Fruit shape in cucumber as influenced by position within the plant, fruit load and temperature

Abstract

The shape of cucumber fruits expressed as the length/circumference ratio is an important quality factor. The fruit shape of parthenocarpic cucumber fruits was measured during fruit development and the effects of position within the plant, fruit load (number of fruits per plant) and temperature were analysed. At 25°C the length/circumference ratio increased until 4 days after anthesis and declined thereafter. The length/circumference ratio of the fruits was low at positions around leaf axil 12 and was highest for fruits from the branches. The shape of the fruits was apparently predetermined by their position within the plant. The number of fruits competing for assimilates had no effect on the pattern of development over time of the length/circumference ratio. With decreasing number of fruits per plant the fruits reached the marketable size (weight) at an earlier developmental stage, resulting in marketable fruits with a large length/circumference ratio. An increase in temperature hastened fruit development, but when the length/circumference ratio was plotted against the temperature sum the effects of temperature on the length/circumference ratio were only small.