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Study Overview

Evaluation of Plantwise - Kenya
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Plantwise (PW) is a global initiative that provides smallholders farmers with information on the maintenance of crop health. PW began working in Kenya in 2010 to gather, organize, manage, and disseminate plant health information to smallholder farmers. This study conducts a mixed methods evaluation of Kenya’s PW program. We draw from qualitative methods to assess the changes that PW brings to the Kenyan plant health system, conduct a cost analysis of the program, and evaluate the fidelity of PW implementation in Kenya. To identify farm-level impacts, we rely on an experimental approach based on the expansion of plant clinics in 2014 and 2015 to qualified areas, where the location of new plant clinics will be randomly selected. Farm-level questionnaires will be administered to a random sample of 2800 households and will focus on intermediate outcome indicators such as knowledge and changes in practice as well as on longer term outcomes such as impacts on yields, farm productivity, gross margins, crop selection, and food security. This evaluation will provide valuable information on how the PW program has affected farmer welfare and agricultural practices in Kenya.

Registration Citation:

Winters, PC. and Bonilla, J., 2014. Evaluation of Plantwise - Kenya. Registry for International Development for Impact Evaluations (RIDIE). Available at: 10.23846/ridie036

Agriculture and Rural Development
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Principal Investigator(s)

Name of First PI:
Paul C Winters
American University - Washington DC, USA
Name of Second PI:
Juan Bonilla
American Institutes for Research

Study Sponsor

CABI (CAB International)
Study Sponsor Location:
United Kingdom

Research Partner

Name of Partner Institution:
Research Solutions Africa
Type of Organization:
Private firm

Intervention Overview


Plantwise-Kenya (PW-K) is implemented through 3 connected activities. First, farmers are able to access trained plant doctors through a network of plant clinics. Clinics are placed in predetermined locations where farmers tend to congregate (e.g. markets) and plant doctors are trained to diagnose plant health diseases and prescribe solutions. Plant clinics provide small farmers with low-cost access to plant health information and diagnoses of plant health issues. Second, Plantwise engages key stakeholders, such as the Ministry of Agriculture, extension programs, researchers, input suppliers, and regulators, to fortify plant health systems through encouraging collaboration. Although all farmers in Kenya are potentially affected, farmers in clinic areas are more likely to be benefitted through clinic interactions. Third, a “knowledge bank” database serves as a repository for plant health information that assists with monitoring pests and diseases, promotes strategies for climate change adaptation and facilitates international trade. The Knowledge Bank is a public web-based tool. CABI believes small farmers do not use this resource given the low internet penetration in rural Kenya.

Theory of Change:
Multiple Treatment Arms Evaluated?

Implementing Agency

Name of Organization:
Ministry of Agriculture, Livestock, and Fisheries with support from CABI
Type of Organization:
Public Sector, e.g. Government Agency or Ministry

Program Funder

Name of Organization:
CABI (CAB International)
Type of Organization:

Intervention Timing

Intervention or Program Started at time of Registration?
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Evaluation Method

Evaluation Method Overview

Primary (or First) Evaluation Method:
Randomized control trial
Other (not Listed) Method:
Additional Evaluation Method (If Any):
Other (specify)
Other (not Listed) Method:
Qualitative Methods

Method Details

Details of Evaluation Approach:

To identify farm-level impacts, we rely on an experimental expansion of the program: Out of 90 sites, 30 will get plant clinics between the baseline and first follow-up and 60 will have the programme by the second follow-up. Baseline and follow-up data (at two points in time: 12 and 36 months after baseline) will be collected on farm households. For each outcome, we will estimate two parameters of interest. First, we are interested in the effect of being assigned to the treatment group (i.e., ITT) which we will implement using both an OLS regression with controls and Difference-in-Difference specifications with controls. Second, we will implement an encouragement design where sampled households from treatment sites will receive text messages to increase the likelihood of attending plant clinics. Thus, receiving a text message will be used as an instrument to estimate the average effect of clinic attendance on the outcomes of interest. In addition to that, we will assess the changes in the plant health system and conduct cost and implementation analyses through in-depth interviews and focus groups conducted at three points in time: at baseline, 12-month, and 36-month follow-ups.

Outcomes (Endpoints):

In the short-run, we would expect treated farmers to improve crop husbandry practices and limit crop damage from plant diseases and pests by changing cultural practices and using inputs (e.g., fertilizers and pesticides) more efficiently. These behavioural changes may result in higher farm yields and farm household welfare in the long-run. Farm-level instruments will collect intermediate outcomes related to welfare-improving behavioural changes by farmers in the short run. These may include investing in better productive inputs, adopting new production practices, and improving disease/pest management. In order to measure the longer-run effects of the program, we will also collect detailed individual plot information for each farm household in the sample. Specifically, we will collect information on all crops planted on each plot operated by the farmer and for those with more than a minimal amount (one-thirty second of an acre) details on all inputs used and the quantity and value of output obtained. Lastly, we will also investigate the experience that farmers in treated areas have had with PW-K in terms of awareness, usage, and support from PW-K and other extension services.

Unit of Analysis:
Farm household

This study tests the following four hypotheses: 1. PW-K leads to stronger institutions for managing the plant health system by expanding knowledge availability, improving identification of new diseases and pests, and improving response to pest and disease outbreaks in a manner that can be sustained over the long term 2. PW-K improves the wellbeing of farmers through improved pest and disease management, increased productivity, and a rise in gross margins which leads to increased income from agriculture and ultimately improved food security. 3. PW-K costs are justified given the benefits the programme provides. 4. The process by which PW-K is implemented and contextual factors influence the effectiveness of the programme.

Unit of Intervention or Assignment:
Random Farm households who are in proximity to plant clinics. That is, households included in the study sample are those living within a 2KM radius from the proposed plant clinic locations
Number of Clusters in Sample:
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Size of Treatment, Control, or Comparison Subsamples:
At baseline: 30 sites treated (960 households) and 60 controls (1920 HHs). After 12 months: 60 sites treated and 30 controls. Treated and control units will remain the same until the end of evaluation

Supplementary Files

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Outcomes Data

Once the treatment and control areas are established, farm household questionnaires will be administered to the sample of 2800 households in order to determine program impacts at the farm level at 3 points in time: at baseline in 2014, 2015, and 2017. We will collect information on farmers clinic attendance through the farm questionnaire and sheets collected in each clinic session. This information will allow us to identify which farmers attend clinic sessions after receiving encouraging SMSs.
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Data Previously Used?
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Data Obtained by the Study Researchers?
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Treatment Assignment Data

Participation or Assignment Information:
The intervention is implemented at the site level. Sites are randomly selected for receiving plant clinics. Between baseline and first follow-up, 30 sites will have received plant clinics and the remaining 60 will be controls. By the second follow-up, the treatment group will have 60 and the control group 30 sites. The location of each plant clinic is publicly known. A dataset with treatment status and site code and name will be used to determine program impacts from the farm household dataset.
Data Obtained by the Study Researchers?
Data Previously Used?
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Data Obtained by the Study Researchers?
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Data Analysis

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Study Materials

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Registration Category

Registration Category:
Prospective, Category 1: Data for measuring impacts have not been collected

Completion Overview

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Preliminary Report:
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Data Availability

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Other Materials

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Description of Changes:

Study Stopped