Time for a second post on plant diseases that I’ve encountered while in Tanzania. All the diseases in this post are caused by obligate pathogens. Obligate plant pathogens are pathogens that can only grow in a living plant host. Unlike many bacteria and fungi, obligate plant pathogens cannot be grown in petri dishes or flasks in the lab.
Viruses in maize
Purslane white rust (pathogen: possibly Wilsoniana portulacae)
A strange looking rust on a weed
A rust on a native grass
Sunflower powdery mildew (pathogen: Erysiphe cichoracearum)
Tomato powdery mildew
Powdery mildew on a Euphorbia (pathogen: Podosphaera euphorbiae)
Root knot nematodes on tomato (pathogen: Meloidogyne sp.)
Striga (with red flowers) is an parasitic plant that gets nutrients by tapping into roots of nearby plants
You can’t make it through a post on obligate plant pathogens without any downy mildews! We saw some downy mildew on cucurbits here, but I don’t have a picture. To make up for that, here’s my favorite picture of quinoa downy mildew (Peronospora variabilis)!
Flashback from a trip to Bolivia
These are great Anna! I am sharing and tweeting to expand the reach of your blog – Horticulture CRSP, OSU Office of Research office and others noticing . . .