FRUIT SET AND FRUIT GROWTH OF PURPLE PASSIONFRUIT AFFECTED BY TEMPERATURE

N. Utsunomiya
The effect of temperature on fruit set and fruit growth of purple passionfruit was examined. When the plants were transferred to 20/15 and 30/25°C growth cabinet prior to anthesis, flowers opened earlier and the flowering period was shorter at high temperature. The fruit set became poor at 30/25°C. With microscopic observation, pollen growth was little different between two temperatures. At flowering time the ovary, having more ovules, was nearly uniform size at 20/15°C. The production of small ovary with less ovules is likely to increase at 30/25°C where ovary size varied greatly. Less ovules were found in the fruit just after setting at 30/25°C. High temperature may adversely affect the ovule formation or fertilization, resulting in less fruit set in purple passionfruit.

The plants were kept at 20/15 and 30/25°C after pollination. Longer number of days were required for fruit maturation. Fruit weight was greater due to the increased peel weight at 20/15°C. Juice production was little affected by temperature. TSS and acids in the juice were higher at 20/15°C. Temperature influenced the ratio of sugar components in the juice. Much more sucrose accumulated at 20/15°C and the contents of glucose and fructose were higher at 30/25°C.

Utsunomiya, N. (1992). FRUIT SET AND FRUIT GROWTH OF PURPLE PASSIONFRUIT AFFECTED BY TEMPERATURE. Acta Hortic. 321, 641-647
DOI: 10.17660/ActaHortic.1992.321.77
https://doi.org/10.17660/ActaHortic.1992.321.77

Acta Horticulturae