Corn yield prediction from NDVI sensor readings collected at V8 from locations in Mexico, Nebraska, Iowa, and Oklahoma where INSEY (in-season estimated yield) was NDVI divided by the cumulative growing degree days from planting to sensing.

 
Corn yield prediction, Ohio, Dr. Robert Mullen
Corn yield prediction equation developed by Dr. Robert Mullen using GreenSeeker NDVI values collected between V6 and V10 divided by the cumulative growing degree days from planting to sensing. 

The above graph shows results over 2 years (6 total sites in Oklahoma) where corn forage N uptake can be predicted from growth stages ranging from V8 to V10.  However, it should be noted that this was from by-plant data (NDVI and N uptake determined by-plant).

Relationship between cotton lint yield and INSEY (NDVI divided by cumulative GDD)

Mean: 9496.17 kg/ha
Standard Deviation: 3737.60 kg/ha

Mean 9983.29 kg/ha
Standard Deviation: 4132.39

Lake Carl Blackwell, Oklahoma.  Variability in by-plant corn yields over 15 m of row.


Shelton, NE, MSEA Site, USDA-ARS 2004.  Work by Paul Hodgen, Kent Martin, and Kyle Freeman has shown that SPAD readings taken "by-plant" at V16 were highly correlated with final "by-plant" grain yields. This relationship would not have been observed unless the by-plant resolution had been used.

 
Reproducibility of NDVI readings over 16m using an on-board shaft encoder, with 50 corn plants sensed at the 7-leaf growth stage on May 23, 2003, Perkins, OK.
Average NDVI (by-plant) determined by collecting sensor readings from the sum of 1/2 the distance left and right to its neighboring plants. Similarly, by-plant yields were determined from the from the exact same area for which NDVI measurements were captured.