PERFORMANCE OF METHYL BROMIDE ALTERNATIVES FOR STRAWBERRY IN FLORIDA AND SPAIN

Tunnel and open field trials were conducted in two locations in Huelva, Spain, and one in Florida to determine the effect of selected methyl bromide (MBr) alternatives on strawberry yield. In Spain, the tunnel treatments were: a) nontreated control, b) MBr + chloropicrin (Pic) 50:50 at a rate of 400 kg·ha –1 ; c) dazomet at 400 kg·ha –1 , d) 1,3-dichloropropene (1,3-D) + Pic 65:35 at 300 kg·ha –1 ; e) Pic at 300 kg/ha; f) dimethyl disulfide (DMDS) + Pic 50:50 at 250 + 250 kg·ha –1 ; and f) propylene oxide at 550 kg·ha –1 . All treatments were covered with virtually impermeable film (VIF), except the nontreated control, which was covered with low-density polyethylene (LDPE) mulch. Dazomet was rototilled 10 cm deep, whereas the other fumigants were injected with four chisels per bed. In Florida, the open-field treatments were a) nontreated control, b) MBr + Pic 67:33 at a rate of 400 kg/ha with LDPE; c) MBr + Pic 67:33 at 310 kg·ha –1 with VIF; d) 1,3-D + Pic 65:35 at 300 kg·ha –1 with VIF; e) methyl iodide (MI) + Pic 50:50 at 230 kg·ha –1 with VIF; f) Pic at 300 kg·ha –1 with VIF; g) DMDS + Pic 50:50 at 250 + 250 kg·ha –1 with VIF; and g) propylene oxide at 500 kg·ha –1 with VIF. The fumigants were applied with three chisels per bed. In Spain, the results showed that 1,3-D + Pic, DMDS + Pic, and Pic consistently had similar marketable yields as MBr + Pic. Similar results were found in Florida, with the exception of propylene oxide, which also had equal marketable fruit weight as MBr + Pic.