Monday theme 3 1545 1600 room 2 okello

1. DETERMINANTS AND EFFECT OF QUALITY SEED POTATO USE BY
SMALLHOLDER FARMERS: THE CASE OF SEED FROM KISIMA
FARM-KENYA
Julius J Okello, Yuan Zhou, Norman Kwikiriza, Sylvester Ogutu, Ian Barker, Elmar
Schulte-Geldermann and Elly Atieno
Presentation made at the 10th Triennial African Potato Association Conference
Addis Ababa, Ethiopia, October 9th -13th, 2016

2. Introduction
• Potato is a major food and cash crop in tropical highland regions of
sub-Saharan Africa
• However yields remain very low 8-10 tons/ha; cf to 40 tons/ha in
developed countries
• Low yields attributed to use of poor quality (disease-infected seeds)
95% of the seed used by farmers locally sourced: own or from
local market
• Recent innovation in seed production has resulted in the
development of rapid multiplication technique >>> the 3G

3. Introduction- cont’d
• The technique allows the production of quality in 3 G cf 5-7 G
• Using the technique Kisima Farm, a private seed company in
Central Kenya, has increased availability and access to seed by
smallholder farmers
• This study used data from 408 farmers stratified by use of quality
seed (QSP) to:
 Examine determinants of decision to use of QSP from Kisima Farm
 Analyze factors affecting extent of use of QSP from theKisima Farm
 Assess the effect of using QSP on yield, input use and food security

4. Study methods
• Decision to use QSP is binary choice, hence was analyzed using a
Probit regression model.
• The dependent variable was 1 if farmers planted QSP from Kisima
Farm; 0 Otherwise
• The implicit functional form of the estimated model was specified as:
qseed = f(gender, hhsize, lnage, mobiphone, experience, groupmember,
lnowneland, lndistmkt, lndistkisima, lndistagric, lnassetvalue, pest,
blight, taste, market, risk, foodsec) + ε

5. Study methods Cont’d
The extent of use of QSP was analyzed using two approaches:
Approach #1: Number of QSP varieties from Kisima Farm planted by the
farmer.
• Dependent variable took the values 0 to 4
• Hence count variable model was used – Poisson regression model
• Explanatory variables same as in the Probit model
Approach #2: Total area put under QSP from Kisima Farm by the farmer
• The dependent variable defined as acres of land planted with QSP from
Kisima Farm, and is censored at zero
• Hence Tobit Regression model was used
• The explanatory variables same as above
All the 3 models were estimated using Survey regression
technique, with the village as the cluster/primary sampling
unit, to control for clustering effect of the variance at the
village.

6. Effect of using quality seed estimated …..
• Using propensity score matching method (PSM)
• Probit regression model estimated as the first step, to generates
propensity scores used for matching
• Three matching algorithms used to ensure robustness of the results
• Nearest Neighbor method
• Radius method
• Kernel-based method
• Outcome variables were:
• Value of purchased pesticides/fungicides (USD/ha),
• Potato yield (Kg/acre)

7. Definition of variables used
Variable Description
qseed 1= farmer planted quality seed; 0=otherwise
gender 1=male; 0=female
hhsize Number of household members
lnage Natural log of respondent age (years)
mobiphone 1= Farmer has mobile phone; 0 Otherwise
groupmember 1= member of farmer group; 0 Otherwise
lnownedland Total land owned by the farmer (acres)
lndistmkt Natural log of distance to nearest market in walking minutes
lndistkisima Natural log of distance to Kisima Farm in kilometers;
lndistagric Natural log of distance to nearest agricultural office in walking minutes

8. Definition of variables used Contd…..
lnassetvalue Natural logarithm of the value of physical assets in Kenya Shillings
foodsec Prevalence of food insecurity (HFIAP) based on HFIAS dev by FANTA
risk 1=farmer perceives ware potato market as very risky 0=Otherwise
market Farmer perception of marketability; Likert scale: 1= poor; 5=very good
pest, taste Perceptions on (a) pests, (b) taste measured as 1= Poor; 0 Otherwise
lnassetval Natural log of the value of physical assets in Kenya Shillings

9. Study area and sampling design
Farmers in close proximity to Kisima Farm
were targeted.
Study covered Buuri, Igembe Central, Igembe
South, Laikipia East, Meru Central and Tigania
East counties
34 villages were selected from the 6 districts
In each village, all farmers who had planted
QSP from Kisima Farm in the 2 years were
listed
A 2nd list of farmers that used seed from other
sources was drawn
167 users of QSP and 241 non-users were
randomly sampled using PPS sampling

10. So what did we find?

11. Summary statistics
Users (N=167) Non-usersb (N=241)
Variable Mean (SD) Mean (SD) Mean diffa-b (t-value)
Distance to Kisima Farm (kilometers) 27 (26.51) 33 (29.24) -5.393* (-1.937)
Distance to nearest main road (minutes) 28 (27.85) 29 (24.95) -0.40 (-0.149)
Distance to agric office (minutes) 102 (111.58) 80 (81.28) 21.891** (2.168)
Age (years) 49 (12.53) 48 (13.89) 0.59 (0.45)
Gender (1=Male, 0=Female) 0.55 (0.5) 0.47 (0.5) 0.08 (1.63)
Education (years) 9 (3.86) 8 (3.76) 1.03*** (2.69)
Farming experience (years) 20 (12.41) 18 (12.64) 1.1 (0.87)

12. What affects the use of QSP?.....
Variable Probit Poisson Tobit
Mobile phone - - -
Group member + + +
Land size + + +
Distance to market -
Distance to Kisima Farm - -
Asset endowment + + +
Taste - - -
Risk - - -
Food security
Pest resistance - - -
Market + +
1% = 5% = 10% =

13. Effect of using QSP : Summary statistics
Non-labor inputs Users (N=167)
A
Non-users (N=241)
B
Mean diff (A-B)
Mean Mean
Input use
Purchased seed (USD/ha) 535 459 76.2***
Foliar feed (USD/ha) 10 7 3.3***
Fertilizer (USD/ha) 265 213 52.2***
Insecticide (USD/ha) 9 6 3.9***
Fungicide (USD/ha) 52 53 -0.8
Purchased manure (USD/ha) 91 81 10.2
Potato production, utilization and incomes
Potato yield (Kg/ha) 11584 8787 2797.7***
Ware potato sales (Kg/ha) 7740 5337 2403.5***

14. Results of propensity score matching analysis
Matching algorithm Nearest neighbor Radius Kernel-based
Outcome Variables ATT t-stat ATT t-stat ATT t-stat
Purchased fungicide
(USD/ha)
14 0.78 8 0.99 8 0.97
Purchased insecticide
(USD/ha)
7** 2.36 6** 2.78 7** 2.83
Potato yield ( Kg/ha) 9521** 2.24 2975** 2.12 3322** 2.33
Purchased fertilizer
(USD/ha)
235 0.99 31 1.02 43 1.40
HFIAP score (food sec) - 2.5*** -3.25 - 2.2*** - 2.86 - 2.3*** -3.90

15. Summary, Conclusions and Implications (some)
• Distance to source of QSP & to market affect its use
• Asset endowment (physical capital assets, group membership), and
land ownership increase use of QSP
• Use of QSP increases yields & reduces prevalence of food insecurity
Use of QSP has positive welfare effects on small farm households.
These findings imply the need to:
Improve access to clean seed >> improve the distribution network
Reduce transaction costs farmers face >> access to markets
Continue paying attention to varietal attributes