Florida Agricultural Experiment Station


 Description: Southern blight is usually not detected until a
wilting of the growing tips is observed. The wilting takes place
during the middle of the day at first but a day or two later the
whole plant wilts and fails to revive at night and then dries out
rapidly. When such a plant is found in the field it is well to
examine the main root near the soil surface. There the fungus
causing the death of the plant will be readily seen and can be
definitely identified by the presence of the small, mustard-seed-
like, brown sclerotia clustered on the stem at the soil line.
 Control: The only control practicable is the careful removal of
the diseased plants with the sclerotia from the field wherever
found. If severe in the whole field, rotate with a forage crop.

 FUSARIUM WILT
 This wilt of cucumbers is caused by the fungus Fusarium
cucurbitae Taube. The disease is not common in Florida and
has been found in only a few scattered places. In the greenhouses,
however, it has at times become a serious factor and has caused
considerable loss. The organism causing this disease lives from
one season to the next in the soil and plants set in infected soil or
seed planted on it are liable to become diseased. The spores of
the fungus are formed on the roots and stems of the plants that
are killed and it lives over unfavorable seasons in this way and
by the infection of wild host plants. The disease is most easily
detected during hot weather before the summer rains.
 Description: The only symptoms of Fusarium wilt are the wilt-
ing of the growing tips, followed by the wilting of the whole
plant. After wilting, the plant rapidly dries up and dies. This
disease is often confused with southern wilt but southern wilt
can be readily distinguished from Fusarium wilt by the presence
of the sclerotia.
 Control: The only control in the field is rotation of crops.
When the disease appears in the greenhouse it is necessary to
remove the diseased plants and either remove the soil or sterilize
it. Soil used in greenhouses should always be sterilized before seed
are planted. Sterilize it with either live steam or formaldehyde.

 MACROSPORIUM BLIGHT OF CUCUMBERS
 This leaf blight is caused by the fungus Macrosporium cucum-
erinum E. & C. It is not found commonly on cucumbers in Flor-
ida, although it may be considered common on cantaloupe and
watermelon. The disease has not been of economic importance