Occurence of spike disease in sandal plantations in southern Karnataka.

摘要

Results are presented of a systematic roving survey conducted from September 2011 to June 2012 to explore the prevalence/incidence of spike disease, caused by phytoplasmas, in sandal (Santalum album) plantations in different districts of Karnataka (Tumkur, Chickballpur, Shimoga, Chitradurga and Chikkamagalur), India. In the surveyed 24 sandal plantations, the disease incidence ranged from 0 to 18%. A maximum incidence of 18% was recorded in Sira in Tumkur district. In Shimoga, the maximum incidence was 1.60% in Adderi village, followed by 1.09% in Thaligere village and the minimum incidence (0.33%) was recorded in Tyagarthi village of Sagara tuluk. There was no incidence found among 5 plantations in Chitrudurga, 4 in Chickballapur and 5 plantations in Chikkamagalur. The infected samples collected during the survey were subjected to PCR analysis and found positive to spike phytoplasma.