Art literature in the poem that includes the lines, this is the dead land, this is cactus land, to what work is the first epigraph an allusion?

In the poem that includes the lines, this is the dead land, this is cactus land, the first epitaph is an allusion to Heart of Darkness, a novel written about Joseph Conrad.

The clue is when the poet says "Mistah Kurtz-he dead." because Kurtz is a character from Heart of Darkness.