Journal of Chemical Ecology

, Volume 42, Issue 7, pp 689–697

Push-Pull: Chemical Ecology-Based Integrated Pest Management Technology

  • Zeyaur Khan
  • Charles A. O. Midega
  • Antony Hooper
  • John Pickett
Article

DOI: 10.1007/s10886-016-0730-y

Cite this article as:
Khan, Z., Midega, C.A.O., Hooper, A. et al. J Chem Ecol (2016) 42: 689. doi:10.1007/s10886-016-0730-y

Abstract

Lepidopterous stemborers, and parasitic striga weeds belonging to the family Orobanchaceae, attack cereal crops in sub-Saharan Africa causing severe yield losses. The smallholder farmers are resource constrained and unable to afford expensive chemicals for crop protection. The push–pull technology, a chemical ecology- based cropping system, is developed for integrated pest and weed management in cereal–livestock farming systems. Appropriate plants were selected that naturally emit signaling chemicals (semiochemicals). Plants highly attractive for stemborer egg laying were selected and employed as trap crops (pull), to draw pests away from the main crop. Plants that repelled stemborer females were selected as intercrops (push). The stemborers are attracted to the trap plant, and are repelled from the main cereal crop using a repellent intercrop (push). Root exudates of leguminous repellent intercrops also effectively control the parasitic striga weed through an allelopathic mechanism. Their root exudates contain flavonoid compounds some of which stimulate germination of Striga hermonthica seeds, such as Uncinanone B, and others that dramatically inhibit their attachment to host roots, such as Uncinanone C and a number of di-C-glycosylflavones (di-CGFs), resulting in suicidal germination. The intercrop also improves soil fertility through nitrogen fixation, natural mulching, improved biomass, and control of erosion. Both companion plants provide high value animal fodder, facilitating milk production and diversifying farmers’ income sources. The technology is appropriate to smallholder mixed cropping systems in Africa. Adopted by about 125,000 farmers to date in eastern Africa, it effectively addresses major production constraints, significantly increases maize yields, and is economical as it is based on locally available plants, not expensive external inputs.

Keywords

Cereal crops Stemborer pests Parasitic striga Semiochemicals Allelopathy 

Copyright information

© Springer Science+Business Media New York 2016

Authors and Affiliations

  • Zeyaur Khan
    • 1
  • Charles A. O. Midega
    • 1
  • Antony Hooper
    • 2
  • John Pickett
    • 2
  1. 1.International Centre of Insect Physiology and Ecology (icipe)NairobiKenya
  2. 2.Biological Chemistry and Crop Protection DepartmentRothamsted ResearchHarpendenUK