Biometric features and oil contents of macauba (Acrocomia aculeata) palms natively growing in sites representatives of the Brazilian Cerrados (Campo Grande-CG, and Sao Gabriel do Oeste-SGO), and Pantanal (Corumba-CO, and Aquidauana-AQ) biomes were studied. The objective was to obtain data that could assist better planning for the exploitation of natural populations, and knowledge to help selection and breeding programs. Plant (spines presence; stem circumference; number and length of bunches) and fruits characteristics (fruits per bunch; size; mass; proportion of components-husk, pulp, shell and kernel; fruits moisture at ripening; pulp and kernel oil content) were measured from ten native palms from each site. There was variability in biometrics, biomass production potential and oil yield in the palms within each site and among the sites. No correlation was found between biometrics features and oil contents. On average, plants from CG showed better general productive characteristics than any other of the studied sites, but a large variability in fruits size. Palms from CO presented smaller fruits, but they were more homogeneous in size and with higher kernel oil contents. Fruits from SGO show bigger mass and size, but it did not result in higher fruit biomass production or oil yield. Although oil yields potential were almost half of what is usually measured in other areas of Brazil, results provided interesting data for a better planning to rational exploitation of native macauba groves in these areas. Variability within plants from all sites indicate that they could be a reserve of genetic materials for further development of cropping systems aiming production of oil and other useful products.

Abbreviations MAPA -Ministry of Agriculture, Husbandry and Food SupplyANVISA -Brazilian Health Surveillance Agency AI -acidity index PV-peroxide RI -refractive index K 232 -molar absorptivity at 232 nm K 270 -molar absorptivity at 270 nm FID -flame ionization detector SFC -Solid fat content FAC -composition of fatty acids MUFA -monounsaturated fatty acids † This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as doi: AbstractMacauba or macaw palm (Acrocomia aculeata) has great potential for oil production in tropical America biomes. This work aimed to describe a full set of procedures to obtain high quality crude and refined pulp oil. Crude oil was extracted by forced pressing of dried, mechanically pulped fruits that were collected directly from the bunch at ripening stage. Preliminary refining process sequentially encompassed degumming, neutralization, bleaching and deodorization. Identity and quality parameters (fatty acids composition, peroxide value, molar absorptivity at 232 and 270 nm, moisture, refractive index, saponification index, unsaponifiable matter, color, total carotenoids and solid fat content) were determined in all steps. Crude and refined oils presented about 64% of monounsaturated acids (oleic acid) and 26% saturated acids (mostly palmitic acid). Oil composition and physicochemical characteristics were maintained after refining, rendering high quality oil, suitable for multipurpose employments, such as food processing and biodiesel production. Practical applicationsMacauba palm is a widespread and high-yield oil bearing fruit from Tropical America that is being domesticated in Brazil. A whole processing of the pulp oil, including fruits harvest and postharvest, was developed at lab scale to render suitable oil for food and biofuels usages. Onwards the procedures could be scaled up and the cost effectiveness must be evaluated. Graphical abstractGood practices of harvesting, processing fruits, and refining, resulted in high oleic quality macauba pulp oil that complies with most standard requirements for crude and refined edible oils.

SUMMARYCowpea (Vigna unguiculata L. Walp) is the most important food grain legume in Africa. Cowpea is nodulated by rhizobium bacteria in almost all soils of the tropics, but studies performed in the 1970s and 1980s in Nigeria suggested only modest responses of grain yield in the field to inoculation of selected rhizobium strains. More recently, experiments performed in Brazil have shown that cowpea responded to inoculation of rhizobium selected locally and grain yields increased by up to 30%. We tested some of the Brazilian strains on cowpea at a site in northern Mozambique and at several sites in Northern Ghana. At all sites phosphorus fertilizer (26 kg P ha−1) was added to all plots. At the site in Mozambique despite considerable damage to the crop by the parasitic yellow witchweed (Alectra vogelii), grain yields were more than doubled by inoculation of one of the Brazilian strains and reached 1.4 Mg ha−1. In on-station experiments conducted in 2012 in June and August in northern Ghana using the local cowpea variety Padi-Tuya as the test crop, nodule weight at 35 days after planting (dap) tripled with rhizobium strain BR 3299 (530 mg plant−1) in August with the other inoculants (BR 3267 and a mixture of BR 3267 and BR 3299) also increased nodule weight to over 300 mg plant−1. In the first on-station experiment, grain yields were doubled by the inoculation of any of the three rhizobium strains, and in the second experiment, significant increases in grain yield ranged from 39% to 57% and reached over 2.0 Mg ha−1. Similar increases in nodulation and grain yield due to inoculation were observed in 22 on-farm trials. Nitrogen fertilizer application promoted vegetative growth but did not increase grain yield and nodulation. Inoculating cowpea with highly effective rhizobium strains can therefore enhance grain yield of smallholder farmers in Africa.

Contributions of plant-associated biological nitrogen fixation (BNF) may be important to N nutrition of grass~s. Eleven ecotypes of Panicum maximum were planted in the field in concrete cylinders containing soil (Typic Hapludult) that had a low but stable ' 5 N enrichment. Brachiaria radicans (cv. IRI 442) was used as the non-fixing control, and the plant aerial tissue was harvested eight times over a 390-day period. At the first harvest of the experiment (17 May 1984), the concentration of N in all the grasses was high and, subsequently, declined during the first 270 days of growth, reflecting the decreasing availability of soil N. Until soil N availability had become the main factor limiting plant growth, it was thought unlikely that any significant contribution of BNF would occur, and this was confirmed by the 15 N-enrichment data. At later harvests (February-April 1985), the N concentrations in the plants were lower and all the P. maximum ecotypes accumulated more than the B. radicans. Over this period, the '!N enrichment of all the P. maximum ecotypes was significantly lower than that of the B. radicans, indicating a contribution of plant associated BNF to the P. maximum ecotypes. Contributions of associated BNF to the P. maximum ecotypes were estimated to be between 24 and 38% of total N incorporated, equivalent to between S and 10 kg N ha -• per 30 days. The significant differences observed in 15 N enrichment between P. maximum genotypes suggest that further screening and selection of P. maximum ecotypes for high associated BNF is a worthwhile objective.

RESUMO -Quantificou-se a fixação biológica de nitrogênio (FBN) em cinco acessos de Arachis pintoi (BRA31534, BRA31828, BRA31796, BRA15121 e BRA30333) e dois de A. repens (BRA31801 e BRA31861). Os mesmos foram estabelecidos em um solo Latosolo Vermelho Escuro sujeito a inundação estacional, sendo a FBN estimada segundo a técnica da abundância natural do isótopo 15 N (d 15 N). Estolões dos acessos foram plantados em novembro de 1999, em parcelas de 2,0 m x 2,0 m, com quatro repetições, distribuídas em blocos ao acaso. A massa verde das plantas acima de cinco centímetros do solo foi colhida em janeiro de 2000 e seca em estufa a 65 o C até peso constante, sendo posteriormente pesada e moída para análise dos conteúdos em N e d 15 N, em espectrômetro de massa. Verificaram-se diferenças significativas entre os genótipos quanto à produção de matéria seca (MS) e N total, sobressaindo-se BRA31534 e BRA31828, com produções de 4,2 t/ha e conteúdos totais de N de 102 e 110 kg/ha, respectivamente. Os acessos BRA30333 e BRA31861 produziram apenas 2,6 t de MS/ha, com 59 e 65 kg/ha de N total, respectivamente. As taxas de FBN dos acessos testados, medidas por comparação dos seus teores de d 15 N com os de plantas não fixadoras crescendo na mesma área, variaram de 36% (BRA15121) a 90% (BRA31828) do N total das plantas, equivalente a 26 e 99 kg de N/ha, respectivamente. Verificou-se correlação positiva e significativa (r = 0,92, p<0,05) entre os conteúdos totais de N da planta e os conteúdos totais de N obtidos de fixação biológica (NDF), e correlação negativa e significativa (r = -0,93, p<0,01) entre NDF e o N total obtido do solo. Concluiu-se que a produção dos acessos mais promissores foi resultado de simbiose mais eficiente com as estirpes de Bradyrhizobium nativas do solo, com a FBN suprindo as necessidades nutricionais de N das plantas. Palavras-chave: Bradyrhizobium, cerrados, leguminosas forrageiras, isótopos de 15 N, leguminosas Determination of Biological Nitrogen Fixation by the Forage Groundnut (Arachis spp.)Using the 15 N Natural Abundance Technique ABSTRACT -The biological nitrogen fixation (BNF) of five Arachis pintoi (BRA31534, BRA31828, BRA31796, BRA15121 E BRA30333) and two A. repens (BRA31801 e BRA31861) accessions, grown in a Dark Red Latosol prone to seasonal flooding was evaluated using the 15 N natural abundance method (d 15 N). Stolons of each accession were planted in November 1999, in plots of 2.0 m by 2.0 m, with four replications allotted to randomized blocks. Plant mass above five cm was harvested in January 2000. There were significant differences among the tested accessions for dry matter (DM) production and total N content, with BRA31534 and BRA31828 producing 4.2 t/ha of DM, and 102 and 110 kg N/ha respectively. BRA3033 and BRA31861 produced only 2.6 t DM/ha and 59 and 65 kg/ha of total N, respectively. The proportion of N derived from N 2 fixation, estimated by comparison of the d 15 N of Arachis accessions with non N-fixing plants growing in the same area, ranged from 36% (BRA15121) to 90% (BRA31...