Improving seed selection and storage to increase yields among Ugandan potato growers

Last registered on July 15, 2021

Pre-Trial

Trial Information

General Information

Title
Improving seed selection and storage to increase yields among Ugandan potato growers
RCT ID
AEARCTR-0001014
Initial registration date
January 27, 2016
Last updated
July 15, 2021, 3:24 AM EDT

Locations

Region

Primary Investigator

Affiliation
Ifpri

Other Primary Investigator(s)

PI Affiliation
IITA
PI Affiliation
LICOS-KULEUVEN

Additional Trial Information

Status
Completed
Start date
2016-02-15
End date
2017-05-10
Secondary IDs
Abstract
To spur sustainable intensification in potato growing in southwestern Uganda, previous research within PASIC has shown that it’s primarily a seed quality issue. While increasing access to potato seed derived from basic pathogen free starter seed should remain a key policy priority, existing seed systems may currently be too weak to be scaled up in a relatively short time. Therefore, small interventions aimed at increasing awareness about the importance of the quality of existing planting material, as well as increasing skills in selection and handling of seed material may be more cost effective. This view was share by IFDC-Catalyst, who have set up seed screen houses in a rather ad-hoc way. The hypothesis is also in line with previous research that identified knowledge gaps as a significant barrier to crop intensification methods more in general. This research will engage in action research on the (relative) effectiveness of providing information on how to select, store and handle planting material to improve potato seed quality. To do so, we will use a social experiment in the field that exposes farmers to short agricultural extension messages (for example through a short video) on how to select the best planting materials and on how to store and handle planting materials between the last harvest and the next planting season. The experiment will use a design that will enable us to also disentangle the effect of information on the selection of seeds from the effect of information on storage and handling.

Registration Citation

Citation
Van Campenhout, Bjorn, Piet Van Asten and Senne Vandevelde. 2021. "Improving seed selection and storage to increase yields among Ugandan potato growers." AEA RCT Registry. July 15. https://doi.org/10.1257/rct.1014-13.0
Former Citation
Van Campenhout, Bjorn et al. 2021. "Improving seed selection and storage to increase yields among Ugandan potato growers." AEA RCT Registry. July 15. https://www.socialscienceregistry.org/trials/1014/history/96003
Experimental Details

Interventions

Intervention(s)
We will use a social experiment in the field that exposes farmers to short agricultural extension messages (for example through a short video) on how to select the best planting materials and on how to store and handle planting materials between the last harvest and the next planting season. The experiment will use a design that will enable us to also disentangle the effect of information on the selection of seeds from the effect of information on storage and handling.
Intervention Start Date
2016-04-01
Intervention End Date
2017-05-01

Primary Outcomes

Primary Outcomes (end points)
potato yield, household consumption expenditure.
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
2X2 factorial design. About 100 households will receive information on how to select the best planting materials from the previous harvest. About 100 households will receive information on how to store and handle planting materials between the last harvest and the next planting period. This will be done in such a way that there are 50 households that receive both types of information and 50 households that do not receive any information at all (a control group).
Experimental Design Details
Randomization Method
We have access to baseline data. Randomization will be done on a computer after bloc matching. An algorithm was developed to perform a hierarchical clustering in groups of equal cluster size using nearest neighbor matching. The algorithm also tries to maximize distance between households within each cluster (based on GPS coordinates) to minimize spillover effects. We have used the following cluster variables: household size, age of household head, average productivity of potato, gender of household head, total area of potato cultivation , consumption per capita, distance to input distributor, amount of credit received in the last year and whether the household had access to extension for potato growing. The algorithm can be found here (http://is.gd/ZGP3cF), the script that generates the randomization here (http://is.gd/fmfgCm) and the allocation of treatment here (http://is.gd/1FfWIW). The last is also uploaded as supporting materials to this registration.
Randomization Unit
household level: potato growing farm households in eastern uganda
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
200
Sample size: planned number of observations
200
Sample size (or number of clusters) by treatment arms
200
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
The agronomy survey suggests an increase in yields from about 4.5 tons/ha to 14 tons/ha. Power calculations to detect ¼ th of such an effect suggests we need about 94 observations in each treatment arm. We therefor propose to run an experiment that involves about 200 observations in a 2x2 factorial design. In such a design, about 100 households will receive information on how to select the best planting materials from the previous harvest. About 100 households will receive information on how to store and handle planting materials between the last harvest and the next planting period. This will be done in such a way that there are 50 households that receive both types of information and 50 households that do not receive any information at all (a control group).
Supporting Documents and Materials

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IRB

Institutional Review Boards (IRBs)

IRB Name
IFPRI IRB #00007490 FWA #00005121
IRB Approval Date
2016-02-26
IRB Approval Number
2016-12-DSGD-M
Analysis Plan

Analysis Plan Documents

pap

MD5: 29018654dcc1251de9c779e2df4f5dc8

SHA1: ba234146244b792c1d81496100ae603f0b242163

Uploaded At: April 22, 2016

Post-Trial

Post Trial Information

Study Withdrawal

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Intervention

Is the intervention completed?
Yes
Intervention Completion Date
May 01, 2016, 12:00 +00:00
Data Collection Complete
Yes
Data Collection Completion Date
May 01, 2017, 12:00 +00:00
Final Sample Size: Number of Clusters (Unit of Randomization)
246
Was attrition correlated with treatment status?
No
Final Sample Size: Total Number of Observations
246
Final Sample Size (or Number of Clusters) by Treatment Arms
246
Data Publication

Data Publication

Is public data available?
Yes

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Program Files

Program Files
No
Reports, Papers & Other Materials

Relevant Paper(s)

Abstract
To feed a growing population, agricultural productivity needs to increase dramatically. Agricultural extension information, with its public, non-rival nature, is generally undersupplied, and public provision remains challenging. In this study, simple agricultural extension video messages, delivered through Android tablets, were tested in the field to determine if they increased farmers’ knowledge of recommended practices on (i) potato seed selection and (ii) seed storage and handling among a sample of potato farmers in southwestern Uganda. Using a field experiment with ex ante matching in a factorial design, it was established that showing agricultural extension videos significantly increased farmers’ knowledge. However, results suggested impact pathways that went beyond simply replicating what was shown in the video. Video messages may have triggered a process of abstraction, whereby farmers applied insights gained in one context to a different context.
Citation
Van Campenhout B, Vandevelde S, Walukano W, Van Asten P (2017) Agricultural Extension Messages Using Video on Portable Devices Increased Knowledge about Seed Selection, Storage and Handling among Smallholder Potato Farmers in Southwestern Uganda. PLoS ONE 12(1): e0169557. https://doi.org/10.1371/journal.pone.0169557
Abstract
Pervasive use of poor quality seed remains an important reason for low yields throughout the developing world. We explore cost-effective ways to increase the quality of the local stock of seed tubers among a sample of Ugandan potato farmers. We do this by providing agricultural extension information on (i) how to select the best seed tubers and (ii) how to properly handle and store seed tubers until the next planting season. The information is conveyed in the form of engaging videos, shown to individual farmers on mobile devices. The relative effectiveness of the information interventions is tested using an individually randomized controlled trial with a 2x2 factorial design. However, such interventions are prone to spillovers, and there are indications that control farmers might have learned about seed selection, storage and handling through their proximity to, or contacts with, farmers in the treatment group. Therefore, we explicitly model spillovers ex post using a randomization-based framework and use both farmers' GPS locations as well as survey data on actual interactions between treatment and control farmers to define the social networks through which information travels. After accounting for spillovers, we find evidence that especially the video containing information on seed selection translated into a higher awareness and adoption of recommended practices, a higher probability of using improved inputs as well as higher consumption
Citation
Vandevelde, Senne; Van Campenhout, Bjorn; and Walukano, Wilberforce. 2018. Spoiler alert! Spillovers in the context of a video intervention to maintain seed quality among Ugandan potato farmers. LICOS Discussion Paper 407/2018. Leuven, Belgium: LICOS Centre for Institutions and Economic Performance
Abstract
Purpose

Pervasive use of poor quality seed remains an important reason for low yields throughout the developing world. We explore ways to increase the quality of the local stock of seed tubers among a sample of Ugandan potato farmers.

Design/methodology/approach: Using videos, we provide agricultural extension information on (i) how to select the best seed tubers and (ii) how to properly handle and store seed tubers until the next planting season. The relative effectiveness of the information interventions is tested using an individually randomized controlled trial where we model spillovers using a randomization-based framework for estimating causal effects under interference between units.

Findings: Especially the video on seed selection translated into increased awareness and adoption of recommended practices, increased probability of using improved inputs, as well as higher consumption.

Practical implications: Interventions aimed at improving seed quality are important in the absence of access to high-quality seed. Video messages are becoming increasingly useful as a complementary tool in agricultural extension.

Theoretical implications: Randomization-based inference can be used to take into account spillover effects in the analysis rather than the design phase of an experiment.
Citation
Vandevelde, S., Van Campenhout, B., & Walukano, W. (2021). Accounting for spillovers in assessing the effectiveness of video messages to improve potato seed quality: evidence from Uganda. The Journal of Agricultural Education and Extension, 1-32.

Reports & Other Materials