Good correlation was noted between NDVI readings and grain yield (grams/2.4m2, 2 rows, 0.75m *1.6m), largely because there was a wide range in yield differences (3000 to 8000 kg/ha).  Normally, it is more difficult to observe large differences in breeding nurseries, simply because most are advanced lines and all have good yield potential.  However, in the winter of 2002 at El Batan, there was a significant infestation of yellow rust.  Thus, it may well be that the sensor was useful in detecting stress as a function of disease.

It is important to note that we did not find any correlation between NDVI readings and yield in the other nurseries sensed where yield levels were high, and where no disease symptoms were present.  Thus, the sensor may be useful for 'rust' and other disease nurseries, but not for detecting subtle differences in yield when all lines are between 6000 to 8500 kg/ha.