In Morocco, no operational system actually exists for the early prediction of the grain yields of wheat (Triticum aestivum L.).
This study proposes empirical ordinary least squares regression models to forecast the yields at provincial and national levels. The
predictions were based on dekadal (10-daily) NDVI/AVHRR, dekadal rainfall sums and average monthly air temperatures. The
Global Land Cover raster map (GLC2000) was used to select only the NDVI pixels that are related to agricultural land. Provincial
wheat yields were assessed with errors varying from 80 to 762 kg ha1
, depending on the province. At national level, wheat yield
was predicted at the third dekad of April with 73 kg ha1 error, using NDVI and rainfall. However, earlier forecasts are possible,
starting from the second dekad of March with 84 kg ha1 error, at least 1 month before harvest. At the provincial and national levels,
most of the yield variation was accounted for by NDVI. The proposed models can be used in an operational context to early forecast
wheat yields in Morocco.
#