African Journal of
Agricultural Research

  • Abbreviation: Afr. J. Agric. Res.
  • Language: English
  • ISSN: 1991-637X
  • DOI: 10.5897/AJAR
  • Start Year: 2006
  • Published Articles: 6849

Full Length Research Paper

Economic Injury level and yield loss assessment for carmine spider mite (Tetranychus cinnabarinus Boisduval) on tomato Solanum lycopersicum under greenhouse conditions

Mitch M. Legwaila
  • Mitch M. Legwaila
  • Botswana National Museum, Box 00114, Gaborone, Botswana.
  • Google Scholar
Motshwari Obopile
  • Motshwari Obopile
  • Botswana University of Agriculture and Natural Resources, P/Bag 0027, Gaborone, Botswana.
  • Google Scholar
Bamphitlhi Tiroesele
  • Bamphitlhi Tiroesele
  • Botswana University of Agriculture and Natural Resources, P/Bag 0027, Gaborone, Botswana.
  • Google Scholar


  •  Received: 22 July 2022
  •  Accepted: 19 August 2022
  •  Published: 30 April 2023

Abstract

A study was undertaken over two cropping seasons, 2018/2019 and 2019/2020, to determine the economic injury level for carmine spider mite, Tetranychus cinnabarinus (Boisduval) on tomato Solanum lycopersicum in Botswana. Tomato plants were infested with adult spider mites for durations of 0 (no exposure), 1, 2, 3, 4, 5, 6 and 7 weeks (complete exposure). The corresponding treatments were 7, 6, 5, 4, 3, 2, 1 and 0 sprays with Abamectin. The results showed a significant reduction in the number of spider mites per plant as the frequency of spraying increased. An inverse relationship between spider mite exposure and yield was also observed following three weeks exposure. Yield loss increased to more than 50% when the pesticide was not applied to control spider mites. Economic decision levels are fundamental components of cost effective IPM programs and can be effective tools for making decisions about the application of pesticides against carmine spider mite in Botswana.

Key words: Spider mite exposure, Tetranychus cinnabarinus, economic injury level, yield loss, Solanum lycopersicum.