Water scarcity in desert environments shapes plants’ characteristics as they adapt to it. To improve water status in dry habitats, some plants utilize non-rainfall water inputs (NRWI) such as dew, by adjusting their physical properties. Dew condensation can be promoted by surface cooling, capillary, and rough microstructures or surface orientation. As a dominant trait of the leaf surface, Plants’ trichomes can contribute to the thermal and structural properties enhancing dew formation. The annual desert extremophyte: the true rose of Jericho was tested for the ability to harvest dew, in an experiment in which half of the plants will be treated for trichomes removal. Measurements were conducted every 2 hours on a 24-hour campaign, as well as evening and morning coupled measurements. The weight of the pots was measured, since it is assumed to change according to the water accumulation, and thermal images were taken to reveal the trichomes and orientation effect on the leaf temperature. The leaf water content will be measured from leaves before and after dew events. Higher weight and leaf water content in hairy plants when dew is recorded indicates the role of trichomes in this process. Potential differences in leaf temperature between treatments can indicate whether the trichomes cool the surface. In case cooling is not found, dew collection is more likely due to the surface microstructures. The orientation, if affecting temperature differences within the plant, may affect dew capturing, although orientation contribution to the water status needs to be better investigated.

Ms. Yuval Siboni
Does the True Rose of Jericho Capture Dew? Trichomes and Plant Orientation as Thermal and Structural Mechanisms for Dew Capturing
Ben-Gurion University of the Negev, Israel