Frontiers in Agronomy最新文献

{"title":"The acquisition of macro- and micronutrients is synergistic in species mixtures: example of mixed crucifer-legume cover crops","authors":"Antoine Couëdel, L. Alletto, E. Justes","doi":"10.3389/fagro.2023.1223639","DOIUrl":"https://doi.org/10.3389/fagro.2023.1223639","url":null,"abstract":"Cover crops are often mentioned as a way to decrease nutrient losses during the fallow period. Species mixtures of crucifer-legume have been shown to effectively take up nitrogen (N) and sulphur (S) to decrease losses due to leaching, but their ability to simultaneously take up other key macro- and micronutrients remains unknown. Our study assessed the performances of a wide variety of bispecific crucifer-legume mixtures to provide synergetic uptake of multiple nutrients to target nutrient-recycling ecosystem services. Cultivars from eight crucifer and seven legume species were tested as sole and bispecific cover crops at an experimental site near Toulouse, France. Seven macronutrients (C, N, P, K, S, Ca and Mg) and six micronutrients (B, Cu, Mn, Zn, Fe and Na) were measured in both species. Crucifer-legume mixtures showed synergetic uptake of nutrients per ha compared to sole cover crops for some nutrients through niche complementarity and facilitation processes and net competition for other nutrients. Species mixtures induced both i) higher nutrient concentrations for Mn and Fe in crucifers and Ca and B in legumes) and ii) lower concentrations for P, K, Ca and B in crucifers and Cu and Fe in legumes, indicating that the interactions differed among the species mixtures. Nevertheless, the nutrient uptake measured in shoots were always higher in species mixtures than in sole crops (LER > 1) demonstrating the compatibility and complementarity of crucifer and legume mixtures in providing multiple-nutrient catch-crop and recycling related ecosystem services. Despite overall positive interactions and synergetic complementarities, the results also highlight that some net negative competition occurred for some nutrients. Thus, further investigation is still necessary to completely understand the processes behind multiple-nutrient acquisition in species mixtures.","PeriodicalId":34038,"journal":{"name":"Frontiers in Agronomy","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45833920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Compaction, aeration and addition of mycotoxin contaminated silage alters the fermentation profile, mycotoxin content and aerobic stability of ryegrass (Lolium perenne) silage","authors":"T. Snelling, D. Davies, J. Huntington, N. Adams, H. Warren, J. Taylor-Pickard, L. Sinclair","doi":"10.3389/fagro.2023.1146505","DOIUrl":"https://doi.org/10.3389/fagro.2023.1146505","url":null,"abstract":"This study investigated the effect of compaction, aeration and addition of a naturally mycotoxin contaminated ryegrass silage (MCS) containing 1803 µg/kg DM penicillic acid, on the nutritional value and mycotoxin content after ensiling and subsequent aerobic stability of ryegrass Lolium perenne silage (second-cut, June 2020, UK). Mini silos (30 L) were filled with differential compaction (500 kg FW/m3 and 333 kg FW/m3), aeration by injection of air (1L per 48h for 30d then 1L per 7d) and addition of MCS (1.5 g/kg FW ensiled forage) in a 2×2×2 factorial design. During ensilage, mean CO2% (kg FW) in the aerated silos increased with low compaction. Crude protein (CP) increased and ash decreased with aeration. Mean silage fermentation end products acetic (AA), lactic (LA) and propionic acid (PA) concentrations increased with MCS. PA concentration increased with aeration/low compaction. LA decreased and ethanol increased with low compaction. Mycotoxin profiles differed between the silages on opening and after 14-days incubation in aerobic conditions with disappearance of fusarenon X and penicillic acid and appearance of mycophenolic acid and roquefortine C (318 µg/kg DM and 890 µg/kg DM). Addition of MCS, increased the concentration of penicillic acid on opening with an interaction with aeration (80.6µg/kg DM MCS × aerated, 40.0 µg/kg DM in the MCS × sealed). Aerobic stability was affected by aeration and low compaction with reduced time taken to heat to +5°C and +10°C above ambient temperature, higher rate of increase in pH and higher cumulative temperatures to the first peak temperature. Higher mycotoxin concentration at opening had a similar effect increasing time to heat +5°C and +10°C above ambient temperatures in aerobic conditions. Regression analysis showed predominantly direct relationships between silage fermentation end-product concentrations and aerobic stability. This study revealed interactions between silage bacteria and fungi activity from the concentrations of fermentation end-products and mycotoxins during ensilage and subsequent aerobic spoilage. The results supported current best practice for silage making, promoting conditions for improved preservation and aerobic stability. The addition of MCS had unexpected positive effects. However, factors associated with the MCS benefiting aerobic stability were not determined.","PeriodicalId":34038,"journal":{"name":"Frontiers in Agronomy","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43152869","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recent advances in cowpea IPM in West Africa","authors":"A. Togola, B. Datinon, Amadou Laouali, F. Traoré, C. Agboton, Patrick Obia Ongom, J. Ojo, Barry Pittendrigh, O. Boukar, M. Tamò","doi":"10.3389/fagro.2023.1220387","DOIUrl":"https://doi.org/10.3389/fagro.2023.1220387","url":null,"abstract":"Cowpea is an important and climate-resilient grain legume for human and livestock nutrition worldwide. Its grains represent a valuable source of protein for rural families in Sub-Saharan Africa while its haulms offer nutritious fodder for livestock, especially, in the Sahel regions. Cowpea production, unfortunately, faces substantial challenges of field and storage insect pests which can cause up to 100% losses. The use of synthetic pesticides, although providing farmers with a good level of pest control, has underscored the critical need for the development of integrated pest management (IPM) alternatives, due to their detrimental effects on humans, animals and the environment. This review examines recent advances in West Africa in cowpea IPM approaches, highlighting research on host plant resistance, biological control, biopesticides, good cultural practices, and on-farm participatory research and training undertaken to support sustainable cowpea production. Numerous IPM options have been developed, tested and validated for combating cowpea insect problems in West Africa by research institutions and disseminated through farmer field schools (FFS), field demonstrations, training sessions, and community-based education. Reviewing these environmentally safer and scalable IPM innovations will provide cowpea stakeholders with insights into workable, sustainable solutions for minimizing crop pest problems, reducing reliance on harmful pesticides and ultimately ensuring the long-term viability of cowpea production and its contribution to food security.","PeriodicalId":34038,"journal":{"name":"Frontiers in Agronomy","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43770968","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Contribution of biochar application to the promotion of circular economy in agriculture","authors":"G. Enaime, M. Wichern, M. Lübken","doi":"10.3389/fagro.2023.1214012","DOIUrl":"https://doi.org/10.3389/fagro.2023.1214012","url":null,"abstract":"The traditional linear model in agriculture based on the so-called ‘take-make-waste’ has created many problems such as resource scarcity, waste generation, climate change and biodiversity loss. Recently, with the increase in public awareness, the attentiveness in developing a circular economy model was doubled with a focus on proper waste management to bring some benefits to the agricultural sector. Although the increasing acceptance of biochar as a carbon-based material capable of playing a multidimensional role in reducing waste, mitigating climate change, and creating a closed-loop agricultural system, it is still far to move to a final conclusion that biochar application in agriculture could bring attractive environmental and economic benefits. Research conducted so far has led to many insights into how to enhance agricultural sustainability through biochar application, as the impact of biochar is strongly interrelated to their inherent properties, which vary deeply with the nature of biomass and the preparation conditions. In the present study, a systematic literature review was performed to investigate the state- of-the-art research related to the application of biochar in agriculture and its contribution in the establishment of circular economy concept. The interlinking between biochar application in agriculture with energy-water systems and its contribution to successfully build up a circular economy model has also been investigated.","PeriodicalId":34038,"journal":{"name":"Frontiers in Agronomy","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49147751","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simulating the effect of perennialized cropping systems on nitrate-N losses using the SWAT model","authors":"Grace L Wilson, D. Mulla, N. Jordan, J. Jungers, B. Gordon","doi":"10.3389/fagro.2023.1180232","DOIUrl":"https://doi.org/10.3389/fagro.2023.1180232","url":null,"abstract":"Several newly released crop varieties, including the perennial intermediate wheatgrass (grain marketed as Kernza®), and the winter hardy oilseed crop camelina, have been developed to provide both economic return for farmers and reduced nutrient losses from agricultural fields. Though studies have indicated that these crops could reduce nitrate-nitrogen (N) leaching, little research has been done to determine their effectiveness in reducing nitrate-N loading to surface waters at a watershed scale, or in comparing their performance to more traditional perennial crops, such as alfalfa. In this study, nitrate-N losses were predicted using the Soil and Water Assessment Tool (SWAT) model for the Rogers Creek watershed located in south-central Minnesota, USA. Predicted looses of nitrate-N under three perennialized cropping systems were compared to losses given current cropping practices in a corn (Zea mays L.)-soybean (Glycine max L. Merr.) rotation. The perennialized systems included three separate crop rotations: intermediate wheatgrass (IWG) in rotation with soybean, alfalfa in rotation with corn, and winter camelina in rotation with soybean and winter rye. Model simulation of these rotations required creation of new crop files for IWG and winter camelina within SWAT. These new crop files were validated using measured yield, biomass, and nitrate-N data. Model results show that the IWG and alfalfa rotations were particularly effective at reducing nutrient and sediment losses from agricultural areas in the watershed, but smaller reductions were also achieved with the winter camelina rotation. From model predictions, achieving regional water-quality goals of a 30% reduction in nitrate-N load from fields in the watershed required converting approximately 25, 34, or 57% of current corn-soybean area to the alfalfa, IWG, or camelina rotations, respectively. Results of this study indicate that adoption of these crops could achieve regional water quality goals.","PeriodicalId":34038,"journal":{"name":"Frontiers in Agronomy","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41625951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Establishing phosphorus critical values for tomato (Solanum lycopersicum) fertilization with phosphate fertilizers on the Sudan savanna soils using three soil phosphorus extraction methods and field experimentation in Kano State, Nigeria","authors":"Yahaya Mohammad Yusuf, D. K. Madukwe, F. Kebede","doi":"10.3389/fagro.2023.1181045","DOIUrl":"https://doi.org/10.3389/fagro.2023.1181045","url":null,"abstract":"Phosphorus (P) is an essential nutrient for tomato (Solanum lycopersicum L.) production, as it stimulates root growth by improving water use efficiency and nutrient uptake. It also helps control the metabolic processes of ATP (energy), sugars, and nucleic acids. Therefore, it is imperative to effectively manage the phosphorus requirements of tomatoes to bolster their productivity. The objective of this study was to evaluate the effectiveness of three different soil P testing methods that are suitable for the soils of Kano State, Nigeria, and to develop a critical P-value for fertilizer recommendations for tomatoes. Accordingly, sixty topsoil samples were collected for soil available P testing according to the Bray II, Mehlich 3, and Olsen methods. Moreover, to establish the phosphorus critical value (Pc) for tomatoes, a field experiment was conducted with seven different rates of P using triple super phosphate fertilizer (TSP), viz., 0, 15, 30, 45, 60, 75, and 90 kg P/ha, laid out in a randomized complete block design with three replications on 15 experimental sites representing the various agroecological zones of the state. Phosphorus fertilizer was applied and incorporated into the soil 1 week before tomato transplanting. Then, soil samples from 0 to 20 cm depth were taken 3 weeks after transplanting from all the plots across the experimental sites for separate Mehlich 3, Bray II, and Olsen extractable P analysis to determine the critical soil P (Pc) test. The study revealed that available P was varied and increased in the order of Olsen (2.19 ppm)< Mehlich 3 (5.37 ppm)< Bray II (5.44 ppm), and the Mehlich 3 and Bray II extraction methods were strongly correlated, whereas Olsen underestimated the available P, showing a weak correlation with both Mehlich 3 and Bray II. Furthermore, the study showed that phosphorus critical (Pc) values were 17.00, 14.00, and 4 ppm for Mehlich 3, Bray II, and Olsen respectively. Finally, Bray II was a more reliable method for estimating the available P on moderately acid soils as it showed the highest correlation r = 0.83 with the relative yield of the tomatoes and, therefore, was the most effective method for developing the equation for the soil test-based phosphatic fertilizer recommendation for maximizing tomato production in the soils of Kano State. Hence, the equation developed for the P fertilizer recommendation (Pr) for tomatoes in Kano State was found to be “Pr (kg P2O5 ha−1) = (14.0 − Pi) × 9.02”.","PeriodicalId":34038,"journal":{"name":"Frontiers in Agronomy","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43252390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of Philippine-sourced clay particles as coating agents of cacao pods and carrier of entomopathogen against cacao pest, Helopeltis bakeri Poppius","authors":"Sharin C. Albacete, D. Amalin, Thaddeus M. Carvajal, J. Wise","doi":"10.3389/fagro.2023.1213131","DOIUrl":"https://doi.org/10.3389/fagro.2023.1213131","url":null,"abstract":"Evaluation of the efficacy of clay particles as a coating agent of cacao pods and carrier of entomopathogen, Metarhizium anisopliae Sorokin, was conducted for the control of cacao mirid bug (CMB), Helopeltis bakeri Poppius. Choice and no-choice tests were performed to evaluate Philippine-sourced clay particles as a coating agent of cacao pods to deter CMB feeding, in comparison with the commercially available particle film (US kaolin Surround®). To determine the most efficient local clay particles in protecting the pods from CMB feeding, six (6) treatments were evaluated namely, Philippine-sourced kaolin (PH kaolin), zeolite (PH zeolite), bentonite (PH bentonite), US kaolin, water (negative control), and a commercial synthetic insecticide thiamethoxam (Actara®) (positive control). All treatments were subjected to choice and no-choice tests. Among the Philippine clay particles tested in both tests, PH zeolite showed significant coating and deterred CMB from feeding. Since the US Kaolin and zeolite showed significant feeding deterrent effects on CMB, these treatments were tested as carriers of entomopathogenic fungi, M. anisopliae, including water (negative control) and thiamethoxam. Results showed that zeolite is a good carrier of the spores of M. anisopliae as its effects to deter CMB feeding started 24 hours after exposure. This was confirmed by positive M. anisopliae extraction from dead CMB through potato dextrose agar (PDA) plating.","PeriodicalId":34038,"journal":{"name":"Frontiers in Agronomy","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43436951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Agronomic and environmental aspects of organo-mineral fertilizers produced with a by-product of the intermediate process of tanning","authors":"F. Lima, A. O. Silva, Helen C. S. Amorim, Eduardo Sobrinho Santos Figueredo, Rafael Marta Carbone Carneiro, Madeliny Saracho Jara, M. Carneiro, L. Guilherme","doi":"10.3389/fagro.2023.1215448","DOIUrl":"https://doi.org/10.3389/fagro.2023.1215448","url":null,"abstract":"The by-product of the intermediate process of tanning (BPIPT) can be used in the manufacturing of environmentally-friendly organo-mineral fertilizers (OMF). However, the presence of potentially toxic elements (e.g., chromium, Cr), can hinder the use of BPIPT in agriculture. This study aimed: i) to evaluate soil chemical and biological properties following the application of fertilizers produced with a BPIPT, in contrast to other OMF produced with traditional organic matrices; and ii) to assess the impacts of such products on wheat growth and nutrition.Samples (0-0.2 m) of two Oxisols [Red-Yellow Latosol (LVAd) and Red Latosol (LVd)] were used in this study, consisting of two experiments (with five treatments and five replicates) using different OMF, in a sequence: 1) incubation of fertilizers in soil samples for 30 days, and 2) wheat cultivation (30 days) after the fertilizer incubation. The treatments consisted of an arrangement of mineral fertilizers based on nitrogen, phosphorus, and potassium (NPK fertilizers), associated with OMF based on BPIPT (OM-IPT and OM-IPT+S) or commercial manure (OM-CM and OM-CM+S), with or without sulfur (S), and a control treatment. Elemental availability in soils and microbial attributes were determined after the incubation of the OMF in the soils. After wheat cultivation, plant biomass, nutritional composition, β-glucosidase activity, and fluorescein diacetate hydrolysis (FDA) were measured.The application of BPIPT-derived OMF in the present study increased available Cr fraction contents in both soils. However, OM-IPT caused low soil acidification, enhanced wheat growth and nutrition, and stimulated microbial activity in soils (FDA and β-glucosidase), thus evidencing the agronomic and environmental benefits of this OMF and their potential to contribute to a cleaner, more sustainable agriculture.","PeriodicalId":34038,"journal":{"name":"Frontiers in Agronomy","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42419544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigating the effects of APSIM model configuration on model outputs across different environments","authors":"R. Chapagain, T. Remenyi, N. Huth, Caroline L. Mohammed, Jonathan J. Ojeda","doi":"10.3389/fagro.2023.1213074","DOIUrl":"https://doi.org/10.3389/fagro.2023.1213074","url":null,"abstract":"Soil type plays a major role in nutrient dynamics and soil water which impacts crop growth and yield. The influence of soil characteristics on crop growth is usually evaluated through field experimentation (in the short term) and through crop-soil modelling (in the long-term). However, there has been limited research which has looked at the effect of model structural uncertainty of model outputs in different soil types.To analyze the impact of soil inputs on model structural uncertainty, we developed eight model structures (a combination of two crop models, two soil water models and two irrigation models) within the Agricultural Production Systems sIMulator (APSIM) across three soil types (Ferralsols, Alisols and Chernozems). By decomposing the mean proportion of variance and simulated values of the model outputs (yield, irrigation, drainage, nitrogen leaching and partial gross margin) we identified the influence of soil type on the magnitude of model structural uncertainty.For all soil types, crop model was the most significant source of structural uncertainty, contributing &gt;60% to variability for most modelled variables, except irrigation demand which was dominated by the choice of irrigation model applied. Relative to first order interactions, there were minimal (&lt;12%) contributions to uncertainty from the second order interactions (i.e., inter-model components). We found that a higher mean proportion of variance does not necessarily imply a high magnitude of uncertainty in actual values. Despite the significant impact of the choice of crop model on yield and PGM variance (contributing over 90%), the small standard deviations in simulated yield (ranging from 0.2 to 1 t ha-1) and PGM (ranging from 50.6 to 374.4 USD ha-1) compared to the mean values (yield: 14.6 t ha-1, PGM: 4901 USD ha-1) indicate relatively low actual uncertainty in the values. Similarly, the choice of irrigation model had a contribution of over 45% to variance, but the relatively small standard deviations ranging from 11 to 33.3 mm compared to the overall mean irrigation of 500 mm suggest low actual uncertainty in the values. In contrast, for the environmental variables- drainage and nitrogen leaching, the choice of crop model had contributions of more than 60% and 70% respectively, yet the relatively large standard deviations ranging from 7.1 to 30.6 mm and 0.6 to 7.7 kg ha-1 respectively, compared to the overall mean values of drainage (44.4 mm) and nitrogen leaching (3.2 kg ha-1), indicate significant actual uncertainty.We identified the need to include not only fractional variance of model uncertainty, but also magnitude of the contribution in measured units (e.g. t ha-1, mm, kg ha-1, USD ha-1) for crop model uncertainty assessments to provide more useful agronomic or policy decision-making information. The findings of this study highlight the sensitivity of agricultural models to the impacts of moisture availability, suggesting that it is important to give more attention","PeriodicalId":34038,"journal":{"name":"Frontiers in Agronomy","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43721474","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling the early phases of epidemics by Phakospora pachyrhizi in Brazilian soybean","authors":"B. Kassie, D. Onstad, L. Koga, Tim Hart, R. Clark, G. W. van der Heijden","doi":"10.3389/fagro.2023.1214038","DOIUrl":"https://doi.org/10.3389/fagro.2023.1214038","url":null,"abstract":"Asian soybean rust, caused by the biotrophic basidiomycete Phakospora pachyrhizi, is a foliar disease that often causes considerable damage to soybean crops. The purpose of our work was to create a mechanistic model that can reliably represent epidemics of ASR in commercial soybean fields in Brazil. The most important inputs for the model are weather data (observations and forecast) and the initial observation of disease (or uredospore arrival). Our focus is on the first two or three cycles of infection after immigration into a soybean field. The model includes state variables for latent, infectious and senesced lesions, disease severity, uredospores, and soybean leaf area. Processes modeled include maturation through the latent and infectious periods, germination, sporulation, and processes affecting uredospores in the canopy. The model results were tested against field observations from trials at four locations in Brazil for the 2019/2020 growing season. The predictions generally matched the daily dynamics of disease progress in the field trials. The predictions reproduced the observed severity well with R2 value of 0.84. This high correlation indicates that our model is accurate enough to be used as a tool to predict the dynamics of ASR epidemics during the first few cycles after uredospore invasion into a soybean field. A sensitivity analysis was performed that showed that the model is sensitive to time and duration of the initial spore arrival. This indicates that spore traps or other observations should measure not only the first day of arrival but also subsequent days.","PeriodicalId":34038,"journal":{"name":"Frontiers in Agronomy","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48480925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}