Phytophthora blight on pepper

Disease name: Phytophthora blight on pepper

The scientific name: Phytophthora capsici

Type of disease: fungal

Disease family: Peronosporaceae

(Infection of pepper plants with Phytophthora blight)

• The causes of disease:

Phytophthora blight is caused by the fungal pathogen Phytophthora capsici. The pathogen overwinters in the soil forming oospores of the fungus, survival structures that can persist for more than 10 years.

• Symptoms of the disease:

The fungus shows a wide range of symptoms depending on the specific part of the plant affected and the stage of the crop. Symptoms usually appear first at the soil line in the roots and crown. The fungus is a soil-borne pathogen. The most common symptoms on peppers are crown rot and fruit rot, which becomes Eventually covered with white to cottony mold.

• Disease development cycle:

The fungus spreads quickly through water and can contaminate irrigation ponds and streams, as infection can occur on any part of the plant under the right conditions.

• Conditions suitable for the spread of the disease:

Pepper fruits can become infected when rain falls or by overhead irrigation on infested soil, under humid conditions and warm temperatures of 20 to 30°C.

(White mold on pepper plants due to Phytophthora blight)

• Losses resulting from the spread of the disease:

As the infection progresses, the fungus on the crown turns into dark brown to black spots that extend upward to encircle the trunk. The roots also appear to wilt, causing the plant to die, which leads to significant crop losses.

• Control:

1. Avoid using surface water such as ponds for irrigation as it may be infested.
2. Remove infected pepper fruits or diseased plants and dispose of them away from the field.
3. Drip irrigation application provides protection against fungus and avoids overhead irrigation.
4. Use fungicides such as mefenoxam in irrigation water or spray it to limit the spread of the fungus.

• preventive measures:

1. Cultivation of disease-resistant varieties.
2. Plant in a field that has good drainage and even terrain that does not promote standing water for long periods of time.
3. Sterilize agricultural equipment before and after use to avoid spreading the fungus.
4. Good fertilization helps the plant resist disease.
5. Field monitoring for early detection of the disease.

• Sources:
• https://content.ces.ncsu.edu/phytophthora-blight-of-peppers
• https://plantix.net/ar/library/plant-diseases/100155/blight-of-pepper/