il 
$R 
50 
4 
nwick (a) 9 
nwick (b) 30 
otest 20 
10 
O 
l samples 
  
T 
600 
950 
  
500 700 800 900 wavelength (nm) 
Fig. 3 Spectral reflectance of leaves of turgid and non-turgid 
  
  
  
(i.e. non-infested and nematode-infested) sugar beets 
turgid 
es mw non-turgid 
7 --petioles 
d --Soil 
« 
v B . : — > 
500 600 700 800 900 950 wavelength 
(nm) 
Fig. 4 Spectral reflectance of petioles and soil