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Farmers’ Willingness to Pay for Virus-free sweetpotato

vines in Central Uganda

Sylvia NakanyikeMakerere University

First Bio-Innovate Regional Scientific ConferenceUnited Nations Conference Centre (UNCC-ECA)Addis Ababa, Ethiopia, 25-27 February 2013

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Scarcity of quality planting material is a key constraint affecting sweetpotato productivity in Uganda (Yanggen and Naggujja, 2006; CIP,2009; Hagenimana,1999; Kapinga et al.,1995 ).

Yet, use of farmer saved planting material is associated with the spread of SPVD.

SPVD caused yield losses of up to 90% and disappearance of the would good varieties.

Fortunately, biotechnological initiatives (e.g. TC and virus indexing) are now available that could be used in rapid production of virus free sweetpotato planting material (PM).

BACKGROUND

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A sustainable use of such initiatives will depend on farmers’ willingness to pay (WTP) for the virus–free sweetpotato vines, whose price will certainly be higher than for farmer-saved PM.

Thus, use of QPM may have a cost implication which could make the technology less affordable by resource poor sweetpotato farmers.

And, adoption of QPM will depend on farmers’ willingness to pay.

Problem Statement

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Major Objectives: To assess farmers’ WTP for Virus-free sweetpotato vines

Specific Objectives:1. To characterize sweetpotato farmers in C.Ug 2. To determine the value farmers are willing to

pay for virus- free sweetpotato vines3. To determine factors affecting famers’ WTP

for virus- free sweetpotato vines4. To estimate the market potential for Virus –

free sweetpotato vines

Objectives

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Study done in Mpigi and Wakiso district 200 farmers sampled and questionnaire used Contingency valuation methods used to

estimate price Data AnalysisObjective 1: Farmers categorized into 2 groups Descriptive statistics, t tests and chi square

tests used to test significance Objective 2: Means estimated and compared

using t test

Methodology

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Objective 3: Tobit model specified as:

Ai* - latent variable indexing WTP.

βo – Intercept

β1…………… β10 are parameters to be estimated

X1…………X10 are the various independent variable

Methodology Cont’d

ebbbbb +------------++++= 10103322110* XXXXAi

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Description of independent variables used in Analysing Factors Affecting

Farmers’ WTP for Virus-free Sweetpotato Vines

Variable Description Unit of measurement

1X Age of the farmer Number of years

2X Education level of hoousehold head Number of years spent in school

x3 Membership in Association 0 = no, 1 = yes

x4 Access to extension services Number of times per year

x5 Access to credit s ervices 0 = no, 1 = yes

x6 Farmer sells sweetpotato 0 = no, 1 = yes

x7 Access to quality vines 0 = no, 1 = yes

8X Revenue from sweetpotato Uganda shillings

9X Market access Distance (km)

10X Total area under sweetpotato production acres

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Objective 4:

Where: MP = is the market potentialN= Number of farmers willing to buy virus-free vines.P= Mean WTPQ=Number of planting seasons per yearA= Average number of bags required by each farmer

Methodology Cont’d

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Results: Obj. 1Socio-economic characteristics

Unit of measure

Farmers not willing to pay more than 8000/=

Farmers willing to pay more than 8000/=

P value

Age Years 39.29(13.40)

45.12(14.12

0.005

Education level

Number of years spent in school

6.78(3.82)

6.68(3.41)

0.849

Land access Acres 4.77(4.51)

5.54(4.94)

0.321

Family size People 5.92(3.31)

5.69(3.41)

0.636

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Socio-economic characteristics

Unit of measure

Percentage numbers of farmers not willing to pay more than 8000/=

Percentage number of farmers willing to pay more than 8000/=

P value

Gender MaleFemale

51.5652.89

48.4447.44

0.863

Experiencing SPVD

YesNo

50.9165.00

49.0935.00

0.233

Access to good quality vines

YesNo

51.5552.87

48.4547.13

0.624

Results Obj.1. cont’d

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T-test Results Comparing mean prices

Results: Obj.2

Variable Mean

(UShs)

Confidence

interval

(UShs)

P Value

Price for

virus-free

vines

8459

(4239)

7,844 -9,074 0.0000

Price for

farmer-saved

vines

2611

(1991)

800 - 4421

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Results Obj.3 Dependent variable Price of Virus-free Vines

Units of measure Uganda Shillings

Coefficient t-statistic Pvalue

Constant 6958.685 2.48 0.014 Age of the farmer Years 40.740 1.72* 0.088 Education of the farmer years in school 15.094 0.16 0.871 Membership in association (0 = no, 1= yes) -206.814 -0.26 0.797 Access to extension services No. of times/yr -98.60 -0.46 0.644 Access to credit services (1= no, 2= yes) 792.045 1.14 0.255 Farmer sells sweetpotato Access to quality vines Revenue from sweetpotato

(1= no, 2= yes) (1= no, 2= yes)

Uganda Shillings

1751.372 709.1317 0.0037

2.09** 1.12 2.34**

0.038 0.262 0.021

Market access Distance (km) -169.5612 -3.30*** 0.001 Total area under sweetpotato (Acres) 654.739 1.91* 0.058 No. Observations=180 Prob>chi2 = 0.012

Pseudo R2= 0.0067 Loglikelihood = -1672.1928

Note: 1. (*) is significance at 10%, (**) Significance at 5%, (***) significance at 1%.

Observation Summary: 4 left- censored observations at WTP<=1000;

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Results Obj.4

Detail Amount Units

Number of possible

buyers

532,543 Farmers

Mean WTP Price 8400 Uganda Shillings

Average annual

purchasing rate

2 planting

seasons

Average purchasing

quantity

4 bags per season

Market potential 35.8 Billion Uganda Shillings

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There is no major variation between the two categories of farmer. Only variation is age, implying more experience and better appreciation of effects of SPVD

Farmers were willing to pay for quality vines

Commercial oriented sweetpotato farmers expressed a higher WTP than subsistence sweetpotato farmers

There is a big market potential for virus-free sweetpotato vines

Key findings

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Thank you for listening!

Cassava Potato and Sweetpotato Bioinnovate Consortium - MAK