Monosporascus Root Rot/Vine Decline

Causal Agent: (fungus ‑ Monosporascus cannonballus)

Infected plants usually do not develop symptoms until near harvest time.  Infected plants wilt [wmd8.jpg] and eventually die.  Sometimes, there is vascular browning [wmd9.jpg].  Brown lesions may be found on the roots [wmd10.jpg], even on plants that are not wilting. Root lesions may be caused by other soilborne fungi, such as Pythium sp. and Rhizoctonia solani [wmd52.jpg]. This disease is primarily a problem on silt or clay soils of the Lower Rio Grande Valley.  The fungus is indigenous to the soil and populations build up with continued cucurbit monoculture, particularly cantaloupe. Soil fumigation is an effective control, but is not usually economical.  Soils with consistent problems should not be planted to cucurbits.