Banana farming has an important position in Brazilian agricultural production. This position was earned due to the use of cultivation technologies and adequate fertilization made through recommendations of evaluation of foliar analyzes. The objective of this study was to determine the seasonality of the nutritional status of the diagnostic leaf during the development of banana tree. The experiments took place in the city of Sete Barras / SP, with cultivars such as Grande naine and Prata, on summer and winter. It was evaluated the influence of the collection of the diagnostic leaf in the stations, in six seasons during the development of the banana bunch and it was compared with the standard sampling. The values were submitted to analysis of variance, and when the F was significant, a comparison of means was performed. The sampling stations and the collection stages influence the nutrient behavior in the diagnostic leaf of both varieties, with exceptions for Mg and Mn. The average levels of nutrients during the collection stages showed no difference among the 1st, 2nd, 3rd and 4th (standard). Even for the ‘Prata’ and Grande Naine banana plants cultivated in the Ribeira Valley, there is no significant alteration in the nutrient content of the foliage among the 1st to 4th stages, allowing an increasing of collection for foliar tissue analysis.

The quantification of nutrients accumulated and exported by banana bunches provides information on the crop nutritional requirements. Thus, the aim of this work was to determine the nutritional demand of 'Grande Naine' and 'Prata Comum' banana bunches in the region of Vale do Ribeira, state of São Paulo. Bunch sampling was carried out in six harvest seasons, summer, and winter. The results of dry matter production and nutrient accumulation in bunches were submitted to analysis of variance. Relative growth rates (TCR), organogenic net accumulation (TALON), export and order of nutrient accumulation in bunches were estimated. K and N were the nutrients most accumulated and exported by both cultivars. In har-vest period 5 (commercial harvest), more dry matter was produced in the summer and more nutrients were accumulated in the winter. The highest TCR values were observed between periods 2 and 3 in the summer and between 0 and 1 in the winter, but it did not always follow TALON. The results obtained are important to adapt the nutritional management of these cultivars to the study region, especially in relation to the growing season, due to the longer permanence of the bunch on the plant in the winter and greater demand for nutrients until commercial harvest.

Pseudostem is an abundant residue after harvesting of the banana bunch, serving as a source of water, nutrients and organic substances. The present study aimed to evaluate the effect of pseudostem waste on ‘Nanica’ banana (Musa spp. AAA) cultivar in greenhouse under contrasting environmental conditions. For this, an experiment was carried out in in the São Paulo State University -UNESP in a randomized block design in a 2 x 2 factorial scheme (presence or absence of waste and two seasons), consisting of four replicates of three experimental plots with two pots per plant. One season was early November/2018 (Summer) and the other half of May/2019 (Winter). A 40 cm portion of the pseudostem collected from of a freshly harvested plant was sectioned into 10 cm portions and placed under the substrate of the seedling-containing pot at both times. Periodically, height, pseudostem diameter and leaf emission were evaluated. After the release of leachate by the residue, plants were taken to the laboratory, and the area of leaves and roots, their respective masses, and the leaf nutrient content were determined. The nutritional composition of the residue was evaluated before being applied for both seasons. In summer, accumulated dry matter in the different organs, leaf area and root area was higher in the presence of the residue, while in winter, only root dry mass was higher (P < 0.01). The application of residue had a consistent effect on root growth, which can be exploited in the field.

Banana fruits are susceptible to chilling injury (CI) under field conditions, which significantly impairs fruit quality. Cold tolerance varies among genotypes; however, only a limited number of cultivars have been identified as tolerant and are commercially cultivated. This study aimed to investigate the physiological responses and quality attributes of banana cultivars exposed to natural cold fronts during development, compared with fruits developed under summer conditions. Furthermore, it evaluated whether the B genome confers greater cold tolerance, driven by a more efficient antioxidant mechanism, thereby supporting its recommendation for cultivation in regions prone to low temperatures. Bunches were harvested in winter following five natural cold fronts, during which air temperatures fell below 12 °C (137 h). The experimental design followed a completely randomized design in a factorial arrangement. Consecutive cold fronts intensified CI symptoms up to the fourth exposure event. CI severity was highest in ‘Grande Naine’ (AAA), which exhibited lower L*, a*, and b* values at the ripe stage compared to ‘BRS Princesa’ (AAAB) and ‘Prata Catarina’ (AAB), along with greater deviations relative to summer-harvested fruits. Malondialdehyde (MDA), total phenolic content, and antioxidant enzyme activities (SOD, CAT, APX, and POD) in the peel of unripe fruits were significantly higher during winter, particularly in ‘BRS Princesa’ and ‘Prata Catarina’, compared to ‘Grande Naine’. Proline accumulation followed a similar pattern, with the highest levels observed in ‘BRS Princesa’, followed by ‘Prata Catarina’ and ‘Grande Naine’. The findings indicate that ‘BRS Princesa’ exhibits greater tolerance to cold stress and highlights of the contribution of the B genome. Phenolic content was identified as a consistent marker of seasonal variation across cultivars.

A avaliação nutricional das plantas é feita por meio de análises químicas ou pela diagnose visual e é preciso conhecer os padrões característicos de deficiência nutricional de cada elemento. O processamento digital de imagens (PDI) é um exemplo do uso de tecnologia na agricultura. Neste trabalho aplica-se o PDI para identificação da sintomatologia de deficiência em imagens digitais de folhas de bananeiras, induzidas à deficiência dos nutrientes de N, P e K. Realizou-se o experimento em duas etapas: 1) em casa de vegetação, com mudas submetidas ao delineamento experimental em blocos casualizados em esquema fatorial 5x5, com três repetições. Os fatores foram variação nutricional (Solução completa, omissões individuais de N, P, K e um controle com o cultivo em solo), e época de amostragem aos 0, 30, 60, 90 e 120 dias após a aplicação dos tratamentos; 2) experimento com PDI, aplicado em quatro fases: coleta e digitalização das amostras, extração dos histogramas, seleção de atributos e classificação, executados com uma base de dados para cada época estudada (0, 30, 60, 90 e 120 dias). As maiores taxas de acurácias do experimento foram apresentadas pelos classificadores com redes neurais artificiais (RNA), iguais a 66,7%, 62%, 76,7%, 62,3%, 68,3%, nas épocas 0, 30, 60, 90 e 120, respectivamente. Evidencia-se um bom desempenho encontrado pelos classificadores com RNA, verificado pelas especificidade (90%, 98%, 97%, 97% e 98%) sensibilidade (93 %, 77%, 93%, 75% e 82%) nas épocas 0, 30,60,90 e 120, respectivamente, dos modelos.

Floods are increasing worldwide because of the climate change. On the other hand, it is necessary to provide an adequate destination for the large amount of residue produced after banana harvesting. The objective of this study was to evaluate the effect of pseudostem residue on the recovery of banana seedlings subjected to waterlogging. The experiment was carried out in Registry, SP, Brazil, in a greenhouse, in the autumn and spring in 2021, using a design in divided plots with two factors and six repetitions. Waterlogging treatment was carried maintaining a layer of water in pots for three days (72 h). After drainage, pseudostem residue was added to half of the pots. seven days after the start of recovery, detected reduction of 20.3% in height and 28.7% in leaf area, accumulation of soluble carbohydrates in roots and leaves in autumn, reduction in chlorophyll, N, Mg and Zn contents, as well as the activity of POD, SOD and APX enzymes in roots and leaves. The residue proved to be beneficial after stress due to a 37.8% increase in the root area, recovery of Mg and Zn levels in root and leaf, prevention of elevation of activity of POD and SOD enzymes in leaves, APX in root. In the absence of stress, it reduced the activity of antioxidant enzymes; therefore, it should be used regardless of crop area be subject waterlogging.