Martinez M.A.,Technical University of Cartagena |
Martinez M.C.,IMIDA Mayor S n |
Torres J.,IMIDA Mayor S n |
Ros C.,IMIDA Mayor S n |
And 2 more authors.
Acta Horticulturae | Year: 2010
In Southeast Spain about 2,000 ha of pepper crops are grown as a monoculture under greenhouse conditions. Soils have been usually disinfested with methyl bromide (MB) for over 25 years until its banning in 2005. There were two main reasons that justified the use of MB in this area: the reduction of the incidence of soil-borne pathogens (Phytophthora capsici and Meloidogyne incognita) and the effect of "soil fatigue". There are signs of a strong microbiological component in the soil fatigue effect. Assays were performed in greenhouses where different alternatives to MB were studied: the combination of 1,3-dicholoropropene +chloropicrin (1,3-D+Pic) and propylene oxide. Both fumigants were compared with MB. Disinfestation effects were measured through the soil fungal density isolated before and after fumigation, only in one greenhouse, with two types of analyses to determine the total fungal density as well as the Fusarium spp. density. In addition, soil samplings were made during the growing season in two greenhouses to complete our knowledge of fumigant effects. Results showed that 1,3-D+Pic at 50 g*m -2 was the only fumigant able to reduce significantly the total fungal density (from 8,470 CFU-g -1 dry soil before soil fumigation to 2,500 CFU*g -1 dry soil after soil fumigation) while both MB (from 9,000 CFUg -1 to 12,730 CFUg -1) and propylene oxide at 600 Lha-1 (from 13,700 CFUg -1 to 14,770 CFUg -1) were not able to do. In relation-1 to the total Fusar-i1um spp. density, MB did not reduce it eithe-1r (from 394.30 CFUg -1 to 318.63 CFUg -1) although 1,3-D+Pic (from 111.69 CFUg -1 to 1.80 CFU g -1) and propylene oxide (from 983.61 CFUg -1 to 16.21 CFUg -1) did.