The Effect of Hexadecanol-Octadecanol on the Leaf Water Balance of Zea mays L.

Abstract

The effect of a soil application of an equal mixture of hexadecanol-octadecanol on the factors influencing the water balance of corn leaves (Zea mays L) was determined by measuring stomatal movement, temperature, water potential, osmotic potential, turgor pressure, and transpiration rate in field- and greenhouse-grown plants. An average of 57% of the stomates of the treated plants remained open at 2:00 P M. each day, and the leaf surface temperature of the treated plants exceeded by 9 C that of the control plants The leaf water potential of treated plants exceeded that of the control plants by as much as 58 bars and generally stayed greater than 1-2 bars. Turgor pressure was as much as 4 9 bars greater in the treated plants, and transpiration was reduced by 34.9% The maintenance of high water potential and turgor pressure in leaves of treated plants indicates that transpiration reduction takes place in the substomatal cavities rather than by simple root impedance.