Helen Wheeler is a Research Scientist at Silsoe Research Institute and has been undertaking NDVI studies using Skye light sensors. She says:-
“I have been using Skye Instruments’ 2-channel light sensors for 7 years. They are type SKR 1800 (660nm & 730nm). I have used them mostly mounted on a sprayer boom with an upward facing sensor & cosine diffuser, and six downward sensors looking at the crop canopy. They have assisted in the detection of weeds as well as crop density and stress. (see the schematic diagram on the right).
I have re-calibrated them (probably twice) and both times they had hardly changed.
They have been on the sprayer for about 4 years, which although kept under cover, still leaves them open to the damp and cold.
As for operating conditions I have used them in bright sunlight through to overcast drizzle”
1) Matching the application of fungicides to crop canopy characteristics. (2000) Miller, P.C.H., Lane A.G., Wheeler, H.C. Proceedings, BCPC – Pests & Diseases, 629-636
2) Matching spray applications to canopy characteristics in cereal crops. (2001) Miller, P.C.H., Lane A.G., Wheeler, H.C. Pesticide Outlook, 12(3), 100-102
Thanks to Helen Wheeler, Research Scientist, Silsoe Research Institute for this application