Is Using biscuits to strengthen joints necessary?

I have a project I've mad in woodshop and didn't get to finish it and I plan on doing so. However it has been suggested that I use biscuits but I don't have a biscuit jointer(plate jointer). I'm making a lid for my oak blanket chest the lid will be solid oak except the outside border which will be walnut. Will I need biscuits to attach he oak and he walnut