Universally Optimality for One-Sided Interference Model

In many areas such as agriculture, forestry and medicine the interference models are arised when the response of a treatment is affected by the other treatments in neighbor experimental plots. There are many experiments specially in agricultre that the block size (k) is greater than the number of treatments (t) and if k t, the universally optimal designs under the interference models are usually difficult to obtain. In circular block designs with t k 2t, we consider the interference model with left-neighbor effects such that the observations are uncorrelated. The universally optimal designs are obtained based on the Kushner’s method.