**7.1 Fruits results**

*Organic Agriculture*

**Figure 10.**

control (TA) treatments.

of 57 strains of the genus *Bacillus* spp. isolated from the rhizosphere of commercial sowing chile plants in Northeast Mexico was analyzed, which showed an apparent antagonistic effect against *P. capsici*, *F. oxysporum*, and *R. solani* fungi. The plants inoculated with *Bacillus* spp. strains significantly increased height and dry weight in 191 and 60.2%, respectively [12]. The application of native *Bacillus* spp. strains shows a clear tendency to produce more biomass compared to chemical (T) and

*Root length (A), dry rot weight (B), height (C), fresh fruit weight (D), and increments in chile pepper plant by effect* Bacillus *strains (B1, B3, B13) against chemical (T = thiabendazole) and control (TA). Different* 

*letters with bars indicate significant differences among treatments (p* ≤ *0.05)*.

Likewise, del Ángel et al. [45] found a decrease in the incidence and severity of the disease caused by *Rhizoctonia solani* and *Fusarium oxysporum* with formulated endophytic bacteria, which induce a positive effect on the promotion of growth in the bean crop, increasing height and stem diameter in the treatments. Those formulated with bacteria in the absence of the phytopathogen stood out for their stimulating effect on the growth of the plants under study. This stimulating growth effect is observed in

*Effect of endophytic bacteria on plant height and stem diameter in bean crop under greenhouse condition.*  Fusarium solani*: height (A), diameter (B), and* Rhizoctonia solani*: height (C), diameter (D). Means with the same letter are not significantly different according to the Tukey test (p* ≤ *0.05). Error bars are a standard* 

**108**

**Figure 11.**

*error of the mean.*

Jimenez et al. [36] report results obtained on apple fruit and trees under the direct influence of the application of CFU from *Bacillus* spp., and *Trichoderma* spp., as control agents against the incidence and severity of *Venturia inaequalis* under field conditions in commercial apple cultivar. **Table 4** shows the incidence of fungus *Venturia inaequalis* in fruit, and this incidence varied from 5.6 to 6.25 when biological agents (*Trichoderma* spp. and *Bacillus* spp.) were used in maxima doses (2 L ha<sup>−</sup><sup>1</sup> ) to 19.3% for the control, respectively, after 15 days of a first application. After 60 days from the start of the applications, the incidence is expressed in a range of 42.5– 46.62% for *Bacillus* spp. and *Trichoderma* spp. at doses of 2 L ha<sup>−</sup><sup>1</sup> and for the control observed a 91.2%. The range of severity is observed between 1.8 and 2.6 of lesions per fruit by treatment *Trichoderma* spp. 2 L ha<sup>−</sup><sup>1</sup> and control, respectively, after 15 days of application initiation. After 60 days of treatment application appears first symptoms, so it was evaluated on a range of the number of lesions per fruit (severity) from 5.3 to 14.5 corresponding to *Bacillus* spp., 2 L ha−1, and control, respectively (**Table 4**). The treatment with the best antagonism effect under field conditions was *Bacillus* spp., 2 L ha<sup>−</sup><sup>1</sup> , who expressed 42.5% by incidence and five lesions per fruit in contrast to the control, which showed 91.2% incidence and 14.5 lesions per fruit (**Figure 12**).

The field experiment is carried out to test biocontrol agents for control *V. inaequalis* in commercial apple cultivar; the statistical analysis showed highly significant differences between treatments (p ≤ 0.5), the incidence in foliage treated with *Trichoderma* spp. 2 L ha<sup>−</sup><sup>1</sup> was lower in first evaluation (after 15 days of first application) and until harvest. This treatment expressed 10.6% incidence and two lesions per leaf, in contrast to the control which showed 31.8% and three lesions per leaf (**Table 5**). On the other hand, severity did not show significant differences among treatments.

## **7.2 Vegetable results**

Espinoza-Ahumada et al. [40] aimed to find more environmentally friendly alternatives to the wilting of chile pepper; they evaluated the application of


#### **Table 4.**

*The incidence in apple fruits by* Venturia inaequalis.

#### **Figure 12.**

*Expression of symptoms caused by* Venturia inaequalis *in apple trees. (a) Without treatment, (b)* Bacillus *spp. effect, and (c)* Trichoderma *spp. effect.*


#### **Table 5.**

*The incidence in apple leaves by* Venturia inaequalis.

biological agents for this purpose under field conditions. For this, an experiment is established where different genotypes of chile pepper are evaluated (Serrano, HS-52, Coloso, HS-44, Centauro, Paraíso and Tampiqueño 74 cv.) generated by INIFAP-Mexico. In this experiment, the microbial agents *T. asperellum*, *T. harzianum*, *T. yunnanense* [23, 29], *B. amyloliquefaciens*, *B. licheniformis*, and *B. subtilis* [24] under a mixture of microbial propagative ferment (consortium ferment) are based on *Trichoderma* spp. and *Bacillus* spp. Treatments of bioassay by *Trichoderma* spp. were different: consortium treatment one consists of a *Trichoderma* spp. at 1×108 CFU; treatment two consists of ferment consortium; treatment three consists of a *B. consortium* at 1×108 CFU; treatment four consists of a chemical control by thiabendazole prepared at 60% W/V; and the treatment five consists of an absolute control. A dose of 1 L.ha−1 was applied for treatments one, two, and three, while the dose applied for thiabendazole was 0.5 kg.ha−1. Field sowing is done with chile seedlings (10 cm), transplanted in 1.5 m double row beds. The application is made to drench with a manual sprinkler at 7, 28, and 49 days after the transplant (DDT). After 85, 105, 125, and 145 DDT, the yield per block (4.5 m<sup>2</sup> ) is determined and transformed to t ha. To determine yields and improvements of treatments, ten fruits were evaluated, where the weight (g) and size (mm) per fruit were determined. In the first and last harvest, the incidence assessed and transformed into a percentage. The severity is evaluated through the visual scale, where 0 = no visible symptoms; 1 = initial light chlorosis and presence of flowers and fruits; 2 = intermediate, partial wilt, severe chlorosis, and premature ripening of fruits; and 3 = advanced. For total wilt without recovery, the leaves and fruits remain stuck to the stem. The field results observed as the effects of biological agents are shown in **Table 6**. The disease incidence values between HS-52 and Coloso treatments were statistically different (p ≤ 0.05); in the other varieties, there were no differences between treatments. The treatment based on *Trichoderma* is the biological one that suppresses in higher

**111**

*LSD test.*

**Table 8.**

*agents.*

the latter.

*LSD test.*

**Table 7.**

*LSD test.*

**Table 6.**

*Biological Efficacy of* Trichoderma *spp. and* Bacillus *spp. in the Management of Plant Diseases*

*Trichoderma* spp. 10.67a 18.17ab 16.84a 19.17a 12.5a 10.00a Consortium 26.67ab 15.5ab 10.50a 15.33a 19.83a 10.67a *Bacillus* spp. 29.17ab 29.67b 20.07a 20.5a 21.83a 19.5a Thiabendazole 21.00ab 6.83a 19.51a 24.17a 10.33a 16.17a Control 31.83b 21.33ab 21.51a 23.33a 24.67a 22.33a *Mean values on the same column indicated by different letters are statistically different (p < 0.05) according to the* 

**HS-52 Coloso HS-44 Centauro Tampiqueño 74 Paraíso**

**Microbial agents Serrano chile pepper varieties**

percentage the incidence of wilting disease in chile pepper crops; in this case, the lowest incidence was in the HS-52 variety which showed a value of 10.67%, while that in the witness it was 31.87%, which represents a decrease of 71% concerning

*Incidence of the disease (%) in serrano chile pepper varieties inoculated with microbial agents in the field.*

demonstrates the lowest incidence percentage with values between 14.39 and 16.39%, while the control and *Bacillus* spp. were having high levels of the presence of symptoms (24.08 and 23.36%). In the case of severity, it also behaves differently between treatments. **Table 7** shows the values related to the severity of the disease

**Treatment Serrano chile pepper varieties**

*Severity of the disease (%) in serrano pepper with respect to treatments.*

Disease evaluation in the presence of treatments of consortium and *Trichoderma*

*Trichoderma* 11.3ab 18.43a 10.8a 6.83a 7.83ab 6.93a Consortium 8.33a 16.28a 24.45a 12.76a 14.35ab 6.46a *Bacillus* spp. 14.4ab 19.16a 15.09a 11.54a 17.6b 16.22ab Thiabendazole 20.04b 14.07a 17.97a 15.74a 6.56a 18.24b Control 19.45ab 24.35a 24.07a 13.65a 17.96b 18.43b

*Mean values on same column indicated by different letters are statistically different (p < 0.05) according to* 

**Microbial agents Total yield in chile pepper varieties (t ha<sup>−</sup><sup>1</sup>**

*Trichoderma* spp. 15.67a 13.22a 8.48b 7.55a Consortium 10.37ab 11.52ab 10.59a 13.04a *Bacillus* spp. 7.26b 8.18ab 5.41b 10.3a Thiabendazole 10.02ab 8.69ab 7.44b 10.62a Control 5.98b 5.15b 2.59b 6.94a *Mean values on the same column indicated by different letters are statistically different (p < 0.05) according to the* 

*Total yield, length, and weight of fruit of the serrano chile pepper crop obtained with the use of microbial* 

**HS-52 Coloso HS-44 Centauro Tampiqueño 74 Paraíso**

**HS-52 Centauro Paraíso HS-44**

**)**

*DOI: http://dx.doi.org/10.5772/intechopen.91043*

*Biological Efficacy of* Trichoderma *spp. and* Bacillus *spp. in the Management of Plant Diseases DOI: http://dx.doi.org/10.5772/intechopen.91043*


*Mean values on the same column indicated by different letters are statistically different (p < 0.05) according to the LSD test.*

#### **Table 6.**

*Organic Agriculture*

**Figure 12.**

*spp. effect, and (c)* Trichoderma *spp. effect.*

biological agents for this purpose under field conditions. For this, an experiment is established where different genotypes of chile pepper are evaluated (Serrano, HS-52, Coloso, HS-44, Centauro, Paraíso and Tampiqueño 74 cv.) generated by INIFAP-Mexico. In this experiment, the microbial agents *T. asperellum*, *T. harzianum*, *T. yunnanense* [23, 29], *B. amyloliquefaciens*, *B. licheniformis*, and *B. subtilis* [24] under a mixture of microbial propagative ferment (consortium ferment) are based on *Trichoderma* spp. and *Bacillus* spp. Treatments of bioassay by *Trichoderma* spp. were different: consortium treatment one consists of a *Trichoderma* spp. at

*Expression of symptoms caused by* Venturia inaequalis *in apple trees. (a) Without treatment, (b)* Bacillus

*Bacillus* spp. 1 L ha<sup>−</sup><sup>1</sup> 8.12 ± 6.9ab 11.25 ± 1.2bc 13.12 ± 2.1bc 22.50 ± 4.8b *Bacillus* spp. 2 L ha<sup>−</sup><sup>1</sup> 6.25 ± 2.1ab 11.25 ± 2.5bc 11.87 ± 2.4bc 17.50 ± 4.6b *Trichoderma* spp. 1 L ha<sup>−</sup><sup>1</sup> 8.13 ± 3.8ab 13.12 ± 5.5bc 13.75 ± 4.7bc 20.62 ± 2.4b *Trichoderma* spp. 2 L ha<sup>−</sup><sup>1</sup> 2.50 ± 1.7b 6.25 ± 1.4c 6.25 ± 1.4c 10.62 ± 1.3c Control 18.12 ± 4.1a 21.87 ± 3.1a 23.75 ± 4.3a 31.87 ± 3.8a

**Treatments Incidence (%) in leaves**

*Treatments with the same letter are statistically equal to each other (p < 0.05).*

*The incidence in apple leaves by* Venturia inaequalis.

CFU; treatment two consists of ferment consortium; treatment three consists

thiabendazole prepared at 60% W/V; and the treatment five consists of an absolute control. A dose of 1 L.ha−1 was applied for treatments one, two, and three, while the dose applied for thiabendazole was 0.5 kg.ha−1. Field sowing is done with chile seedlings (10 cm), transplanted in 1.5 m double row beds. The application is made to drench with a manual sprinkler at 7, 28, and 49 days after the transplant (DDT).

transformed to t ha. To determine yields and improvements of treatments, ten fruits were evaluated, where the weight (g) and size (mm) per fruit were determined. In the first and last harvest, the incidence assessed and transformed into a percentage. The severity is evaluated through the visual scale, where 0 = no visible symptoms; 1 = initial light chlorosis and presence of flowers and fruits; 2 = intermediate, partial wilt, severe chlorosis, and premature ripening of fruits; and 3 = advanced. For total wilt without recovery, the leaves and fruits remain stuck to the stem. The field results observed as the effects of biological agents are shown in **Table 6**. The disease incidence values between HS-52 and Coloso treatments were statistically different (p ≤ 0.05); in the other varieties, there were no differences between treatments. The treatment based on *Trichoderma* is the biological one that suppresses in higher

After 85, 105, 125, and 145 DDT, the yield per block (4.5 m<sup>2</sup>

CFU; treatment four consists of a chemical control by

**15 days 30 days 45 days 60 days**

) is determined and

**110**

1×108

**Table 5.**

of a *B. consortium* at 1×108

*Incidence of the disease (%) in serrano chile pepper varieties inoculated with microbial agents in the field.*

percentage the incidence of wilting disease in chile pepper crops; in this case, the lowest incidence was in the HS-52 variety which showed a value of 10.67%, while that in the witness it was 31.87%, which represents a decrease of 71% concerning the latter.

Disease evaluation in the presence of treatments of consortium and *Trichoderma* demonstrates the lowest incidence percentage with values between 14.39 and 16.39%, while the control and *Bacillus* spp. were having high levels of the presence of symptoms (24.08 and 23.36%). In the case of severity, it also behaves differently between treatments. **Table 7** shows the values related to the severity of the disease


*Mean values on same column indicated by different letters are statistically different (p < 0.05) according to LSD test.*

#### **Table 7.**

*Severity of the disease (%) in serrano pepper with respect to treatments.*


*Mean values on the same column indicated by different letters are statistically different (p < 0.05) according to the LSD test.*

#### **Table 8.**

*Total yield, length, and weight of fruit of the serrano chile pepper crop obtained with the use of microbial agents.*

#### **Figure 13.**

*Expression of incidence of coffee rust. (a) Plants with treatment based on bio formulate based on* Bacillus *spp., and (b) plants without treatment, where leaf defoliation is clearly expressed.*

as transformed percentages (p ≤ 0.05). It can be seen that *Trichoderma* spp.-based treatments alone or in combination have lower severity values.

The effects on yield as the weight and size of the fruit showed by the use of microbial agents applied alone or in combination as shown in **Table 8**. When *Trichoderma* is used, the yield increased; for example, its increase in the production was 62% when used alone and up to 76% when used as a mixture in comparison with the control.

This behavior of positive effect has already evidenced with the use of different *Trichoderma* species on habanero pepper plants (*Capsicum chinense*) [46], lettuce (*Lactuca sativa*), and radish (*Raphanus sativus*) [47]. In the same context, Cubillos-Hinojosa et al. [48] tested *T. harzianum* in the passion fruit crops (*Passiflora edulis*) where they were able to determine an antagonist to *F. oxysporum* and *F. solani*, in addition to stimulating germination, increased biomass, and root length.

In other field tests with *Bacillus* spp. bioformulate prototypes, a reduction in incidence and severity of coffee rust (*Hemileia vastatrix*) was observed. It was observed that the control presented 38% of incidence; nevertheless, it showed defoliation compared with the prototype treatments, which present an incidence between 5 and 15%, while with the chemist, the incidence was 9% (**Figure 13**).

The positive interaction between *Trichoderma* spp. and the host plant is attributed to a complex chemical activity of volatile and diffusible secondary metabolites and release of phytohormones and antibiotics in the rhizosphere, which promote root development and increased nutrient absorption, which helps control phytopathogens and increase yield [49]; this effect explains the results produced in this research. Microbial extracts as biofertilizers can generate hormones that stimulate development and increase yield, which are verified with the application of exudates from consortium *Trichoderma* spp. and *Bacillus* spp., which showed an effect on disease control and crop development in the same or better percentage than when using microorganisms.

#### **8. Resistance induction by** *Trichoderma* **spp. and** *Bacillus* **spp.**

In addition to the above aspects, plants can develop an increase in resistance to pathogen infection by treatment with a wide variety of biotic and abiotic inducers. Among the biotic inducers, we have the same phytopathogens, the growth-promoting rhizobacteria, and the microbial agents of the species of the genera *Bacillus* spp.*, Streptomyces*, *Pseudomonas*, *Burkholderia*, and *Agrobacterium* and nonpathogenic microorganisms such as *Trichoderma* species (antibiotics or siderophores that lead to induction of resistance).

**113**

in plants.

**Figure 14.**

**9. Conclusions**

*Biological Efficacy of* Trichoderma *spp. and* Bacillus *spp. in the Management of Plant Diseases*

Among the abiotic inducers are salicylic acid (SA), jasmonic acid (JAS), β-aminobutyric acid, ethylene, chitosan, potassium, sodium or magnesium phosphate, acibenzolar-S-methyl (ASM), menadione, sodium bisulfite, and phosphites. The application of these inducers causes specific biochemical changes that occur after their application such as expression of genes that code for PR proteins; the increase of certain defense-related enzymes such as polyphenol oxidase, lipoxygenase, peroxidase, superoxide dismutase, and phenylalanine ammonia-lyase (PAL); the accumulation of phytoalexins and phenolic compounds; and the reinforcement

*(a) Salicylic acid production on potato leaves in a different time. T1 =* Bacillus *spp. and* Pseudomonas fluorescens*, T2 = jasmonic ac. 1500 ppm, T3 = mezcla T1 0.5% + T2 0.1%, T4 = Milor®, and T5 = control (agua). Different letters indicate significant difference. (b) Jasmonic acid production on potato leaves in different time. T1 =* Bacillus *spp. and* Pseudomonas fluorescens*, T2 = jasmonic ac. 1500 ppm, T3 = mezcla T1* 

In this regard, we have observed changes in the endogenous levels of salicylic acid and jasmonic acid in potato plants in response to foliar application of microbial consortiums based on *Bacillus* spp. and *Pseudomonas fluorescent*. The microbial consortium of *Bacillus* spp. significantly increased the production of SA 3 h after spraying raising to 114.02 μg/g DW. This is 496% more than the control (**Figure 14a**). Jasmonic acid is not detected in control plants but detected in plants treated with the microbial consortium. The level of jasmonic acid, 6 h later, reached

The resistance induction is associated with some defense gene expression as encoding pathogenicity-related proteins (PR), for example, phenylalanine ammonia-lyase, which is crucial in the synthesis of phytoalexins, because these constitute highly toxic compounds to the pathogen. On the other hand, PAL is part of the synthesis of salicylic acid and phenolic compounds that reduce the incidence of diseases in plants. It has also shown that *B. amylolicheniformis*, *B. subtilis*, *B. pumilus*, and *B. cereus* are capable of eliciting and activating the induced systemic resistance by increasing the levels of biochemical compounds related to resistance induction. Besides, it reported that some *Pseudomonas* species could induce systemic resistance

The results shown in this chapter allow to demonstrate the efficacy of *Bacillus* and *Trichoderma,* as agents of biological control of fungi and stramenopiles that are causatives of plant diseases; these beneficial microorganisms can be used under a sustainable agriculture program or under integrate management pest program in a conventional agriculture. The microbial agents also express other advantages due

*DOI: http://dx.doi.org/10.5772/intechopen.91043*

of the cell wall with lignin deposition.

*0.5% + T2 0.1%, T4 = Milor®, and T5 = control.*

a level of 550 μg/g DW (**Figure 14b**).

*Biological Efficacy of* Trichoderma *spp. and* Bacillus *spp. in the Management of Plant Diseases DOI: http://dx.doi.org/10.5772/intechopen.91043*

#### **Figure 14.**

*Organic Agriculture*

the control.

**Figure 13.**

length.

using microorganisms.

to induction of resistance).

as transformed percentages (p ≤ 0.05). It can be seen that *Trichoderma* spp.-based

*Expression of incidence of coffee rust. (a) Plants with treatment based on bio formulate based on* Bacillus *spp.,* 

The effects on yield as the weight and size of the fruit showed by the use of microbial agents applied alone or in combination as shown in **Table 8**. When *Trichoderma* is used, the yield increased; for example, its increase in the production was 62% when used alone and up to 76% when used as a mixture in comparison with

This behavior of positive effect has already evidenced with the use of different *Trichoderma* species on habanero pepper plants (*Capsicum chinense*) [46], lettuce (*Lactuca sativa*), and radish (*Raphanus sativus*) [47]. In the same context, Cubillos-Hinojosa et al. [48] tested *T. harzianum* in the passion fruit crops

(*Passiflora edulis*) where they were able to determine an antagonist to *F. oxysporum* and *F. solani*, in addition to stimulating germination, increased biomass, and root

In other field tests with *Bacillus* spp. bioformulate prototypes, a reduction in incidence and severity of coffee rust (*Hemileia vastatrix*) was observed. It was observed that the control presented 38% of incidence; nevertheless, it showed defoliation compared with the prototype treatments, which present an incidence between 5 and 15%, while with the chemist, the incidence was 9% (**Figure 13**). The positive interaction between *Trichoderma* spp. and the host plant is attributed to a complex chemical activity of volatile and diffusible secondary metabolites and release of phytohormones and antibiotics in the rhizosphere, which promote root development and increased nutrient absorption, which helps control phytopathogens and increase yield [49]; this effect explains the results produced in this research. Microbial extracts as biofertilizers can generate hormones that stimulate development and increase yield, which are verified with the application of exudates from consortium *Trichoderma* spp. and *Bacillus* spp., which showed an effect on disease control and crop development in the same or better percentage than when

**8. Resistance induction by** *Trichoderma* **spp. and** *Bacillus* **spp.**

In addition to the above aspects, plants can develop an increase in resistance to pathogen infection by treatment with a wide variety of biotic and abiotic inducers. Among the biotic inducers, we have the same phytopathogens, the growth-promoting rhizobacteria, and the microbial agents of the species of the genera *Bacillus* spp.*, Streptomyces*, *Pseudomonas*, *Burkholderia*, and *Agrobacterium* and nonpathogenic microorganisms such as *Trichoderma* species (antibiotics or siderophores that lead

treatments alone or in combination have lower severity values.

*and (b) plants without treatment, where leaf defoliation is clearly expressed.*

**112**

*(a) Salicylic acid production on potato leaves in a different time. T1 =* Bacillus *spp. and* Pseudomonas fluorescens*, T2 = jasmonic ac. 1500 ppm, T3 = mezcla T1 0.5% + T2 0.1%, T4 = Milor®, and T5 = control (agua). Different letters indicate significant difference. (b) Jasmonic acid production on potato leaves in different time. T1 =* Bacillus *spp. and* Pseudomonas fluorescens*, T2 = jasmonic ac. 1500 ppm, T3 = mezcla T1 0.5% + T2 0.1%, T4 = Milor®, and T5 = control.*

Among the abiotic inducers are salicylic acid (SA), jasmonic acid (JAS), β-aminobutyric acid, ethylene, chitosan, potassium, sodium or magnesium phosphate, acibenzolar-S-methyl (ASM), menadione, sodium bisulfite, and phosphites. The application of these inducers causes specific biochemical changes that occur after their application such as expression of genes that code for PR proteins; the increase of certain defense-related enzymes such as polyphenol oxidase, lipoxygenase, peroxidase, superoxide dismutase, and phenylalanine ammonia-lyase (PAL); the accumulation of phytoalexins and phenolic compounds; and the reinforcement of the cell wall with lignin deposition.

In this regard, we have observed changes in the endogenous levels of salicylic acid and jasmonic acid in potato plants in response to foliar application of microbial consortiums based on *Bacillus* spp. and *Pseudomonas fluorescent*. The microbial consortium of *Bacillus* spp. significantly increased the production of SA 3 h after spraying raising to 114.02 μg/g DW. This is 496% more than the control (**Figure 14a**). Jasmonic acid is not detected in control plants but detected in plants treated with the microbial consortium. The level of jasmonic acid, 6 h later, reached a level of 550 μg/g DW (**Figure 14b**).

The resistance induction is associated with some defense gene expression as encoding pathogenicity-related proteins (PR), for example, phenylalanine ammonia-lyase, which is crucial in the synthesis of phytoalexins, because these constitute highly toxic compounds to the pathogen. On the other hand, PAL is part of the synthesis of salicylic acid and phenolic compounds that reduce the incidence of diseases in plants. It has also shown that *B. amylolicheniformis*, *B. subtilis*, *B. pumilus*, and *B. cereus* are capable of eliciting and activating the induced systemic resistance by increasing the levels of biochemical compounds related to resistance induction. Besides, it reported that some *Pseudomonas* species could induce systemic resistance in plants.

#### **9. Conclusions**

The results shown in this chapter allow to demonstrate the efficacy of *Bacillus* and *Trichoderma,* as agents of biological control of fungi and stramenopiles that are causatives of plant diseases; these beneficial microorganisms can be used under a sustainable agriculture program or under integrate management pest program in a conventional agriculture. The microbial agents also express other advantages due

to their beneficial effects on the increase of the yields, growth, and development of plants, as well as the induction of systemic resistance in plants to phytopathogens. Currently our workgroup has any projects on the development of prototypes based on these microbial agents, alone or in consortium, as well as micro- and nanoencapsulated formulations.
