Frontiers in Agronomy最新文献

{"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 >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 (<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}