Integrated pest management: the push–pull approach for controlling insect pests and weeds of cereals, and its potential for other agricultural systems including animal husbandry

Abstract

This paper describes the 'push-pull' or 'stimulo-deterrent diversionary' strategy in relation to current and potential examples from our own experiences. The push-pull effect is established by exploiting semiochemicals to repel insect pests from the crop ('push') and to attract them into trap crops ('pull'). The systems exemplified here have been developed for subsistence farming in Africa and delivery of the semiochemicals is entirely by companion cropping, i.e. intercropping for the push and trap cropping for the pull. The main target was a series of lepidopterous pests attacking maize and other cereals. Although the area given to the cereal crop itself is reduced under the push-pull system, higher yields are produced per unit area. An important spin-off from the project is that the companion crops are valuable forage for farm animals. Leguminous intercrops also provide advantages with regard to plant nutrition and some of the trap crops help with water retention and in reducing land erosion. A major benefit is that certain intercrop plants provide dramatic control of the African witchweed (striga). Animal husbandry forms an essential part of intensive subsistence agriculture in Africa and developments using analogous push-pull control strategies for insect pests of cattle are exemplified.

Forty research issues for the redesign of animal production systems in the 21st century

“…In areas where vector-borne diseases are widespread, there is a need to reduce contact with livestock. The use of repellents and attractors to control diseases transmitted by ticks, mosquitoes or flies is a promising option (Hassanali et al, 2008).…”

“…Mixing several plant species in innovative forage systems thus provides a diversity of not only food and feed resources but also regulating, supporting and cultural ecosystem services (Hassanali et al, 2008;Murgueitio et al, 2011). Studies on the management of forage-based systems have started to quantify these non-provisioning services, but usually one service at a time rather than in bundles of services.…”

“…For instance, the dissemination in Kenya of the push-pull technology operates through farmer-teachers working as village extension staff. Women's groups establish legume monocultures for seed production, which improves gender equality and family cohesiveness (Hassanali et al, 2008). At the other end of the product chain, APS could benefit from short and specific channels, with strong links between food production and local communities (Rosset and Martínez-Torres, 2012), such as direct sales in farmers' markets, regular basket schemes, ecological meal initiatives in canteens and community gardens.…”

New Synthesis: Plant Volatiles as Functional Cues in Intercropping Systems

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The practice of intercropping has begun to show its enormous potential to translate discoveries in chemical ecology to improve crop pest control and reduce dependence on pesticides (Hassanali et al, 2008). However, the actual mechanism by which intercropping works remains elusive, and the proposed plant-chemistry based hypothesis was recently challenged (Finch and Collier, 2012).

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“…Maize is intercropped with the legume Desmodium uncinatum or the grass Melinis minutiflora, both of which dramatically reduce plant damage by repelling (pushing) the adult stem-borer moths out of the field, while Napier grass (Pennisetum purpureum) is planted around the field edges to attract (pull) gravid females away from maize. The combined use of these two types of stimuli reduces stem borer damage by two thirds and at least doubles maize yields in comparison with control plots (Hassanali et al, 2008).The success of this approach has been attributed to release of attractive and repellent semiochemicals by the "push" and "pull" companion plants, respectively. Identification of specific volatile organic compounds (VOC) through GC-EAG and corroboration of their behavioral significance suggest attractive as well as repellent functions of intercrop VOCs (Hassanali et al, 2008).…”