Natural Crop Protection in the Tropics: The Mothers, Fathers and Midwives of Invention

Zamorano’s natural pest control course

by Jeffery W. Bentley, PhD

Background and context

Maize and beans are the main food crops of Honduras and the rest of Central America. Beginning in 1980, Zamorano (Escuela Agricola Panamericana) provided scientific, IPM (integrated pest management) research for smallholder maize & bean farmers. Early efforts were led by Keith Andrews, a US entomologist, who founded the Department of Crop Protection at Zamorano. Although the Department’s focus was IPM, it had a broad enough philosophy to allow for participatory research in natural crop protection.

Project history

From 1983 to 1991, the centrepiece of the Department of Crop Protection was its Maize-Bean Section, which was Zamorano’s first experience working on-farm with smallholders. The Maize-Bean’s work was influenced by FSR (Farming Systems Research) and by anthropologists. The agronomists did formal on-farm trials, and were influenced by farmers, who helped manage the trials. The Maize-Bean Section invented several useful technologies (e.g. trash traps to control bean slugs, Sarasinula plebeia), and conducted some formal experiments with extension, which showed that visual aids were expensive, but did not necessarily aid in teaching. Perhaps the Section’s most important contribution was the notion that IPM research/extension programmes should teach farmers basic biological information, e.g. life cycles of key pests, to give farmers the concepts that underlie IPM technologies.

Between 1988 and 1989, Project members tried to induce 14 farmers in a village near Zamorano to invent new technologies for managing maize ear rots (a disease complex caused by the fungi Stenocarpella spp. and Fusarium maydis). We gave a scientific seminar on ear rots to farmers, emphasizing the causal agents (fungi) of maize ear rots, the one topic about the disease which farmers understood poorly. We gave samples of seed to farmers to test for resistance (an improved, open-pollinated variety, and a local variety from another province). Farmers also looked through stereoscopes to observe the fungus better. Of 14 farmers who received plant pathology training, 13 planted varietal trials, but only one of them conducted a more novel experiment. He planted a maize field where the irrigation water flowed from the west and the wind blew from the north, so he could use the pattern of ear rots in his field to determine whether the inoculum was transported by water or air.

That experience taught us that farmers could invent things, by blending scientific and local knowledge, but that we would need to work with many more farmers to get a large enough sample of really good farmer experimenters to invent many useful techniques. We formed the Hillsides IPM Section team in 1991 to do that.

Organizational structure and stakeholders

At first, we taught short courses at Zamorano (described below), to NGO extensionists, para-technicals and farmers associated with the NGOs. Team members drove hundreds of kilometres every week to visit remote NGO personnel and farmers who had taken the short course. There were eventually 10 people in the Section, including 2 Honduran farmers. In 1993, 2 of the Salvadoran agronomists began teaching courses to NGOs in El Salvador. In 1994, we opened a Hillsides IPM Programme in Nicaragua with Swiss support.

10 Farmer inventions in response to natural pest control training

1. Sugar water to control fall armyworm in maize.

2. Caterpillar soup for spreading entomopathogens

to caterpillars in beans.

3. Gliricidia sepium leaves to reduce white grub

(Phyllophaga spp., Coleoptera: Scarabaeidae)

damage to crop roots.

4. Neem leaf slurry to deter fire ants from seeds.

5. Crushed June beetles (adult Phyllophaga spp.)

to discourage females from laying eggs in soil.

6. Bell pepper and onion to deter chilli weevils

(Anthonomus eugenii, Coleoptera: Curculionidae).

7. Cabbage planted under maize to deter diamondback

moths, (Plutella xylostella, Lepidoptera: Plutellidae)

with maize as a habitat for earwigs, natural enemies

of Plutella xylostella.

8. Sacks as barriers against whiteflies

(Bemisia tabaci, Homoptera: Aleyrodidae).

9. Gourd fruit to distract leaf cutter ants

(Hymenoptera: Formicidae: Attini).

10. Chilli, marigold & alcohol applied on slugs in trash traps.

The printed version contains more information about the following themes:

Motivations and expectations of the farmers

Research

Outputs

Linkages

Economics

Sustainability of the approach

Assessment

Conclusions and recommendations for others