Articles
CONTROL OF AIR TEMPERATURE FOR CUCUMBER PRODUCTION
The plants were grown as vertical cordons and trained to the Dutch "umbrella" system.
Two cropping methods (i.e. removal or retention of mainstem fruits) were included in the experimental design.
The highest temperatures generally produced the earliest fruits but a high day temperature appeared to be more effective than a high night temperature.
Early fruit yield (i.e. after 4 weeks picking) increased with increasing night temperature up to 23°C but showed no increase at day temperatures above 22°C. After 20 weeks of picking the highest scumulative fruit yields were obtained at a night temperature of 20°C (when day temperature was 20°C) and at a day temperature of 22°C (when night temperature was 19°C). Profitability, estimated from fuel usage figures, was also highest from these two temperature regimes.
Fruit production rate was largely independent of the temperature treatments applied before the start of harvesting.
Restricting stem fruits to one per leaf node or leaving them unrestricted produced no significant differences in either the yield or quality of fruit picked from any of the temperature treatments.