1. Presented by: Kwaw Andam
Co-authors: Mulu Amare, Patricia Zambrano, Judy Chambers, Temi Bamiwuye, Tunji Fasoranti,
Chibuzo Nwagboso, Jonathan Mockshell
African Conference of Agricultural Economists, Durban, South Africa, September 2023
Evaluating the impacts of using the Pod Borer
Resistant Cowpea variety in Nigeria: Research
design and characteristics of study participants

2. Background
1. Nigeria approved commercial release of transgenic pod-borer insect-
resistant (PBR) cowpea variety in 2019
2. First commercial genetically modified (GM) food crop in Nigeria and
for cowpea worldwide
3. A unique opportunity for a rigorous evaluation following the example
of evaluation of Bt. brinjal in Bangladesh (Ahmed et al. 2019)
Photo credits:
AATF

3. Evaluation Questions
1. What is the productivity change gain for PBR cowpea compared
to a conventional variety?
2. What is the effect of PBR cowpea on insecticide applications?
3. Does reduction in pesticide application translate to better health
indicators for farmers and their families?
4. Does the cultivation of PBR cowpea change household
consumption of cowpea and/or increase cowpea surpluses?
5. What are the heterogeneous impacts of PBR cowpea adoption by
gender, age, and other household characteristics?

4. Sampling Procedure

5. Treatment 1
400 farmers
PBR cowpea plus inputs
We assign farm households randomly to…
Treatment 2
600 farmers
PBR cowpea (no inputs)
Control
400 farmers
Conventional cowpea

6. Selected Descriptives from Household Survey

7. Household characteristics
• Head of households are predominantly male (95%)
• About 46 percent of plot managers are females
• About 59 percent of head of HH have at least some secondary
education, although 41 percent have no formal/elementary
education
• Agriculture is the main source of income of almost all HH (89%)

8. Plot characteristics
• The average plot size where
cowpea is planted is 3.1 hectares
Adamawa: 2.0 hectares
Kwara: 4.3 hectares
• Intercropping in 41 percent of
plots; maize is the most common
crop planted with cowpea
• Plots are on average 36 minutes
away from home
Percent
Plot Size (ha)
2.0
Adamawa
4.3
Kwara
3.1
Total

9. Cowpea Main Pests
Number
Farmers’ self-reporting
Cowpea affected by (% answering yes)
71.4
Cowpea aphids
66.9
Pod sucking bugs
62.8
Flower thrips
52.7
Maruca Vitrata
105.2
Quantity loss attributed to pests (Kg)

10. Pesticide and Herbicides Use and Cost
• Most farmers use pesticides
(95%) and herbicides (85%)
• Most have a jerrycan to mix
insecticides and half have
manual pesticides sprayers,
but almost none have spraying
machines
Mean
*per hectare
Sprays (pesticides)
4.7
Number of sprays
Quantity (number of liters)
5.3
Quantity of pesticides used per
hectare
Cost (in 1,000 Naira)
25.5
Cost of herbicides
24.2
Cost of pesticides

11. Cowpea Production Uses
(percentages)
SD
Mean
State
1029.1
442.4
Adamawa
1819.8
1082.7
Kwara
1564.3
808.7
Total
Cowpea Yield (kg/ha)
54.3
64.0
13.5
9.1
5.5 3.0
16.5 18.0
Adamawa Kwara
Others
Seed Stock
Home Consumption
Sold

12. Balancing Test: Pesticides applications & quantity of
pesticide used
Significance
Diff
Control
Treatment (1 & 2 )
0.26
0.80
4.74
5.54
Quantity of pesticides per hectare
0.69
1.44
36.10
37.54
Cost of herbicides per hectare (in Naira in
1000)
0.52
2.55
39.71
42.25
Cost of pesticides per hectare (in Naira in
1000)
0.94
6.64
803.87
810.51
Yield (kg/ha)
0.64
27.17
85.49
112.65
Quantity discarded (kg)

13. Conclusions from Baseline Survey
1. Balance between treatment and control groups on key covariates
We can attribute impacts to treatment (after controls)
2. Maruca affects over fifty percent of cowpea area
Controlling maruca through PBR cowpea can reduce harvest losses
3. High pesticide/herbicide application and costs
PBR cowpea can improve incomes and health of farm households by reducing
pesticide costs and applications
4. Cowpea is commercial (~60% production sold; 11% consumed)
Investment in cowpea can improve food system transformation
5. Low share (5%) of female-headed households in cowpea
46 percent of plot managers are women

14. FIELD IMPLEMENTATION
Inputs distribution in Patigi LGA, Kwara State
Registration of farmers in Song LGA, Adamawa State
A farm in Edu LGA, Kwara state
Training of Extension Agents in Yola, Adamawa State
Sorting of Inputs in Yola, Adamawa State
Inputs distribution in Edu LGA, Kwara State

15. Acknowledgements
• Funding: USAID and CGIAR Initiative on National Policies and
Strategies
• Implementation: African Agricultural Technology Foundation
(AATF) and partners including OFAB
• Research inputs: John Komen, Jose Falck–Zepeda, Hyacinth
Edeh, Emmanuel Okogbenin, Francis Onyekachi, Ijeoma
Akaogu, Jean Baptiste De La Salle Tignegre & Participants in
IFPRI Africa Region Brown Bag Seminar