Aqueous Foams for Frost Protection of Plants: Stability and Protective Properties

Efficient technology has been developed for aqueous foam protection of plants against radiative night cooling. Experimental and mathematical simulations together with field tests were carried out in a search of foaming solutions and methods of application of the foam layer that provide optimal protection. A new parameter—insulation endurance—was developed for evaluating the thermal protective properties of unstable insulation materials such as aqueous foam. This parameter combines properties that are the most important for successful protection of plants—heat resistivity and stability. Based on this parameter, the experimental data were interpreted and used to choose the foaming solutions that provide sufficient protection of plants during a night of frost. Foams were studied when applied in various configurations, directly over soil surface and spread over a mesh which covers the plants.