Derivation of Constants (K-E, C-W) for the Viability Equation for Pepper Seeds and the Subsequent Test of Its Applicability

The effect of moisture on seed longevity during experimental storage was investigated in pepper (Capsicum annuum) cultivar Demire. Seeds were stored hermetically at 7.0%, 8.6%, 9.5%, 10.5%, and 12.1% moisture content (MC; percent fresh weight basis) and 35 degrees C for up to 306 d. Viability (normal germination) was assessed periodically and the seed viability equation moisture constants, K-E and C-W, estimated by regression of log sigma (the SD of distribution of seed death in time) with log MC. K-E and C-W values were found to be 7.767 and 4.670, respectively. The newly found moisture constants were combined with the temperature constants that had already been proposed as universal for all orthodox seeds (C-H = 0.0329, C-Q = 0.000478) and their validity was tested by predicting the viability loss in another pepper cultivar, Carliston. The K-i of the Carliston cultivar was determined by controlled deterioration at 40 degrees C and 14% MC. The observed viability loss between 30 and 270 d at 25 degrees C and 10% seed MC was closely related to that predicted by the equation R-2 = 0.982 (P < 0.001).