Integrated Control of Sclerotium rolfsii on Groundnut in South Africa

Abstract

Sclerotium rolfsii Sacc. causes disease of numerous crop plants worldwide, including groundnuts. Control of this pathogen is difficult as it produces sclerotia which overwinter in the soil to emerge as inoculum and cause disease the following season. Various chemical, biological and cultural control strategies have been suggested and implemented, some of which have reduced disease incidence in the field. No studies have yet been undertaken in South Africa to control this disease on groundnut, either chemically, biologically or by cultural practices. In this study, several strategies were investigated for the control of S. rolfsii on groundnuts. Difenoconazole was identified as a fungicide that could possibly be applied in combination with Trichoderma harzianum, a biological antagonist of S. rolfsii, above carbendazim and flusilazole, and chlorothalonil. Difenoconazole significantly reduced the growth rate of S. rolfsii but not of T. harzianum. The cultivation of infected fields with an inversion plough significantly reduced infection of groundnuts by S. rolfsii and also improved the quality of the produce, while yield was not increased. Lower plant density increased the incidence of disease in an infected field, and is therefore not considered to be a viable form of cultural control.

Induction of Systemic Acquired Resistance inArachis hypogaeaL. bySclerotium rolfsiiDerived Elicitors

“…(2005b) demonstrated that the cell free culture filtrates of Pseudomonas aeruginosa inhibits the plant cell wall–degrading enzymes of S. rolfsii and reduces the severity of groundnut stem rot. Cilliers et al. (2003) suggested various biological, chemical and cultural strategies to control the S. rolfsii on groundnut in South Africa.…”

Diseases of Edible Oilseed Crops

“…The application of sterol biosynthesis inhibitors (SBI) also referred to as DMIs and quinone out side inhibitor (QoI) fungicides are now known to be more effective than previously recommended fungicides such as quintozene and carboxin for the control of SSR (Johnson and Subramanyam 2000, Besler et al 2006, Grichar et al 2010, Augusto and Brenneman 2011. The SBI tri azole systemic fungicides, namely, diniconazole, propiconazole, tebuconazole (Minton et al 1990, Culbreath et al 1992, Adiver and Anahosur 1995, cyproconazole (Culbreath et al 1992, Adiver andAnahosur 1995), hexaconazole (Johnson et al 2007b), difenoconazole (Cilliers et al 2003), and prothioconazole (Augusto and Brenneman 2012), and the QoI strobilurin fungicides, that is, azoxystrobin (Johnson and Subramanyam 2000, Rideout et al 2002, Sconyears et al 2007, Hagan et al 2010) and pyraclostrobin (Hagan et al 2007, Grichar et al 2010, have been proved to give very efficient and effective control of SSR of peanuts. The QoI fungicides should be applied preventively or as early as possible in the disease cycle as these are effective in inhibiting early mycelial growth.…”

Characterisation and antifungal activity of extracellular chitinase from a biocontrol fungus, Trichoderma asperellum PQ34

“…Many studies have shown Colletotrichum is a large genus of Ascomycete fungi, containing species that cause serious anthracnose diseases on a wide range of economic value crops such as mango (Rivera-Vargas et al 2006;Ismail et al 2015;Mo et al 2018) and chilli (Than et al 2008;Oo and Oh 2016;Saxena et al 2016). S. rolfsii fungus was also reported that is the cause of serious stem and pod rot disease in peanut production in many peanut-growing regions (Mehan et al 1994;Okabe and Matsumoto 2000;Cilliers et al 2003;Jogi et al 2016). Meanwhile, peanut, mango and chilli are three of agricultural crops of high economic value in Vietnam.…”