
Micosis/Hongos
Spot By Phaeosphaeria
Phaeosphaeria Maydis / Phoma Maydis
Pathogen:
Fungus
Type:
Risk to the plant:
INTERMEDIATE



DESCRIPTION
WHO CAUSES IT?
Phaeosphaeria maydis is an ascomycete fungus that affects corn, causing the disease known as Phaeosphaeria spot. This pathogen spreads mainly through ascospores released from perithecia, fruiting structures formed in infected plant residues. Ascospores are transported by wind and rain to healthy plants, where they germinate and penetrate plant tissues through stomata or wounds. Under favorable conditions of humidity and temperature, the fungus develops a mycelium that spreads through the intercellular spaces, causing the decomposition of the leaf tissue. Phaeosphaeria maydis can survive on crop debris in the soil, allowing its persistence over successive growing seasons.
SYMPTOMS
The disease known as Phaeosphaeria spot mainly affects the leaves of corn, reducing their photosynthetic capacity and weakening the plant. Initially, small chlorotic Taches are observed that evolve into necrotic lesions with a dark center and yellow edges. As the infection progresses, the Taches can coalesce, forming large areas of dead tissue, causing premature defoliation.
- Small chlorotic Taches on the leaves.
- Necrotic lesions with dark centers and yellow edges.
- Coalescence of Taches, forming large necrotic areas.
- Premature defoliation of severely affected leaves.
- Reduction of photosynthesis and plant vigor.
- Presence of sporulation in the lesions under conditions of high humidity.



TEMPERATURE AND HUMIDITY
20-30°C
80-90%

HOW IS IT SPREAD?
Wind, rainwater, infected crop remains, agricultural tools, infected seeds

HOW TO REMOVE IT?
Home remedies
There are no home treatments
Chemical treatments
• AZOXISTROBIN 25% [SC] P/V
• SULFUR 80% [SC] P/V
• SULFUR 80% [WG] P/P
• SULFUR 80% [WP] P/P
• SULFUR 82.5% [SC] P/V
Authorized treatments in organic farming
• SULFUR 80% [SC] P/V
• SULFUR 80% [WG] P/P
• SULFUR 80% [WP] P/P
• SULFUR 82.5% [SC] P/V
Insect allies
PREDATORY MITES
LADYBUGS
LACEWINGS
PARASITIC WASPS
HOVERFLIES OR PARASITIC FLIES
PREDATORY BUGS
There are no natural allies
Mycodiplosis oidii (predatory mosquito)


