THE DYNAMICS OF GROWTH AND DRY-MATTER DISTRIBUTION IN CUCUMBER

The dynamics of growth and proportional dry matter distribution between the vegetative parts and fruits of cucumber were studied daily during a growing season. Most of the changes in daily integral of total solar radiation were reflected by changes in plant growth rate. Sometimes a time lag of a few days occurred, indicating the plants were adapting to radiation. The proportional dry matter distribution between fruits and vegetative parts showed a cyclic pattern. The daily proportional dry matter distribution to the fruits varied between 40 and 90% of the total dry matter. However, the cumulative dry weight of the fruits was fairly constant at 60% of the cumulative plant dry weight. The daily proportional dry matter distribution did not seem to be linked directly to the climate conditions (temperature, CO, concentration, relative humidity or daily light integral). The proportional distribution to the fruits showed a clear positive correlation with the fruit load (number and weight of fruits) on a plant. The number of fruits on a plant changed considerably during the growing season. This number was limited not by the formation of new fruits but by abortion of fruits within about 10 d after flowering. The number of young fruits that did not abort appeared to correlate positively with the growth rate of the vegetative parts. © 1992 Annals of Botany Company.