Temperature and Rate of Moisture Intake in Seeds

Abstract

1. This paper deals with the quantitative influence of temperature on the velocity of moisture intake by certain seeds, chosen for the presence and absence of semipermeable coats. Xanthium pennsylvanicum Wallr. and commercial and garden peas were used, the latter with coats removed. 2. The curves of water intake were found to be complex, but can be represented by a logarithmic equation or series of equations of the form y=a log10(bx+1)+c. 3. The analysis of the data presented does not support the theory of Brown and Worley that the velocity of intake is an exponential function of the temperature, but the velocity of intake at any given moment in the seeds studied is approximately an inverse exponential function of the amount of water previously absorbed. 4. The mean value of Q10 in Xanthium seeds was in one instance 1 55, in another 1 83, and in split peas of the Small Scotch Yellow variety 1 6. 5. These values do not indicate that absorption is conditioned by some single chemical change like simplification of water to hydrone as the temperature rises, but are believed to indicate that absorption at different temperatures involves both physical and chemical changes. 6. The main chemical changes with rise of temperature are believed to occur in the colloids of the seed, and semipermeability, as such, is thought not to be an important factor in determining the rate of water absorption. 7. The paper considers critically the methods and interpretation of the similar work of Brown and Worley on Hordeum seeds.