Viability constant K_E based on the species-specific temperature coefficients

Ke computes the viability constant K_E from the species-specific temperature coefficients in case of storage experiments conducted at constant temperature and varying moisture contents.

Ke(K, temp, temp.coeff = c(0.0329, 0.000478))

Arguments

K	The constant K associated with the relationship of temperature with seed longevity (see Details).
temp	Temperature in °C.
temp.coeff	The species-specific temperature coefficients (CH and CQ.) as a numeric vector of length 2.

Value

The value of species-specific seed viability constant K_E.

Details

From seed storage experiments involving storage of seeds at a constant temperature in a range of moisture contents, the effect of moisture content on seed longevity (σ) can be estimated from the following linear relationship:

logσ = K − C_Wlogm

Where, K is the intercept, C_W is the slope and m is the moisture content.

The constant K associated with the relationship of temperature with seed longevity as follows.

K = K_E − C_Ht − C_Qt²

Where, K_E, C_H and C_Q are the species-specific seed viability constants.

The constant K_E can be estimated from the universal temperature constants (C_H = 0.0329 and C_Q = 0.000478) in case of seed storage experiments at constant temperature and varying moisture content as follows.

K_E = K + C_Ht + C_Qt²

References

Ellis RH, Roberts EH (1980). “Improved equations for the prediction of seed longevity.” Annals of Botany, 45(1), 13--30.

Pritchard HW, Dickie JB (2003). “Predicting seed longevity: The use and abuse of seed viability equations.” In Smith RD, Dickie JB, Linington SH, Pritchard HW, Probert RJ (eds.), Seed Conservation: Turning Science into Practice, 653--721. Kew, UK, Royal Botanic Gardens.

See also

Sigma

Examples

Ke(36, 10)
#> [1] 36.3768