In 1989 there was a severe drought. All agriculture suffered, including Rwanda's main cash crop, coffee, which was further pressured by falling world prices.

In 1991, the RPF invaded Rwanda from Uganda, and almost won, being stopped by the prescence of a handful French troops outside Kigali.

In 1993, the Arusha Accords were signed (and the drop bottoms out, with lag), but:

By that time, over 1.5 million civilians had left their homes to flee the selective massacres against Hutus by the RPF army.

Drought, falling prices, and civil war. The genocide, which was always highly organized and under the firm control of the army and the National Police (it was in no way a panic driven event), nonetheless benefited strongly from the masses of unemployed young Rwandans living in camps in Kigali. A malthusian contribution perhaps, but the genocide in Rwanda was as highly organized as the Holocaust, and politically driven.

Do you suppose that famine always leads to genocide?

"It Can't Be Just About Us"
--Frank Schnittger, ETian Extraordinaire