, gray growth of the fungus covers these, andnumerous spores are soon found, giving the affected area a cottony appearance. Affected leavescollapse and shrink. The fungus progresses into the stem, producing cankers. Affected fruits firstshow a watersoaked, soft area in the points of infection. The dark gray growth of the fungus soon isseen on these spots. Regular fungicide applications should help in controlling this disease. Botryosporium MoldCausal Agent(s): (fungal - Botryosporium sp.)This fungus can often be found on greenhouse tomatoes. It superficially resembles gray mold. Septoria Leaf SpotCausal Agent(s): (fungal - Septoria lycopersici)Infection usually occurs on the lower leaves near the ground, after plants begin to set fruit. At first,small watersoaked spots are observed, which under ideal conditions will become numerous. Largeareas of the leaves may be affected but the individual spots can be recognized. The watersoakedspots become roughly circular, with dark margins surrounding a light gray center. With time, blackspecks which are spore producing bodies can be seen in the center of the spots. If the spots arenumerous, the lower leaves will turn yellow, die and progressively drop from the plant until only afew leaves remain on the top of the plant. The fungus is most active when temperatures range from60 to 80 degrees F., and humidity conditions are high. The disease is usually not serious duringperiods of hot, dry weather. The fungus can overwinter on crop residue from previous crops,decaying vegetation and some tomato-related wild hosts. Crop rotation, plowing under cropresidues, and clean cultivation will reduce the amount of inoculum in tomato fields. Repeatedfungicide applications will keep the disease in check. Southern BlightCausal Agent(s): (fungal - Sclerotium rolfsii)The first symptom is dropping of leaves suggestive of other wilts. Wilting progresses and plants diequickly. Stems show decay of outer tissues at the ...
