CONVERSION OF YIELD DATA FROM EXPERIMENTAL PLOT TO HECTRAGE UNITS

Methods of converting yield data from experimental plot to hectrage un its are proposed to enable reliable estimation of yield potentials of crop varieties. Conventional direct linear extrapolation method of con version gives too high estimates of yield per hectare. The proposed me thods take into account the variability inherent in experimental mater ials and cultural practices as well as different levels of management skills of farmers, and make use of Smith's index of soil heterogeneity . Two models are described for the estimation of the management index, which may further be partitioned into low, medium and high management levels. An example is given to illustrate the method and possible imp lications discussed.