Submitted to: HortTechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 14, 2005
Publication Date: N/A
Interpretive Summary: With the impending phase-out of methyl bromide for soil fumigation, flower growers will require alternative methods to control weeds and diseases for continuous production. Fumigants such as Midas ™ InLine ™, Vapam HL ™ and Multiguard ™ are possible alternatives to methyl bromide. These fumigants can be delivered in drip irrigation systems, permitting better distribution through the soil by the irrigation water. Three trials on 2 sites were conducted to test the efficacy of the afore mentioned fumigants for the control of weeds and disease for the production of the cut flower, Freesia. It was found that Midas preformed as well as a combination treatment of methyl bromide and chloropicrin. InLine preformed as well as Midas, but Multiguard required the addition of Vapam HL to perform as well as Midas and InLine. The study shows that Freesia can be produced following fumigation with Midas, Inline, or Multiguard plus Vapam HL.
Technical Abstract: Field trials were conducted to test fumigants as alternatives to methyl bromide (MB) for production of hybrid freesia (Freesia x hybrida). One trial compared rates of 1,3-dichloropropene (DP) combined with chloropicrin (CP); the second trial compared iodomethane (IM) together with CP, DP:CP, and furfural with and without metham sodium; and the third trial compared rates and formulations of IM:CP to the standard MB:CP treatments. Most treatments reduced populations of Pythium spp. and controlled weeds compared to the untreated controls. Formulations of IM:CP reduced the incidence of disease caused by Fusarium oxysporum. Treatments of IM:CP performed as well as MB:CP, and treatments of DP:CP performed as well as IM:CP. Presently only the DP, CP and metham sodium formulations are registered for use on ornamental crops. Registration of the IM formulations will improve the options available to cut flower growers for management of plant pathogens and weeds.