EFFECT OF AIR HUMIDITY ON GROWTH AND WATER EXCHANGE OF CUCUMBER-SEEDLINGS. PRELIMINARY REPORT.

Cucumber seedlings have been grown during 28 days on nutrient solution at 90% or 60% relative air humidity.
Growth analysis showed, that relative humidity hardly affected growth.
Root growth was slightly restricted in favor of stem growth.
Leaf area ratio might be lower at constant high humidity.
This seemed to be due to a somewhat lower specific leaf area.

Cucumber seedlings, grown at 90% or 60% relative humidity, did not differ in their respons (net assimilation rate, transpiration rate, leaf water content) to suddenly decreasing relative humidity from nearly saturated to 60%.

A difference has been observed in the response of the leaf water content,when humidity is decreasing at the start of the light period (dehydration of the leaf tissue) or in the middle of the light period (no effect on leaf water content). Possible explanations for these responses are presented.

Symposium Greenhouse Climate and its Control

P.A.C.M. van de Sanden

https://doi.org/10.17660/ActaHortic.1985.174.32