RESUMO O umbuzeiro e umbu-cajazeira demandam informações sobre as características de acessos potenciais para implantação comercial e preservação. Assim, objetivou-se avaliar o teor foliar e ciclagem dos nutrientes de 15 acessos de umbuzeiro e um de umbucajazeira. Os tratamentos constaram de 16 acessos: BGU -44, BGU-45, BGU-47, BGU-48, BGU-50, BGU-75, EPAMIG-01, EPAMIG-03, EPAMIG-04, EPAMIG-05, EPAMIG-06, EPAMIG-07, EPAMIG-09, EPAMIG-13, umbuzeiro de origem desconhecida e umbu-cajazeira Princesa. Adotou-se o delineamento experimental inteiramente casualizado, com três repetições, constituídas de uma planta cada. Foram mensurados os teores de nutrientes nas folhas, nas fases de emissão de fluxo foliar e senescência das folhas, nas safras de 2015/2016 e 2016/2017, e determinou-se a taxa de retranslocação de N, P, K e Mg. Verificou-se que os acessos denotaram teores médios de nutrientes na folha de 28,6; 27,6; 9,5; 4,20; 2,5 e 2,0 g kg-1 com ordem decrescente N>Ca>K>Mg>S>P, respectivamente, e 103,61; 86,22; 82,12; 60,2; 16,0 e 3,52 mg kg-1 de Fe>B>Na>Mn>Zn>Cu, respectivamente. O acesso BGU-48 revelou maior eficiência de retranslocação de N e P nas folhas e o BGU-50 expressou eficiência de reciclagem para K e Mg. A ordem das taxas de retranslocação é K>P>N>Mg sendo maior na safra 2015/2016.

ABSTRACT Information is needed on the characteristics of potential accessions of Spondias tuberosa Arruda Câmara (umbu) and Spondias sp.(umbu-caja) for commercial planting and preservation. Thus, the objective was to evaluate the leaf contents and cycling of nutrients of 15 accessions of umbu and one of umbu -caja. The treatments consisted of 16 accessions: BGU-44, BGU-45, BGU-47, BGU-48, BGU-50, BGU-75, EPAMIG-01, EPAMIG-03, EPAMIG-04, EPAMIG-05, EPAMIG-06, EPAMIG-07, EPAMIG-09, EPAMIG-13, umbu of unknown origin and the umbu-caja Princesa. A completely randomized experimental design was adopted, with three replicates, consisting of one plant each. Nutrient contents in the leaves were measured in the leaf flushing and leaf senescence phases in the 2015/2016 and 2016/2017 seasons, and the N, P, K and Mg retranslocation rates were determined. The accessions showed average leaf nutrient contents of 28.6, 27.6, 9.5, 4.20, 2.5 and 2.0 g kg-1 with the descending order N>Ca>K>Mg>S>P, respectively, and 103.61, 86.22, 82.12, 60.2, 16.0 and 3.52 mg kg-1 of Fe>B>Na>Mn>Zn>Cu, respectively. The accession BGU-48 had higher N and P retranslocation efficiency in the leaves and BGU-50 showed recycling efficiency for K and Mg. The order of retranslocation rates is K>P>N>Mg, being higher in the 2015/2016 season.

ABSTRACT Amphibians inhabiting agricultural areas are constantly exposed to large amounts of chemicals, which reach the aquatic environment during the rainy season through runoff, drainage, and leaching. We performed a comet assay on the erythrocytes of tadpoles found in the surroundings of agricultural fields (soybean and corn crops), where there is an intense release of several kinds of pesticides in different quantities. We aimed to detect differences in the genotoxic parameters between populations collected from soybeans and cornfields, and between them and tadpoles sampled from non-agricultural areas (control group). Tadpoles collected from ponds located at soybean fields had significantly more DNA damage, followed by tadpoles collected from cornfields. In contrast, animals sampled from non-agricultural areas had the lowest incidence of DNA damage. In addition, we found a negative correlation between the parameters of the comet assay and the area of the ponds surrounding soybean. This correlation indicates a possible dilution effect in the concentration of pesticides. Finally, Physalaemus cuvieri Fitzinger, 1826 seems to be a good bioindicator for detecting the genotoxic effects of field agricultural insecticides; therefore, we suggest that this species should be used in environmental biomonitoring studies, since it is common and abundant where it occurs.