Affiliations: Faculty of Resource and Environment Center, China
Agricultural University, Wuhan 430070, China | Guangdong Key Laboratory of Agricultural Environment
Pollution Integrated Control, Guangdong Institute of Eco-Environment and Soil
Sciences, Guangzhou 510650, China | South China Institute of Botany, Chinese Academy of
Sciences, Guangzhou 510650, China
Abstract: TiO_2 and
l%Ce^{3+}-TiO_2 prepared by hydrothermal
method were characterized by means of XRD and UV-visible diffusive reflectance
spectra (DRS). The results of DRS analysis indicated that the
1%Ce^{3+}-TiO_2 catalyst had significant
optical absorption in the visible region between 400–450 nm because
electrons could be excited from the valence band of TiO_2 or
cerium oxides to Ce 4f level. To investigate the photocatalytic activity of
different catalysts for crop fungal disease control, a series of Quine tests
were carried out for cucumber powdery mildew and litchi downy blight control in
home-made photocatalytic reactor. The results showed that
TiO_2 photocatalysis technique should be effective to
inhibit the growth of fungal diseases to some extent and P-25 had a higher
activity for antifungal control than home-made TiO_2
catalysts. TiO_2-A prepared with
Ti(SO_4)_2 is more active to contro 1
antifungal disease than TiO_2-B prepared with
TiOSO_4 as precursor because the crystalline of
TiO_2-A was higher than that of TiO_2-B.
The antifungal index litchi downy blight control was greatly enhanced by doping
1% cerium ion. The antifungal index of
1.0%Ce^{3+}-TiO_2 was (47.0±4.7)%,
(82.2±3.5)%, (100±0.0)% under indoor weaker light, solar light
and black light, respectively. The results of field experiments showed that the
antifungal index of 1.0%Ce^{3+}-TiO_2 was
more than that of P-25. The antifungal index of
1.0%Ce^{3+}-TiO_2 was (81.7
±6.5)%, (67.5 ±4.7)%, (38.6 ±1.9)% for litchi downy
blight, maize southern leaf spot, and rice blast, respectively. It was
concluded that TiO_2 photocatalysis technique should be an
effective way for litchi fungal disease control in practice.
