than 1 g per tube), demonstrating that the mini-lysimeters are suitable for monitoring daily evapotranspiration.
Comparison of in vitro regeneration and transformation efficiency among five vietnamese indica rice cultivars
(Estonian University of Life Sciences, 2025) Cao, L.Q.; Nguyen, P.D.; Pham, X.H.; La, V.H.; Nguyen, X.V.; Nguyen, T.D.
This study optimized the in vitro regeneration and transformation processes for five popular indica rice cultivars in Vietnam named as BC15, Bac Thom 7 (BT7), Khang Dan 18 (KD18), OM5451, and TBR225. The highest callus induction rates (83–93.67%) were achieved on a medium containing 2.5 mgL-l 2,4-D, supplemented with 500 mg L-l each of L-proline, L-glutamine, and casein. Higher or lower concentrations of 2,4-D resulted in reduced callus induction. Among tested cultivars, BT7 exhibited the highest callus induction rate of 93.67%. Shoot regeneration was optimized on a medium with a combination of 0.5 mg L-l kinetin, 2.0 mg L-l BAP, and 0.5 mg L-l NAA, resulting in regeneration rates ranging from 80.23% to 90.77% across cultivars, with BT7 exhibiting the highest regeneration rate (90.77%). Hygromycin at 20 mg L-l was optimal for selecting transgenic calli, with BT7 showing the highest transformation efficiency opdetermined to be optimal for selecting transgenic calli, with BT7 achieving the highest transformation efficiency (44% hygromycin-resistant callus and 29% GUS expression). PCR analysis confirmed a high proportion (87.5%) of transgenic plants in the BT7 cultivar. These findings indicate that the BT7 is the most suitable cultivar for genetic transformation and gene editing applications.
Bolstering household resilience to food insecurity in protracted crisis: the Case of Upper-Nile State, South Sudan
(Estonian University of Life Sciences, 2025) Bisetsa, E.; Burny, P.; Bititi, G.; Mumararungu, I.; Rwirahira, J.; Rutabagaya, E.
This study assessed food insecurity in four counties of Upper Nile State using the Food Consumption Score (FCS) and Household Hunger Scale (HHS). It also ascertained the coping mechanisms adopted by households in response to food insecurity using the Reduced Coping Strategy Index (rCSI), it also formulated recommendations to bolster the ability of households to withstand food insecurity. Quantitative data were collected through a structured household survey of 440 randomly selected respondents from 21 payams using two-stage cluster sampling with probability proportionate to size. Qualitative data were gathered via focus group discussions and interviews with community leaders. The findings reveal alarming food insecurity levels. Over half (55%) of households fall into the poor FCS category, characterized by minimal dietary diversity and insufficient protein, fruits, and vegetables, while 34.3% are borderline, and only 10.7% achieve acceptable dietary standards. The HHS shows 76.1% of households experience moderate hunger, reflecting significant health and well-being challenges. Coping mechanisms reveal further distress, with Baliet County reporting the highest mean rCSI (21.5), followed by Ulang (20.7), Melut (19.3), and Nasir (18.9). These findings underscore the urgent need for targeted interventions. Recommendations include promoting resilience through diversified livelihood activities such as small-scale agriculture, poultry, and goat-rearing, coupled with training and resource provision. Investments in drought-resistant seeds, improved farming techniques, and market access initiatives are essential. Additionally, community-based projects to rehabilitate irrigation systems and provide agricultural extension services could help sustain food security. The FCS, HHS, and rCSI metrics offer crucial insights into the extent and nature of food insecurity, guiding efforts to support the most vulnerable populations in Upper Nile State.
Gender and intersectional analysis of agricultural value chains for youth engagement in Rwanda
(Estonian University of Life Sciences, 2025) Rutabagaya, E.; Burny, P.; Ya-Bititi, G.M.; Bisetsa, E.; Mumararungu, I.; Rwirahira, J.
Youth engagement in agriculture is recognized as a quick and effective way to address problems of rural unemployment, poverty and food insecurity. This paper explores factors influencing youth engagement in agricultural value chains across nine districts in Rwanda, focusing on five major crops in Rwanda: maize, Irish potatoes, beans, chilies, and avocados. The study employed both quantitative and qualitative methods, including a survey of 635 youth engaged in selected value chains across nine districts in Rwanda, supplemented by key informant interviews and focus group discussions. Results from this study revealed a segmentation of youth engagement in value chains along gender lines, both in the selection of value chains and accross different segments. The study identified differences in the prioritization of needs among different youth social identities in agricultural, along with gender disparities in the ownership and control of productive resources. The study further noted that young women encounter particular barriers limiting their participation in leadership roles in agricultural organizations, including limited skills, restricted mobility, low education, and heavy domestic responsibilities. The study recommends deliberate measures to address these challenges, entailing the introduction of financial solutions to improve youth access to productive resources, affirmative actions to enhance young women’s inclusion in lucrative value chain segments, and awareness interventions to address social norms. Likewise, strengthening governance structures of farmer cooperatives for youth engagement will unlock employment opportunities for young people in agriculture.
Biodiversity of phytoplankton (non-diatoms) as bio- indicators in assessing the water quality and trophic status of the Euphrates river between Al- Baghdadi and Al-Ramadi Cities, Western Iraq
(Estonian University of Life Sciences, 2025) Al-Tamimi, Abdul-Nasir A.M.; Al-Obeidi, Nawras A.S.
Given the global climate changes, especially the drought conditions that Iraq's climate has been suffering from in recent years, along with the stifling water scarcity, the current study aimed to focus on developing quantitative and qualitative tools and strategies for phytoplankton (non-diatoms) as vital indicators in order to protect ecosystems, enhance their resilience, and promote sustainability. Four sites were chosen for the most prominent cities. The main site within the river basin for the period from July 2022 to April 2023 to collect water samples and phytoplankton cells (non-diatoms). The current study showed that the water of the Euphrates River at the current study sites is warm, pH neutral, with high basicity and medium hardness, with EC, TDS and turbidity, and the BOD is high, exceeding permissible limits, with good ventilation. Cl and Na salts, nutrients as NO3, were available in normal proportions, with PO4 concentrations exceeding the permissible limits due to the river water’s impact on agricultural lands around the river basin. During the study, 137 species belonging to five main classes were identified. Chlorophyceae were dominant at a rate of 55%, followed by Cyanophyceae at a rate of 34%, then Euglenophyceae at a rate of 4%, then Pyrrophyceae at a rate of 4%, and Chrysophyceae at a rate of 1%, where the highest density was recorded. For phytoplankton cells (non-diatoms) in site 1 (Al-Baghdadi) 2,438.8 cells L-1, while the lowest density was recorded in site 4 (Al-Ramadi Dam) 1,761.2 cells L-1. The results of biodiversity indices showed that the waters of the Euphrates River have low to moderate biological diversity, little to moderate pollution, and moderate species richness, with high homogeneity in their distribution between sites. The predominant groups of species during the study period were Oscillatoria formosa, Pediastrum simplex, p. duplex, Scenedesmus alternate, S. dimorphus, S. quadricauda, S. artcuatus var. platydiscus, microporium crassior, Pediastrium boryanum, Coeloastrum microporium, Chrococcus limeticus, C. minor.
Efficiency of seed priming and co-treatment strategies in salt effect mitigation using Nicotiana glauca leaf extract on tomato seedlings (Solanum lycopersicum L.)
(Estonian University of Life Sciences, 2025) Maaroufi-Dguimi, H.; Gamal Mohammed, S.; Nasraoui Hajaji, A.; Abdalgadir, H.
The Al-Baha region suffers from soil salinity, negatively impacting agriculture. Current study examined aqueous extracts from Nicotiana glauca as plant-based biostimulants to alleviate salinity's effects and reduce chemical fertilizer use. An aqueous extract of N. glauca, applied in ascending doses of 20%, 50%, and 100%, was being used. This biostimulant was applied using two methods: seed priming and co-treatment on the seeds of Solanum lycopersicum L. Results indicated that all tested doses, whether applied through seed priming or co-treatment, enhanced the final germination percentage (FGP) and reduced the mean germination time (MGT) under saline conditions. With priming, the 20% dose was most effective in reducing salt treatment effects on FGP, improving it by 5% compared to untreated salt-stressed seeds. In co-treatment, the 100% dose showed a 4.5% reduction in FGP decline referring to untreated and stressed seeds. For priming treatments, the 20% dose reduced MGT by 22%, while the 50% dose in co-treatment reduced it by 28% compared to untreated and stressed seeds. The priming strategy used in this study did not result in significant enhancements in growth parameters, particularly in the fresh weight (FW) and dry weight (DW) of the epicotyls. As priming, the 20% dose had the most significant mitigation effect on epicotyl FW, DW and chlorophyll (Chl) content by 15%, 10% and 30% referring to untreated and stressed seedlings, respectively. However, all tested biostimulant doses used as co-treatment proved effective in mitigating the negative effects of salt on epicotyl and root FW, DW, and Chl content. Seedlings treated with various strategies and doses showed a smaller increase in malondialdehyde (MDA) and proline (Pro) levels under salinity stress. As stress indicators, both Pro and MDA levels were significantly reduced when a co-treatment strategy was applied. Furthermore, the results indicated that the effectiveness of the N. glauca aqueous extract in alleviating salt stress could be attributed to its content of several phenolics, flavonoids, and tannins, which possess antioxidant properties that enhance the plant's tolerance against salt-induced oxidative stress.
Development of tropical grassland biomass prediction model based on UAV RGB images
(Estonian University of Life Sciences, 2025) Ramos, B.L.P.; Seixas, A.A.; Nascimento, L.M.G.; Dias, D.L.S.; Amorim, J.M.S.; Lemos, O.L.; Pedreira, M.S.
The objective of this study is to assess the predictive potential of indices derived from RGB images captured by a camera mounted on a remotely piloted vehicle (RPV) to estimate the fresh and dry forage yield of grasses from the Urochloa genus. The experiment was conducted between December 2021 and January 2023, involving four cultivars of the Urochloa genus (U. brizantha cv. Braúna, U. brizantha cv. Paiaguás, U. hybrid cv. Camello, and U. decumbens cv. Basilisk), with flights conducted at two heights (20 and 100 metres). The values of the Green Leaf Index (GLI) and Digital Vegetation Model (DVM) extracted were correlated with the yields of fresh (FFY), dry forage yield (DFY), dry matter content (DM), and crude protein (CP). The results showed that DVM exhibited greater efficiency in estimating DM and CP at a flight altitude of 20 m. In contrast, GLI proved more efficient in estimating FFY and DFY at 100 m altitude, suggesting the potential for combining DVM and GLI to develop predictive models. The RGB images obtained via RPV have potential for estimating forage productivity and quality, expanding the possibilities of pasture management techniques.
Evaluation of maize (Zea mays L.) inbred lines for tolerance to Aluminum toxicity using selection indices
(Estonian University of Life Sciences, 2025) Zishiri, R.M.; Mutengwa, C.S.; Tandzi, L.N.; Manyevere, A.
Selection of genotypes with better yield performance when exposed to stress (biotic or abiotic) is key objective for every plant breeding program. Aluminum toxicity is one of the significant constraints to maize production in acidic soils in many parts of the world. The aim of this study was to identify desirable genotypes with Al tolerance based on selection indices at seedling stage and identify the most effective selection indices under Al stress conditions. 75 Quality Protein Maize (QPM) genotypes were evaluated in CRD with three replicates in the laboratory using a nutrient solution screening method. Additionally, the same genotypes were also screened in the greenhouse arranged in RCBD with three replicates using soil bioassays. The genotypes were exposed to aluminum (Al) toxicity and non-toxic conditions. Data were collected and seven selection indices namely: Stress susceptibility index (SSI); stress tolerance index (STI); geometric mean productivity (GMP); Tolerance index (TOL); Stress Resistance Index (SRI); Percentage Reduction (PCRD); and Mean Productivity (MP) were calculated. Dry Matter (DM) yield under Al toxicity and non-toxic conditions had highly significant (p < 0.001) effects with GMP, STI, SRI and MP, suggesting that these indices have the potential to differentiate genotypes for Al tolerance. Significant and negative correlations were observed between DM and PCRD, TOL, and SSI. Indices that had highly significant and very strong correlations amongst themselves were PCRD with SSI (r = 1.00), and GMP with STI (r = 1.00). The most desirable selection indices that can be used to select tolerant QPM genotypes included GMP, STI, SRI, PCRD, and TOL as they had strong correlations with dry matter under Al toxicity. The tested genotypes were classified into four groups using the principal component (PCA) analysis known as QPM genotypes with high performance under both environments (Group 1), those with high performance under optimum conditions (Group 2), genotypes with high performance under Al stress conditions (Group 3) and those with low performance under both conditions (Group 4). The top five most tolerant maize inbred lines were CML 486, QSY 2, IBL 9, IBL 5 and IBL 4. These tolerant genotypes could be used as parent material for hybridization programs in developing Al tolerant cultivars.
Diazotrophic plant growth-promotion bacteria and sugarcane straw levels: Effects on sugarcane productivity and on soil enzymatic and microbiological activities
(Estonian University of Life Sciences, 2025) Vieira, R.F.; Luiz, A.J.B.; Ramos, N.P.
Due to the rising demand for bioenergy, a certain amount of sugarcane straw is often removed for ethanol production, but this practice may compromise health soil. In addition to the amount of straw, growing concern with the environment has made the use of diazotrophic plant-growth promotion bacteria (DPGPB) an alternative to the use of nitrogen fertilizers. A research was designed with the aim of evaluating the effect of different amounts of straw kept on the soil on soil microbial and enzymatic parameters and on sugarcane yield during the first ratoon. The field experiment was carried out in randomized blocks, using nitrogen fertilizer (NF) or DPGPB (BI), both with four straw levels. The parameters evaluated were: β-glucosidase (GA), urease (UR) and acid phosphatase (APA) activities, fluorescein diacetate activity, basal soil respiration, microbial biomass N, total C, total N and labile carbon. Responses were not obtained for various parameters with respect to the straw levels which was attributed to the short experimental period. In general, the evaluated parameters were always higher in the BI treatment, except for APA, which was lower in this treatment. This fact could be attributed to the greater capacity of the inoculated plants to make phosphorus available to the plants, which could reduce APA. The absence of a response for sugarcane yield between the NF and BI treatments demonstrates the beneficial effect of the bacteria in the inoculant in suppressing plants with adequate nitrogen contents. Greater yields were obtained for the L64 and L100 straw levels with no significant difference. This demonstrates the adequateness of removing part of the straw to produce second generation ethanol.
Productive and biochemical responses of Marandu grass under fertilization protocols
(Estonian University of Life Sciences, 2025) Dutra, I.C.; Pires, A.J.V.; Jardim, R.R.; Silva, H.S.; Santos, B.E.F.; Silva, N.V.; Ribeiro, A.S.; Dutra, G.C.; Filho, C.A.A.O.; Publio, P.P.P.; Silva, A.P.G.; Nogueira, M.S.
The aim of this study was to evaluate the effects of liming and chemical fertilization protocols, containing different combinations of nitrogen (N), phosphorus (P) and potassium (K), on the photosynthetic pigments, productive characteristics and carbohydrate concentration of Urochloa brizantha cv. Marandu. Five fertilization protocols were evaluated (PK fertilizer combination; NP fertilizer combination; NK fertilizer combination; NPK fertilizer combination; and without fertilizer - control), associated or not with soil correction via liming, in a completely randomized design, with four replicates. The experimental units consisted of plastic pots with a capacity of 12 liters, which were filled with 10 dm³ of sandy clay loam soil. Seeds of Urochloa brizantha cv. Marandu, with 80% cultural value were used. With the corrected soil, the NP protocol provided greater production of dry mass of residue (PMSRE), root volume, leaf area, leaf area index, total sugar content (AST) and starch in the root, compared to the other protocols. Without liming, the NP protocol provided greater production of aerial part dry mass (PMSPA), root volume, leaf aerial volume, leaf aerial index and AST content in leaves, roots and residue. The NPK protocol, with liming, was 73% higher in chlorophyll a content, 50% in carotenoid content, 90% in PMSPA, 78% in leaf area and 76.2% in leaf area index, compared to the soil without correction. The use of NP fertilization with liming is recommended as it provides positive responses on the photosynthetic pigments, productive characteristics and total sugar content of Marandu grass.
The impact of straw application on growth dynamics and proline accumulation in drought-stressed rice
(Estonian University of Life Sciences, 2025) Ria, R.P.; Kartika, K.; Lakitan, B.; Sulaiman, F.; Meihana, M.
The frequent occurrence of unpredictable extreme droughts necessitates investigating measures to mitigate their impacts, as drought may occur at any growth phase of rice. This study evaluated the efficiency of straw applications to conserve soil moisture and mitigate the negative effect of drought stress on rice in tropical riparian wetlands. Rice straw was applied as organic matter (S1) and as mulch (S2) and then subjected to drought stress during early vegetative (D1), late vegetative (D2), and generative (D3) phases. The result of this study showed that the utilization of straw slowed down the water loss through evaporation as indicated by soil moisture. However, both rice straw applications, organic matter and mulch, were inefficient in maintaining the optimum plant growth when the soil moisture declined to < 10%. Drought stress at the early vegetative phase reduced the number of leaves by 63.68%, the number of tillers by 50.58%, and the total leaf area by 72.36%. Drought stress at the early vegetative phase also delayed flowering time for 11 days. Meanwhile, drought stress during the generative phase reduced the number of filled spikelets by 45.18% and increased sterile spikelets to 247.05%, which significantly reduced the yield. Plants that experienced drought stress during the vegetative and generative phases eventually increased the proline content by about 10 times (18.47 mmol g-1) compared to unstressed plants (1.62 mmol g-1). Straw mulching is recommended for mild to moderate droughts, but additional methods are needed to maintain soil moisture below 10%.
Toxicity of insecticides for adults of Diceraeus melacanthus Dallas, 1851 (Hemiptera: Pentatomidae) in three exposure modes
(Estonian University of Life Sciences, 2025) Vieira, E.C.S.; Ávila, C.J.; Vieira, M.C.S.; Silva, P.G.
Phytophagous stink bugs are considered the important pest in second-crop corn cultivation in Brazil, especially when they occur during the early stage of plant development. This study aimed to evaluate the efficiency of insecticides in controlling adults of the Diceraeus melacanthus (Dallas, 1851) stink bug when applied separately in three different modes of exposure. The treatments were evaluated in three modes of exposure of insecticides to D. melacanthus adults as described below: direct contact (direct application of the insecticide to the insects); tarsal contact (exposure through their walking on the treated surface) and ingestion (contact through their feeding on previously treated fresh bean pods). Mortality was assessed at 1, 5, 24 and 48 hours post-exposure. We observed that the percentage of accumulated mortality of D. melacanthus adults was significant through direct contact with chemical treatments. However, if the target insect does not receive direct spraying on its body, indirect contact through its tarsus walking on the treated surface can guarantee a significant final mortality of the stink bugs. In addition, although the mode of exposure through ingestion has shown low mortality, it may also contribute to the final mortality of stink bugs in the field depending on the chemical treatment applied to the crop.
Assessment of new citrus hybrid rootstocks to salinity at the early seedling stage under greenhouse conditions
(Estonian University of Life Sciences, 2024) Majji, M.; Chetto, O.; Talha, A.; Bouaaza, G.; Beniken, L.; Benkirane, R.; Benyahia, H.
The citrus industry in arid areas is largely constrained by the salinity of irrigation water and soil. This study was conducted to determine how six novel citrus hybrid rootstocks will respond to salinity at the seedling stage. Three different NaCl concentrations, 0, 2, and 5 g L-1, were added to the half-concentrated Hoagland solution (corresponding to 1.3 (control), 4 and 9 dS m-1, respectively). Three-month-old seedlings grown in greenhouse conditions and transplanted in plastic pots were used. After two months of stress, different responses from the rootstocks and salt levels were observed. The addition of NaCl to the irrigation solution considerably decreased the fresh and dry weight and leaf chlorophyll content. Additionally, the proline content, soluble sugar, and the leaf chloride content increase with the increase in salinity. Our findings demonstrated that the hybrid Poncirus Trifoliata× Citrus reshni Hort. ex Tan. (V5) H6 is salt-sensitive, accumulating a high leaf chloride level of 46.92 mg g-1 of dry matter and a low chlorophyll content of 1.12 mg g-1 of fresh matter associated with signs of leaf toxicity, leading to poor fresh and dry weight. Although hybrid Poncirus Trifoliata× Citrus reshni Hort. ex Tan. (V1) H2 is thought to be salt-tolerant, it accumulates 38.88 mg g-1 of dry-matter leaf chloride and 1.72 mg g-1 of fresh-matter chlorophyll content.

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