First Report of Ratoon Stunt of Sugarcane Caused by Leifsonia xyli subsp. xyli in Pakistan

Sugarcane (Saccharum hybrids), the second largest cash crop of Pakistan, is planted on 1.029 million ha with an annual production of 50 million tons. During a survey of the sugarcane crop in Faisalabad, Sargodha, and the Dera Ghazi Khan Division of the Punjab Province of Pakistan from 2007 to 2010, symptoms consistent with ratoon stunting, including stunted growth and reddening of the vascular bundles at the nodal regions (1), was observed on sugarcane cvs. CP77-400, SPF-241, CP72-2086, and NCo-310. CP72-2086 and NCo-310 showed severely stunted growth in both crop cycles. A chemical test was performed for detecting ratoon stunt from the field. Longitudinal sections of mature nodes were treated with a combination of hydrogen peroxide and hydrochloric acid. Healthy canes developed a blue-green color in the parenchymatous tissue around the fibrovascular bundles, diseased cane did not. This field test illustrated that as much as 25% of the plants were infected by ratoon stunt in the survey area. Aerobic bacte...