Enjoy idMicrobe TOTALLY FREE, with no trial periods.

Late Blight

Phytophthora Infestans

Pathogen:

Oomycete

Type:

Risk:

CRITICAL

DESCRIPTION

Pathogen description

Phytophthora infestans is an oomycete, often called water mold, that causes the disease known as late blight in potato crops. This pathogen reproduces through spores that are dispersed through the air and water, infecting potato plants in conditions of high humidity and moderate temperatures. During its life cycle, Phytophthora infestans can produce asexual spores (sporangia) that spread rapidly and cause infection in nearby crops.

Disease description

Late blight produces symptoms on potato leaves, stems and tubers. The leaves develop dark, moist Taches, which may be surrounded by a whitish halo. In the stems, the infection can cause necrosis and weakening of the plant. Infected tubers show dark, sunken lesions on the skin, which can extend to the pulp, causing rot.

• Dark, wet Taches on the leaves, surrounded by a whitish halo.
• Necrosis in the stems and weakening of the plant.
• Dark, sunken lesions on the tubers.
• Rotting of infected tubers.

TEMPERATURE AND HUMIDITY

15°C - 20°C

90% - 100%

VOIES DE TRANSMISSION

Spores transported by air, water, direct contact with infected plants or tubers.

Chemical treatments

CONTROL

• POTASSIUM PHOSPHONATES 25.5% (Exp. as phosphorous acid) + AZOXYSTROBIN 6.25% [SC] P/V
• POTASSIUM PHOSPHONATES 51% (Exp. as phosphorous acid) [SL] P/V
• CUPRIC HYDROXIDE 50% (EXPR. IN CU) [WP] P/P
• METALAXIL 25% [WP] P/P
• COPPER OXYCHLORIDE (Exp. in Cu) 52% [SC] P/V
• COPPER OXYCHLORIDE 25% (EXPR. IN CU) [WG] P/P
• COPPER OXYCHLORIDE 30% (EXPR. IN CU) [WP] P/P
• COPPER OXYCHLORIDE 35% (exp. in Cu) [WG] P/P
• COPPER OXYCHLORIDE 38% (EXPR. IN CU) [SC] P/V
• COPPER OXYCHLORIDE 50% (EXPR. IN CU) [WG] P/P
• COPPER OXYCHLORIDE 52% (EXPR. IN CU) [SC] P/V
• CUPROCALCIC SULFATE 12.4% (EXPR. IN CU) [SC] P/V
• CUPROCALCIC SULFATE 20% (EXPR. IN CU) [WG] P/P

Treatments authorized in organic farming

• POTASSIUM PHOSPHONATES 25.5% (Exp. as phosphorous acid) + AZOXYSTROBIN 6.25% [SC] P/V
• POTASSIUM PHOSPHONATES 51% (Exp. as phosphorous acid) [SL] P/V
• CUPRIC HYDROXIDE 50% (EXPR. IN CU) [WP] P/P
• COPPER OXYCHLORIDE (Exp. in Cu) 52% [SC] P/V
• COPPER OXYCHLORIDE 25% (EXPR. IN CU) [WG] P/P
• COPPER OXYCHLORIDE 30% (EXPR. IN CU) [WP] P/P
• COPPER OXYCHLORIDE 35% (exp. in Cu) [WG] P/P
• COPPER OXYCHLORIDE 38% (EXPR. IN CU) [SC] P/V
• COPPER OXYCHLORIDE 50% (EXPR. IN CU) [WG] P/P
• COPPER OXYCHLORIDE 52% (EXPR. IN CU) [SC] P/V
• CUPROCALCIC SULFATE 12.4% (EXPR. IN CU) [SC] P/V
• CUPROCALCIC SULFATE 20% (EXPR. IN CU) [WG] P/P

Biological control

• BACILLUS AMYLOLIQUEFACIENS subsp. plantarum (strain D747) 5% [SC] P/V

Preventive treatments

• BACILLUS AMYLOLIQUEFACIENS subsp. plantarum (strain D747) 5% [SC] P/V
• POTASSIUM PHOSPHONATES 25.5% (Exp. as phosphorous acid) + AZOXYSTROBIN 6.25% [SC] P/V
• POTASSIUM PHOSPHONATES 51% (Exp. as phosphorous acid) [SL] P/V
• CUPRIC HYDROXIDE 50% (EXPR. IN CU) [WP] P/P
• METALAXIL 25% [WP] P/P
• COPPER OXYCHLORIDE (Exp. in Cu) 52% [SC] P/V
• COPPER OXYCHLORIDE 25% (EXPR. IN CU) [WG] P/P
• COPPER OXYCHLORIDE 30% (EXPR. IN CU) [WP] P/P
• COPPER OXYCHLORIDE 35% (exp. in Cu) [WG] P/P
• COPPER OXYCHLORIDE 38% (EXPR. IN CU) [SC] P/V
• COPPER OXYCHLORIDE 50% (EXPR. IN CU) [WG] P/P
• COPPER OXYCHLORIDE 52% (EXPR. IN CU) [SC] P/V
• CUPROCALCIC SULFATE 12.4% (EXPR. IN CU) [SC] P/V
• CUPROCALCIC SULFATE 20% (EXPR. IN CU) [WG] P/Pç

• Use potato varieties resistant to Phytophthora infestans.
• Apply specific fungicide treatments before and during risk periods.
• Improve field ventilation and drainage to reduce humidity.
• Avoid overhead irrigation, which can spread spores.
• Practice crop rotation to reduce the accumulation of spores in the soil.
• Regularly monitor crops for early signs of the disease.

Recommendations

Would you like to add this disease to your field notebook?

*The recommended treatments are recommendations based on the authorities' databases and do not replace in any way the guidelines established by the legislation of each country.