Trichoderma species is a heterotrophic saprobion organism, which competes with other microorganisms, preventing them from developing. This fungus has mechanisms of action, among which are: production of antibiotics and metabolites, and hyperparasitism, which also promotes the induction of systemic resistance in plants. In this study, five native Trichoderma strains which were collected from agricultural land in Tamaulipas, Mexico were evaluated. The objective of this research was to identify the secondary metabolites produced by native strains of Trichoderma spp. under in vitro conditions and evaluation of the effect of these compounds on the growth of the pathogen Fusarium oxysporum and the germination of tomato seeds (Solanum esculentum). The production of Trichoderma's metabolites was performed by culturing in 150 ml of potato broth supplemented with sucrose (5%) and yeast extract (5%). Inoculation was performed by the addition of a 4 mm disk of active mycelium and allowed to grow at 25C ± 2°C and 12 h light/dark on a rotary shaker at 150 rpm for three weeks. Subsequently, the extraction of metabolites was performed using liquid: liquid phase which consisted of the filtrate and methylene chloride in a ratio of 1:3, and then the organic phase was recovered. The organic fraction was evaporated at 40°C with the aid of a rotary evaporator (Buchi®); the sample was recovered in 1 ml of methylene chloride. Analysis by GC-MS indicates that Trichoderma isolates produced 41 secondary metabolites of volatile and semi-volatile molecules and was observed, such that the number of compounds varies from the species analyzed and the collection site. The evaluation of the antagonistic activity of the extracts of Trichoderma spp. on F. oxysporum showed no significant differences between treatments (P=0.05); however, it was observed that pigmentation decreased in the mycelium of the pathogen. Regarding the evaluation of the effect of the extracts on the seeds of tomato, it was observed that the compounds of Trichoderma asperellum (TV1) induced the germination and the development of the seedling. Key words: Volatile compounds, Trichoderma, gas chromatography-mass spectrometry secondary metabolites, Solanum esculentum.

Five samples of agricultural soil and five samples of Aloe barbadensis (P. Mill., 1768) plants with symptoms of wilt and root necrosis were collected in five localities of the state of Tamaulipas, México. The aims of this study were the morphological identification, molecular identification and in vitro evaluation of the antagonistic activity of Trichoderma spp. on Fusarium spp. Four strains of Trichoderma asperellum, one strain of Trichoderma harzianum and five strains of Fusarium oxysporum were identified by morphological and molecular methods. The evaluation of the antagonistic activity of T. harzianum isolate (TP) showed the highest inhibition in Fusarium spp. (78.80%). The evaluation of the antagonistic activity of Trichoderma spp. extracts in Fusarium spp. did not show significant differences between treatments (P ≤ 0.05), with Trichoderma growth percentages that oscillated between 81.08 and 94.38%. The native isolate of T. harzianum (TP) showed significant competitive capability against the mycelial growth of F. oxysporum. Trichoderma species are promising agents of biological control in the central area of the State Tamaulipas, Mexico.

The objective of this study was to evaluate the insecticidal activity of native entomopathogenic fungi and neem extract on Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) attacking maize (Zea mays L.). The treatments were the following: Metarhizium robertsii J.F. Bisch., Rehner & Humber and Fusarium solani (Mart.) Sacc at 1 × 108 spores ml-1 and 15% vegetable oil, neem extract in two combinations of 4% mass per volume, commercial insecticide, and a control without application. Response variables were incidence of S. frugiperda, severity of leaf damage, and grain yield. M. robertsii was most effective because of low incidence of S. frugiperda and severity of leaf damage; as leaf damage increased, grain yield decreased. Therefore, a high severity by insect attack can significantly decrease grain yield. It was observed that during the autumn-winter cycle the S. frugiperda incidence was lower, compared to the spring-summer cycle. M. robertsii decreased S. frugiperda incidence in both cycles.

Synthetic chemicals are mainly used for the control of fungal diseases in tomato, causing the phytopathogens to generate resistance to the chemical active ingredient, with a consequent risk to human health and the environment. The use of plant extracts is an option for the control of these diseases, which is why the main objective of this research was to study an alternative biocontrol strategy for the management of plant diseases caused by fungi through obtaining polyphenol extracts from mistletoe plants growing on three different tree species—mesquite (Prosopis glandulosa), cedar (Cedrus), and oak (Quercus), which contain flavones, anthocyanins, and luteolin. The overall chemical structure of the obtained plant extracts was investigated by RP-HPLC-ESI-MS liquid chromatography. The antifungal effect of these extracts was examined. The target phytopathogenic fungi were isolated from tomato plantations located in Altamira, Tamaulipas, Mexico. The microorganisms were characterized by classical and molecular methods and identified as Alternaria alternata, Fusarium oxysporum, Fusarium sp., and Rhizoctonia solani.

The objective was to evaluate the effects of In vitro biocontrol of Trichoderma spp. and Bacillus spp. against Fusarium oxysporum and its in vivo effect on Solanum lycopersicum plants. The antagonistic effect in vitro of microcapsules of Trichoderma spp. and Bacillus spp. against F. oxysporum, was evaluated by inhibition and antagonism classification, in the in vivo part growth variables in plant and fruit were measured. Trichoderma asperellum showed inhibition of 84.7% and class 1 and Bacillus spp., obtained an inhibition of 83.7% with a positive classification. The canonical correspondence analysis of the fruit, the T1 treatment indicates that the variables that highlight the effect of the treatment are the firmness of the fruit and the Brix. The canonical correspondence analysis of the plant, the height presents a significant difference (P < 0.05), highlighting B. subtilis, Bacillus liquefasciens, T. harzianum and T. asperellum + Bacillus amiloliquefasciens, with 1.05 and 1.1 m compared to the control of 74 cm, also highlighted the number of total fruits in the T. harzianum treatment with an average of 22.6 fruits and root weight in B. subtilis with 37.12 g. Strains of Trichoderma spp. and Bacillus spp. successfully inhibited F. oxysporum also induced growth in the tomato plant.