Abstract
We investigated the relationship between the water status of watermelon fruits and sugar accumulation during fruit growth and ripening. In 2007 and 2009 the water status of various part of the fruit's flesh from 0 to 44 days after pollination was measured with an isopiestic psychrometer. We also determined the sugar (glucose, fructose and sucrose) contents by means of high-performance liquid chromatography. When the osmotic pressure created by the sugar content of tissue at the center of the fruit were calculated by using Van't Hoff's equation, the osmotic potential (the negative of the osmotic pressure) accounted for 47% to 66% of the total osmotic potential measured by the psychrometer, indicating that the sugar content decreases the water potential of watermelon flesh during fruits development.
