LEAF AND POD SPOT OF COWPEA CAUSED BY TALAROMYCES TRACHYSPERMUS IN EL-MINYA GOVERNORATE OF EGYPT, AND PATHOGEN SURVIVAL ON CROP RESIDUES.

Cowpea is subject to attacks by a wide range of plant pathogens
including bacteria, fungi, viruses, and nematodes. In this study, a field
survey conducted among cowpea growing regions of El-Minya governorate
of Egypt including Minya, and Maghagha districts for leaf and pod spot
disease. Our results revealed that the disease was present in all surveyed
fields with the highest disease incidence and severity found in Minya
District. The causal agent determined to be Talaromyces trachyspermus
based on morphology of the fungal isolates, internal transcribed spacer
sequence homology to a T. trachyspermus strain, as well as fulfillment of
Koch’s postulates. Our study showed that detached pods of soybean, cowpea
and plant foliage of thyme were the most susceptible to T. trachyspermus,
presenting between 97.77 –77.78% DI% and 38.78- 61.66 DS%, whereas
moderate infection was recorded on Chill pepper, Colored bell pepper, bean,
faba been, Black seed, Green (sweet) pepper showed the lowest infection
caused by this pathogen, while okra, sage and rosemary were the most
resistant showed no infection. In addition, survival of T. trachyspermus was
studied on non-buried and soil buried plant residues for 30 months. Data
showed that colony forming units (CFUs) of the pathogen were recovered up
to 30 months under both conditions, with a significant decrease in CFUs at
each time point. However, the causal pathogen remained capable of
producing diseases in cowpea plants. These results highlight the ability of
this pathogen to survive on plant residues for long time with the capacity to
infect plants.