1. Dry matter partitioning
What is it ?
How is it measured ?
For what ?
Source & sink relationship

2. Dry matter distribution or partitioning
Biomass or dry matter Y biol.
Economic yield Y econ.
Dry matter allocation or distribution
Harvest Index
Ear
Translocation
Photosynthate
Stem or shooot
Root

3. Source - Sink relationship
Flower , Seed, Fruit
Stem, Root
SOURCE
Leaves
Reproductive / Vegetative growth
Photosynthesis / Light interception

4. Dry matter distribution or partitioning
ระหว่าง organ ในต้นพืช เช่นใบ ลำต้น ดอก ผล หรือ ราก
ระหว่างเซลล์ หรือเนื้อเยื่อ ในส่วนอวัยวะพืช เช่น supporting cells กับ meristematic cell (tissue)
ระหว่าง orgenel ในเซลล์พืช
สามารถอธิบายได้ด้วยสัดส่วน (Dry weight ratio or %) หรือ สัมประสิทธิของการกระจายน้ำหนักแห้ง ( h : partitioning coefficient)

5. hl, hs, hr What does it mean ?
Ability of plant to accumulate Photosynthate in a particular part (each has specific function and value)
Mechanism of plant in response to certain environment

6. Translocation of Photosynthate
Can be measured by using radioisotope eg.
14C , 13C
12 , 15N
32P
Hydrolytic pressure gradient depend on activity and size of supply (SOURCE) and demand (SINK)

7. SOURCE - SINK relationship
Translocation
Feedback inhibition
STRENGTH / CAPACITY
SIZE x ACTIVITY
Absolute rate of change in Wl
STRENGTH / CAPACITY
SIZE x ACTIVITY
Absolute rate of change in Wg

8. Potential Source Capacity
LAI
LAID, leaf longivity
Increase light interception
Extinction coefficient of canopy
Increase Photosynthesis rate

9. Potential Sink Capacity
Reprodutive phase
Flowering bud initiation
No. of flower developed to be a fruit
No. of fully developed fruit
Fruit size
Rate of fruit or seed growth

10. Vegetative growth vs Reproductive growth
Do vegetative growth enhance SOURCE SIZE ??? depend on Dry matter partitioning (Dry Weight Ratio or Partitioning coefficient)
high LWR ie. ability to produce more PHOTOSYNTHATE at an expense of Root or Stem weight, but ability to find water or minerals may be reduced or less ability to flower

11. Reproductive stage Flower, fruit or seed are ACTIVE SINK
HI = Yecol. / Y biol.
Distribution index = Change in Y ecol. / Change in Y biol. after anthesis

12. Reproductive stage Current Photosynthate Storage Photosynthate
Remobilization
EAR
1 st
SOURCE
SINK
2 nd
ROOT

13. Yield components Size of the SINK
Nr, No. of reproductive unit
Ng, No. of grain per reproductive unit
Wg, Grain weight
each component is determined at different times of vegetative and reproductive stages

14. Application in crop production
SOURCE or SINK LIMIT ??
ALTER SOURCE
Defoliation
Shading
Thining
Light suppliment, Pruning
Fetilizer
Weed control

15. Application in crop production
ALTER SINK
Root pruning
Deflowering or debuding
Fruit thinning
Watering and Fertilizer application

16. แนะนำ paper ให้อ่าน
Board, J.E. and Qiang, Tan Assimilatory capacity effects on soybean yield components and pod number. Crop Sci. 35(2) :
Cirilo, A.G. and F.H. Andrade Sowing date and maize productivity. I crop growth and dry matter partitioning. II. Kernel number determination. Crop Sci. 34(4) :
James, J H Canopy characteristics associated with deficient and excessive cotton plant population density. Crop Sci. 34(5) :
Jiang, H. and D.B. Egli Soybean seed number and crop growth rate during flowering. Agron. J. 87(2) :
Jonathan, Lynch and N.S. Rdrignez, H Photosynthetic nitrogen-use efficiency in relation to leaf longevity in common bean. Crop Sci. 34(4) :

17. แนะนำ paper ให้อ่าน
Kining, J.R. and D.P. Knievel Response of maize seed number to solar radiation interception soon after anthesis. Agron. J. 87(2) :
Pau, W.L., J.J. Canberato, R.H. Mall, E.J. Kamprath and W.A. Jackson Altering source-sink relationship in prolific maize hybrids: Consequences for nitrogen uptake and remobilization. Crop Sci. 35(2) :
Pendelton,B.B., G.L. Teetes and G.C. Paterson Phenology of sorghum flowering. Crop Sci. 35(4) :
Pettigrew, W.T. and W.R. Meredith Jr Leaf gas exchange paratmeters vary among cotton genotypes. Crop Sci. 34(3) :

18. References
Amthor, J.S Respiration and Crop Productivity. Spring-Verlag. New York : pp. (QK891 A )
Amthor, J.S. and Mcree, K.J Carbon balance of stresses plants: A conceptual model for integrating research results. in (Alscher, R.G. and Cumming, J.R. eds) Stress Responses in Plants: Adaptation and Acclimation Mechanisms. Wiley-Liss, Inc. New York. 407 pp. (QK 754. S v.12.)
Biscoe, P, and Gallagher, J.N Weather, dry matter production and yield. in (Landsberg, J.J. and Cutting, C.V. eds) Environmental Effects on Crop Physiology. Academic Press. London (S600.2 S )
Cowan, I Optimization of productivity: carbon and water economy in higher plants. in (Pearson, C.J. ed) Control of Crop Productivity. Academic Press. Sydney (S600.5 C )
Evans, L.T Crop Evolution Adaptation and Yield. Cambridge Univ. Press. Cambridge : pp. (SB106 D74 E )

19. References
Gardner, F.P., R.B. Pearce and R.L. Mitchell Physiology of Crop Plants. Iowa State Univ. Press. Ames. 327.
Incoll, L.D Field studies of photosynthesis monitoring with 14 CO2. in (Landsberg, J.J. and C.C. Cutting eds) Environmental Effects on Crop Physiology. Academic Press. London :
Loomis, R.S. and Connor, D.J Crop Ecology: Productivity and Management in Agricultural Systems. Cambridge Univ. Press. Cambridge. 538 pp. (S589.7 L )
Milthrope, F.L. and J.Moorby An Introduction to Crop Physiology. 2nd ed. Cambridge Univ. Press. Sydney. 244pp.
Raghavendra, A.S Physiology of Trees. John Wiley & Sons, Inc. New York 21-51pp. (QK711.2 P )
Sheehy, J.E. and Johnson, I.R Physiological model of grass growth. in (Jones, M.B. and Lazenby, A. eds) The Grass Crop: The Physiological Basis of Production. Chapman and Hall. London: (SB197 G )
Wardlaw, I.F Translocation and source-sink relationships. in (Carlson, P.S. ed) The Biology of Crop Productivity. Academic Press. New York :