Quality characteristics of wheat and rice straw traded in Indian...
Transcript of Quality characteristics of wheat and rice straw traded in Indian...
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Quality characteristics of wheat and rice straw traded in Indian urban centres
ICDD, Faisalabad, Pakistan20/10/2011
Nils Teufel1, Arindam Samaddar1, Michael Blümmel2, Olaf Erenstein31ILRI, New Delhi; 2 ILRI, Hyderabad; 3CIMMYT, Addis Ababa
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Why straw quality?
• Straw is most important feed in South Asia
• Weak link: nutritional quality – grain yield
• Small improvements in nutritional quality can generate considerable gains
• Genetically determined quality (in varieties)can be efficiently distributed through seeds
• But: How is straw quality perceived?
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44 45 46 47 48 49 50 51 52 53 54 552.8
3.0
3.2
3.4
3.6
3.8
4.0
4.2y = -4.9 + 0.17x; R2 = 0.75; P = 0.03
Stover in vitro digestibility (%)
Stov
er p
rice
(IR/k
g D
M)
Relation between digestibility and price of sorghum stover
Blummel and Rao 2006
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Research questions
• How do traders perceive quality?
• What is the nutritional quality and its variation– in wheat and paddy straw?
– in northern and eastern Indian urban markets?
• Are perceived and nutritional qualities linked?
• How do markets value quality characteristics?
• What are major price determinants?
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Methodology / approach
• Monthly sampling during 06/2008 - 06/2009(13 months)
• In three urban centres– Delhi (wheat)
– Patna (wheat & paddy)
– Kolkata (paddy)
• 12 samples per site and type each monthfrom 43 traders(some traders had several qualities)
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Data – collected at sampling
• Quality perception by traders
• Numerical evaluation (scale 1-5) of main traits – chopped (wheat & paddy)
short, soft, pure, bright, dry, tasty
– whole (only paddy):long, thin, base bright
– overall quality
• Current price of sample
• Variety & origin information is not available
• Collection of 4 reps /sample for lab analysis
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Data - laboratory analysis• ILRI office Hyderabad, Michael Bluemmel
• Near InfraRed Spectroscopy (NIRS)– 1mm ground feed
– exposed to near infrared light ray
– analysis of absorption/reflection spectrum
• Calibration with traditional lab methods
• Regression models on NIRS data
• Variables generated for this study– nitrogen %, in vitro digest., metabol. energy
– ash, silica, ndf, adf, adl , gas24
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Study locations
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Urban trader in Patna
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Sampling interview
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Large paddy straw bundles
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Results – quality, bright1.00
2.00
3.00
4.00
5.00
806 807 808 809 810 811 812 901 902 903 904 905 906
YearMonth
DelhiWheat KolkataPaddy PatnaWheat PatnaPaddy
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Results – quality perception, all1.00
2.00
3.00
4.00
5.00
806 807 808 809 810 811 812 901 902 903 904 905 906
YearMonth
DelhiWheat KolkataPaddy PatnaWheat PatnaPaddy
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Trait effects on overall qualityDep. Variable: Overall Quality
Wheat (n=294, adj R2: 0.659)
Paddy (n=274, adj R2: 0.536)
Stand. Beta Sig. Stand. Beta Sig.
(Constant) - .888 - .515 Short .387 .000 .105 .019 Soft .182 .000 .135 .004 Pure .077 .069 -.129 .016 Bright .241 .000 .276 .000 Dry .001 .976 -.067 .163 Tasty .197 .000 .341 .000 Long (whole) - - .090 .033 Thin (whole) - - .157 .001 BaseBright
(whole) - -
.193 .000
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Results – digestibility, means
35
37
39
41
43
45
47
49
51
806 807 808 809 810 811 812 901 902 903 904 905 906
%
YearMonth
PatnaWheat PatnaPaddy DelhiWheat KolkataPaddy
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Results – digestibility, range (Patna)
33353739414345474951
806 807 808 809 810 811 812 901 902 903 904 905 906
%
YearMonth
PatnaWheatMax PatnaWheatMean PatnaWheatMin
PatnaPaddyMax PatnaPaddyMean PatnaPaddyMin
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Traits effects on digestibilityDep. Variable: InVitro Digest.
Wheat (n=294, mod. sig: 0.248)
Paddy (n=274, adj R2: 0.030)
Stand. Beta Sig. Stand. Beta Sig.
(Constant) .000 Short -.213 .001 Soft .021 .749 Pure .017 .823 Bright .022 .788 Dry -.123 .079 Tasty -.038 .632 Long (whole) .010 .872 Thin (whole) .071 .290 BaseBright
(whole)
-.061 .390
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Traits effects on metabol. energyDep. Variable: ME [MJ/kg]
Wheat (n=294, mod. sig: 0.572)
Paddy (n=274, adj R2: 0.140)
Stand. Beta Sig. Stand. Beta Sig.
(Constant) - .000 Short -.097 .112 Soft -.109 .084 Pure .037 .606 Bright .074 .335 Dry -.280 .000 Tasty -.116 .122 Long (whole) .053 .362 Thin (whole) -.046 .469 BaseBright
(whole)
-.099 .136
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Results – price, means
1.001.502.002.503.003.504.004.505.005.50
806 807 808 809 810 811 812 901 902 903 904 905 906
Rs/kg
YearMonth
PatnaWheat PatnaPaddy DelhiWheat KolkataPaddy
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Price determinants – 1 Dep. Variable: (after box cox)
Delhi - Wheat Price Rs/kg
(n=147, adj R2: 0.598)
Kolkata - Paddy inv (Price Rs/kg)
(n=126, adj R2: 0.982) Stand. Beta Sig. Stand. Beta Sig.
(Constant) .000 Trend .644 .000 PaddyHarvest -.214 .000 WheatHarvest -.334 .000 Digestibility -.161 .085 MetabEnergy .357 .000 NitrogenCont .151 .006 Short .131 .034 .175 .026 Soft .188 .015 Pure .144 .048 Bright .130 .047 -.171 .043 Dry .129 .089 Tasty .162 .050 .617 .000
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Price determinants - 2 Dep. Variable: (after box cox)
Patna - Wheat ln(Price Rs/kg)
(n=156, adj R2: 0.471)
Patna - Paddy Price Rs/kg
(n=146, adj R2: 0.738) Stand. Beta Sig. Stand. Beta Sig.
(Constant) .000 .000 Trend -.442 .000 -.773 .000 PaddyHarvest .125 .038 .147 .002 WheatHarvest -.310 .000 MetabEnergy -.092 .062 Soft -.162 .002 Tasty -.096 .083 WholeThin -.108 .031 WholeBase
Bright .137 .008
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Price determinants - 3 Dep. Variable: (after box cox)
Patna - Wheat & Paddy ln(Price Rs/kg)
(n=306, adj R2: 0.676)
Stand. Beta Sig.
(Constant) .000 PaddyDummy -.436 .000 Trend -.526 .000 PaddyHarvest .116 .001 WheatHarvest -.151 .000 Soft -.153 .000
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Conclusions - 1
• Quality differences are recognisedin wheat & paddy straw
• Traders & consumers evaluate by appearance– traits are often related to (post)-harvest processes
– variety & origin information is not carried forward
• Lab analysis shows– superior nutritional quality of wheat straw
– paddy straw digestibility below expectations (avg of variety tests > 40%)
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Conclusions - 2
• Perceived and nutritional quality are poorly linked
• Price variations are mainly temporal & regional– separate analysis of individual markets
– wheat & rice straw are substitutes in Patna
– 1 year too short to capture inter-year effects
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Outlook
• What are the underlying characteristics and effects of the perceived quality traits?
• How do effects of improved nutritional quality compare to other improvements(e.g. in harvest & storage processes)?
• Can the benefits of various quality improvements be quantified & who gains?
• What are the effects of the price volatility and could it be reduced?
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Thank you
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Results – quality, soft1.00
2.00
3.00
4.00
5.00
806 807 808 809 810 811 812 901 902 903 904 905 906
YearMonth
DelhiWheat KolkataPaddy PatnaWheat PatnaPaddy
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Results – metabol. energy, means
5.0
5.5
6.0
6.5
7.0
7.5
806 807 808 809 810 811 812 901 902 903 904 905 906
MJ/kg
YearMonth
PatnaWheat PatnaPaddy DelhiWheat KolkataPaddy
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Results – metabol. energy, range
4.5
5.0
5.5
6.0
6.5
7.0
7.5
8.0
806 807 808 809 810 811 812 901 902 903 904 905 906
MJ/kg
YearMonth
PatnaWheatMax PatnaWheatMean PatnaWheatMin
PatnaPaddyMax PatnaPaddyMean PatnaPaddyMin
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Results – price, range
1.00
1.50
2.00
2.50
3.00
3.50
4.00
4.50
5.00
806 807 808 809 810 811 812 901 902 903 904 905 906
Rs/kg
YearMonth
PatnaWheatMax PatnaWheaMeans PatnaWheatMin
PatnaPaddyMax PatnaPaddyMeans PatnaPaddyMin
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Trait effects on priceDep. Variable: Price Rs/kg
Wheat (n=294, adj R2: 0.093)
Paddy (n=272, adj R2: 0.288)
Stand. Beta Signfc. Stand. Beta Signfc.
(Constant) - .000 - .000 Short -.012 .856 -.057 .306 Soft -.156 .026 -.030 .599 Pure -.301 .000 -.176 .008 Bright .159 .022 .245 .001 Dry -.064 .293 .278 .000 Tasty .094 .227 -.178 .010 Long (whole) - - -.050 .339 Thin (whole) - - -.429 .000 BaseBright
(whole) - -
.016 .787
Quality characteristics of wheat and rice straw traded in Indian urban centres���ICDD, Faisalabad, Pakistan�20/10/2011�Why straw quality?Slide Number 3Research questionsMethodology / approachData – collected at samplingData - laboratory analysisStudy locationsUrban trader in PatnaSampling interviewLarge paddy straw bundlesResults – quality, brightResults – quality perception, allTrait effects on overall qualityResults – digestibility, meansResults – digestibility, range (Patna)Traits effects on digestibilityTraits effects on metabol. energyResults – price, meansPrice determinants – 1Price determinants - 2Price determinants - 3Conclusions - 1Conclusions - 2OutlookThank youResults – quality, softResults – metabol. energy, meansResults – metabol. energy, rangeResults – price, rangeTrait effects on price