Impact of percentage and particle size of sugarcane biochar on the sorption behavior of clomazone in Red Latosol

Biochar is a carbonaceous material that has excellent potential as a fertilizer and soil conditioner. However, there is a lack of information concerning the effects of the amount and particle size of this pyrogenic material on the soil sorption capacity. In this work, evaluation was made of changes in clomazone (CMZ) sorption in a Red Latosol following soil conditioning using different percentages (0.25, 0.5, and 1% w/w) of sugarcane biochar in three particle sizes (<106, 106-508, and 508-610 μm). The conditioned soils presented apparent sorption coefficients (Kd) up to 1300 times higher than that of pure soil, besides changes in the behavior of CMZ sorption. The biochar particle size and percentage influenced sorption of the herbicide as well as its retention in the amended soil during desorption processes. Both sorption and desorption Freundlich constants were linearly correlated with the external surface area of the biochar present in the soil

Parâmetros genéticos, dissimilaridade e desempenho per se em acessos de abóbora

A abóbora tem grande importância na alimentação humana e animal, principalmente para a agricultura familiar. O banco de germoplasma de hortaliças da Universidade Federal de Viçosa (BGH-UFV) possui coleção de acessos de abóbora com ampla variabilidade genética. Toda esta variabilidade genética é de grande importância para o melhoramento genético. Porém, pouco se sabe sobre o verdadeiro potencial do BGH-UFV, pois há poucos estudos com informações desses acessos. Objetivou-se obter informações sobre os parâmetros genéticos, dissimilaridade e desempenho per se de acessos de abóbora do BGH-UFV. Foram avaliados 11 descritores morfoagronômicos em 55 acessos e três cultivares comerciais. Foram estimados parâmetros genéticos, ganho esperado com a seleção, correlações fenotípicas, genotípicas e ambientais. Para o estudo de dissimilaridade, foi realizado o teste Tocher e dispersão gráfica das duas primeiras variáveis canônicas. Houve variabilidade genética entre os acessos, com predominância dos efeitos genéticos sobre os ambientais. É esperado maior ganho de seleção para a massa por fruto, aspecto fitossanitário e localização do nó da primeira flor masculina. As cultivares comerciais Butternut e Tetsukabuto se destacaram em função da menor massa por fruto e maior precocidade de florescimento, porém tiveram os piores resultados quanto ao aspecto fitossanitário. Há estimativas negativas de correlação entre o aspecto fitossanitário com o hábito de crescimento, comprimento e taxa de crescimento da rama principal, indicando que plantas compactas podem ter maiores problemas fitossanitários. O cruzamento do acesso BGH-7003 ou da cultivar Butternut com os acessos BGH-1946 ou BGH-7765 podem gerar progênies com potencial para o melhoramento genético.Pumpkin is very important in human and animal food, especially concerning family farms. The germplasm bank of vegetables of Universidade Federal de Viçosa (Federal University of Viçosa, UFV-BGH), Brazil, has several pumpkin accessions with wide genetic variability. All this genetic variability is of great importance for plant breeding. However, little is known about the true potential of BGH-UFV, because there are few scientific papers published with information on these accessions. The objective was to obtain information on genetic parameters, dissimilarity and performance of BGH-UFV pumpkin accessions. We evaluated 11 morphological descriptors of 55 accessions and three cultivars. The genetic parameters, expected gain with selection, phenotypic, genotypic and environmental correlations were estimated. For the dissimilarity study, the Tocher test was carried out and graphic dispersion of the canonical variables was evaluated. There was genetic variability among accessions, with a predominance of genetic effects over the environment. Higher gain selection for mass per fruit, plant appearance and location of the first male flower node are expected. The commercial cultivars Butternut and Tetsukabuto have excelled due to the lower mass per fruit and precocity of flowering, but they had the worst results in terms of phytosanitary aspect. There are negative correlation estimates between the phytosanitary aspect and growth habit, length and growth rate of the main stem, indicating that compact plants may have greater phytossanitary problems. Crossing accession BGH-7003 or cultivar Butternut with accessions BGH-1946 or BGH-7765 can generate progenies with potential for breeding

Genomic history of coastal societies from eastern South America

Sambaqui (shellmound) societies are among the most intriguing archaeological phenomena in pre-colonial South America, extending from approximately 8,000 to 1,000 years before present (yr bp) across 3,000 km on the Atlantic coast. However, little is known about their connection to early Holocene hunter-gatherers, how this may have contributed to different historical pathways and the processes through which late Holocene ceramists came to rule the coast shortly before European contact. To contribute to our understanding of the population history of indigenous societies on the eastern coast of South America, we produced genome-wide data from 34 ancient individuals as early as 10,000 yr bp from four different regions in Brazil. Early Holocene hunter-gatherers were found to lack shared genetic drift among themselves and with later populations from eastern South America, suggesting that they derived from a common radiation and did not contribute substantially to later coastal groups. Our analyses show genetic heterogeneity among contemporaneous Sambaqui groups from the southeastern and southern Brazilian coast, contrary to the similarity expressed in the archaeological record. The complex history of intercultural contact between inland horticulturists and coastal populations becomes genetically evident during the final horizon of Sambaqui societies, from around 2,200 yr bp, corroborating evidence of cultural change

Impact of percentage and particle size of sugarcane biochar on the sorption behavior of clomazone in Red Latosol

Abstract Biochar is a carbonaceous material that has excellent potential as a fertilizer and soil conditioner. However, there is a lack of information concerning the effects of the amount and particle size of this pyrogenic material on the soil sorption capacity. In this work, evaluation was made of changes in clomazone (CMZ) sorption in a Red Latosol following soil conditioning using different percentages (0.25, 0.5, and 1% w/w) of sugarcane biochar in three particle sizes (<106, 106-508, and 508-610 µm). The conditioned soils presented apparent sorption coefficients (Kd) up to 1300 times higher than that of pure soil, besides changes in the behavior of CMZ sorption. The biochar particle size and percentage influenced sorption of the herbicide as well as its retention in the amended soil during desorption processes. Both sorption and desorption Freundlich constants were linearly correlated with the external surface area of the biochar present in the soil