Sathianandan, T VGeorge, K CKAU2019-03-302019-03-301986Agricultural Research Journal of Kerala, 24(2), 185-188.http://krishikosh.egranth.ac.in/handle/1/5810100008A general method of construction of designs that are balanced for first order residual effects, when the number of treatments is prime or power of a prime number, using orthogonal latin squares has been given. The residual effects are more efficiently estimated in this type of designs and are useful in long term experiments like perennial crop experiments, feeding trials etc.ennullArticle