Kiran, KapoorLohmor, Nisha2016-10-212016-10-212015http://krishikosh.egranth.ac.in/handle/1/81261A study of uniformity trial for the determination of optimum size and shape of plots and blocks, optimumnumber of replications and to compare relative efficiency of various designs was conducted on sunflower on a field of size 35m × 40m which after eliminating border effects reduced to 32 m x 36 m. The total area divided into 1152 units each unit have size of1m × 1m. Based on coefficient of variation, the plots elongated in E-W direction were more effective in reducing error variation than those elongated in N-S direction. Also the blocks elongated in N-S direction were more effective in reducing error variation than those elongated in E-W direction. The coefficient of variation decreases with the increase in the block size, thuslarger blocks were found to be more efficient than smaller ones. In general, blocks were found to be moreefficient than without blocking arrangement. The optimum plot sizes were estimated to be 2 m2 for without blocking and 2 m2 or 1 m2 for withblocking using the maximum curvature method and Smith’s method. The number of replications requiredfor detecting the true difference between the treatment means for a given level of accuracy decreased withthe increase in the plot size. It was found that randomized block design (RBD) was more efficient in reducing error variation over completely randomized design (CRD). Latin square design (LSD) was found to be more advantageous over CRD and over RBD only when the columns were considered as blocks. In case of factorial experiments, the confounding resulted in gain of efficiency.enCosts, Manpower, Productivity, Tillage equipment, Diseases, area, Crops, Economics, Biological development, biological phenomenaThesis