DISEASE INCIDENCE OF CHOCOLATE SPOT OF FABA BEAN IN EL-DAKAHLIA AND EL-SHARKIA GOVERNORATES

Faba bean chocolate spot disease caused by Bo/ry/is fabae is the most
important disease affecting the faba bean yield. the cisease is widely spread in both
EI-Dakahlia and EI-Sharkia governorate during winter of season 2000-2001 and 2001-
2002. The highest percentage of infection and disease severity were recorded in
Senbel!awein district during 2000·2001 growing season. while the lowest percentage
was found in Menia At-Kamh district during 2002-2003 growing season. The causal
pathogen of chocolate spot was isolated from infested leaves. Samples were collected
from different locations of El-Dakahlia and EI-Sharkia governorates. The causal
organism fungal was isolated and identified as Botrytis fabae. All tested isolates of B.
fabae were pathogenic with different degree to faba bean plants of the two tested
cultivars Giza 3 and Giza 402.
Increased the inoculum concentration of B. fabae inoculum led to increase the
disease incidence. There are significant differences in linear growth of different
isolates of B. fabae. All the tested cultivars were different in their response to
chocolate spot disease. Giza blanka cultivar was the most resistant followed by Giza
667. while Giza 402 and Giza 716 were high susceptible. On the olher hand. Giza 3,
Giza 429, Giza 543. Giza 667. Giza 714. Giza 716 and Giza 843 were moderately
infesled.