A Chlorotic Streak Disease of Merker Grass (Pennisetum purpureum)

Abstract

The chlorotic streak disease of Merker grass (Pennisetum purpureum Schumac.) has many features in common with the chlorotic streak disease of sugarcane. The leaf symptoms are similar. Both, are carried in seed pieces, and seed of both is rendered disease-free by submerging in hot water (52°C.) for 20 minutes. The diseased grass usually grew close to diseased sugarcane, or on a site adjacent to diseased cane. Infection in both cane (1, 6) and the grass results in heavy losses in tonnage. Some experiments with sugarcane (1, 6) report losses in sucrose as well as tonnage. In this work with Merker grass the chlorotic streak disease delayed maturity. Possibly, chlorotic streak disease of sugarcane upsets normal maturation under some conditions, and in this way lowers sugar yield. Until transmission studies have been made to determine the possible relationships between the chlorotic streak diseases of Merker grass and sugarcane, the observational evidence of their similarities seems strong enough to warrant proceeding on the assumption that they are caused by the same virus. Chlorotic streak-control programs in both hosts should advance together for the greatest safety.