Simone Rodrigues da Silva

Climate change continues to be one of the most significant challenges facing global horticultural production

The high dropout rate in higher education courses is widely recognized as a significant challenge in the Brazilian educational context, prompting extensive academic analysis and debate. Researchers highlight that socioeconomic factors play a crucial role in increasing dropout rates among students. Understanding these factors is essential for formulating effective strategies to promote retention and completion of university courses. Investigating and understanding the specific causes of dropout in Chemistry Teaching degree programs is vital for developing targeted interventions, guiding adjustments in student welcoming processes, curriculum structure, and the support offered to students, thus improving the educational experience and increasing course completion rates. The objective of this article was to identify the main factors that determine dropout in the Chemistry Teaching degree program at the Federal University of Roraima, considering the cohorts of students who dropped out between 2016 and 2023. A case study with a qualitative and quantitative investigation was conducted, using online questionnaires to identify the determining causes of dropout. The sample included 33 dropouts, of whom 17 responded to the questionnaire. The responses allowed the identification of the main reasons cited as causes of dropout, such as difficulties adapting to university life and socioeconomic aspects, closely related to the challenges of balancing work and study.

The production of fruit crops plays a vital role in the agricultural sector, contributing significantly to the social and economic development of rural communities. In Brazil, fruit production is diverse due to favorable edaphoclimatic conditions, with avocado (Persea americana Mill.) emerging as an important crop. Its production continues to expand in both cultivated areas and yield, making it a key export to non-producing countries. However, despite its importance, nutritional management information, crucial for achieving high yields, remains limited. Current guidelines on nutrition monitoring are outdated, general, and based on data from other countries with different edaphoclimatic conditions, making them not directly applicable to Brazilian orchards. Furthermore, outdated nutritional information becomes less reliable over time, as climate change alters soil conditions and crop nutrient concentrations and requirements, reinforcing the need for the establishment of up-to-date and specific nutritional information. This study aimed to establish nutritional standards for ‘Hass’ avocado production using the Diagnosis and Recommendation Integrated System (DRIS) and Compositional Nutrient Diagnosis (CND) methodologies, and to define sufficiency ranges (SRs) and Critical Levels (CLs) for both macronutrients (N, P, K, Ca, Mg, and S) and micronutrients (B, Cu, Fe, Mn, and Zn). The analyses were based on yield (t ha⁻¹) and leaf nutrient content data from commercial orchards, with datasets divided into younger (4–9 years) and older (10–26 years) plant groups. The DRIS effectively established nutritional standards for younger plants, explaining 11% of yield variation through nutritional balance. CND, in turn, was effective for both groups, accounting for 14% of yield variation and outperforming DRIS in associating nutritional status with productivity. SRs and CLs for ‘Hass’ avocado production were defined using both DRIS and CND. Together, these indices and diagnostic parameters offer valuable tools for enhancing nutritional monitoring and fertilization strategies in Brazil. Notably, SRs and CLs varied according to plant age.

Health-conscious consumers are looking for healthier foods that promote health and well-being

Cambuci [Campomanesia phaea (O.Berg) Landrum] is a native Brazilian fruit tree species from the Atlantic Forest, belonging to the Myrtaceae family, with great potential for commercial exploitation. The propagation of this species is limited to seeds, which exhibit low and uneven germination, posing a challenge for large-scale seedling production due to potential dormancy. The objective of this study was to verify the existence of dormancy in cambuci seeds and determine the most effective dormancy-breaking treatment. First, an X-ray test was conducted on the seeds, and the results were correlated with their germination and tetrazolium test outcomes. Subsequently, different methods were applied to overcome dormancy, including stratification, soaking, and gibberellin treatments. Cambuci seeds exhibit simple non-deep physiological dormancy, which can be overcome by stratification for 28 days at 15 ^oC.

Native to the Brazilian Atlantic Rainforest, cambuci fruits can be consumed either in natura or in the processed form, and cambuci trees can be used to recover degraded areas. However, studies regarding cambuci germination and seedling development are scarce. The main aim of this study was to understand how different substrates and containers influence the growth of cambuci seedlings. To this end, two experiments were conducted: five different substrates were tested in the first experiment, and based on the multivariate analysis of the first experiment, the effect of combination of the best-performing substrates and three commonly employed plant growth containers on seedling development was investigated. Overall, good quality cambuci seedlings were obtained when they were grown in the commercial pine bark substrate and peat and perlite mixture in a 260 cm3 container.