Cantaloupe Diseases and Their Control
Vegetable Disease Information Note 13 (VDIN-0013)
Extension Plant Pathology
are affected by several diseases which often cause serious crop losses
and steps must be taken to control them. Often diseases may not be present,
however, commercial growers should always employ preventative measure
that will help avoid the diseases or reduce their severity if they appear.
Diseases are usually more frequent and serious in late season and during
periods of high humidity. Diseases are a major cause for the rapid decline
of cantaloupes after the first harvest. A total disease control program,
as described in this publication, along with good cultural practices,
as described in Horticultural Leaflet Number 8, will increase yields and
quality and extend the productive life of the plant.
caused by nematodes (Meloidogyne spp.) that live in the soil and
are very destructive to cantaloupes and may also make wilt diseases more
severe. The immature nematodes enter young roots to feed and cause galls
or swellings on the roots. Where the disease is severe, the plants are
stunted, frequently wilt on hot days, and may die prematurely. Root-knot
is more prevalent on sandy soils and more severe during hot, dry weather,
and losses of 20 to 80% are not uncommon. Crop rotations of 2 to 4 years
with non- susceptible corn, oats, and fescue will reduce the nematode
and stem rot (Southern blight), caused by the soil-borne fungus, Sclerotium
rolfsii, causes a watery fruit rot and may also attack the stem. In
advanced stages, brown mustard seed-like reproductive bodies (the sclerotia)
are found in abundance embedded in the white moldy growth on the underside
of the fruits or around the base of the infected stems. The disease is
controlled by burying sclerotia and previous crop trash 10 to 14 inches
deep using moldboard turning plows equipped with concave disk coulters.
Subsequent cultivation should be as shallow as possible. Growing the plants
on plastic or polyethylene-covered beds will greatly reduce the fruit
wilt is caused by the soil-borne fungus Fusarium oxysporum
f. melonis and infected plants wilt and die. The fungus remains
in the soil for 3 or more years, thus long rotations with non-cucurbit
hosts are necessary to reduce soil infestation. The disease is much worse
in fields infested with nematodes; an effective nematode control program
will reduce the severity. Fusarium wilt-resistant varieties should be planted in areas where the disease is a problem.
stem blight, caused by the fungus Didymella bryoniae, affects
the leaves, stems and fruits. On the stem, a gummy substance exudes from
lesions, hence the name. It produces large, dark leafspots with diffuse
borders. In some cases there is considerable leaf margin blighting without
stem lesions. Avoid planting
after cotton, snap beans, okra, or any cucurbit crop. Because the disease
can be seed-borne, only disease-free, treated seed should be planted.
caused by the fungus Colletotrichum lagenarium is a leafspot and
fruit rot disease. During wet weather the leafspots and fruit lesions
develop a salmon-colored substance (spore masses). One or two year rotations with non-cucurbit
crops are useful in reducing the disease. Anthracnose is seed-borne and
only disease-free, and treated seed should be planted.
leafspot, caused by the fungus Alternaria cucumerina, is recognized
by the dark brown leaf spots with concentric rings.
rot of fruit is caused by the bacterium Erwinia carotovora
and related species. They usually enter at the stem end of the fruit and
cause a soft, smelly rot. Soft rots also start where the skin of the fruit
has been broken by accident or by chewing insects. These rots are more
common in warm, wet weather.
Disease Control Program for Cantaloupes
of cantaloupes can be controlled by properly using all disease control
practices described herein. This program will help avoid diseases and
minimize their severity if they do occur. Consult the NC Agricultural Chemicals Manual or your local extension service for recommendations for fungicides and nematode control.
North Carolina Cooperative Extension Service
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of specific chemicals are based upon information on the manufacturer's
label and performance in a limited number of trials. Because environmental
conditions and methods of application by growers may vary widely, performance
of the chemical will not always conform to the safety and pest control
standards indicated by experimental data. All recommendations for pesticide
use were legal at the time of publication, but the status of registration
and use patterns are subject to change by actions of state and federal
Revised Sept. 2007 Tom Creswell