The effect of season on the growth and maturation of bell peppers

Document Type: Research Paper

Authors

Laboratory of Vegetable Production, Department of Crop Science, Agricultural University of Athens, 75 Iera Odos, 11855, Athens, Greece.

Abstract

Bell peppers grown in greenhouses in the Mediterranean region are frequently
subjected to high temperatures in summer and low temperatures in winter. The
present experiment was designed to quantify the effect of season on pepper fruit
growth, maturation and ripening. Three bell pepper (Capsicum annuum L.) cultivars
(Yolo Wonder, California Wonder and E84066) were cultivated in an unheated
greenhouse during summer and autumn. Fruit size, fresh weight and volume were
higher in the autumn due to increased fruit length and pericarp weight. However,
colour transition from green to red was significantly delayed in the autumn and the
vitamin C concentration was also lower than in the summer. Similarly, the internal
C2H4 concentration was lower at the mature red stage of the autumn-grown fruit than
in the summer, whereas the respiration rate and the internal CO2 concentration did
not differ. Irrespective of season, the internal C2H4 and CO2 concentrations correlated
with the number of seeds per fruit, suggesting that seed metabolism significantly
influenced the internal atmosphere of the fruit. Additionally, the number of seeds per
fruit in the autumn correlated with fresh fruit weight and volume, but not in the
summer. In conclusion, bell pepper fruits produced in the autumn were larger in size,
but lower in nutritional value (less vitamin C), while the effects of growth season on
the pepper fruit morphology and physiology closely related to the number of seeds
per fruit in autumn, but to a less extent in summer.

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