STRATEGIES FOR MANAGING FUSARIUM CROWN AND ROOT ROT ON ASPARAGUS
Fusarium oxysporum f. sp. asparagi is a common pathogen on asparagus (Asparagus officinalis) and has been associated with asparagus decline. In many areas, the amount of virgin asparagus land is limited, leading to high numbers of replanted fields. Many of the replanted fields have a shortened production life. The objective of this study was to determine whether fungicides applied pre-plant or via drip irrigation during the growing season limit crown and root rot. In 2001, fungicides were applied as a crown dip or as in-furrow applications at planting and included the following: 1) untreated, 2) thiophanate-methyl, 3) benomyl, 4) Trichoderma harzianum, 5) arbuscular mycorrhizae (AM), 6) nonpathogenic F. oxysporum, and 7) fludioxonil (low and high rate). Significant differences (P<0.01) among treatments were observed for plant stand but not fern height (P<0.25). Thiophanate-methyl resulted in the densest plant stand followed by T. harzianum. In 2003, five treatments were investigated: 1) thiophanate-methyl, 2) fludioxonil, 3) nonpathogenic F. oxysporum, 4) T. harzianum, and 5) AM. Each treated plot was paired with an untreated control. Significant differences (P<0.73) in fern height or plant stand were not observed, but trends were noted. While application of fungicides via drip irrigation is promising as a means to transport treatments to the crowns, no significant differences were observed among treatments. A trend was observed whereby applications of nonpathogenic F. oxysporum and T. harzianum resulted in taller plants and higher stand counts when compared to the untreated control. Symptoms of Phytophthora megasperma were observed in 2004 following excessive rainfall.
Counts, J.W. and Hausbeck, M.K. (2008). STRATEGIES FOR MANAGING FUSARIUM CROWN AND ROOT ROT ON ASPARAGUS. Acta Hortic. 776, 167-174
Asparagus officinalis, Fusarium oxysporum f. sp. asparagi, biological and chemical control, irrigation