The Durham Council of Garden Clubs was founded in 1929 in federation with the National Garden Club and The Garden Club of North Carolina, Inc.
The Council served more than eight decades as the umbrella group for garden clubs and junior garden clubs in Durham, NC. Today, Durham Garden Clubs continue the same mission of philanthropic projects of preservation, conservation, education and beautification under District 9 of the Garden Clubs of NC.
Wednesday, July 3, 2013
Late blight of Tomato: humid and wet weather perfect conditions!
By Kelly Ivors, Extension Plant Pathologist
Pathogen: Late blight of tomato is caused by the fungus-like organism Phytophthora
infestans.The pathogen is best known
for causing the devastating Irish potato famine of the1840's, which killed over a million people,
and caused another million to leave the country.
Host crops and plants: Besides tomatoes,P.
infestans can only infect a few other closely related plants including potato,
petunia and related solanaceous weeds such as hairy nightshade.
Host parts affected: All above-ground portions of the plant.
Symptoms of late blight: The first symptoms of late blight on tomato leavesare irregularly shaped, water-soaked lesions,
often with a lighter halo or ring around them; these lesionsare typically found on the younger, more
succulent leaves in the top portion of the plant canopy. During high humidity,
white cottony growth may be visible on underside of the leaf. Spots are visible
on both sides of the leaves. As the disease progresses, lesions enlarge causing
leaves to brown, shrivel and die (Figure 3). Late blight can also attack tomato
fruit in all stages of development. Rotted fruit are typically firm with greasy
spots that eventually become leathery and chocolate brown in color; these spots
can enlarge to the point of encompassing the entire fruit.