Defense Against Blackline

摘要

California researchers attempt to determine if English rootstocks can help reduce blackline in walnuts. SAN Joaquin County, CA, has a high incidence of walnut blackline disease, caused by cherry leaf roll virus. Trees on black walnut and Paradox rootstock are susceptible to black-line, but trees on English rootstock are not. Seedlings of Eureka and a few other varieties have been available as rootstocks for many years, but no thorough study of their performance has ever been done.