SAMP                   SAMP 1      SAMP 2  

Calculating the Ellis and Roberts' Seed
Viability Equation in EXCEL

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Viability Equation:    

n =  Ki -  P · ( 1/10Ke - CwlogM - ChT - CqT2 )

n = final % viability after p days storage
Ki = initial viability at p = 0 days
P   = storage days
M  = moisture content of the seed (hermetically sealed)
T   = temperature (not fluctuated)
Ke, Cw, Ch, Cq = viability constants, species specified

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some references:

Dickie, J.B., R.H. Ellis, H.L. Kraak, K. Ryder and P.B. Tompsett 1990 Temperature and seed storate longevity. Ann. Bot., 65:197-204.

Ellis, R.H., T.D. Hong and M.T. Jackson (1993) Seed production environment, time of harvest, and the potential longevity of seeds of three cultivars of rice (Oryza sativa L.). Annals of Botany, 72:583-590.

Ellis, R.H., T.D. Hong and E.H. Roberts 1992 The low-moisture-content limit to the negative logarithmic relation between and longevity and moisture content in the three subspecies of rice. Ann. Bot., 69:53-58.

Ellis, R.H., T.D. Hong and E.H. Roberts 1995 Survival and vigour of lettuce (Lactuca sativa L.) and sunflower (Helianthus annus L.) seeds stored at low and very-low misture contents. Ann. Bot., 76: 521-534.

Roberts, E.H. and R.H. Ellis 1989 Water and seed survival. Ann. Bot., 63:39-52.

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press: SAMP 1  or    SAMP 2   to open the file, if  using IE 4.0 or higher, or stored in hard disk and open as an excel file.

SAMP 1:

  1. stored the seed sample bags at constant environment.
  2. at due time, withdraw one bag and test % germination.
  3. get at least three tests.
  4. input A4 and B4 for the fist test, A5 and B5 for the second......
  5. viability equation instantly presented: i.e. Y = 2.8799 -0.092168132 X
  6. to predict viability after x days storage, just key in E14 or below
  7. or consult the figure in other worksheet: probit / percent

SAMP 2: to predict storage days or storage condition (temperature, seed moisture content) needed in some species..

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