## 4 Discussion
Our hypothesis was that we would observe a smaller number of larvae in the treated plants. In the field trial Experiment 1, there was no significant difference between the germination of the negative control and _B. bussiana_ treated plants, whereas there was a small decline in comparison with laboratory results. This decrease might be due to the uncontrolled environmental conditions and the type of seed (Criollo race) that was used; however, the percentage of _Z. mays_ plants germination was not affected by the presence of _B. bussiana_. This conclusion is in contrast with the study of [PERSON] et al. (2018), who reported a 77% germination of negative control, compared with 89% germination of _B. bussiana_-treated _Z. mays_ plants. Moreover, the average number of leaves per plant did not show any significant difference between the negative control and _B. bussiana_-treated plants. Despite there was a non-significant difference in the frequency of _S. frugiperda_ larvae between the _B. bussiana_-treated plants and negative control plants (Figure 7), there was a slight increment in the number of larvae in the furrows of _B. bussiana_-treated plants that were immediately close to the negative control plants. This eventually decreased to zero in the last 12 rows of _B. bussiana_-treated plants, which were only 30 meters from neighboring maize fields that had _S. frugiperda_ presence. Therefore, the insects showed some avoidance of feeding on the treated plants. These are preliminary results that are similar to what we observed in our laboratory bioassays. (Figure 7, Table 1). In addition, we wanted to test if an increase in the concentration of _B. bussiana_ GHA strain could show any effect on plant growth or insect presence in the field, as a second peak of _S. frugiperda_ insects was expected in the area of study. In the second field trial, there were no significant differences observed in terms of germination percentage and the average number of leaves of _Z. mays_ plants in both treatments, whereas a small increment in plant height was observed with _B. bussiana_-treated plants. In addition, increased germination was observed, from 71.5% (first trial) in negative control plants to 91.20% (second trial) and from 80.33% (first trial) to 87.20% (second trial) in _B. bussiana_-treated plants. In terms of the average number of leaves per plant, we observed an increase of 3.12 (first trial) to 5.20 (second trial) leaves per plant in negative control and from 3.49 (first trial) to 5.23 (second trial) leaves per plant in _B. bussiana_-treated plants. This difference might be due to the use of a higher concentration of blastospores (from \(1\times 10^{6}\) blastospores/mL in the first trial to \(1\times 10^{8}\) blastospores/mL in the second trial) or to the change in cultivation cycle conditions (intermediate). These results are similar to those by [PERSON] and [PERSON], who indicated that _Gossypium hirsutum_ height increased by establishing _B. bussiana_ as an endophyte in the plants ([PERSON] et al., 2013). [PERSON] et al. reported an increasing number of leaves of _P. vulgaris_ after _B. bussiana_ treatment ([PERSON] et al., 2013). We found that the length of the cob corn was slightly higher in the negative control plants than in _B. bussiana_-treated plants. However, most _B. bussiana_-treated plants yielded more than two corn cobs per plant (Figure S6). We did not find any significant difference in the corn cobs weight among the treatments, which is in agreement with [PERSON] et al. (2016), who found that application of _Metarhizium robertsii_ to maize plants did not show any significant difference in grain yield per hectare among the treatments tested, whereas [PERSON] et al. [8] found an increase in maize corn yield after applying _B. bassiana_ under field conditions. [PERSON] [20] reported a decrease in tomato size after colonizing the plants with _B. bassiana_.