Álvaro Brasil Barbosa Neto

In Amazonian Spodosols, soil acidity and nutrient constraints limit the cultivation of cutleaf groundcherry. One sustainable alternative for cultivating this species is the use of Trichoderma inoculants, but studies on their use in this crop are scarce. This study evaluated whether rice-based inocula of Trichoderma harzianum (TH) CCB-LA101 and T. viride (TV) CCB-LA103 improved growth and fruit production of cutleaf groundcherry and whether the responses varied with the application dose. Plants were grown in a randomized complete block design with a 2 × 3 factorial arrangement: two Trichoderma species and three inoculum doses applied to the soil (0, 4, and 8 g plant⁻¹; Trichoderma concentration of 3.2 × 10⁹ CFU g⁻¹). Species and dose affected fruit width, length, number, and yield, with TH more effective than TV at increasing fruit number and yield. The contrast between inoculated and non-inoculated plants was significant for all traits. The 8 g plant⁻¹ dose significantly increased fruit number and yield by 22.8% and 17.7%, respectively, relative to the non-inoculated control, whereas fruit width and fruit length decreased by 8.3% and 7.3%, respectively. Considering the six treatment combinations, the 8 g plant⁻¹ TH inoculum (TH8) was the only treatment to significantly increase fruit yield, with net returns for smallholders estimated at USD 1104.46 ha⁻¹. Therefore, under the tested conditions, TH8 could be used to grow cutleaf groundcherry in Amazonian Spodosols.

O cubiu (Solanum sessiliflorum Dunal) é uma planta amazônica subutilizada. A fim de retirar a pilosidade urticante do fruto, foram criadas 1000 plantas mutantes irradiando com 150 Gy de radiação no genótipo CUB-08. Em seguida, a partir da geração M2 foi iniciado a seleção pelo método genealógico. A fim de avaliar precocemente a produtividade das famílias mutantes M2:3 um experimento foi realizado em um Latossolo Amarelo em Manaus, Amazonas, nos meses de dezembro a maio de 2018/2019, com nove progênies M2:3 mais a testemunha CUB-08. A semeadura foi feita em copos de plástico de 180 mL, após 90 dias as mudas foram transplantadas a campo seguindo o delineamento de blocos casualizados com 10 tratamentos, 4 repetições e 8 plantas por parcela no espaçamento de 1,2x1,0 m. Antes do transplante foi colocado na cova, um litro de esterco de galinha curtido, 30 g de superfosfato triplo e 20 g de cloreto de potássio. Foram realizadas 5 colheitas e avaliada a massa total de frutos por parcela. Os dados foram submetidos a ANOVA e teste de médias de Duncan. Os resultados mostraram que a produtividade das progênies variou de 6,11 a 12,44 t ha-1 e média de 8,57 t ha-1. Entretanto, CUB-08 produziu 7,86 t ha-1. Isto mostra que a radiação gama criou variabilidade genética para produtividade, tendo destaque as progênies P12 (12,44 t ha-1) e P28 (11,35 t ha-1), as quais foram significativamente mais produtivas que CUB-08. Portanto, a radiação gama poderia ser utilizada para aumentar a produtividade de frutos em cubiu.

The study carried out in Porto Velho-Rondônia evaluated soil erodibility in forest and pasture (brachiaria) areas. A total of 130 soil samples were collected, 70 in the pasture and 60 in the forest, in 90 m x 60 m and 90 m x 50 m grids, respectively, at a depth of 0.00 - 0.20 m. The samples were analyzed for texture, organic matter (OM) and erodibility (K, Ki ppeh, Tcppeh factors). In the forest, there was a higher clay and OM content, which increased soil stability, while the pasture area had a higher sand content. The K factor was higher in the forest (0.03) than in the pasture (0.01), suggesting greater susceptibility to erosion in the forest, possibly due to the sand content. Spatial variability was low in both areas, with the greatest variability in the silt variable (33.27% in the forest and 30.07% in the pasture). Spatial dependence was strong in most variables for both areas, especially for the Tcppeh factor in the pasture (28.10). The spherical model adjusted better to the forest, while the exponential model was more suitable for the pasture. In the pasture area compared to the forest area, the measures of central tendency presented a symmetrical distribution, and both showed very close values, which justifies normal distributions of the analyzed data. In the k factor, it was lower in the brachiaria area (0.01), and a higher value was observed in the forest area (0.03). Therefore, the high value in the forest area may be related, in addition to the OM attribute, to the sand factor, which may also be influencing the forest, since the higher the sand content, the more difficult the bonding between the particles will be, making the soil less aggregated. Topography influenced erosion, especially in sloping pasture areas, where runoff transports fine particles such as clay and OM. In general, pasture presented greater heterogeneity and erodibility compared to forest, despite adequate management. These results reinforce the importance of considering soil structure in areas with different types of vegetation.

New tomato lines adapted to Amazonian conditions have been developed by the National Institute for Amazonian Research, but have not yet been evaluated for hydroponic cultivation. The aim of this study was to evaluate the production of these lines in a hydroponic system in the municipality of Manaus-AM. The experiment was carried out at Hidroponia Green Health (02°58'26.35“ S and 60°04'39.94” W), in a greenhouse, using the NFT (Nutrient Film Technique) system during the rainy season (January to April). A PLANTPAR nutrient solution were used for the vegetative phase and another for the productive phase, adjusting the pH (5.5-6.5) and electrical conductivity (1.3-1.5 dS m-1) daily and replacing the nutrient solution every 15 days. A completely randomized block design was adopted, with 10 treatments [8 lines + 2 controls (Yoshimatsu and Santa Cruz Kada), 3 replications and 5 plants per plot, with a spacing of 0.60 × 0.50 m between lines and plants respectively, and conducted with a single stem. Cultivation and pest and disease were control with the application of acaricide, insecticide and fungicide. The results showed that the lines varied from 3 to 30 t/ha, Yoshimatsu 17 t/ha and Santa Cruz Kada 10 t/ha. The lines P28-4-4-8 (30 t/ha) and P28-8-40-7 (27 t/ha) produced significantly more than the controls according to Duncan's test (P<0.05). This indicates that these strains could be launched as cultivars for hydroponic cultivation.