Our study was designed to 1) assess the potential of MODIS GPP for estimating wheat yield in Montana and North Dakota and 2) define the practical limits within which wheat yield can be sufficiently estimated using these data. To achieve these objectives MODIS GPP data were integrated over different time periods within the 2001 and 2002 growing seasons and converted to wheat yield using a simple harvest index logic, across three spatial domains including counties, climate districts and states. The study area consists of Montana and North Dakota. Most wheat in Montana (97 %) and North Dakota (99%) isgrown under dryland conditions (i.e. without irrigation).
Estimated wheat yields from MODIS GPP were compared with observed yield at the county, climate district, and state levels. Only state level wheat yield analysis was sufficiently accurate. Predicted wheat yields for both Montana and North Dakota were sufficiently accurate, and never deviated more than 4.5% from actual yield for the duration of the study.
Reeves, M. C., Zhao M., and Running S. W. 2005. Usefulness and limits of MODIS GPP for estimating wheat yield. International Journal of Remote Sensing, Volume 27, Number 7, p.1403-1421.