Resource Allocation to Select for Yield in Soybean

Breeders need information on the best way to allocate resources to develop higher‐yielding soybean [Glycine max (L.) Merr.] lines using a fixed amount of resources. Our objectives were to determine the best resource allocation for first‐year yield tests by varying the number of replicates, number of lines per population, and number of populations. Thirty lines developed from each of 10 populations were tested in two selection environments. All 300 lines were evaluated in each of the seven environments. Five environments were used as validation environments to compare the mean of the selected lines to the overall mean. Increasing the number of replicates did not increase the effectiveness of selection. When 30 lines were tested from five populations, the realized selection differential varied from 170 to 310 kg ha−1, depending on which of the five populations were evaluated. We concluded that no more than 15 lines should be sampled from as many different populations as possible. The best allocation of resources to maximize the response to selection for first‐year yield evaluation was the use of a single replicate at one location.