Soil solarization effects

Numerous and complex mechanisms are reported in literature for soil solarization effects, involving also the combination of several interrelated processes (Katan 1987 Stapleton and DeVay 1995 Stapleton 1997), but main effects of solarization treatments were found related essentially to the thermal action of solarization and the consequent chemical and biological changes occurring in the soil. 

Since the first demonstration of soil solarization effectiveness against phytonematodes (Katan et al. 1976), nematicidal effects of solar heating were largely investigated on many genera of plant-parasitic nematodes. 

Pullman GS, DeVay JE, Garber RH, Weinhold AR (1981b) Soil solarization Effects on Verticillium wilt of cotton and soilbome populations of Verticillium dahliae, Pythium spp., Rhizoctonia solani, and Thielaviopsis basicola. Phytopathology 71 954-959 Rabinowitch HD, Katan J, Ben David B, Rotem L, Zig U (1985) Soil solarization in onion effects in successive years. Hassadeh 65 1792... 

Field soil solarization was effective in dramatically reducing or completely eliminating the infection of Pythium spp. in carrot (Daucus carota L.) and strawberry roots (Becker and Wrona 1995 Pinkerton et al. 2002), as well as reduced inoculum levels of P. aphanidermatum in watermelon and potato down to 25-30 cm soil depth (Mansoori and Jaliani 1996 Triki et al. 2001). Summer soil solarization in greenhouse reduced Pythium root rot even in the temperate climate of Denmark (Christensen and Thinggaard 1999). 

Fate of plant viruses after a soil solarization treatment was almost completely ignored by researchers, as only one study documented a stabilizing effect of heat treatment on tobacco mosaic virus degradation in a sandy loam soil (Triolo and Materazzi 1992). 

Fig. 9.4 Effect of soil solarization on root galling in tomato plants in soil infested by the root-knot nematode Meloidogyne incognita in plastic greenhouse in Sothem Italy. On the left a tomato root from solarized soil, on the right a root from nonsolarized soil, deformed by large galls...

Fig. 9.5 Effects of soil solarization in field on weed infestation in an experiment in Southern Italy. On the left melon plants free of weeds in solarized soil on the right the heavy weed infestation in nonsolarized soil...

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