Lead is a toxic metal that affects plant growth and the ecosystem. This study evaluated the lead (Pb) bioaccumulation potential of vetiver (Vetiveria zizanioides L.), sunflower (Helianthus annuus L.), elephant ear (Alocasia macrorrhiza) and ‘embaúba’ (Cecropia sp.). The plant species were tested in a 50% nutrient solution - Hoagland and Arnon, constantly aerated, containing five Pb concentrations: 0, 50, 100, 200 and 400 mg L^-1). The treatments were arranged in a completely randomized design in a 4 x 5 factorial scheme, with four replicates. The Pb contents in the plants increased linearly with the Pb exposure concentration. Vetiver was the species with the highest Pb content in the shoots (260.24 mg kg^-1) and sunflower, in the roots (44925.20 mg kg^-1). Pb concentration of up to 100 and 50.9 mg L^-1 stimulated sunflower biomass and root length, respectively. None of the evaluated species met the hyperaccumulator criterion; however, sunflower and vetiver have the potential to be tested for phytostabilization purposes.

The objective of the present research was to evaluate different types and proportions of organic wates and soil classes for substrate formulation for Caesalpinia pulcherrima cultivation. The experiment was performed in a greenhouse, and treatments were composed by two soil classes (Oxisol and Entisols), three types of residues (organic compound from pruning + manure, urban waste compost and residue from the extraction of Agave sisalana fibers) and five residue:soil proportions (0:100, 20:80, 40:60, 60:40, 80:20, v/v). Plant height, stem diameter, number of leaves, rates of a, b and total chlorophyll, leaf area, root length, shoots and roots dry weight and the Dickson Quality Index were evaluated 90 days after sowing. All three types of residues evaluated showed potential to be used in the elaboration of growth substrates for the production of C. pulcherrima L. Sw. seedlings. The substrates formulated with 33%, 23% or 5% of organic tree pruning + animal manure, urban waste compost and residue of the Agave sisalana fiber extraction, respectively, promoted better quality of seedlings 90 days after sowing, regardless of the soil class.

Microorganisms with multiple ecological functions can be a useful biotechnological resource in integrated pest- and disease-management programs. This work aimed to investigate the potential endophytic and virulent effects of a strain of Purpureocillium lilacinum on organic cultivation in Brazil. Specifically, the strain’s ability to establish itself as an endophyte in common bean, soybean, and sunflower plants when inoculated via seed was evaluated. Furthermore, its antifungal activity against phytopathogens and its pathogenicity and virulence against insects of the order Lepidoptera, Coleoptera, and Hemiptera were evaluated. Furthermore, the strain was evaluated for its biochemical and physiological characteristics. For virulence bioassays, the experiments were conducted under a factorial scheme (2 × 3), with the following factors: (a) fungal inoculation and control without inoculum and (b) types of inocula (blastospores, aerial conidia, and metabolites). The treatments were sprayed on insect species at different stages of development. In summary, it was found that the SBF054 strain endophytically colonized the common bean, with partial recovery from the root tissues of soybean and sunflower plants, 30 days after inoculation; suppressed 86% of Rhizoctonia solani mycelial growth in an in vitro assay; and controlled eggs, nymphs, and Euschistus heros adults. These multifunctional abilities are mainly attributed to the strain’s mechanisms of producing metabolites, such as organic acids, soluble nutrients, and hydrolytic enzymes.

The objective of this work was to evaluate the initial growth of Bauhinia variegata L. when inoculated and fertilized with different proportions of organic compost. The experiment was performed in greenhouse in a completely random factorial (2 x 5) + 1 design, with 9 replicates, constituted by the presence or absence of inoculation, five proportions of organic compost:soil (0:100, 20:40, 40:60, 60:40 and 80:20; v/v) and one additional treatment with chemical fertilization without inoculation. Ninety days after sowing, the plant height, stem diameter, number of leaves, radicular length, dry mass of the aerial portion, dry mass of roots, total dry mass, Dicksosn's quality index (IQD), contents of nitrogen and carbon and the C/N ratio of the dry mass of the aerial portion, were evaluated. The inoculation with diazotrophic bacteria stimulated growth in height, stem height/diameter ratio, dry mass of the aerial portion, dry mass of roots, total dry mass and the foliar contents of nitrogen and carbon in seedlings of B. variegata L. Seedlings grown using organic compost showed better development when compared to seedlings grown only in soil with or without chemical fertilization. Seedlings grown with formulated substrate at a proportion of 16:84 (organic compost:soil + inoculation) exhibited higher IQD, therefore, this constitutes the recommended proportion for production of B.variegata L. seedlings.

O amendoim é uma oleaginosa de grande importância para a região nordeste, pois geralmente é cultivado por pequenos produtores que, em média, não ultrapassam dez hectares e que visam a aumentar sua renda e a diversificar a produção. Este trabalho objetivou avaliar o efeito das relações entre formas nitrogenadas (amoniacal e nítrica) de adubação no desenvolvimento inicial do amendoinzeiro. Para isso foi utilizada solução nutritiva completa com concentração única de 210 mg N L-1 fornecida em cinco proporções entre NH4+:NO3-: 100:0; 75:25; 50:50; 25:75 e 0:100. As unidades experimentais foram dispostas em delineamento inteiramente casualizado, com quatro repetições. As variáveis avaliadas foram: comprimento da parte aérea, comprimento da raiz, número de folhas, diâmetro do caule, massas de matérias fresca e seca da parte aérea e massas de matérias fresca e seca da raiz. Nas relações 100:0; 75:25 e 50:50, o amônio causou toxidez, reduzindo a fitomassa das plantas. Contudo, o nitrato (relação 0:100) causou menor redução, comparada com as reduções nas maiores concentrações do amônio. Nas relações 25:75 e 0:100, as plantas desenvolveram-se normalmente, apresentando maior fitomassa. O fornecimento exclusivo de nitrogênio na forma amoniacal não é a melhor opção para a nutrição do amendoinzeiro em fase inicial de crescimento.