South African Journal of Plant and Soil最新文献_第10页

First report of glyphosate and paraquat resistance in two Plantago biotypes 两种车前草生物型对草甘膦和百草枯抗性的首次报道

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South African Journal of Plant and Soil Pub Date : 2021-03-15 DOI: 10.1080/02571862.2021.1879287

Vhuthu Ndou, Frederick Eksteen, E. Phiri, P. Pieterse

{"title":"First report of glyphosate and paraquat resistance in two Plantago biotypes","authors":"Vhuthu Ndou, Frederick Eksteen, E. Phiri, P. Pieterse","doi":"10.1080/02571862.2021.1879287","DOIUrl":"https://doi.org/10.1080/02571862.2021.1879287","url":null,"abstract":"Resistance to glyphosate in plantago (Plantago lanceolata L.), a serious weed in South Africa, was confirmed in 2003. More recently, a plantago biotype that is putatively resistant to both glyphosate and paraquat was reported. Seeds from a putatively susceptible (S) plantago population and from two putatively resistant populations (R1 and R2) were subjected to glyphosate and paraquat. To investigate possible multiple resistance, sequential application of glyphosate and paraquat was explored. The results showed an LD50 of 891.89 g a.e. ha−1 and 387.75 g a.i. ha−1 for glyphosate and paraquat respectively for the S biotype. For glyphosate, the LD50 value for R1 was 3842.61 g a.e. ha−1. The LD50 for the R2 biotype to glyphosate was 2020.39 g a.e. ha−1. The paraquat LD50 values for the R1 and R2 biotypes were 785.14 and 1246.43 g a.i. ha−1 respectively, resulting in resistance indices of 2 and 3 respectively. Sequential application of glyphosate and paraquat was not effective in plantago management. The R biotypes showed resistance to both glyphosate and paraquat indicating possible multiple resistance.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":"38 1","pages":"134 - 139"},"PeriodicalIF":0.9,"publicationDate":"2021-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/02571862.2021.1879287","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47245238","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}

引用次数: 3

Long-term wheat production management effects on soil fertility indicators in the semi-arid eastern Free State, South Africa 长期小麦生产管理对半干旱的南非自由州东部土壤肥力指标的影响

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South African Journal of Plant and Soil Pub Date : 2021-03-15 DOI: 10.1080/02571862.2020.1858512

P. F. Loke, Johannes Jacobus Schimper, E. Kotzé, C. D. du Preez

{"title":"Long-term wheat production management effects on soil fertility indicators in the semi-arid eastern Free State, South Africa","authors":"P. F. Loke, Johannes Jacobus Schimper, E. Kotzé, C. D. du Preez","doi":"10.1080/02571862.2020.1858512","DOIUrl":"https://doi.org/10.1080/02571862.2020.1858512","url":null,"abstract":"This study evaluated temporal effects of wheat production management practices on soil fertility under semi-arid conditions. Treatments applied for 37 years included straw management (unburned and burned), tillage practices (no-tillage, stubble mulch, and mouldboard ploughing) and weed control methods (chemical and mechanical). Soil samples were collected from 0–50, 50–150 and 150–250 mm layers, in 1990, 1999, 2010 and 2016, and analysed for organic carbon (OC), total nitrogen, pH, phosphorus (P) and potassium (K). Supplied grain yield data were used to estimate straw yield. Uptake of N, P and K by grain (removal) and straw (recycle) were estimated across sampling periods. Results revealed that OC, C:N ratio and P generally increased from 1990 to 1999 or 2010, and that conservation tillage increased soil fertility as compared with mouldboard ploughing. The only year × treatment interaction effects were on pH and K in the soil layers 0–50 and 50–150 mm in some treatments. However, all soil fertility indicators increased from 1990 to 1999 or 2010, then declined or stabilised across all treatments. The results suggest that adoption of conservation tillage with associated straw and nutrient recycling and additions cannot enable farmers to maintain or improve soil fertility and yields over time.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":"38 1","pages":"93 - 106"},"PeriodicalIF":0.9,"publicationDate":"2021-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/02571862.2020.1858512","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42367704","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}

引用次数: 6

A comparison of zinc sources and extraction methods on sandy soils suitable for maize cropping 适宜玉米种植的沙质土壤锌源及提取方法比较

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South African Journal of Plant and Soil Pub Date : 2021-03-15 DOI: 10.1080/02571862.2021.1891473

CF Wessels, L. van Straaten, C. du Preez, G. Ceronio

{"title":"A comparison of zinc sources and extraction methods on sandy soils suitable for maize cropping","authors":"CF Wessels, L. van Straaten, C. du Preez, G. Ceronio","doi":"10.1080/02571862.2021.1891473","DOIUrl":"https://doi.org/10.1080/02571862.2021.1891473","url":null,"abstract":"Maize is the most important crop produced for human and animal nourishment in South Africa. The crop is susceptible to zinc (Zn) deficiencies, which result in lower grain yields with poorer nutritional value. Knowledge of the nature and behaviour of Zn fertilisers is therefore important for sustainable maize production, especially in sandy soils. The aim of this incubation study was to test the effect of inorganic (ZnO, ZnCl2, ZnCO3 and ZnSO4) and chelated (ZnEDTA, ZnDTPA, ZnEDDHA and ZnHEDTA) sources of Zn applied at different rates on Zn extracted by diluted HCl, DTPA, Mehlich-1, Ambic-2 and Na2EDTA methods. Analyses showed that ZnO was the least effective source, and ZnSO4 was the most effective source at increasing the extractable Zn of sandy soils. The extractable Zn content of the soils increased almost linearly with increasing application rates of all the zinc sources. Generally, the Na2EDTA method was most efficient in extracting the applied Zn. These results must be validated with crop growth response in glasshouse and especially field studies.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":"38 1","pages":"152 - 158"},"PeriodicalIF":0.9,"publicationDate":"2021-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/02571862.2021.1891473","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48811397","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}

引用次数: 1

Colletotrichum gloeosporioides s.l. causes an outbreak of anthracnose of cacao in Ghana 炭疽病在加纳引起可可炭疽病的爆发

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South African Journal of Plant and Soil Pub Date : 2021-03-15 DOI: 10.1080/02571862.2020.1863485

E. Asare, O. Domfeh, S. Avicor, P. Pobee, Y. Bukari, I. Amoako-Attah

{"title":"Colletotrichum gloeosporioides s.l. causes an outbreak of anthracnose of cacao in Ghana","authors":"E. Asare, O. Domfeh, S. Avicor, P. Pobee, Y. Bukari, I. Amoako-Attah","doi":"10.1080/02571862.2020.1863485","DOIUrl":"https://doi.org/10.1080/02571862.2020.1863485","url":null,"abstract":"Outbreak of anthracnose of cacao (Theobroma cacao L.), covering an estimated total growing area of 248.47 hectares, occurred in parts of Ghana from July to October 2019. Disease samples were collected from the outbreak areas to isolate and identify the pathogen and establish its pathogenicity. Disease symptoms appeared on leaves as dark brown patches with yellow halo margins. Colletotrichum gloeosporioides s.l. was isolated from infected plant tissues and pathogenicity tests confirmed it as the causative agent. The disease was widespread in the Prestea-Huni Valley district of the Western Region, particularly in the Yareyeya community, where a 14.8-hectare farm was seriously affected. Anthracnose has long been known as a sporadic but minor disease of cacao in Ghana. The current shift in status and rapid spread of the disease from infected farms to new farms, though it may or may not be contiguous, cannot be readily explained. Application of copper fungicides, namely Nordox 75 WG (86% cuprous oxide), Champion (77% cupric hydroxide) and Royal Cop 50 WP (77% copper hydroxide) at 75 g, 100 g and 100 g, respectively, each in 15 litres of water, at 2-week intervals for four months, effectively managed the disease.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":"38 1","pages":"107 - 115"},"PeriodicalIF":0.9,"publicationDate":"2021-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/02571862.2020.1863485","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47313236","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}

引用次数: 5

Effects of biostimulants on tissue and rhizospheric acid phosphatase activity of chickpea genotypes 生物刺激剂对鹰嘴豆基因型组织和根际酸性磷酸酶活性的影响

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South African Journal of Plant and Soil Pub Date : 2021-03-15 DOI: 10.1080/02571862.2021.1881634

R. M. Moloto, F. Dakora, P. Soundy, S. Maseko

引用次数: 1

Incidence of gummosis disease in silky hakea under natural conditions in South Africa 南非自然条件下丝胶猴软胶病的发病率

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South African Journal of Plant and Soil Pub Date : 2021-03-15 DOI: 10.1080/02571862.2021.1879286

A. Wood, A. D. Breeyen

{"title":"Incidence of gummosis disease in silky hakea under natural conditions in South Africa","authors":"A. Wood, A. D. Breeyen","doi":"10.1080/02571862.2021.1879286","DOIUrl":"https://doi.org/10.1080/02571862.2021.1879286","url":null,"abstract":"The pathogen Colletotrichum acutatum J.H.Simmonds was developed in South Africa during the 1980s as a mycoherbicide to control invasive silky hakea (Hakea sericea Schrad. & J.C.Wendl.) and was subsequently widely used by a variety of land managers to induce gummosis disease. To determine persistence under natural conditions, disease incidence and severity were monitored annually at five sites in the Western Cape and Eastern Cape provinces, from 2008 until 2017. Disease incidence ranged between 12% and 95% of trees with gummosis in the first year. At four of the sites, high levels of mortality were recorded during the first four years of monitoring. In the year with the highest mortality, between 38 and 64% of trees were dead. No mortality was recorded at the fifth site. Disease incidence and mortality were reduced in the latter years, coinciding with drier conditions. At three of the sites, fires occurred once during the course of monitoring and the disease reappeared one to three years post-fire. It was concluded that although the disease will persist under natural conditions, for maximum benefit the fungus should be actively applied to maintain high levels of incidence and mortality. Depending on site characteristics and weather trends, this should be on an annual, bi- or triennial basis, or following fires or dry years.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":"38 1","pages":"126 - 133"},"PeriodicalIF":0.9,"publicationDate":"2021-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/02571862.2021.1879286","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49292248","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}

引用次数: 3

A comparison of the results of phosphorus analyses of alkaline and calcareous soils amongst South African laboratories 南非实验室中碱性和钙质土壤磷分析结果的比较

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South African Journal of Plant and Soil Pub Date : 2021-01-01 DOI: 10.1080/02571862.2020.1845829

AE Venter, C. du Preez

{"title":"A comparison of the results of phosphorus analyses of alkaline and calcareous soils amongst South African laboratories","authors":"AE Venter, C. du Preez","doi":"10.1080/02571862.2020.1845829","DOIUrl":"https://doi.org/10.1080/02571862.2020.1845829","url":null,"abstract":"Large areas of alkaline and calcareous soils are irrigated in South Africa. For these soils, proper fertilisation programs based on soil phoshorus (P) analyses are required. Little is known about P analyses of alkaline and calcareous soils. The study aimed to compare P analyses by three laboratories, each using Bray 1, Mehlich 3 and Olsen extraction methods. Six soils with a pH of 7.1 to 8.2 that contain 0.6 to 12.4% of CaCO3 were incubated for two months after application of mono-ammonium phosphate (MAP) at levels equivalent to 0, 16.8, 33.6, 50.4, 67.2, 84.0 and 100.8 kg P ha−1, subjected to several wetting and drying cycles. The P contents that were reported differed in many instances between the laboratories. The differences were sometimes of such an extent that it will influence P fertiliser programs significantly. This should be a concern for farmers and their advisors. This is probably inter alia due to the chemical composition of the extractants. An in-depth investigation into a larger number of laboratories’ P analyses of alkaline and calcareous soils is warranted to confirm the results.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":"38 1","pages":"70 - 76"},"PeriodicalIF":0.9,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/02571862.2020.1845829","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43953403","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}

引用次数: 0

Phosphorus extraction by selected methods in alkaline and calcareous soils after mono-ammonium phosphate application at different rates 不同配比施用磷酸一铵后碱性和石灰性土壤中磷的选择方法

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South African Journal of Plant and Soil Pub Date : 2021-01-01 DOI: 10.1080/02571862.2020.1845828

AE Venter, C. du Preez

{"title":"Phosphorus extraction by selected methods in alkaline and calcareous soils after mono-ammonium phosphate application at different rates","authors":"AE Venter, C. du Preez","doi":"10.1080/02571862.2020.1845828","DOIUrl":"https://doi.org/10.1080/02571862.2020.1845828","url":null,"abstract":"Little research has been done on extractable phosphorus (P) in alkaline and calcareous irrigated soils of South Africa. This study aimed to quantify extractable P by selected methods in these soils after application of mono-ammonium phosphate (MAP) at different rates. Six soils with a pH of 7.1 to 8.2 that contained 0.6–12.4% CaCO3 were incubated for two months after application of MAP at levels equivalent to 0, 16.8, 33.6, 50.4, 67.2, 84.0 or 100.8 kg P ha−1. After incubation, soil P was extracted with the Olsen, Bray 1, Mehlich 3 and Ambic 1 methods. The most soil P was extracted with the Mehlich 3 method, and the least soil P was extracted with either the Bray 1 or Olsen methods, regardless of the MAP application rate. The differences in P extracted by the methods were attributed to the chemical composition of the extractants and the soil properties. Olsen and to a lesser extent Ambic 1 were the most reliable methods for establishing the amount of P required to raise the P status of the alkaline and calcareous soils. Future research should focus on establishing specific threshold values for soil and crop combinations with the Olsen method.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":"38 1","pages":"60 - 69"},"PeriodicalIF":0.9,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/02571862.2020.1845828","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45507498","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}

引用次数: 1

Effect of encroaching woody plant species on soil nutrients and selected soil chemical properties in communally managed semiarid savanna grazing lands in the North West province, South Africa 南非西北省公共管理半干旱稀树草原草地木本植物入侵对土壤养分和土壤化学特性的影响

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South African Journal of Plant and Soil Pub Date : 2021-01-01 DOI: 10.1080/02571862.2020.1829117

P. Malan, M. Tiawoun, Khumoetsile S Molatlhegi, S. Materechera

{"title":"Effect of encroaching woody plant species on soil nutrients and selected soil chemical properties in communally managed semiarid savanna grazing lands in the North West province, South Africa","authors":"P. Malan, M. Tiawoun, Khumoetsile S Molatlhegi, S. Materechera","doi":"10.1080/02571862.2020.1829117","DOIUrl":"https://doi.org/10.1080/02571862.2020.1829117","url":null,"abstract":"Woody plant encroachment is recognised as one of the major threats to biodiversity in ecosystems. In many arid and semiarid areas of South Africa, indigenous encroacher species are proliferating, but the factors that favor their abundance are poorly understood. This study investigated the effect of encroaching woody species on soil properties. The effects of two encroaching species, Senegalia mellifera and Dichrostachys cinerea, on soil nutrients and chemical properties were investigated in 8 communally managed grazing sites and compared to the effects of the non-encroacher, Vachellia karroo, in two non-encroached benchmark sites. Three belt transects were laid out to determine woody plant density. Three soil samples (0-20 cm deep) per belt were sampled to determine soil properties. Senegalia mellifera was the most abundant with a mean density of 5907 TE ha−1. Soil properties in the benchmark sites had no significant differences (p > 0.05) than soil under encroaching D. cinerea regarding organic C, total N, C:N, exchangeable Na, CEC, EC, ESP, SAR and soil texture. Plant influence on soil differed among encroaching species and between encroaching and non-encroaching species. Plant diversity explain the variation of soil properties and prove the important specific role of each species in the ecosystem.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":"38 1","pages":"27 - 35"},"PeriodicalIF":0.9,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/02571862.2020.1829117","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47609488","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}

引用次数: 1

Assessing the impact of climate change on crop production in southern Africa: a review 评估气候变化对南部非洲作物生产的影响:综述

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South African Journal of Plant and Soil Pub Date : 2021-01-01 DOI: 10.1080/02571862.2020.1844325

A. Franke

{"title":"Assessing the impact of climate change on crop production in southern Africa: a review","authors":"A. Franke","doi":"10.1080/02571862.2020.1844325","DOIUrl":"https://doi.org/10.1080/02571862.2020.1844325","url":null,"abstract":"This paper provides a systematic review of studies assessing the impact of climate change on crop yields in southern Africa. Moreover, it synthesises the current knowledge of the impact of elevated ambient CO2 levels (eCO2) and temperatures on physiological processes, and the application of this knowledge in mechanistic crop models. While eCO2 evidently has a strong impact on photosynthesis and crop water use, it is uncertain how this will work out for the climatic and crop management conditions prevailing in southern Africa. The impact of heat stress on crop reproductive processes and the process of transpiration cooling mitigating heat stress are poorly represented in models, while both process are relevant given the climatic conditions prevailing in southern Africa. Twenty studies assessing the impact of climate change on future yields of crops, mostly maize, have been retrieved. The results suggest that potato, Bambara groundnut and sugarcane yields may improve. No consistent trends for maize and sorghum could be identified. While yield predictions are obviously context-specific, large uncertainties related to climate predictions and crop models imply results should be treated with caution. Suggestions are made for field experimentation and the improved application of crop models for climate change research in the region.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":"38 1","pages":"1 - 12"},"PeriodicalIF":0.9,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/02571862.2020.1844325","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44730299","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}

引用次数: 3