Effects of innovative films in soil solarization for the control of soil-borne pathogens

The effectiveness of soil solarization during autumn was evaluated in Sicily (36°48’N, 14°36’E) in a multi-span tunnel greenhouse through the survival of two soil-borne pathogens Fusarium oxysporum f. sp. radicis-lycopersici (FORL) and Cylindrocladium pauciramosum. The greenhouse was covered with a 130-μm thick ethlylene vynilacetate film (EVA) and with a 60 μm-tick ethlylene tetrafluoroethlylene film (ETFE). Nylon mesh bags containing carnation leaves and basal tomato stems infested respectively with C. pauciramosum and FORL were buried 15 and 30 cm deep. Soil solarization was performed during a 30-day period using a 30 μm-thick clear EVA film. Under the ETFE cover a plot mulched with a 35 μm-thick green coextruded film was also used. ETFE cover allowed to keep maximum soil temperature over 40 °C at 15 cm depth in the plot mulched with the EVA film for most of the period considered. The green coextruded film though inducing a lower thermal regime than the EVA film allowed to provide a good reduction of viability of pathogens. Inoculum recovery of FORL was strongly decreased in tomato stem buried in the mulched plots inside the greenhouse covered with the ETFE film after 15 days. C. pauciramosum was not recovered from carnation leaves in solarized plots sampled of both greenhouses covered with ETFE and EVA film. In contrast, inoculum recovery of C. pauciramosum ranged from 26.5 to 50.5 % for samples of unsolarized plots. Solarization using ETFE as cover in closed greenhouses also in autumn could provide a good management for several important soil-borne pathogens in eastern Sicily.