Alfalfa Stem Nematode

	Healthy plant (left), infected plant (right). Notice the stunted stems and leaves on the infected plant as compared to the healthy plant.

Bacterial Wilt

	Plants infected with the bacterial wilt pathogen Clavibacter insidiosum have a chlorotic appearance as illustrated in this image.
	Image of the inner bark of an alfalfa plant infected with bacterial wilt. The discolored portions are caused by pockets of bacteria called gum pockets.
	Discolored tap root characteristic of bacterial wilt. The "slimy" appearance of the tap root is due to gumming produced by Clavibacter insidiosum.

Phytophthora Root Rot

	Alfalfa root infected with Phytophthora root rot. Arrow indicates advancing canker caused by this disease.
	Alfalfa plant infected with Phytophthora root rot. Root tips are the first plant portion to become infected. The infection will then move up the tap root causing wilt symptoms in the arial portion of the plant. Arrow indicates the advancing canker tissue.

	Alfalfa plant infected with Downy Mildew, showing classic pale appearance of new tissues and twisting of leaflets.
	Leaflets with symptoms of a Downy Mildew infection.

Root Knot Nematode

Alfalfa root infected with Root Knot Nematode. Roots infected with this nematode will have small galls on them.