Soil amendments and fumigation for the management of Fusarium wilt of bunching spinach in Ontario, Canada
2021
McDonald, Mary Ruth | Collins, Brian | duToit, Lindsey | Adusei-Fosu, Kwasi
Fusarium wilt, caused by Fusarium oxysporum f. sp. spinaciae, is a significant constraint to the summer production of bunching spinach in Ontario, Canada. Trials were conducted to assess soil amendments (limestone) and fumigants (metam sodium, chloropicrin and dazomet) for the suppression of Fusarium oxysporum f. sp. spinaciae. Dolomitic limestone applied at a rate of 10 and 20 t ha⁻¹ reduced the incidence of fusarium wilt by 10 and 47%, respectively, even though there was little change in soil pH (7.4–7.5) or soil calcium concentration (1598 vs 1483 in 20 t lime vs control, respectively. Fusarium wilt severity was lower in the 2013 than in the 2014 growing season. In 2014, the fumigants metam sodium, chloropicrin and dazomet reduced the population of Fusarium spp. propagules in the soil by 84, 93 and 100%, respectively. Chloropicrin provided the best control of the spinach fusarium wilt pathogen compared to the other fumigants but was only assessed one year. Chloropicrin was the only treatment to truly reduced spinach Fusarium wilt by preventing vascular discolouration. Brassica juncea and calcium cyanamide were not effective at suppressing the disease. A high rate of nitrogen, consisting of polymer coated sulphur coated urea, was applied to provide the same rate of nitrogen as the Brassica juncea and calcium cyanamide treatments. Applying nitrogen in this formulation was as effective as metam sodium in reducing the incidence and severity of Fusarium wilt and should be evaluated further to determine the economics and environmental impact of this approach.
显示更多 [+] 显示较少 [-]