Nematodes—parasitic in and on the roots of grapevines—probably represent one of the most important factors in the premature decline of vineyards in California.

The above progress report is based on Research Project No. 1354.

University of California Farm Advisors F. Gordon Mitchell, San Joaquin County; Verner Carlson, Merced County; Paul Baranek, Madera County; A. Kasimatis, Kern County, assisted in the studies reported in the above article.

L. A. Lider, Assistant Professor of Viticulture, University of California, Davis, has cooperated in rating the vines and evaluating their growth.