This study aimed to evaluate the effect of inoculants of endophytic bacteria producing indoleacetic acid (IAA) on the physiological quality of seeds and the production of seedlings of Corymbia citriodora (Hook.) KD Hill & LAS Johnson. In the physiological quality test of the seeds, the treatments used were individual inoculation with Priestia megaterium, Exiguobacterium sibiricum, Pantoea vagans strain 45URP4-1, and Bacillus sp.; joint effect of the four strains (mix); inoculation only with the carrier (cassava starch and activated charcoal); carrier with 1.0 μg mL⁻¹ of IAA; and non-inoculated control without IAA and without a carrier. In the production of seedlings in a greenhouse, the treatments were the same, except for the mix, which was replaced by P. vagans strain 7URP1-6 (Pvs7), as inoculation with the mix increased the number of abnormal seedlings. In the physiological quality test of seeds, seeds inoculated with the bacteria individually did not have the physiological quality impaired and the carrier created a microenvironment around the seeds, benefiting germination percentage, germination speed index, average germination time, and average germination speed. In the greenhouse, seedlings inoculated with Pvs7, P. megaterium and E. sibiricum were taller, with a larger stem diameter and dry mass of shoot, roots, and total. Seeds inoculated with E. sibiricum had higher averages for height, chlorophyll b content, and shoot and total dry mass, as well as a greater ability to colonize the rhizosphere and roots of C. citriodora, resulting in the production of higher-quality seedlings. Inoculation of seeds of C. citriodora with endophytic bacteria proved to be a promising alternative for plant development.

The objective of this work was to evaluate the influence of using a semi-hydroponic system on the agronomic and postharvest variables of strawberry cultivars. The experiment was conducted in a randomized complete block design, with cultivars Aromas, Camarosa, Festival, Merced, Oso Grande, and San Andreas, with eight plants per plot and five replicates. Agronomic and postharvest variables were evaluated. Cultivar San Andreas showed the highest values for the agronomic variables number of commercial fruits and total and commercial yield per plant, with the highest yield in October, November, and December. The postharvest variables moisture, firmness, pH, titratable acidity, and reducing sugars did not differ between cultivars. In a semi-hydroponic system, the San Andreas cultivar presents the best results for the agronomic variables related to fruit yield, with the highest yield in October and November.

Elaeis guineensis Jacq. (Arecaceae), commonly known as oil palm, is a major oilseed crop with wide applications in the food, cosmetic, and biofuel industries. Based on this, many somatic embryogenesis systems have been developed to enable clonal propagation. However, rooting responsiveness and acclimatization success are dependent on the genotype, which has been exhibiting low responsiveness. This study evaluated the in vitro performance of oil palm emblings from different genotypes in response to activated charcoal. Four genotypes (AM-05, AM-21, AM-29, and AM-33) were cultured under four activated charcoal concentrations (1.0, 2.0, 3.0, and 4.0 g L⁻¹) and in a charcoal-free control. Viable emblings were obtained for all genotypes, although protocol adjustments are required for less responsive materials. Genetically related genotypes exhibited superior development, suggesting a parental effect. Embling’s elongation was more effective at low concentrations or in the absence of activated charcoal. Furthermore, the addition of 2.8 g L⁻¹ activated charcoal to the culture medium enhanced secondary somatic embryogenesis, resulting in increased embling production. Additionally, the controlled conditions of in vitro cultivation, combined with activated charcoal, promoted anatomical changes, including reduced foliar and root structures and aerenchyma formation. These findings support the stage-specific use of activated charcoal as a practical strategy to improve the efficiency of E. guineensis clonal propagation through somatic embryogenesis.

Aims: Soil compaction is one of the main challenges in agriculture, negatively affecting cotton growth (Gossypium hirsutum L.), nutrition, and productivity. This study evaluated the efficacy of plant growth-promoting bacteria (PGPB), Exiguobacterium sibiricum, and Pantoea vagans in mitigating the effects of different soil compaction levels (65%, 75%, 85%, and 95%) on cotton performance. Methods: Parameters such as plant height, stem diameter, number of leaves, shoot dry matter (SDM), and nutrient content in leaves, stems, and roots were assessed. The methodology included variance analysis and mean clustering to identify significant differences among treatments using R software. Results: The results indicated that PGPB inoculation improved plant growth and nutrition even under high compaction levels. Cotton height increased by up to 45% in compacted soils (95%), while stem diameter and SDM also showed significant gains. Foliar nutrient levels of N (37.2 g kg⁻¹), Ca, and Mg remained within the adequate range for cotton cultivation, reflecting the efficiency of PGPB in enhancing nutrient absorption. Under severe compaction, Ca accumulation dropped to 18.2 g kg⁻¹, highlighting the physical constraints imposed on the roots; however, the bacterial action mitigated this impact. Additionally, bacterial strains increased the availability of N and P in the soil due to their ability to fix nitrogen, solubilize phosphates, and produce exopolysaccharides that improve soil structure. Conclusions: In conclusion, inoculation with Exiguobacterium sibiricum and Pantoea vagans is an effective strategy to mitigate the impacts of soil compaction on cotton. These bacteria promote plant growth and nutrition and enhance the soil’s physical and biological properties.

The area planted with Corymbia spp. clones is expected to increase in the coming years, despite their propagation challenges. This study aimed to evaluate mini-cutting size, mini-tunnel opening time, and the use of growth regulators in the clonal propagation of Corymbia spp. Four experiments were conducted using three clones: C. citriodora × C. torelliana, C. torelliana × C. citriodora, and E. urophylla, where E. urophylla was used as a control due to its ease of propagation. The results from each experiment were used to optimize the methodology for the subsequent one. Initially, three mini-cutting sizes were tested: 5, 10, and 15 cm in length. The second experiment evaluated three collection times of mini-cuttings after mini-tunnel opening: 0, 24, and 48 hours. The third experiment tested five concentrations of indole-3-butyric acid (IBA): 0, 500, 1000, 1500, and 2000 mg kg⁻¹. Finally, five concentrations of a formulated product containing different plant growth regulators (0, 1, 2, 3, and 4 mL L⁻¹) were assessed. All experiments were arranged in a randomized block design in a factorial scheme according to genotype. The following variables were evaluated: final rooted mini-cutting yield, survival, plant height, root length, and root, shoot, and total dry mass. Mini-cuttings of 15 cm performed best in promoting the growth of both hybrids. Regarding mini-tunnel opening time, the 24-hour interval after opening was optimal for C. citriodora × C. torelliana. Applications of 2000 and 1000 mg kg⁻¹ IBA promoted rooting in Corymbia spp., and rooted mini-cutting quality was improved with the application of 4 mL L⁻¹ of the growth regulator formulation.

Strawberry production in Brazil relies predominantly on cultivars developed outside the country. This study aimed to evaluate the agronomic and postharvest performance of strawberry cultivars, quantify the genetic dissimilarity among them using phenotypic data and SSR markers, and perform controlled crosses to initiate a breeding program. Five short-day cultivars and two day-neutral cultivars were evaluated for 18 quantitative traits. A total of 5,291 achenes and 332 seedlings were obtained from 19 successful hybrid combinations. The phenotypic characterization and genetic dissimilarity assessment of the cultivars enabled the identification of seven promising crosses for future breeding efforts.