African Journal of
Plant Science

  • Abbreviation: Afr. J. Plant Sci.
  • Language: English
  • ISSN: 1996-0824
  • DOI: 10.5897/AJPS
  • Start Year: 2007
  • Published Articles: 748

Full Length Research Paper

Evaluation of plant extracts for the management of Cercospora leaf spot of groundnut (Arachis hypogaea L.)

Moses Neindow
  • Moses Neindow
  • Department of Agronomy, Faculty of Agriculture, University for Development Studies, P. O. Box TL 1882, Nyankpala Campus, Tamale, Ghana.
  • Google Scholar
Elias Nortaa Kunedeb Sowley
  • Elias Nortaa Kunedeb Sowley
  • Department of Agronomy, Faculty of Agriculture, University for Development Studies, P. O. Box TL 1882, Nyankpala Campus, Tamale, Ghana.
  • Google Scholar
Frederick Kankam
  • Frederick Kankam
  • Department of Agronomy, Faculty of Agriculture, University for Development Studies, P. O. Box TL 1882, Nyankpala Campus, Tamale, Ghana.
  • Google Scholar


  •  Received: 08 June 2020
  •  Accepted: 15 October 2020
  •  Published: 30 November 2020

Abstract

Groundnut (Arachis hypogaea L.) is a leguminous crop with high economic and nutritional value. However, increased production is hampered by Cercospora leaf spot (CLS) caused by Cercospora arachidicola and Cercosporidium personatum. Studies were conducted in vitro and in vivo to evaluate the efficacy of aqueous extracts of desert date seed (DDSE), neem seed (NSE), jatropha seed (JSE) and tobacco leaf (TLE) for the management of CLS. The antifungal activities of 25, 50, 75 and 100 g/l concentrations of each of the plant extracts was assessed in vitro on potato dextrose agar using the food poison technique. The field study was a factorial experiment consisting of 18 treatments laid in a Randomised Complete Block Design with four replications over two cropping seasons. The in vitro results revealed that all the botanicals at 100 g/l recorded the highest inhibition percentages. DDSE at 100 g/l significantly (P < 0.001) inhibited the highest mycelia growths compared to other levels of plant extracts used with inhibition percentages of 90.33 and 84.96% in C. arachidicola and C. personatum, respectively. Three out of the four aqueous extracts (DDSE, NSE and JSE) at 100 g/l significantly (P < 0.05) lowered disease incidence, severity and defoliation in the field and increased yield. Pod yield was significantly (P < 0.05) higher in plants treated with JSE, NSE, DDSE and Topsin-M, compared to those treated with TLE and the negative control plants. For most of the parameters, DDSE produced similar results as Topsin-M followed by NSE and JSE. Farmers can adopt DDSE, NSE and JSE as alternatives to fungicides leading to minimal effect on the environment since they are biodegradable. 

 

Key words: Cercospora leaf spot, plant extracts, groundnut, incidence, severity, aqueous.