Crop yield estimation can be done by sampling a representative area of the field and counting or weighing the harvested crop. The sampled area should be carefully chosen to reflect the overall field conditions. By extrapolating the measurements to the entire field, an estimate of the crop yield can be obtained.
Good response Sundip, but it is best to take several samples to get a statistically valid mean which is then used to calculate the total yield. More work but much the best, more reliable, estimate .
Crop yield is generally estimated by random sampling in large areas as suggested by Sudip Ghimire However, in small areas, it is always best to evaluate the whole crop population as said by David W. Lawlor. The crop yield estimation may vary with crops, in some cases, only the fruits, while in some instances, yield means leaves, flowers, roots, stems, etc.
Sorry, Heiplanmi Rymbai, I did NOT suggest that for small areas it is best to evaluate the whole area as in your response. Sudip Ghimire gave the impression that only one sample of a known area was needed and could then be used to calculate the crop for a much larger area. I pointed out that more samples would be desirable so that a statistics could be applied.