Pub Date : 2022-07-15DOI: 10.1080/02571862.2022.2087922
G. J. van Coller, F. Kloppers, V. Coetzee, Toinette van Rooyen, L. Rose, S. Lamprecht, A. Viljoen
Chemical control of a yield-limiting, quality-reducing wheat disease like Fusarium head blight (FHB) is an important management strategy; however, no fungicides are registered against it in South Africa. The aim of this study was to determine foliar fungicides and seed treatment efficacy for FHB management. Three commercial fungicides and two seed treatments were evaluated in a naturally infested field during 2011 and 2012. Significant interactions between the seed treatments and the foliar fungicides were obtained for FHB incidence and yield. When the fungicide Abacus® was sprayed in combination with either of the two seed treatments, FHB incidence was significantly decreased compared with use of the fungicide alone. Prosaro® sprayed in combination with Galmano® Plus as a seed treatment significantly decreased yield compared with the use of Prosaro alone or in combination with Vitavax® Plus as a seed treatment. The fungicide treatments significantly reduced FHB incidence and the percentage of Fusarium-damaged kernels (%FDK) when compared with control treatments, and significantly increased the yield. A weak but significant correlation was recorded between deoxynivalenol (DON) and %FDK. Strong negative correlations were observed between hectolitre mass (HLM) and FHB incidence and %FDK, respectively, and between yield and %FDK. These results indicate that the chemical control of FHB of wheat can be used to manage the disease in South Africa. Future research, therefore, must focus on integrating chemical control with host resistance to obtain optimal results.
小麦赤霉病(Fusarium head blight, FHB)是一种限制产量、降低品质的小麦病害，化学防治是一项重要的管理策略。然而，在南非没有杀菌剂登记。本研究的目的是确定叶面杀菌剂和种子处理对FHB管理的效果。2011年和2012年在自然侵染地对3种商业杀菌剂和2种种子处理进行了评价。种子处理与叶面杀菌剂对赤霉病发病率和产量有显著的交互作用。当杀菌剂Abacus®与两种种子处理中的任何一种联合喷洒时，与单独使用杀菌剂相比，FHB发病率显著降低。与单独使用Prosaro或与Vitavax®Plus联合使用相比，Prosaro®与Galmano®Plus联合喷洒作为种子处理显著降低了产量。与对照处理相比，杀菌剂处理显著降低了赤霉病发病率和赤霉病损粒率(%FDK)，显著提高了产量。脱氧雪腐镰刀菌烯醇(DON)与%FDK之间存在微弱但显著的相关性。百升质量(HLM)与赤霉病发生率、%FDK、产量与%FDK呈显著负相关。这些结果表明，小麦赤霉病的化学防治可用于南非小麦赤霉病的防治。因此，未来的研究必须注重将化学防治与宿主抗性结合起来，以获得最佳效果。
{"title":"Foliar fungicides provide chemical control of Fusarium head blight of wheat in South Africa","authors":"G. J. van Coller, F. Kloppers, V. Coetzee, Toinette van Rooyen, L. Rose, S. Lamprecht, A. Viljoen","doi":"10.1080/02571862.2022.2087922","DOIUrl":"https://doi.org/10.1080/02571862.2022.2087922","url":null,"abstract":"Chemical control of a yield-limiting, quality-reducing wheat disease like Fusarium head blight (FHB) is an important management strategy; however, no fungicides are registered against it in South Africa. The aim of this study was to determine foliar fungicides and seed treatment efficacy for FHB management. Three commercial fungicides and two seed treatments were evaluated in a naturally infested field during 2011 and 2012. Significant interactions between the seed treatments and the foliar fungicides were obtained for FHB incidence and yield. When the fungicide Abacus® was sprayed in combination with either of the two seed treatments, FHB incidence was significantly decreased compared with use of the fungicide alone. Prosaro® sprayed in combination with Galmano® Plus as a seed treatment significantly decreased yield compared with the use of Prosaro alone or in combination with Vitavax® Plus as a seed treatment. The fungicide treatments significantly reduced FHB incidence and the percentage of Fusarium-damaged kernels (%FDK) when compared with control treatments, and significantly increased the yield. A weak but significant correlation was recorded between deoxynivalenol (DON) and %FDK. Strong negative correlations were observed between hectolitre mass (HLM) and FHB incidence and %FDK, respectively, and between yield and %FDK. These results indicate that the chemical control of FHB of wheat can be used to manage the disease in South Africa. Future research, therefore, must focus on integrating chemical control with host resistance to obtain optimal results.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45601530","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}
Pub Date : 2022-05-27DOI: 10.1080/02571862.2022.2069874
Zoleka Ncoyini-Manciya, M. J. Savage, S. Strydom, A. Clulow
Global warming is widely recognised, and its effects are becoming apparent throughout the world. Evaporation and evapotranspiration, the key components of the hydrological cycle, are generally expected to increase due to the rise in air and surface temperatures. However, previous studies suggest a decrease in these phenomena despite the observed global warming. The decreasing evaporation and evapotranspiration have been attributed to various factors. In this study, reference evapotranspiration (ETo) trends estimated using the Penman-Monteith method were studied over the KwaZulu-Natal midlands area of South Africa for the period 1997–2017. This study employed the Mann–Kendall test and linear regression model to analyse annual and seasonal ETo trends. In addition, the trends of climate parameters and their contribution towards ETo variation were analysed. The results indicate a generally decreasing ETo trend for most weather stations studied over the study period. The climate variables analysed indicate an average decreasing trend in wind speed, solar irradiance, and relative humidity while average air temperature exhibited no significant change. Relative humidity and solar irradiance were found to greatly influence ETo variation in the study area. We therefore conclude that atmospheric condition studies should consider both local and global climate phenomena to understand the actual drivers of change in any atmospheric factor.
{"title":"Long-term reference evapotranspiration trend and causative factors analysis in the sugarbelt area of the midlands of KwaZulu-Natal, South Africa","authors":"Zoleka Ncoyini-Manciya, M. J. Savage, S. Strydom, A. Clulow","doi":"10.1080/02571862.2022.2069874","DOIUrl":"https://doi.org/10.1080/02571862.2022.2069874","url":null,"abstract":"Global warming is widely recognised, and its effects are becoming apparent throughout the world. Evaporation and evapotranspiration, the key components of the hydrological cycle, are generally expected to increase due to the rise in air and surface temperatures. However, previous studies suggest a decrease in these phenomena despite the observed global warming. The decreasing evaporation and evapotranspiration have been attributed to various factors. In this study, reference evapotranspiration (ETo) trends estimated using the Penman-Monteith method were studied over the KwaZulu-Natal midlands area of South Africa for the period 1997–2017. This study employed the Mann–Kendall test and linear regression model to analyse annual and seasonal ETo trends. In addition, the trends of climate parameters and their contribution towards ETo variation were analysed. The results indicate a generally decreasing ETo trend for most weather stations studied over the study period. The climate variables analysed indicate an average decreasing trend in wind speed, solar irradiance, and relative humidity while average air temperature exhibited no significant change. Relative humidity and solar irradiance were found to greatly influence ETo variation in the study area. We therefore conclude that atmospheric condition studies should consider both local and global climate phenomena to understand the actual drivers of change in any atmospheric factor.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48625523","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}
Pub Date : 2022-05-27DOI: 10.1080/02571862.2022.2043470
D. Du Toit, P. Swanepoel, A. Hardie
Little information is available regarding the liming efficiency of various local lime sources and products currently available in South Africa. Recently, granulated micro-fine limes are being widely marketed as being superior to class A limes. Therefore, the aim of this study was to compare the effectiveness of various local, commercially available hydrated, calcitic and dolomitic lime sources (i.e., from different quarries) and forms (class A, micro-fine and granulated micro-fine) at increasing soil pH over time (365 days) under controlled conditions in two contrasting acid soils (sand and loam). Liming materials were applied adjusted for calcium carbonate equivalence (CCE) to achieve a target pHKCl of 5.5 and incubated at 85% field capacity. Micro-fine calcitic limes and hydrated limes increased pH the fastest (first 30–60 days), but the difference between these materials and class A limes attenuated over time. The difference in performance between class A limes was relatively minor (0.5 pH units), if applied based on CCE. Chemical purity (Ca%, CCE) was the main factor controlling liming effectiveness and particle fineness only related to the short-term reaction (4–7 days). Granulated limes showed the poorest performance in terms of pH correction attributed to poor solubility and spatial zonation of liming effects.
{"title":"Effect of lime source, fineness and granulation on neutralisation of soil pH","authors":"D. Du Toit, P. Swanepoel, A. Hardie","doi":"10.1080/02571862.2022.2043470","DOIUrl":"https://doi.org/10.1080/02571862.2022.2043470","url":null,"abstract":"Little information is available regarding the liming efficiency of various local lime sources and products currently available in South Africa. Recently, granulated micro-fine limes are being widely marketed as being superior to class A limes. Therefore, the aim of this study was to compare the effectiveness of various local, commercially available hydrated, calcitic and dolomitic lime sources (i.e., from different quarries) and forms (class A, micro-fine and granulated micro-fine) at increasing soil pH over time (365 days) under controlled conditions in two contrasting acid soils (sand and loam). Liming materials were applied adjusted for calcium carbonate equivalence (CCE) to achieve a target pHKCl of 5.5 and incubated at 85% field capacity. Micro-fine calcitic limes and hydrated limes increased pH the fastest (first 30–60 days), but the difference between these materials and class A limes attenuated over time. The difference in performance between class A limes was relatively minor (0.5 pH units), if applied based on CCE. Chemical purity (Ca%, CCE) was the main factor controlling liming effectiveness and particle fineness only related to the short-term reaction (4–7 days). Granulated limes showed the poorest performance in terms of pH correction attributed to poor solubility and spatial zonation of liming effects.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44259158","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}
Pub Date : 2022-05-27DOI: 10.1080/02571862.2022.2059115
Trevan Flynn, A. Rozanov, F. Ellis, W. D. de Clercq, C. Clarke
This study involved the evaluation of farm-scale digital soil classification in the Sandspruit catchment of the Western Cape Province, South Africa. The study aimed to evaluate a digital soil mapping (DSM) method, from feature selection, spatial predictions and sample design. The results showed that feature selection with the least absolute shrinkage and selection operator (LASSO) technique is a robust method as it had a high relative efficiency and achieved the highest accuracy for three out of the four soil classes predicted. This implies that covariate selection is the most notable aspect in DSM at the farm-scale. The top-performing predictive models achieved satisfactory results for soil associations (kappa = 0.64, accuracy = 74%), presence of a bleached topsoil (kappa = 0.64, accuracy = 74%) and soil depth (kappa = 0.48, accuracy = 74%), whereas only moderate results were achieved for soil texture (kappa = 0.43, accuracy = 66%). Lastly, the expert sampling locations had a higher average probability of occurrence (geographic and feature space distribution coverage) yet achieved similar performance to conditioned Latin hypercube sampling (cLHS).
{"title":"Farm-scale digital soil mapping of soil classes in South Africa","authors":"Trevan Flynn, A. Rozanov, F. Ellis, W. D. de Clercq, C. Clarke","doi":"10.1080/02571862.2022.2059115","DOIUrl":"https://doi.org/10.1080/02571862.2022.2059115","url":null,"abstract":"This study involved the evaluation of farm-scale digital soil classification in the Sandspruit catchment of the Western Cape Province, South Africa. The study aimed to evaluate a digital soil mapping (DSM) method, from feature selection, spatial predictions and sample design. The results showed that feature selection with the least absolute shrinkage and selection operator (LASSO) technique is a robust method as it had a high relative efficiency and achieved the highest accuracy for three out of the four soil classes predicted. This implies that covariate selection is the most notable aspect in DSM at the farm-scale. The top-performing predictive models achieved satisfactory results for soil associations (kappa = 0.64, accuracy = 74%), presence of a bleached topsoil (kappa = 0.64, accuracy = 74%) and soil depth (kappa = 0.48, accuracy = 74%), whereas only moderate results were achieved for soil texture (kappa = 0.43, accuracy = 66%). Lastly, the expert sampling locations had a higher average probability of occurrence (geographic and feature space distribution coverage) yet achieved similar performance to conditioned Latin hypercube sampling (cLHS).","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47057938","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}
Pub Date : 2022-05-27DOI: 10.1080/02571862.2022.2062623
Samuel Kofi Tutu, H. R. Mloza Banda, C. Tfwala
Uncertainties about the effects of nutrient amendment on the culinary attributes of sweetpotato have limited fertiliser use in Eswatini. The study was carried out at a moist and dry location of Eswatini to investigate the culinary and nutritional attributes of sweetpotato cultivated with no amendments, cattle manure and/or inorganic fertiliser. Treatments were replicated three times in a 3 × 5 factorial arrangement using a randomised complete block design. Three sweetpotato varieties used: Ligwalagwala, Kenya White, and Lamngititi, with five nutrient amendments: no fertiliser/manure, 450 kg ha−1 NPK, 6 t ha−1 manure, 3 t ha−1 manure + 225 kg ha−1 NPK, and 4.5 t ha−1 manure + 112.5 kg ha−1 NPK. Yield differences of 59.8% and 47.3% over the control were recorded with Kenya White and 3 t ha−1 manure + 225 kg ha−1 NPK, and 4.5 t ha−1 manure + 112.5 kg ha−1 NPK at Malkerns and Luve, respectively. Protein, calcium, and magnesium content of the varieties improved under 4.5 t ha−1 manure + 112.5 kg ha−1 NPK amendments. Taste, flavour, palatability, and acceptability accounted for the greatest amount of culinary variability while soil amendments contributed the least. The present study suggests that nutrient amendments contribute to the agronomic performance and nutritional quality of sweetpotato.
营养改良对红薯烹饪特性影响的不确定性限制了斯威士兰的化肥使用。这项研究是在斯威士兰潮湿干燥的地方进行的，目的是调查不添加改良剂、牛粪和/或无机肥料种植的红薯的烹饪和营养特性。在3 × 使用随机完全区组设计的5因子排列。使用的三个红薯品种：Ligwalagwala、Kenya White和Lamngtiti，有五种营养改良剂：无肥料/粪肥，450 kg ha−1 NPK，6 t ha−1粪肥，3 t ha−一粪肥 + 225 kg ha−1 NPK和4.5 t ha−1粪肥 + 112.5 kg ha−1 NPK。与对照相比，肯尼亚白和3 t ha−1肥料的产量差异分别为59.8%和47.3% + 225 kg ha−1 NPK和4.5 t ha−1粪肥 + 112.5 kg ha−1 NPK。施用4.5t ha−1肥料后，改良品种的蛋白质、钙和镁含量 + 112.5 kg ha−1 NPK修正案。味道、风味、适口性和可接受性是烹饪变化最大的原因，而土壤改良剂的影响最小。本研究表明，营养改良有助于甘薯的农艺性状和营养品质。
{"title":"Yield, nutritional composition, and consumer acceptability of sweetpotato cultivars cultivated with soil amendments in the Middleveld of Eswatini","authors":"Samuel Kofi Tutu, H. R. Mloza Banda, C. Tfwala","doi":"10.1080/02571862.2022.2062623","DOIUrl":"https://doi.org/10.1080/02571862.2022.2062623","url":null,"abstract":"Uncertainties about the effects of nutrient amendment on the culinary attributes of sweetpotato have limited fertiliser use in Eswatini. The study was carried out at a moist and dry location of Eswatini to investigate the culinary and nutritional attributes of sweetpotato cultivated with no amendments, cattle manure and/or inorganic fertiliser. Treatments were replicated three times in a 3 × 5 factorial arrangement using a randomised complete block design. Three sweetpotato varieties used: Ligwalagwala, Kenya White, and Lamngititi, with five nutrient amendments: no fertiliser/manure, 450 kg ha−1 NPK, 6 t ha−1 manure, 3 t ha−1 manure + 225 kg ha−1 NPK, and 4.5 t ha−1 manure + 112.5 kg ha−1 NPK. Yield differences of 59.8% and 47.3% over the control were recorded with Kenya White and 3 t ha−1 manure + 225 kg ha−1 NPK, and 4.5 t ha−1 manure + 112.5 kg ha−1 NPK at Malkerns and Luve, respectively. Protein, calcium, and magnesium content of the varieties improved under 4.5 t ha−1 manure + 112.5 kg ha−1 NPK amendments. Taste, flavour, palatability, and acceptability accounted for the greatest amount of culinary variability while soil amendments contributed the least. The present study suggests that nutrient amendments contribute to the agronomic performance and nutritional quality of sweetpotato.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48000066","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}
Pub Date : 2022-05-27DOI: 10.1080/02571862.2022.2078516
Jacobus FN Smith, A. Hardie
Despite the global importance of rooibos tea (Aspalathus linearis (Burm.f.) R.Dahlgren) as a health-promoting crop, foliar nutrient sufficiency ranges have not yet been determined for commercially cultivated rooibos. Determination of these ranges is critical for assessing plant nutrient status and maximising productivity. The aim of this study was to determine optimal rooibos foliar macro- and micronutrient ranges using the boundary-line approach (BLA) method across the main rooibos production areas in South Africa. Foliar nutrient and yield data were collected from 120 different commercial rooibos plantations in the six main rooibos producing areas of the country: Nardouwsberg/ Agterpakhuys, Clanwilliam, Gifberg/ Vanrhynsdorp, Nieuwoudtville, Citrusdal and Sandveld. The BLA-derived optimum (late winter) rooibos foliar macronutrient and 90%-yield sufficiency range concentrations (%) were: 1.55 (1.30–1.80) for N, 0.12 (0.09–0.14) for P, 0.54 (0.34–0.75) for K, 0.20 (0.14–0.26) for Ca, 0.22 (0.19–0.25) for Mg, and 0.10 (0.08–0.11) for S. Optimum micronutrient contents and ranges (mg kg−1) were: 85.8 (57.6–114.1) for Fe, 58.2 (26.9–113.8) for Mn, 16.6 (12.7–20.5) for Zn, 2.8 (1.3–4.2) for Cu, and 26.9 (21.8–32.0) for B. Maintaining foliar nutrient concentrations within these ranges will support maximal yields (1 200 kg ha−1). The foliar nutrient guidelines are of importance for enhancing sustainable rooibos production in South Africa.
尽管rooibos茶（Asplatus linearis（Burm.f.）R.Dahlgren）作为一种促进健康的作物在全球具有重要意义，但商业种植的rooibos的叶面营养充足范围尚未确定。确定这些范围对于评估植物营养状况和最大限度地提高生产力至关重要。本研究的目的是使用边界线法（BLA）确定南非主要鲁伊博产区的最佳鲁伊博叶片宏观和微量营养素范围。从该国六个主要菜豆产区的120个不同的商业菜豆种植园收集了叶片营养和产量数据：Nardouwsberg/Agterpakhuys、Clanwilliam、Gifberg/Vanrhynsdorp、Nieuwudtville、Citrusdal和Sandveld。BLA得出的最佳（晚冬）菜油叶大量营养素和90%产量充足度范围浓度（%）为：N为1.55（1.30–1.80），P为0.12（0.09–0.14），K为0.54（0.34–0.75），Ca为0.20（0.14–0.26），Mg为0.22（0.19–0.25），S为0.10（0.08–0.11）。最佳微量营养素含量和范围（Mg kg−1）为：Fe为85.8（57.6–114.1），Mn为58.2（26.9–113.8），Zn为16.6（12.7–20.5），Cu为2.8（1.3–4.2），B为26.9（21.8–32.0）。将叶面养分浓度保持在这些范围内将支持最大产量（1200 kg ha−1）。叶面营养指南对提高南非的可持续鲁伊博生产具有重要意义。
{"title":"Determination of foliar nutrient sufficiency ranges in cultivated rooibos tea using the boundary-line approach","authors":"Jacobus FN Smith, A. Hardie","doi":"10.1080/02571862.2022.2078516","DOIUrl":"https://doi.org/10.1080/02571862.2022.2078516","url":null,"abstract":"Despite the global importance of rooibos tea (Aspalathus linearis (Burm.f.) R.Dahlgren) as a health-promoting crop, foliar nutrient sufficiency ranges have not yet been determined for commercially cultivated rooibos. Determination of these ranges is critical for assessing plant nutrient status and maximising productivity. The aim of this study was to determine optimal rooibos foliar macro- and micronutrient ranges using the boundary-line approach (BLA) method across the main rooibos production areas in South Africa. Foliar nutrient and yield data were collected from 120 different commercial rooibos plantations in the six main rooibos producing areas of the country: Nardouwsberg/ Agterpakhuys, Clanwilliam, Gifberg/ Vanrhynsdorp, Nieuwoudtville, Citrusdal and Sandveld. The BLA-derived optimum (late winter) rooibos foliar macronutrient and 90%-yield sufficiency range concentrations (%) were: 1.55 (1.30–1.80) for N, 0.12 (0.09–0.14) for P, 0.54 (0.34–0.75) for K, 0.20 (0.14–0.26) for Ca, 0.22 (0.19–0.25) for Mg, and 0.10 (0.08–0.11) for S. Optimum micronutrient contents and ranges (mg kg−1) were: 85.8 (57.6–114.1) for Fe, 58.2 (26.9–113.8) for Mn, 16.6 (12.7–20.5) for Zn, 2.8 (1.3–4.2) for Cu, and 26.9 (21.8–32.0) for B. Maintaining foliar nutrient concentrations within these ranges will support maximal yields (1 200 kg ha−1). The foliar nutrient guidelines are of importance for enhancing sustainable rooibos production in South Africa.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44619548","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}
Pub Date : 2022-05-27DOI: 10.1080/02571862.2022.2068084
Vhuthu Ndou, E. Phiri, P. Pieterse
Herbicide mixtures are beneficial since they delay the occurrence of resistance to herbicides, provided that the herbicides used are effective at controlling the target weed species. Recently, plantago (Plantago lanceolata L.) was found to show 23 and 10-fold-resistance to glyphosate and paraquat. Experiments were carried out under controlled conditions to determine the efficacy of various herbicide concentrations and mixtures for the control of multiple resistant plantago at the two to three leaf stage. Proven plantago resistant (R) biotypes which had been shown to survive high glyphosate and paraquat dosages were used together with one susceptible (S) biotype in each experiment. The herbicides 2-methyl-4-chlorophenoxyacetic acid (MCPA), (400 g a.i. ha−1), carfentrazone-ethyl (400 g a.i. ha−1), and glufosinate (200 g a.i. ha−1), and two combined mixtures consisting of paraquat + diquat (120 + 80 g a.i. ha−1), and terbuthylazine + S-metolachlor (497.2 + 102.8 g a.i. ha−1) were applied either alone or in mixtures resulting in 12 treatments. The herbicides and combinations were chosen for their distinct modes of action. The mixtures achieved 0% survival rates for the R and S biotypes except for glyphosate + MCPA and MCPA applied alone. The herbicide mixtures identified in the study together with other non-chemical control options may be used in the management of glyphosate- and paraquat-resistant plantago infestations.
除草剂混合物是有益的，因为它们延缓了对除草剂产生抗性的发生，只要所使用的除草剂能有效地控制目标杂草种类。最近发现车前草(plantago lanceolata L.)对草甘膦和百草枯的抗性分别为23倍和10倍。在一定条件下进行了不同除草剂浓度和混合药剂对车前草二、三叶期多重抗性的防治效果试验。已证实的车前草抗性(R)生物型在高草甘膦和百草枯剂量下存活，在每个实验中与一种敏感(S)生物型一起使用。除草剂2-甲基-4-氯苯氧乙酸(MCPA) (400 g a.i. ha−1)、卡芬曲酮-乙基(400 g a.i. ha−1)和草铵膦(200 g a.i. ha−1)，以及由百草枯+双甘菊(120 + 80 g a.i. ha−1)和特丁基嗪+ s -甲草胺(497.2 + 102.8 g a.i. ha−1)组成的两种组合混合物单独或混合施用，共12次处理。所选择的除草剂和组合是根据其不同的作用方式选择的。除草甘膦+ MCPA和单独使用MCPA外，R和S生物型的混合物存活率均为0%。研究中确定的混合除草剂与其他非化学控制方法可用于管理抗草甘膦和百草枯的车前草虫害。
{"title":"Screening herbicides and herbicide mixtures to identify alternative chemical controls for resistant plantago biotypes","authors":"Vhuthu Ndou, E. Phiri, P. Pieterse","doi":"10.1080/02571862.2022.2068084","DOIUrl":"https://doi.org/10.1080/02571862.2022.2068084","url":null,"abstract":"Herbicide mixtures are beneficial since they delay the occurrence of resistance to herbicides, provided that the herbicides used are effective at controlling the target weed species. Recently, plantago (Plantago lanceolata L.) was found to show 23 and 10-fold-resistance to glyphosate and paraquat. Experiments were carried out under controlled conditions to determine the efficacy of various herbicide concentrations and mixtures for the control of multiple resistant plantago at the two to three leaf stage. Proven plantago resistant (R) biotypes which had been shown to survive high glyphosate and paraquat dosages were used together with one susceptible (S) biotype in each experiment. The herbicides 2-methyl-4-chlorophenoxyacetic acid (MCPA), (400 g a.i. ha−1), carfentrazone-ethyl (400 g a.i. ha−1), and glufosinate (200 g a.i. ha−1), and two combined mixtures consisting of paraquat + diquat (120 + 80 g a.i. ha−1), and terbuthylazine + S-metolachlor (497.2 + 102.8 g a.i. ha−1) were applied either alone or in mixtures resulting in 12 treatments. The herbicides and combinations were chosen for their distinct modes of action. The mixtures achieved 0% survival rates for the R and S biotypes except for glyphosate + MCPA and MCPA applied alone. The herbicide mixtures identified in the study together with other non-chemical control options may be used in the management of glyphosate- and paraquat-resistant plantago infestations.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41442956","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}
Pub Date : 2022-05-27DOI: 10.1080/02571862.2022.2070935
Emc Theron, S. Magano
Tick infestations and tick-borne diseases continue to be the leading causes of loss in livestock and revenue, particularly in developing countries, despite the prevalent use of synthetic acaricides. Research on plants as alternative sources of anti-arthropod agents has received attention from many researchers in the recent past. This interest is mainly motivated by the compelling need to move away from over-reliance on anti-arthropod synthetic chemicals, which have harmful effects on the environment and livestock. While many plants have been shown to possess anti-tick properties, such studies are in the main laboratory-based and thus their effects cannot be accounted for in the natural environments. Furthermore, knowledge on the mechanisms by which plant extracts impact ticks is sparse and not coordinated for ease of reference. The literature explored in this study was collected from indices included in the University of South Africa (UNISA) library database following keyword searches on plant extracts used as tick control methods and reviews. This article provides a consolidation of literature on the anti-tick properties of plant-based material and their prospects for being integrated with current tick control methods.
{"title":"A reflection on tick control and the potential role of botanical products in integrated management practices","authors":"Emc Theron, S. Magano","doi":"10.1080/02571862.2022.2070935","DOIUrl":"https://doi.org/10.1080/02571862.2022.2070935","url":null,"abstract":"Tick infestations and tick-borne diseases continue to be the leading causes of loss in livestock and revenue, particularly in developing countries, despite the prevalent use of synthetic acaricides. Research on plants as alternative sources of anti-arthropod agents has received attention from many researchers in the recent past. This interest is mainly motivated by the compelling need to move away from over-reliance on anti-arthropod synthetic chemicals, which have harmful effects on the environment and livestock. While many plants have been shown to possess anti-tick properties, such studies are in the main laboratory-based and thus their effects cannot be accounted for in the natural environments. Furthermore, knowledge on the mechanisms by which plant extracts impact ticks is sparse and not coordinated for ease of reference. The literature explored in this study was collected from indices included in the University of South Africa (UNISA) library database following keyword searches on plant extracts used as tick control methods and reviews. This article provides a consolidation of literature on the anti-tick properties of plant-based material and their prospects for being integrated with current tick control methods.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47694541","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}
Pub Date : 2022-03-15DOI: 10.1080/02571862.2022.2037165
Nokuthula Hlanga, A. Modi, I. Mathew
Assessing agro-morphological variation is important for crop improvement strategies in cultivated species. Bambara groundnut (Vigna subterranea (L.) Verdc.) is a neglected crop that requires extensive agro-morphological characterisation to design suitable agronomic and crop improvement strategies. Nineteen Bambara groundnut lines were evaluated at two sites for agro-morphological traits in 2017 and 2018. The experiments were laid out as a split-split plot completely randomised design with three replications. The lines showed significant differences (p < 0.05) for all the traits except chlorophyll content and stomatal conductance. The observed genotypic differences would be useful for Bambara groundnut improvement if they are underpinned by genetic differences for recombination. Principal components 1 and 2 accounted for 52.31% of the variation showing that agro-morphological traits alone could not adequately discriminate between the Bambara groundnut lines. The most useful traits were root and shoot mass, plant height and leaf number. The negative and unfavourable correlations between seedling emergency and chlorophyll would complicate simultaneous selection for these traits during Bambara groundnut improvement. However, genetic dissimilarity indices indicated that there was genetic variation within the germplasm, which is important for Bambara groundnut improvement. Lines Kenya Capstone, Uniswa-Red-G, Uniswa-Red-R and KANO2 were selected for breeding and recommended for production due to their high performance in several key traits.
{"title":"Agro-morphological diversity of Bambara groundnut lines evaluated under field conditions","authors":"Nokuthula Hlanga, A. Modi, I. Mathew","doi":"10.1080/02571862.2022.2037165","DOIUrl":"https://doi.org/10.1080/02571862.2022.2037165","url":null,"abstract":"Assessing agro-morphological variation is important for crop improvement strategies in cultivated species. Bambara groundnut (Vigna subterranea (L.) Verdc.) is a neglected crop that requires extensive agro-morphological characterisation to design suitable agronomic and crop improvement strategies. Nineteen Bambara groundnut lines were evaluated at two sites for agro-morphological traits in 2017 and 2018. The experiments were laid out as a split-split plot completely randomised design with three replications. The lines showed significant differences (p < 0.05) for all the traits except chlorophyll content and stomatal conductance. The observed genotypic differences would be useful for Bambara groundnut improvement if they are underpinned by genetic differences for recombination. Principal components 1 and 2 accounted for 52.31% of the variation showing that agro-morphological traits alone could not adequately discriminate between the Bambara groundnut lines. The most useful traits were root and shoot mass, plant height and leaf number. The negative and unfavourable correlations between seedling emergency and chlorophyll would complicate simultaneous selection for these traits during Bambara groundnut improvement. However, genetic dissimilarity indices indicated that there was genetic variation within the germplasm, which is important for Bambara groundnut improvement. Lines Kenya Capstone, Uniswa-Red-G, Uniswa-Red-R and KANO2 were selected for breeding and recommended for production due to their high performance in several key traits.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41637862","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}
Pub Date : 2022-03-15DOI: 10.1080/02571862.2022.2056644
Shimbahri Mesfin, H. Haileselassie
Agroforestry tree species play an important role in improving soil fertility. Though studies have confirmed that different species show different potentials to improve soil fertility, it is difficult to compare them as the studies were conducted in different areas. The potential for different tree species to improve soil fertility on croplands in northern Ethiopia is not known. The objectives of this paper are to determine the effects of presence or absence of agroforestry tree species on soil physico-chemical properties and the effect of distance from the tree trunk on the same soil physico-chemical properties. Sixty composite and undisturbed soil samples from beneath canopies and outside canopies and 90 composite and undisturbed soil samples from three different distances from tree trunks were collected. The results revealed that soil bulk density, soil moisture, soil organic carbon (SOC), total nitrogen (TN), available phosphorus (Av.P), exchangeable potassium (Exch.K) and soil organic carbon stock (SOCS) were significantly (p < 0.05) different between soils beneath canopies and outside canopies as well as at different distances from the tree trunk. Soils around these agroforestry tree species have increased SOC, TN, Av.P, Exch.K and SOCS by 11.9 to 91.5%, 22.2 to 125.0%, 31 to 71%, 32 to 151.6% and 15.2 to 90.9%, respectively, compared to soils outside tree canopies. Faidherbia albida (Delile) A.Chev. has the highest potential for soil fertility compared to Balanites aegyptiaca (L.) Delile, Cordia africana Lam., Ziziphus spina-christi (L.) Desf., Acacia sieberiana DC and Croton macrostachyus Hochst. ex Delile. This study could provide useful information for soil fertility management and farmers’ decision-making when selecting tree species. The findings of this study imply that scattered trees on croplands significantly improve soil fertility and reduce the need for external fertiliser inputs.
{"title":"Evaluation of soil physico-chemical properties as affected by canopies of scattered agroforestry trees on croplands","authors":"Shimbahri Mesfin, H. Haileselassie","doi":"10.1080/02571862.2022.2056644","DOIUrl":"https://doi.org/10.1080/02571862.2022.2056644","url":null,"abstract":"Agroforestry tree species play an important role in improving soil fertility. Though studies have confirmed that different species show different potentials to improve soil fertility, it is difficult to compare them as the studies were conducted in different areas. The potential for different tree species to improve soil fertility on croplands in northern Ethiopia is not known. The objectives of this paper are to determine the effects of presence or absence of agroforestry tree species on soil physico-chemical properties and the effect of distance from the tree trunk on the same soil physico-chemical properties. Sixty composite and undisturbed soil samples from beneath canopies and outside canopies and 90 composite and undisturbed soil samples from three different distances from tree trunks were collected. The results revealed that soil bulk density, soil moisture, soil organic carbon (SOC), total nitrogen (TN), available phosphorus (Av.P), exchangeable potassium (Exch.K) and soil organic carbon stock (SOCS) were significantly (p < 0.05) different between soils beneath canopies and outside canopies as well as at different distances from the tree trunk. Soils around these agroforestry tree species have increased SOC, TN, Av.P, Exch.K and SOCS by 11.9 to 91.5%, 22.2 to 125.0%, 31 to 71%, 32 to 151.6% and 15.2 to 90.9%, respectively, compared to soils outside tree canopies. Faidherbia albida (Delile) A.Chev. has the highest potential for soil fertility compared to Balanites aegyptiaca (L.) Delile, Cordia africana Lam., Ziziphus spina-christi (L.) Desf., Acacia sieberiana DC and Croton macrostachyus Hochst. ex Delile. This study could provide useful information for soil fertility management and farmers’ decision-making when selecting tree species. The findings of this study imply that scattered trees on croplands significantly improve soil fertility and reduce the need for external fertiliser inputs.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46394393","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}
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