Benefits of maize resistance breeding and chemical control against northern leaf blight in smallholder farms in South Africa

dc.contributor.authorBerger, David Kenneth
dc.contributor.authorMokgobu, Tumisang
dc.contributor.authorDe Ridder, Katrien
dc.contributor.authorChristie, Nanette
dc.contributor.authorAveling, T.A.S. (Terry)
dc.contributor.emaildave.berger@fabi.up.ac.zaen_ZA
dc.date.accessioned2021-08-30T13:53:10Z
dc.date.available2021-08-30T13:53:10Z
dc.date.issued2020-11-26
dc.description.abstractMaize underpins food security in South Africa. An annual production of more than 10 million tons is a combination of the output of large-scale commercial farms plus an estimated 250 000 ha cultivated by smallholder farmers. Maize leaves are a rich source of nutrients for fungal pathogens. Farmers must limit leaf blighting by fungi to prevent sugars captured by photosynthesis being ‘stolen’ instead of filling the grain. This study aimed to fill the knowledge gap on the prevalence and impact of fungal foliar diseases in local smallholder maize fields. A survey with 1124 plant observations from diverse maize hybrids was conducted over three seasons from 2015 to 2017 in five farming communities in KwaZulu-Natal Province (Hlanganani, Ntabamhlophe, KwaNxamalala) and Eastern Cape Province (Bizana, Tabankulu). Northern leaf blight (NLB), common rust, Phaeosphaeria leaf spot, and grey leaf spot had overall disease incidences of 75%, 77%, 68% and 56%, respectively, indicating high disease pressure in smallholder farming environments. NLB had the highest disease severity (LSD test, p<0.05). A yield trial focused on NLB in KwaZulu-Natal showed that this disease reduced yields in the three most susceptible maize hybrids by 36%, 71% and 72%, respectively. Eighteen other hybrids in this trial did not show significant yield reductions due to NLB, which illustrates the progress made by local maize breeders in disease resistance breeding. This work highlights the risk to smallholder farmers of planting disease-susceptible varieties, and makes recommendations on how to exploit the advances of hybrid maize disease resistance breeding to develop farmer-preferred varieties for smallholder production. SIGNIFICANCE : • Northern leaf blight, grey leaf spot, Phaeosphaeria leaf spot and common rust diseases were widespread in KwaZulu-Natal and Eastern Cape smallholder maize fields where fungicides were not applied. • NLB was the most severe maize leaf disease overall. • NLB caused maize leaf blighting, which reduced grain yields by 36–72% in susceptible maize hybrids. • Maize resistance breeding has produced locally adapted hybrids that do not have significant yield losses under NLB disease pressure.en_ZA
dc.description.departmentBiochemistryen_ZA
dc.description.departmentForestry and Agricultural Biotechnology Institute (FABI)en_ZA
dc.description.departmentGeneticsen_ZA
dc.description.departmentMicrobiology and Plant Pathologyen_ZA
dc.description.departmentPlant Production and Soil Scienceen_ZA
dc.description.librarianam2021en_ZA
dc.description.sponsorshipDepartment of Agriculture, Forestry and Fisheries Research Technology Fund through the National Research Foundation of South Africa; USAID through the University of California Davis Research and Innovation Fellowship for Agriculture.en_ZA
dc.description.urihttp://www.sajs.co.zaen_ZA
dc.identifier.citationBerger DK, Mokgobu T, De Ridder K, Christie N, Aveling TAS. Benefits of maize resistance breeding and chemical control against northern leaf blight in smallholder farms in South Africa. South African Journal of Science 2020;116 (11/12), Art. #8286, 7 pages. https://DOI.org/ 10.17159/sajs.2020/8286.en_ZA
dc.identifier.issn0038-2353 (print)
dc.identifier.issn1996-7489 (online)
dc.identifier.other10.17159/sajs.2020/8286
dc.identifier.urihttp://hdl.handle.net/2263/81542
dc.language.isoenen_ZA
dc.publisherAOSIS Open Journalsen_ZA
dc.rights© 2020. The Author(s). Published under a Creative Commons Attribution Licence.en_ZA
dc.subjectFungicideen_ZA
dc.subjectDisease resistance breedingen_ZA
dc.subjectCommon rusten_ZA
dc.subjectMaizeen_ZA
dc.subjectGrey leaf spot (GLS)en_ZA
dc.subjectNorthern leaf blight (NLB)en_ZA
dc.subjectPhaeospaeria leaf spot (PLS)en_ZA
dc.subjectSouth Africa (SA)
dc.titleBenefits of maize resistance breeding and chemical control against northern leaf blight in smallholder farms in South Africaen_ZA
dc.typeArticleen_ZA

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