ISHS Acta Horticulturae 348: II International Strawberry Symposium
EFFECT OF LIGHT INTENSITY ON GROWTH AND RIPENING OF STRAWBERRY FRUIT |
| Authors: | H. Miura, M. Yoshida, A. Yamasaki |
| Abstract:
Strawberry plants, cultivated in a plastic greenhouse, were shaded by a black cheesecloth with about 60% light transmittance to investigate the effect of the light intensity on the growth, size, coloration and sugar content of a primary fruit in a truss. In the absence of treatment, the changes in the fruit minor diameter after anthesis followed a double sigmoidal pattern, that is, the growth rate (mm/day) showed an early peak 5–6 day after anthesis, immediately after the onset of the measurement, and a second peak 27–29 days after anthesis. The L* value (lightness) of the fruit surface color slightly increased from 23 days to 28 days after anthesis (white stage), and thereafter it decreased considerably. The a* value (redness) rapidly increased after 28 days, then it reached a value of 10 at 30 days (turning-red stage) and a value of 40 at 36 days after anthesis (full red stage). In contrast, the b* value (yellowness) gradually decreased with the number of days after anthesis. In the shade treatment, the growth pattern of the fruit also showed a double sigmoidal curve. The second peak occured at 31 days after anthesis, but it was lower than the peak observed in the absence of treatment. The L* value was high from 23 to 30 days after anthesis (white stage). A rapid increase of the a* value occured after 30 days, while the value of 10 was reached at 32 days (turning-red stage) and the value of 40 at 38 days after anthesis (full red stage). Although the fruits in the shade treatment required a longer period of time after anthesis to reach the full red stage, the size (minor diameter, fresh weight and dry weight) was smaller, e.g., 18% decrease in dry weight, and the contents of fructose, glucose, and sucrose were also lower than those in the fruits in the absence of shading. | |
