Field Guide - Viruses
Mosaic is caused by Potato Virus Y. Primary symptoms of PVY will depend upon potato variety. Symptoms may include mottling or yellowing of leaflets and crinkling of the leaf tissue.
|Potato Leafroll Virus
Potato Leafroll Virus is an aphid vectored virus. Typically the leaves will be rolled with a leathery feel to the touch. When shaken, the leaves will make a sound similar to parchment. The rolled leaves are usually lighter in color than healthy ones. In some varieties, a reddish or purple discoloration occurs on the underside of the leaves.
|Growth Regulator Damage
Herbicide growth regulators such as 2,4D cause irregular growth patterns in potato foliage.