Ana Claudia Costa Baratti

Selenium (Se) can be supplemented in the human diet through the consumption of foods rich in this element. However, these foods are often inaccessible to low-income populations. In this context, the enrichment of staple food crops can increase the nutritional quality of the product and contribute to efforts to reduce malnutrition. Thus, during in vitro culture, the culture medium can be enriched with elements such as Se to biofortify the plantlets. The objective of this study was to evaluate the production of Se-biofortified micropropagated banana plantlets. 'Prata Anã' Gorutuba banana plants were cultured in vitro and subsequently acclimatized. The experiment was conducted in a completely randomized design, and the treatments consisted of the addition of sodium selenate at Se concentrations of 0, 10, 20, 30, 40, and 50 µmol L-¹, with five replicates and six culture tubes per replicate. Growth parameters, photosynthetic pigment contents, biochemical parameters, and Se accumulation were evaluated in each treatment at 30 days of in vitro cultivation. The number of leaves, shoot length, and stem base diameter were evaluated at 90 days of greenhouse acclimatization. The intermediate concentration of 20 μmol L-¹ Se was the most suitable for obtaining plants with greater Se accumulation without adversely affecting phytotechnical traits and resulted in greater photosynthetic activity. Higher Se concentrations increased Se accumulation but negatively affected plant growth, indicating a dose-dependent toxic effect at elevated concentrations. During acclimatization, intermediate Se concentrations maintained a better balance between biofortification efficiency and plantlet quality. Photosynthetic pigments responded positively to lower Se concentrations, whereas antioxidant enzyme activity was not significantly affected. Overall, Se biofortification through micropropagation is feasible when appropriate concentrations are used to maintain plant quality and physiological stability.

The use of herbicides to control weeds in passion fruit orchards is a more accessible and lower-cost alternative. However, the lack of registered agrochemicals for the crop, combined with the scarcity of studies on their phytotoxic effects, makes this aspect one of the main obstacles to production. Thus, this study aimed to evaluate the tolerance of advanced sour passion fruit (Passiflora edulis Sims) seedlings to the application of different herbicides. The experimental design was randomized blocks, with seven treatments, four replications, and three plants per plot. The treatments consisted of a control (without herbicide application), sulfentrazone, diuron, S-metolachlor, ammonium glufosinate, imazethapyr, and terbuthylazine. It was observed that S-metolachlor caused the lowest levels of visual phytotoxicity, followed by imazethapyr and terbuthylazine, throughout the evaluation period. In contrast, ammonium glufosinate, sulfentrazone, and diuron caused greater phytotoxic effects, negatively affecting plant development. Overall, herbicide tolerance in sour passion fruit seedlings varies significantly depending on the active ingredient.

Citrus production is a significant agricultural activity in Brazil, the world's largest producer and exporter of orange juice. However, this production faces phytosanitary challenges, including postbloom fruit drop (PFD) caused by fungi of the genus Colletotrichum . The development of this disease is associated with climate conditions, such as temperature and leaf wetness duration (LWD). Citrus production in Brazil has recently migrated to regions with no records of greening disease (caused by Candidatus Liberibacter spp.), and these areas require assessments of the impacts of other diseases. Such assessments are essential to identify phytosanitary risks and implement effective management strategies to ensure sustainability and support the expansion of citrus production. The objective of this study was to conduct agroclimatic zoning for PFD using climate variables, such as mean temperature and LWD. The analysis covered the entire Brazilian territory, using data from 1989 to 2020, collected from the NASA/POWER platform. The areas were classified climatically as unfavourable, relatively favourable, or highly favourable. The results revealed that the North and Northeast regions are highly favourable for the development of the disease year-round, while the South, Southeast and Central-West regions present lower risk during the winter. The risk of disease occurrence in the main citrus-producing areas of the Southeast region is higher from January to March, and August to December. The analysis indicated that emerging citrus-producing areas exhibit higher climatic suitability from January to May. This study highlights the importance of management strategies, such as the use of fungicides and climate monitoring, to mitigate the impacts of PFD.

O controle químico de plantas daninhas em viveiros de frutíferas requer a escolha de herbicidas seletivos, capazes de controlar espécies invasoras sem comprometer o crescimento das mudas. Entretanto, há escassez de informações sobre a seletividade de herbicidas em espécies frutíferas durante a fase de viveiro. Assim, o objetivo deste estudo foi avaliar a sensibilidade de mudas de araticum-de-terra-fria aos efeitos fitotóxicos de diferentes herbicidas aplicados em pós-emergência. O experimento foi conduzido em delineamento inteiramente casualizado, com oito tratamentos e quatro repetições, utilizando três mudas por parcela com aproximadamente 1,0 m de altura. Foram testados os herbicidas fomesafen, glufosinato de amônio, glifosato, cletodim, carfentrazona-etílica, imazetapir e clorimuron, além de um controle sem herbicida. As avaliações de fitotoxicidade foram realizadas aos 7, 14, 21 e 28 dias após a aplicação, com base na escala da EWRC, bem como na determinação dos teores de clorofila a, b, total e da razão a/b. Os resultados indicaram que glufosinato de amônio e glifosato causaram os maiores níveis de injúria, enquanto fomesafen, cletodim, carfentrazona-etílica e imazetapir apresentaram menor fitotoxicidade. Conclui-se que esses herbicidas são os mais promissores para o manejo seletivo de plantas daninhas em viveiros de araticum-de-terra-fria.

One of the main challenges in citrus nursery plant production under protected environments is the space required for plant growth due to the large volume of containers and substrates, along with nutritional management demands. Hydroponics emerges as a promising alternative, offering more precise nutrient supply, efficient water use, reduced space requirements, and better control of growth conditions. This study aimed to evaluate the production of ‘Ponkan’ mandarin nursery plants in conventional cultivation and hydroponics systems, using five rootstocks: ‘Swingle’ citrumelo, ‘Rangpur’ lime, ‘Limeira’ and ‘Rubidoux’ trifoliate, and ‘Índio’ citrandarin. Two experiments were conducted in randomized blocks with five treatments, four replicates, and 18 plants per plot. One hundred and 50 days after grafting, growth and physiological parameters were measured, including scion length,plant height, stem diameters, number of leaves, root length, root volume, dry mass, Dickson quality index, leaf traits, photosynthetic pigments, chlorophyll a-fluorescence, gas exchange, and water use efficiency. The joint analysis of experiments was performed, and the means were compared using the Tukey’s test. In the conventional system, plants were produced in 3.2 dm3 bags with commercial substrate, while in the hydroponic one they were produced in 280 cm3 tubes with vermiculite placed in pools supplied with nutrient solution. Higher growth of ‘Ponkan’ mandarin nursery plants was obtained in the conventional system with ‘Swingle’ citrumelo, ‘Rangpur’ lime, and ‘Índio’ citrandarin rootstocks. Photosynthetic parameters showed no significant differences between rootstocks and production systems, except for photochemical dissipation coefficient, which was higher in hydroponics for plants grafted onto ‘Swingle’ citrumelo and ‘Rangpur’.

O cultivo da pitaia tem despertado crescente interesse devido ao seu elevado valor comercial e potencial de expansão no mercado. Contudo, a suscetibilidade de algumas cultivares a nematoides e a baixa taxa de enraizamento em determinadas variedades limitam a propagação por estacas, tornando a enxertia uma alternativa promissora. Assim, o presente estudo teve como objetivo avaliar o desempenho da enxertia em diferentes combinações de cultivares de pitaia utilizadas como enxerto e porta-enxerto. O experimento foi conduzido em Ingaí, Minas Gerais, em delineamento fatorial 5 × 2 (cinco cultivares como enxerto: ‘American Beauty’, ‘Golden’, ‘Dark Star’, ‘Vietnamese White’ e ‘Physical Graffiti’; dois porta-enxertos: ‘Cebra’ e ‘Orejona’), com avaliações aos 54, 78, 131 e 188 dias após a enxertia. Foram determinados o percentual de coloração dos cladódios, pegamento da enxertia, número e comprimento de brotações. Os resultados evidenciaram que ‘Golden’ e ‘Vietnamese White’ apresentaram maior proporção de enxertos verdes e menor murcha, sobretudo sobre o porta-enxerto ‘Orejona’. Já ‘Dark Star’ e ‘American Beauty’ tiveram menor compatibilidade, refletida em reduções no pegamento e vigor vegetativo, especialmente sobre ‘Cebra’. Conclui-se que as combinações ‘Golden’/‘Orejona’, ‘Physical Graffiti’/‘Orejona’ e ‘American Beauty’/‘Orejona’ são as mais promissoras para a produção de mudas enxertadas de pitaia.

Citriculture has worldwide importance, and monitoring the nutritional status of plants through leaf analysis is essential. Recently, proximal sensing has supported this process, although there is a lack of studies conducted specifically for citrus. The objective of this study was to evaluate the application of portable X-ray fluorescence spectrometry (pXRF) combined with machine learning algorithms to predict the nutrient content (B, Ca, Cu, Fe, K, Mg, Mn, P, S, and Zn) of citrus leaves, using inductively coupled plasma optical emission spectrometry (ICP-OES) results as a reference. Additionally, the study aimed to differentiate 15 citrus scion/rootstock combinations via pXRF results and investigate the effect of the sample condition (fresh or dried leaves) on the accuracy of pXRF predictions. The samples were analyzed with pXRF both fresh and after drying and grinding. Subsequently, the samples underwent acid digestion and analysis via ICP-OES. Predictions using dried leaves yielded better results (R² from 0.71 to 0.96) than those using fresh leaves (R² from 0.35 to 0.87) for all analyzed elements. Predictions of scion/rootstock combinations were also more accurate with dry leaves (Overall accuracy = 0.64, kappa index = 0.62). The pXRF accurately predicted nutrient contents in citrus leaves and differentiated leaves from 15 scion/rootstock combinations. This can significantly reduce costs and time in the nutritional assessment of citrus crops.

The aim of this work was to evaluate the potential use of the peel of pitaya fruits for jam production. Four pitaya jelly formulations with different peel proportions used in place of the pulp (0, 20, 40 and 60%) were evaluated. The inclusion of peel in the formulation of red pitaya jelly is viable, and the product quality is maintained, especially at a 20% peel proportion, which is better accepted by tasters than are higher proportions. The 20% substitution of pulp with peel resulted in higher mean consistency and overall impression values than the other formulations. The levels of soluble solids and titratable acidity and the soluble solids/titratable acidity ratio did not significantly differ among the products, with mean values of 64.6%, 1.05%, and 61.67% with 20%, 40% and 60% peel addition, respectively. Substituting pulp with pitaya mesocarp resulted in an increase in jelly pH. The adhesiveness and cohesiveness of the jellies increased as the percentage of peel increased. The microbiological results of this study indicate the absence of microorganisms in the jellies. Thus, the use of peel in jam production can minimize production losses while adding value to the product and reducing waste disposal in the environment.