Survey for occurrence and severity of dracaena leaf spot in Egypt

Occurrence of leaf spot of dracaena in the four Egyptian governorates Alexandria, Behira, Cairo and Giza) surveyed over the three years 2007-2010 and the 4 periods. of sampling ranged between 3.95% and 96.33% with disease severity ranged between 4.37% and 66.71% on the fourteen dreaceana cultivars tested. Corn Plant cv. was the most tolerant dracaena cultivar as showed overall mean occurrence and severity over the study being 15.65% and 9.03%, respectively, which was significantly lower than the other thirteen dracaena cultivars. This was followed by, cv. Massangeana and White Stripe with occurrence and severity being 19.04 % & 18.04% and 22.73% & 18.29% for the two cultivars, respectively. The highest occurrence (52.11%) and severity (32.48%) values, i.e. the highest susceptibility, was exhibited by Song of Jamaica. This was followed by cv. Sanderiana as showed occurrence and severity as high as 38.53% and 30.03%, respectively. In same context, periods of sampling significantly affected both occurrence and severity of dracaena leaf spot disease over the three years of the investigation. Period of (November: January) consistently showed the highest occurrence and severity with overall mean of 40.0% and 32.9%, respectively. Period of (May: July) showed the lowest occurrence and severity being 21.3% and 12.9%, respectively, the other periods of sampling i.e., February: April and August: October, exhibited intermediate values. Consequently, the present study revealed the situation of leaf spot disease of dracaena in four of major governorates for draceana cultivation and its occurrence and severity on most dracaena cultivars in Egypt.