Resistance of 43 Sugarcane Clones to Smut (Ustilago scitaminea Sydow)

Abstract

Forty-three sugarcane clones were tested in the greenhouse for resistance to smut, Ustilago scitaminea Sydow, between December 1983 and January 1985. We inoculated forty pieces of seed cane per clone (one bud/seedpiece) by submerging them for 20 minutes in an aqueous suspension of teliospores (5 x 10⁶/ml). Inoculated seedpieces were incubated overnight, then planted in 20-cm diameter metal pots. Incidence of stool and stalk infections were followed. Stool infection increased after ratooning. Nine clones were smut resistant and three were tolerant at planting and at the first ratoon crop. Three clones, PR 70-2085, PR 77-1040, and PR 78-3005, did not show disease symptoms or smut whips during the experiment.