Directions of uniform rotundity in direct sums of normed spaces

Let {(X-i, parallel to.parallel to(i))}(i is an element of I), be an arbitr ary family of normed spaces and let (E, parallel to.parallel to(E)) be a mo notonic normed space of real functions on the set I that is an ideal in R-I . We prove a sufficient condition for the direct sum space E(X-i) to be uni formly rotund in a direction. We show that this condition is also necessary for E = l(proportional to), and it is not necessary for E = l(1). When E i s either uniformly rotund in every direction and has compact order interval s, or weakly uniformly rotund respect to its evaluation functionals we rees tablish as a corollary the result that reads: E(X-i) is uniformly rotund in every direction if and only if so are all the X-i.