These photos of some of the major pests are accessed from the UC ANR Repository, are available courtesy of University of California research and extension personnel and programs, including the UC Statewide IPM Program.

Potassium Deficiency in Walnut.	Foliage damage caused by zinc deficiency.	Potassium Deficiency in Walnut.
Photo by JKClark. UC IPM Project, ©UC Regents	Photo by JKClark. UC IPM Project, ©UC Regents	Photo by JKClark. UC IPM Project, ©UC Regents
Walnut Boron Toxicity.
Photo by JKClark. UC IPM Project, ©UC Regents