Return to the data on yields of wheat genotypes, investigated in an alphalpha design, presented in Table 8.4 in Chapter 8. Exercises 331

(a) Explore the possibility of analysing these data using an autoregressive model, instead of the model based on the alphalpha design fitted in Chapter 8, Section 8.4.

(b) How well does your autoregressive model fit the data, relative to the model fitted earlier? Compare graphically the estimates of the genotype mean yields obtained by the two methods. How much effect will the choice of method have on the decisions made by a breeder seeking genetic improvement?