Effects of Sodium Chloride on Commercial Asparagus and of Alternative Forms of Chloride Salt on Fusarium Crown and Root Rot.

Experiments with applications of NaCl (560 and 1,120 kg/ha) and lime (6,719 kg/ha) were conducted in asparagus fields in commercial production (one healthy and one exhibiting symptoms of early decline), and an experiment with NaCl (1,120 kg/ha) was conducted in a badly declined research field at Michigan State University from 1998 to 2000 to determine whether these treatments control Fusarium crown and root rot of asparagus. Growth chamber and greenhouse studies were conducted to test the ability of alternative forms (CaCl₂, NH₄Cl, and MnCl₂) of chloride salt to reduce disease caused by F. oxysporum f. sp. asparagi and F. proliferatum. NaCl applications increased yield and fern health in the research plot, but not in commercial fields. Soil tests in these fields indicated that NaCl did not decrease levels of calcium, magnesium, or potassium, and did not affect pH. In growth chamber studies with asparagus seedlings in Hoagland's agar test tubes, and in greenhouse studies with asparagus seedlings in soil, none of the alternative forms of chloride salt tested were more effective than NaCl in controlling Fusarium crown and root rot.