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Compatibilidade de biouninema com agrotóxicos e promoção de crescimento de feijoeiro

2025-06-23T17:15:33Z

Título: Compatibilidade de biouninema com agrotóxicos e promoção de crescimento de feijoeiro Autor(es): Leles, Wander Guilherme da Silva Abstract: Beans are considered one of the most important crops for feeding Brazilian society. However, due to several biotic and abiotic problems that occur in bean cultivation, significant reductions in their productivity have been observed, making it necessary to adopt management tactics for this crop. These tactics can be carried out through the use of pesticides as well as biological products based on microorganisms. Among the microorganisms, the rhizobacteria Bacillus subtilis-34 stands out, which has been studied at Unimontes and has proven to be efficient in controlling phytopathogens, in addition to promoting the growth of beans, okra, tomatoes, bananas and lettuce. It is known that both biological products and pesticides are part of agricultural management. Considering the potential of B. subtilis-34 as a phytopathogen controller and growth promoter, it is essential to understand the performance of this microorganism when subjected to pesticides used in bean crops. Furthermore, there are no studies on the effect of B. subtilis-34 as a growth promoter in bean crops through soil application. Therefore, the objective of this study was to evaluate the growth of B. subtilis-34 in the presence of pesticides and its action as a growth promoter in beans. In a first experiment, the in vitro growth of B. subtilis-34 was evaluated when subjected to the presence of fungicides and insecticides, which are commonly used in bean crops. For this, two assays were used for evaluation. In Assay 1, the bacteria grew in the presence of pesticides and in Assay 2, the pesticides were added after the growth of the bacteria. These trials were developed in a completely randomized design, with 8 treatments consisting of 7 pesticides (mancozeb, captan, sulfur, thiophanate-methyl, thiophanate-methyl+chlorothalonil, thiamethoxam and pyriproxyfen+xylene) and a control (without the presence of pesticides) with 4 replicates. To evaluate bacterial growth, serial dilution was performed and the plating of the concentration of 10-5 in 7 cm diameter Petri dishes, containing Trypic Soy Agar (TSA) medium. After a period of 12 hours, the number of colony forming units (CFUs) was counted. In trial I, the fungicides mancozeb and captan inhibited the growth of B. subtilis-34, and these were classified as incompatible. In trial II, the fungicide captan completely inhibited the multiplication of the bacteria, while the fungicide mancozeb and the insecticides thiamethoxam and pyriproxyfen+xylene reduced the number of CFU. B. subtilis-34 was compatible with the pesticides thiophanate-methyl and thiophanate-methyl+chlorothalonil in both trials. The second experiment was carried out in a greenhouse and set up in a completely randomized design with five treatments, namely: 0.0 L ha-1, 2.0 L ha-1, 4.0 L ha-1, 8.0 L ha-1 of Biouninema and 4.0 L ha-1 of Biobaci® (commercial product based on B. subtilis-BV09), with six replicates. After 60 days of transplanting, the following were evaluated: number of leaves, stem diameter, plant height, SPAD, fresh and dry mass of the root, fresh and dry mass of the aerial part, number of pods, fresh and dry mass of the pods and grain weight. The dose of 4.0 Lha-1 of Biouninema provided a greater stem diameter of the bean plants while the dose of 2.0 Lha-1 of Biouninema provided a greater grain weight in relation to the other treatments.

Desempenho fisiológico de sementes de cultivares de algodão sob estresse hídrico

2025-06-23T16:57:23Z

Título: Desempenho fisiológico de sementes de cultivares de algodão sob estresse hídrico Autor(es): Custódio, Débora Cristina Santos Abstract: The water stress represents a challenge for crop productivity and can substantially reduce yields. Therefore, the use of cotton cultivars adapted to deal with this abiotic stress becomes essential. The objective of this study was to evaluate the physiological performance of cotton cultivar seeds under water stress conditions. The experimental design used was completely randomized in a 3 x 5 factorial scheme, with three cultivars (FM 978GLTP, TMG 22GLTP and FM 970GLTP) and five osmotic potentials induced by polyethylene glycol solutions - PEG 6000 (0.0; -0.3; -0.6; -0.9 and -1.2 MPa), with four repetitions of 50 seeds. The variables analyzed were: water content, germination, root protrusion, first germination count, germination speed index, shoot length, root length and seedling fresh mass. The imbibition curve was conducted with four repetitions of 50 seeds distributed on Germitest paper moistened with two potentials (0.0 and -1.2 MPa) of PEG 6000. The seeds were weighed dry, and subsequently moistened at the following times: 0; 2; 4; 6; 8; 10; 12; 14; 16; 18; 20; 22 and 24 hours. The data were subjected to analysis of variance, with the means of osmotic potentials being compared using the F thesis (P<0,05), and the results from the weighing times were subjected to regression analysis. The results showed that severe water stress, in particular with osmotic potentials below -0.9 MPa, negatively affected the physiological performance of the studied cultivars. The FM 970GLTP cultivar was the least affected by water stress, while the TMG 22GLTP and FM 978GLTP cultivars were more sensitive, presenting lower germination and vigor results under water stress conditions. It was possible to observe the water absorption curve of the seeds of the studied cultivars only at 0.0 MPa potential, following the three-phase pattern.

Fenologia e conservação pós-colheita do caquizeiro sob condições semiáridas

2025-06-23T16:46:14Z

Título: Fenologia e conservação pós-colheita do caquizeiro sob condições semiáridas Autor(es): Silva, Luana de Jesus Abstract: Among the fruit plants in subtropical and temperate climates, the persimmon tree represents potential for the semi-arid region, due to its good climate adaptability and rusticity. Thus, the objective of the work was to characterize the phenological stages of the persimmon tree, from pruning to harvesting the fruits, during 2 production cycles in the semi-arid region of Minas Gerais and to evaluate the different packaging in the post-harvest conservation of the persimmon tree. The work was conducted partly in the field and partly in the laboratory. Fieldwork was conducted on a farm located in the municipality of Janaúba-MG, during the 2022/2023 harvest. To evaluate phenology, the behavior of the Giombo and Rama Forte varieties was observed during two production cycles of the crop. The statistical experimental design used was completely randomized (DIC), consisting of two treatments (two varieties), with 10 plants per variety chosen at random and four replications, in each plant four equidistant branches were selected. After pruning, the phenology of the plants was evaluated by determining the stages through weekly assessments: dormant bud, swollen bud, green tip, budding, flowering, fruiting, green fruit and harvest. In the laboratory, the experiment was conducted in a completely randomized design (DIC), in a split plot scheme, with four replications and the experimental unit consisting of four fruits, being: three types of packaging arranged in the plots and two storage periods in the subplots - 1 and 22 days. The attributes evaluated were: pH, titratable acidity, soluble solids, soluble solids and titratable acidity ratio (SS/TA), vitamin C content, carotenoids, phenolic compounds, astringency index, fresh mass, fruit diameter and length, firmness, brightness, Hue angle, and chromaticity. The results obtained allowed us to conclude that: during the 1st production cycle, the vegetative cycle of both varieties begins, on average, 8 days after pruning. There is variation in the duration of the phenological stages of the varieties. In the 2nd production cycle, the vegetative cycle of the varieties begins, on average, 14 and 41 days after the application of hydrogenated cyanamide. The application of hydrogenated cyanamide is efficient in breaking dormancy and sprouting of varieties. The use of polyethylene terephthalate packaging preserves the post-harvest quality of firmness, pH and Vitamin C of the fruits of the persimmon tree cv. ‘Strong Rama’. The different packaging does not affect the fresh mass, length and diameter, soluble solids, titratable acidity, SS/AT ratio, fruit color, and astringency index of persimmon fruits.

Seleção de isolados bacterianos no controle de Colletotrichum musae IN VITRO

2025-06-23T16:29:42Z

Título: Seleção de isolados bacterianos no controle de Colletotrichum musae IN VITRO Autor(es): Almeida, Luciele Barboza de Abstract: Banana (Musa spp.) is an economically important crop whose anthracnose, caused by Colletotrichum musae, is mainly treated using chemical fungicides. Plant growth-promoting bacteria (PGPBs) have several antagonistic mechanisms against phytopathogens and can be used as biological control. However, there is still a lack of studies on its applications in post-harvest treatment. Given this, the objective was to select bacterial isolates to control C. musae in vitro. In the in vitro test, bacterial isolates from the bacteriotheca collection of the Phytopathology Laboratory of the State University of Montes Claros were subjected to antibiosis tests by pairing, and volatile organic compounds by overlap, against C. musae. And subsequently, the fungal colony area, germination and sporulation of C. musae were evaluated. The experiments were conducted in a completely randomized design with 81 treatments (80 bacterial isolates + 1 control), each treatment consisting of three replications. The data were subjected to analysis of variance using the Scott-Knott test (p<0.05) and multivariate analysis. Isolates RZ65 (B. amyloquefaciens), RZ44 (B. pumilus) and RZ41 (B. amyloquefaciens) by the antibiosis test, and isolates B11.16 (B. pumilus) and RZ50 (B. pumilus) by the organic compounds test volatiles, reduced the colony area, number of germinated spores and number of spores produced of C. musae in vitro. Bacillus sp. (B1.18), B. tequilensis (B15.7), B. methylotrophicus (B3.2), B. amyloquefaciens (RZ41), B. pumilus (RZ44) and B. amyloquefaciens (RZ65) were the most promising bacteria in control of C. musae in vitro, by analysis of main components using multivariate. The bacterial isolates studied have the potential to control C. musae in vitro.