Co-Authors:
Shahak, Y., Institute of Plant Sciences, ARO, Volcani Center, Bet-Dagan, Israel
Ratner, K., Institute of Plant Sciences, ARO, Volcani Center, Bet-Dagan, Israel
Zur, N., Institute of Plant Sciences, ARO, Volcani Center, Bet-Dagan, Israel
Offir, Y., Polysack Plastics Industries, Nir- Yitzhak - Sufa, Israel
Matan, E., Southern R and D Network, Besor Experimental Station, Israel
Yehezkel, H., Southern R and D Network, Besor Experimental Station, Israel
Messika, Y., Extension Service, Min. of Agriculture, Israel
Posalski, I., Extension Service, Min. of Agriculture, Israel
Ben-Yakir, D., Institute of Plant Sciences, ARO, Volcani Center, Bet-Dagan, Israel
Abstract:
Photoselective nets were designed to selectively filter different spectral bands of solar radiation, and/or transform direct light into scattered light. The spectral manipulation intends to specifically promote desired physiological responses, while the scattering improves the penetration of the spectrally-modified light into the inner plant canopy. The current paper reviews the photoselective concept and its assessment in various crops. It further describes a recent study on photoselective shade-netting of bell peppers, demonstrating the potential uses of this technology for improving both crop performance and pest control. Thus, the replacing of the traditional black shade net by either a Red, Yellow or Pearl nets (ChromatiNets") of similar shading factors, resulted in 15-40% higher fruit production in different cultivars. The major response to the photoselective filtration was producing more fruits per plant, with essentially no reduction of fruit size or quality. Additional benefits relate to photoselective improvement of pest control. The Yellow shade net decreased whiteflies penetration and establishment by 2-3 folds compared to black nets, even though the net holes were large enough to allow free passage of the pests. The incidence of an aphid borne cucumber mosaic virus (CMV) disease was significantly lower under white, Pearl and Yellow shade nets compared to black or Red nets. Additionally, a photoselective 50 mesh screen (OptiNet®) reduced thrips infestation 3-4 folds relative to the standard screen. The photoselective, lightdispersive shade nets and screens provide a new tool for improving both crop performance and pest control.