GLASSHOUSE CUCUMBER, STEM ELONGATION AND EARLINESS OF FRUIT PRODUCTION AS INFLUENCED BY TEMPERATURE AND PLANTING DATE

For two experiments of glasshouse cucumber, length growth rates of main stems and beginning of production are calculated for three series of temperature treatments and for various plantings.

Stem elongation rates are higher with increased temperatures.
The relation shows as a saturation curve over the range of diurnal (day plus night) values of temperatures of 16 and 23°C. The relation is a practically straight line between 17 and 21°C diurnal average values, both for a series of day temperatures (17 to 26°C) and for night temperatures (12 to 24°C), reaching saturation at about 21°C. Earliness of fruit production is also sensitive over the same diurnal range.
However, the response of earliness to day temperature deviates stronger to that of night temperature than does elongation.

The relation between stem elongation rates and earliness of fruit production is linear over the range of temperatures applied for the day and the night series.
Day and night temperatures show different functions, however, because of the greater difference in sensitivity today and night series of temperature of earliness.
For different planting dates, the relation between elongation rates and earliness is fairly constant.
It can be concluded that average diurnal temperatures cannot be used to describe sensitivity of various aspects of growth to temperature, and that earliness and elongation have specific responses to "within a day" temperature regimes.

Working-party on Greenhouse Cucumber

G. Heij

https://doi.org/10.17660/ActaHortic.1981.118.12