Agriculture Reference
In-Depth Information
the control of fungi, nematodes and yellow and purple nutsedge (
Cyperus
) (Chellemi
et al.,
1997; Gamliel
et al.,
2000b).
10.5.2
Combining solarization with organic amendments
(biofumigation)
Combining organic amendments with SH is another integrated approach to improving the
control of soil-borne pests. Heating of soils covered with plastic fi lm and amended with
appropriate organic material actuates a chain reaction of chemical and microbial degrada-
tion, leading to the generation of toxic compounds in the vapor and liquid soil phases.
The plastic mulch traps the volatile compounds and creates an atmosphere in the soil with
a high concentration of volatile compounds. Thus, organic amendments which generate
volatile compounds are especially desirable. Solarization of soil amended with chicken
manure, chicken litter or plant residues was reported to be effective in controlling sev-
eral soil-borne pathogens and with some pathogens, this combination was more effective
than one treatment alone (Ramirez-Villapudua & Munnecke 1988; Gamliel & Stapleton
1993; Gamliel
et al.,
2000a; Stevens
et al.,
2003). The temperature of solarized soil
amended with compost usually increases by 2-3
o
C over that in solarized, non-amended
soil (Gamliel & Stapleton, 1993). This additional rise in temperature may be an important
factor in improving the control of pathogenic organisms such as
M.
incognita
as well as
heat-tolerant organisms. SH reduced inoculum density, viability and incidence of disease
caused by
S. cepivorum
in garlic and increased yield (Ulacio-Osorio
et al.,
2006).
Combining chemical and non-chemical methods of soil disinfestation (including
solarization) improved the spectrum of pest control in tomato and reduced fumigant rate
(Chellemi & Mirusso, 2006). A very detailed long-term study on integrating SH with
chemical, biological and cultural control for the management of soil-borne diseases of
vegetables was carried out by Stevens
et al.
(2003). Combining SH with reduced dosages
of fungicide, a biocontrol agent (
Trichoderma
virens
) or chicken litter much improved
control of diseases such as root knot nematodes and southern blight caused by
S.
rolf-
sii
in tomato and led to increases in yield. Better long-term effectiveness for more than
2 years was also achieved in that study using the integrated approach. It is diffi cult to
control
M. phaseolina
by solarization since the pathogen is thermotolerant. The use of
organic amendments followed by solarization resulted in better control of charcoal rot
and a higher yield increase in cowpeas in the Sahel desert (Ndiaye
et al.,
2007). On the
other hand, solarization may increase the phytotoxicity of herbicides by suppressing their
degradation in the soil (Avidov
et al.,
1985). This has been demonstrated with the combi-
nation of solarization and the herbicide dacthal used with collards (Stevens
et al.,
1990).
The combination of solarization with organic amendments gives effective results, which
under optimal conditions equal those obtained with the use of fumigants. Benlioglu
et al.
(2005) found optimal combination of solarization with chicken manure for the control of
soil-borne diseases and weeds of strawberry in the Western Anatolia region of Turkey.
The effects of SH for 30 days and treatment with goat manure at 0, 20 and 40 t ha
-1
were studied in terms of their impact on weed management and muskmelon yield (Lira-
Saldivar
et al.,
2004). Solarization reduced the emergence and growth of weeds. Goat
manure also had an antagonistic effect on weed density, but this effect was not clear in
solarized plots.
