transformation, water depletion, soil depletion, metal depletion, carcinogens and
non-carcinogens, water footprint, ecological footprint, greenhouse gases emission,
cumulative energy demand, and global warming, were measured as life cycle
assessment. Briefly, some parameters, particularly the level of energy consumption
and greenhouse gas emission, the non-transgenic rice affected the ecosystem
adversely two times more than the transgenic rice. Since, in the Bt rice fields no
chemical insecticides were used, the ecological impact of chemical application had
to be taken into consideration. Moreover, the emission of heavy metals in air, water
and soil in transgenic cultivars was less than in non-transgenic lines. Therefore, due
to the lower consumption of agricultural machinery and management practices in the
Bt rice fields, fewer pollutants were emitted into the environment (Dastan et al.
2019).
10.14 Implementation of Bt in IPM Programs
To increase the activity spectrum of a microbial insecticide, effective management of
insect pests, application of lower numbers of microbial agents, and more importantly, overcoming or at least delaying the emergence of resistance, integration of
microbial insecticides with other means of insect pests management have been
suggested. Therefore, many studies focused on the compatibility of Bt formulation
with other control practices. Indeed, the interaction and the possible combination of
Bt toxins with other insect pathogens (Marzban et al. 2009; Marzban 2012b;
Magholli et al. 2013; Kalantari et al. 2014; Allahyari et al. 2019), parasitoids
(Sedaratian et al. 2014; Alsaedi et al. 2017; Allahyari et al. 2019), other
bio-insecticides such as Azadirachtin and Spinosad (Abedi et al. 2014; Nazarpour
et al. 2014; Hosseinizadeh and Aramideh 2014; Nouri-Ghnbalani et al. 2016), and
also plant extracts or essential oils (Ghassemi-Kahrizeh et al. 2014), have been
studied. Based on the findings, the combination of Bt with biological control agents,
bio-insecticides and plant materials may increase the efficiency of the insect pest
management.
Due to the emergence of resistance in P. xylostella to several chemical insecticides (Sarfraz et al. 2005) and also in some cases to Bt (Tabashnik et al. 1990), the
application of two different microbial control agents might improve the efficiency of
P. xylostella management. Therefore, the feasibility of using B. thuringiensis subsp.
kurstaki in combination with H. armigera single polyhedrosis virus, HaSNPV, under
laboratory conditions was investigated (Magholli et al. 2013). A synergistic effect
was observed when the lowest concentrations of Bt (2.4 Â 10
1 spores/ml) and
HaSNPV (2.3 Â 10
3 OB/ml) were used together. Moreover, the biological parameters of P. xylostella were negatively affected due to the simultaneous application of
Bt and a baculovirus (Magholli et al. 2013). Further experiments are needed to show
the applicability of this combination in the field.
The simultaneous application of Bt strain and nucleopolyhedrovirus (NPV) in
integrated pest management programs of cotton bollworm, H. armigera, was
426
A. Khorramnejad et al.
non-carcinogens, water footprint, ecological footprint, greenhouse gases emission,
cumulative energy demand, and global warming, were measured as life cycle
assessment. Briefly, some parameters, particularly the level of energy consumption
and greenhouse gas emission, the non-transgenic rice affected the ecosystem
adversely two times more than the transgenic rice. Since, in the Bt rice fields no
chemical insecticides were used, the ecological impact of chemical application had
to be taken into consideration. Moreover, the emission of heavy metals in air, water
and soil in transgenic cultivars was less than in non-transgenic lines. Therefore, due
to the lower consumption of agricultural machinery and management practices in the
Bt rice fields, fewer pollutants were emitted into the environment (Dastan et al.
2019).
10.14 Implementation of Bt in IPM Programs
To increase the activity spectrum of a microbial insecticide, effective management of
insect pests, application of lower numbers of microbial agents, and more importantly, overcoming or at least delaying the emergence of resistance, integration of
microbial insecticides with other means of insect pests management have been
suggested. Therefore, many studies focused on the compatibility of Bt formulation
with other control practices. Indeed, the interaction and the possible combination of
Bt toxins with other insect pathogens (Marzban et al. 2009; Marzban 2012b;
Magholli et al. 2013; Kalantari et al. 2014; Allahyari et al. 2019), parasitoids
(Sedaratian et al. 2014; Alsaedi et al. 2017; Allahyari et al. 2019), other
bio-insecticides such as Azadirachtin and Spinosad (Abedi et al. 2014; Nazarpour
et al. 2014; Hosseinizadeh and Aramideh 2014; Nouri-Ghnbalani et al. 2016), and
also plant extracts or essential oils (Ghassemi-Kahrizeh et al. 2014), have been
studied. Based on the findings, the combination of Bt with biological control agents,
bio-insecticides and plant materials may increase the efficiency of the insect pest
management.
Due to the emergence of resistance in P. xylostella to several chemical insecticides (Sarfraz et al. 2005) and also in some cases to Bt (Tabashnik et al. 1990), the
application of two different microbial control agents might improve the efficiency of
P. xylostella management. Therefore, the feasibility of using B. thuringiensis subsp.
kurstaki in combination with H. armigera single polyhedrosis virus, HaSNPV, under
laboratory conditions was investigated (Magholli et al. 2013). A synergistic effect
was observed when the lowest concentrations of Bt (2.4 Â 10
1 spores/ml) and
HaSNPV (2.3 Â 10
3 OB/ml) were used together. Moreover, the biological parameters of P. xylostella were negatively affected due to the simultaneous application of
Bt and a baculovirus (Magholli et al. 2013). Further experiments are needed to show
the applicability of this combination in the field.
The simultaneous application of Bt strain and nucleopolyhedrovirus (NPV) in
integrated pest management programs of cotton bollworm, H. armigera, was
426
A. Khorramnejad et al.