Alfalfa yield trials are particularly subject to fraud because early generations may yield much better than the commercial generation of a variety. 109 Fraud can be prevented by testing only commercial seed obtained by the scientist from the local market. Large experiment errors occur when too many entries are included in a test, making it impossible to get uniform conditions within an experimental block. Such error can be reduced by limiting the number of entries to, perhaps, no more than 36. Such error can be further reduced by reducing plot size, perhaps to 60 sq.
Many tests have inadequate replication.
Experience teaches that more than four replications are often needed. The value of an alfalfa variety trial can be estimated by the modified coefficient of variation. The LSD expressed as a fraction of the mean will estimate the percentage difference between varieties that can be detected at a stated confidence level. The proper sizing of trials and careful attention to experimental techniques can effectively control error. Principles and Procedures of Statistics.