The present invention relates to methods and compositions for increasing seed yield of a plant. The methods comprise expression of a cytokinin oxidase in the aleurone and/or embryo of a seed. The invention also relates to vectors comprising a nucleic acid encoding a cytokinin oxidase that is operably linked to a promoter capable of driving expression in the aleurone and/or embryo of a seed, and to host cells, transgenic cells and plants comprising such sequences. The use of these sequences for increasing yield is also provided.