Dimethyl disulfide (DMDS), straight and in combined fumigant applications, to control strawberry soil disease complex in Spain
Dimethyl disulfide (DMDS) was tested during the period 2012-2016, in shank and drip applications in seven trials carried out in the southern coastal area of Spain (Huelva), which is the main producing area of strawberry in Europe. A complete randomized block design was used with three replications (80 m2 replicate-1 and 600 plants replicate-1). Strawberry cultivar 'Florida-Fortuna' was used following local cultivation practices under high-tunnel conditions. The soil was sandy (90%) with low organic matter content (0.5-0.75%) and pH ranging from 6.7-7.1. The soil disease complex of strawberry in the area is associated with the presence of several fungi, oomycetes and nematodes, i.e., Macrophomina phaseolina, Phytophthora cactorum, Fusarium spp., Pratylenchus penetrans, Meloidogyne hapla, etc. The following fumigant solutions (straight and combined applications) were used in at least two consecutive seasons representing a minimum three trials: dazomet broadcast application (20 g m-2) + DMDS in shank during bed formation (30 g m-2), dazomet broadcast application (25 g m-2) + DMDS in shank during bed formation (30 g m-2), DMDS (30 g m-2) + metam sodium (38.3 g m-2) both applied by drip, DMDS in shank application (60 g m-2), 1,3-dichloropropene + chloropicrin (40 g m-2) shank, 1,3-dichloropropene + chloropicrin (40 g m-2) drip, and untreated control. Soil fumigations were conducted every year in August and plantings in October. Field evaluations (plant vigor, yield, symptomatic plants) and lab tests (pathogen identification before and after the fumigation, and nematode counting), were carried out in each trial. All fumigant application performed significantly better than the untreated control (average yield of seven trials was 54.1 MT ha-1). Among fumigants, the best performance was shown by the combination dazomet (20 g m-2) + DMDS (30 g m-2) with 78.8 MT ha-1 (average of two years). DMDS straight at 60 g m-2 achieved 66.6 vs. 53.3 MT ha-1 obtained with untreated control in the same conditions. In all cases, DMDS solutions were comparable to 1,3-dichloropropene + chloropicrin in shank and drip applications used as market standard. Therefore, DMDS, once registered, will be a new effective solution to control nematodes and soil fungi in strawberry production in the EU.
Zanon, M.J., de los Santos, B., Talavera, M., Miranda, L. and Myrta, A. (2020). Dimethyl disulfide (DMDS), straight and in combined fumigant applications, to control strawberry soil disease complex in Spain. Acta Hortic. 1270, 243-248
nematodes, Paladin/Accolade, soil fumigants, soil fungi