#Plant blight code

Many clonal lineages affect both tomato and potato, but some lineages are specific to one host or the other.

#Plant blight code

These are called clonal lineages and designated by a number code (i.e. There are many different strains of P.These sporangia easily become air-borne, resulting in prolific spread of the pathogen. infestans can infect and produce thousands of sporangia per lesion in less than five days. Overwintering in a tomato production system is unlikely but infected tomato fruits may give rise to infected volunteer seedlings the following season. infestans can overwinter in Minnesota if protected in potato cull piles.

The most common routes of introduction each season are infected potato seed tubers, infected tomato transplants shipped in from other regions, or windblown sporangia (asexual spores) from the south that then infect fields and circulate locally.

Late blight doesn’t appear in Minnesota every year.

Prolonged hot dry days can halt pathogen spread.

Late blight favors cool (60☏ to 70☏), damp conditions.

Late blight ( Phytophthora infestans) is a water mold.

Infected potato tubers become discolored (anywhere from brown to red to purple), and infected by secondary soft rot bacteria.

In high humidity, thin powdery white fungal growth appears on infected leaves, tomato fruit and stems.

Spots may become mushy as secondary bacteria invade.

In tomatoes, firm, dark brown, circular spots grow to cover large parts of fruits.In cool, wet weather, entire fields turn brown and wilted as if hit by frost.Stem infections are firm and dark brown with a rounded edge.Infections progress through leaflets and petioles, resulting in large sections of dry brown foliage.Leaves have large, dark brown blotches with a green gray edge not confined by major leaf veins.Late blight infects leaves, stems and fruit