A novel approach that extends the potential cultivation season in net houses by reversible sealing of the net pores

Greenhouses that were developed for protected cultivation in cold climates are inadequate for production in hot climatic regions. Cultivation in greenhouses in hot regions during the hot season is sub-optimal. The investment required for greenhouse establishment is high compared with the investment required for other protected cultivation structures. Net houses are inexpensive and provide better conditions for cultivation in the hot season. The main drawback of net houses is the intrusion of water that damages the cultivated plants during the rainy season. An innovative technology that will transform the inexpensive nets into greenhouse like structures will address net house drawbacks and will provide growers with the solution they seek. We developed a technology that covers agricultural-nets with a thin and light transferring film. This sealing of the net holes allows better protection from outside weather (cold temperatures, rain and winds) while allowing reasonable light transfer and maintaining hot temperatures as in a greenhouse. Before the hot season the coating layer disintegrates and the net recovers its initial state. Active removal of the coating layer by pressurized hot water is another option. Prevalent agricultural and paint sprayers are used for the application of sealing and removal agents. The sealing and removal agents are user, crop and environment friendly. The sealing thin film reduces light transfer by 8% over a 50 mesh net. Simulation experiments revealed a similar thermal conductivity for a polyethylene sheet and a sealed net. Coating a net house with our technology increased temperatures by 2 degrees during the night and by 5 degrees during the day. The sealing film was tested under harsh (wind, sun, rain, hail, pollution, etc.) climate conditions and kept their entirety, flexibility and light transfer qualities.