Effects of water deficit on the growth of squash fruit

The growth of squash fruit was followed in the field under normal and drought conditions. The following phenomena were observed: a) under drought conditions the fruit growth is normal in the night while it becomes more and more reduced with progress of time in the daylight period; b) the decrease of growth capacity in the daylight period does not correspond to a dehydration of the fruit tissues and it is accompanied by a conversion of polysomes to monosomes; c) the water deficit also causes a decrease of RNA and protein content in the fruit tissues, but this situation does not affect the rate of growth in the night. The data suggest that under conditions the fruit growth is controlled by water availability through protein synthesis; under ample water supply, water availability or some other factor, rather than RNA and protein level, is limiting the fruit growth.