Isolates of Trichoderma spp., a soil fungus, has been used to control diseases and promote plant growth, reducing the use of chemicals in the production of seedlings of different plant species. We evaluated the effect of some Trichoderma spp. isolates on seed treatment and seedling production of Theobromacacao. Five isolates from the Amazon region were tested. In laboratory, the following variables were evaluated for seed treatments: germination, germination speed index, radicle and hypocotyl lengths, and fungi incidence. In nursery, the following forms of application were tested: via seeds; in the substrate at pre-planting; monthly in post-planting substrate, and also their combination. The following was evaluated: height, diameter, number of leaves, root length, leaf area, and shoot dry mass and root system. Inoculation with Trichoderma increased the length of the radicle and hypocotyl and showed no fungi in the seeds. In seedlings, some treatments increased height and plant root dry mass. The use of Trichoderma was beneficial for seeds and appeared favorable for T. cacao production.

Dipteryx odorata and Dipteryx punctata are species native to the Amazonian, traded by extractivists to obtain coumarin. We aimed to analyze the presence of coumarin in the ethanolic extracts of leaves, branches and fruits of D. odorata and D. punctata and to evaluate the antimicrobial activity of these extracts against phytopathogenic fungi and bacteria of clinical interest. Chemical analyses were performed by thin layer chromatography (TLC) and by gas chromatography coupled to mass spectrometry (GC-MS). For the antifungal assays, the fungi used were Cercospora longissima, Colletotrichum gloeosporioides, two isolates of Fusarium spp. and Sclerotium rolfsii, and the antibacterial assay was performed using the minimum inhibitory concentration (MIC) test with Burkholderia cepacia, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus bacteria. In D. odorata seed extracts and in D. punctata husks, endocarps, and seeds, we identified 1,2-benzopyrone. D. odorata endocarp extracts and D. punctata seeds provided the greatest decrease in mycelial growth of the evaluated phytopathogens, showing promise as an alternative control. The husk and endocarp extracts of both species had a weak effect on E. coli. This research is the first to compare the different parts of species of the genus Dipteryx and to evaluate the use of husks and endocarps of D. punctata fruits to obtain coumarin. Chemical analyses used to quantify the compounds existing in the extracts, and tests with phytopathogens in vitro and in vivo are currently being carried out.

The application of Trichoderma fungus can be used to obtain seedlings of higher quality for plantations. The objective of this study was to evaluate the effects of Trichoderma isolates on the germination and initial growth of açaí seedlings. Two trials were set up. In the laboratory, the seeds were inoculated in suspensions prepared with each of the isolates for 24 h, and they were arranged in trays containing filter paper in a completely randomized design with five replicates containing 50 seeds each. For the control, the seeds were submerged only in water. Part of the seedlings resulting from seeds treated and not treated with Trichoderma were transferred to bags containing forest soil and were submitted to seven modes of application of Trichoderma and kept in a nursery. The speed of germination and hypocotyl were not influenced by the biological treatment. The application of the different Trichoderma isolates positively influenced the height, collar diameter, number of leaves, root size, leaf area and root, and aerial part dry mass of the açaí seedlings. The application of the Trichoderma isolate TAM01 on the preplanting substrate and biweekly applications on the postplanting substrate was the combination that most positively influenced the development of açai seedlings.

The genus Dipteryx, to which the cumaru tree belongs, contains neotropical species native to Central and South American countries. They are used both in the sale of timber and seeds and for the extraction of the active compound coumarin, used as a flavoring agent. This study evaluated the phytochemical profile and antioxidant activity of extracts of leaves, branches, and fruits (residues and seeds) of the species Dipteryx punctata. The plant material for analysis was collected in five seed-producing areas, in Mojuí dos Campos, Pará, Brazil. The extracts were obtained via Soxhlet extractor using 92.8% distilled ethanol as the solvent and operated till exhaustion (8 h). Chromatographic analyses were performed by thin-layer chromatography (TLC) and gas chromatography coupled to mass spectrometry (GC-MS), followed by phytochemical determination of phenolics and flavonoids and analysis of antioxidant activity (TLC and free radical scavenging 2,2-diphenyl-1-picrylhydrazyl (DPPH). The highest extract yields were obtained from D. punctata fruit residues and seeds from all areas, with maximum values of 26.1% and 47.2%, respectively, in Boa Fé (area 3). In the evaluation by TLC, the extracts of leaves, branches, and residues presented the classes of terpenes, condensed and hydrolysable tannins, and flavonoids; coumarin (1,2-benzopyrone) was identified only in residue and seed extracts. The major constituents highlighted in the collection areas were: lupeol in leaves (34.4% in area 5), 4-O-methylmannose in branches and residues (85.5% in area 2 and 90.6% in area 5, respectively), and coumarin in seeds (99.3% in area 3). The best results for the antioxidant action were obtained for extracts from leaves and residues, requiring a concentration of 117.6 µg.mL⁻¹ of the extract from the leaves and 160.4 µg.mL⁻¹ of the extract from the residues to reduce the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical by 50%. This phytochemical study contributes to reducing the scarcity of information on D. punctata. The chemical classes and compounds identified corroborate the antioxidant activity and add value to the species, and the data obtained reinforce the importance of reusing fruit residues, which are chemically rich but discarded in the environment.

Trichoderma spp. e seus efeitos na qualidade fisiológica das sementes e no desenvolvimento de mudas de mogno africano - DOI:10.5039/agraria.v15i1a5843

Cupuaçu (Theobroma grandiflorum (Willd. ex Spreng.) K. Schum.), a fruit native to the Amazon, is widely used in the food industry. However, it generates large amounts of shell and seed residues after processing, which are generally discarded inappropriately. We characterized cupuaçu residues to determine their potential as substrates for seedling production. Shells and fruit seeds were collected from a rural community in the municipality of Belterra, Brazil. The residues were weighed, dried, and crushed for chemical (macro and micronutrients, elemental analysis, and ash content) and physical (density and porosity) analyses. Different proportions of each residue (9:1, 3:1, 2:1, 1:1, and 0:1) were used, and soil alone was used as the control. The chemical analysis of the plant material showed that cupuaçu seed residues had higher concentrations of macro- and micronutrients among the analyzed elements when compared to the fruit shell residues. The macronutrient concentrations (P, K, Ca, and Mg) were, respectively, 5, 1.3, 2.3, and 5.6 times higher than those in the shell residues. Compared with the soil sample, the concentrations of the macronutrients (P, K, Ca, and Mg) in the shell residues were, respectively, 600, 162, 1283, and 12.35 times higher. Analysis of variance and comparison of treatment means were performed using Tukey’s test (p ≤ 0.05). Chemical analysis showed that cupuaçu seed and shell residues had higher concentrations of macro- and micronutrients than soil. All proportions tested with residues had lower densities and greater porosities than soil. The cupuaçu residues showed desirable chemical and physical characteristics for their use as substrate in seedling production.