Estresse salino em genótipos de amendoim na fase inicial

Salt stress impairs the early development of the peanut crop. However, the intensity of its effects depends on other factors, such as species or cultivar. The objective of this study has been to evaluate the effects of salt stress on the early growth of peanut genotypes. The experiment was carried out in an agricultural greenhouse under pot conditions at the University for International Integration of the Afro-Brazilian Lusophony in Redenção/CE/Brazil. The treatments were: two levels of electrical conductivity of the irrigation water (2.0 and 5.0 dS m-1) and five peanut genotypes (cultivar BR-1, Accession 08, 28, 43, and 130). They were implemented in a factorial design (2 × 5) under a completely randomized design with five replications. The following variables were evaluated at 34 days after sowing: number of leaves, plant height, leaf area, stem diameter, shoot dry mass, electrical conductivity of the saturated soil extract, and pH. Irrigation water with a conductivity of 5.0 dS m-1 reduced leaf area, plant height, stem diameter, number of leaves, and shoot dry matter of the peanut genotypes cultivar BR-1, Accessions 08, 28, 43, and 130. It also raised the pH and electrical conductivity of the saturated soil extract in relation to the water with lower conductivity (2.0 dS m-1).O estresse salino prejudica o desenvolvimento inicial da cultura do amendoim. Contudo, seus efeitos possuem intensidade que dependem de outros fatores, como as espécies ou cultivar. Objetivou-se avaliar os efeitos do estresse salino no crescimento inicial de genótipos de amendoim. O experimento foi conduzido em estufa agrícola sob condições de vaso na Universidade da Integração Internacional da Lusofonia Afro-Brasileira em Redenção/CE. Os tratamentos foram: dois níveis de condutividade elétrica da água de irrigação (2,0 e 5,0 dS m-1); e cinco genótipos de amendoim (cultivar BR-1, Acesso 08, 28, 43 e 130). Foi implantado num esquema fatorial (2 × 5) sob delineamento inteiramente casualizado com cinco repetições. Aos 34 dias após a semeadura foram avaliadas as seguintes variáveis: número de folhas, altura de plantas, área foliar, diâmetro do caule, massa seca da parte aérea, condutividade elétrica do extrato de saturação do solo e o pH. A água de irrigação com condutividade de 5,0 dS m-1 reduz área foliar, altura de planta, diâmetro do caule, número de folhas e a matéria seca da parte aérea de genótipos de amendoim, cultivar BR-1, Acessos 08, 28, 43 e 130. Também eleva o pH e a condutividade elétrica do extrato de saturação, em relação à água de menor condutividade (2,0 dS m-1)

Potassium fertiliser on productivity in the lima bean

In Brazil, the lima bean bean is cultivated throughout almost the entire country, and has relative economic importance in the Northeast, which is the main producer. Increasing the availability of K via fertilisation, would increase the productivity of the lima bean. Therefore, the aim of this study was to evaluate different doses of potassium on productivity in the lima bean. The study was carried out in the field between January and July 2019, in the town of Raposa, Baturité, Ceará. The experimental design was of randomised blocks, with five treatments and four replications. The treatments consisted of the following doses of potassium: 60, 90, 120, 150 and 180 kg ha-1 K2O, using potassium chloride as a source, corresponding to 50%, 75%, 100%, 125% and 150% of the recommended dose. As the pods dried and the grain was collected, the following variables were evaluated: number of pods per plant, pod length, pod diameter, pod weight and productivity. The potassium doses of 130, 109 and 180 kg ha-1 K2O afforded the greatest number of pods (124), pod weight (108.64g) and pod diameter (18 mm), respectively. The dose of 106.20 kg ha-1 K2O, lower than the recommended dose for the lima bean, determined the maximum grain yield, 1,567 kg ha-1

Produção de mudas de abobrinha sob estresse salino em diferentes ambientes e substratos

The interaction between agricultural environment and alternative substrates can attenuate salt stress in zucchini seedlings. Based on that, the objective of this work was to evaluate the production of zucchini seedlings irrigated with saline water and cultivated in different types of environments and substrates. The experimental design was completely randomized, using a split-split plots scheme, with the plot being the three cultivation environments (AM1= full sun; AM2= red screen with 50% shading; AM3= black screen with 50% shading), subplot the three substrates (SB1= biochar + soil; SB2= carbonized rice husk + soil; SB3= cattle manure + soil) and the subplot the two irrigation waters (AI1= 0.8 and AI2= 2.5 dS m-1), with four replications of twenty-five seeds. The variables analyzed were: emergence percentage (EP), emergence speed index (ESI), mean time of emergence (MTE), mean speed of emergence (MSE), stem diameter (SD), seedling height (SH) , root length (RL), shoot dry mass (SDM), root dry mass (RDM) and total dry mass (TDM). The AM3 environment presented better conditions for the variables: EP, ESI and MSE. The environment AM2 presented better conditions for the variable MTE with the use of substrates SB2 and SB3 regardless of the salinity of the irrigation water. The SB3 substrate showed better growth conditions for the variables: SH, SD, SDM and TDM. The SB2 substrate provided better conditions for the variable RDM.A interação entre ambiência agrícola e substratos alternativos pode atenuar o estresse salino em mudas de abobrinha. Com base nisso, o objetivo deste trabalho foi avaliar a produção de mudas de abobrinha irrigadas com águas salinas e cultivadas em diferentes tipos de ambientes e substratos. O delineamento experimental foi o inteiramente casualizado, utilizando esquema de parcelas subsubdivididas, sendo a parcela os três ambientes de cultivo (AM1= pleno sol; AM2= telado vermelho com 50% de sombreamento; AM3= telado preto com 50% de sombreamento), a subparcela os três substratos (SB1= biocarvão + solo; SB2= casca de arroz carbonizado + solo, SB3= esterco bovino + solo) e a subsubparcela as duas águas de irrigação (AI1= 0,8 e AI2= 2,5 dS m-1),  com quatro repetições de vinte e cinco sementes. As variáveis analisadas foram: porcentagem de emergência (PE), índice de velocidade de emergência (IVE), tempo médio de emergência (TME), velocidade média de emergência (VME), diâmetro do caule (DC), altura de plântula (AP), comprimento da raiz (CR), massa seca da parte aérea (MSPA), massa seca da raiz (MSR) e massa seca total (MST). O ambiente AM3 apresentou melhores condições para as variáveis: PE, IVE e VME. Já o ambiente AM2 apresentou melhores condições para a variável TME com a utilização dos substratos SB2 e SB3 independente da salinidade da água de irrigação. O substrato SB3 apresentou melhores condições de crescimento para as variáveis: AP, DC, MSPA e MST. O substrato SB2 proporcionou melhores condições para a variável MSR

<i>Bacillus aryabhattai</i> Mitigates the Effects of Salt and Water Stress on the Agronomic Performance of Maize under an Agroecological System

The use of plant-growth-promoting rhizobacteria (PGPR) can be one option for mitigating the impact of abiotic constraints on different cropping systems in the tropical semi-arid region. Studies suggest that these bacteria have mechanisms to mitigate the effects of water stress and to promote more significant growth in plant species. These mechanisms involve phenotypic changes in growth, water conservation, plant cell protection, and damage restoration through the integration of phytohormone modulation, stress-induced enzyme apparatus, and metabolites. The aim of this study was to evaluate the growth, leaf gas exchange, and yield in maize (Zea mays L.—BRS Caatingueiro) inoculated with Bacillus aryabhattai and subjected to water and salt stress. The experiment followed a randomised block design, in a split-plot arrangement, with six repetitions. The plots comprised two levels of electrical conductivity of the irrigation water (0.3 dS m−1 and 3.0 dS m−1); the subplots consisted of three irrigation depths (50%, 75%, and 100% of the crop evapotranspiration (ETc)); while the sub-subplots included the presence or absence of B. aryabhattai inoculant. A water deficit of 50% of the ETc resulted in the principal negative effects on growth, reducing the leaf area and stem diameter. The use of B. aryabhattai mitigated salt stress and promoted better leaf gas exchange by increasing the CO2 assimilation rate, stomatal conductance, and internal CO2 concentration. However, irrigation with brackish water (3.0 dS m−1) reduced the instantaneous water-use efficiency of the maize. Our results showed that inoculation wiht PGPR mitigates the effect of abiotic stress (salt and water) in maize plants, making it an option in regions with a scarcity of low-salinity water

NEOTROPICAL ALIEN MAMMALS: a data set of occurrence and abundance of alien mammals in the Neotropics

Biological invasion is one of the main threats to native biodiversity. For a species to become invasive, it must be voluntarily or involuntarily introduced by humans into a nonnative habitat. Mammals were among first taxa to be introduced worldwide for game, meat, and labor, yet the number of species introduced in the Neotropics remains unknown. In this data set, we make available occurrence and abundance data on mammal species that (1) transposed a geographical barrier and (2) were voluntarily or involuntarily introduced by humans into the Neotropics. Our data set is composed of 73,738 historical and current georeferenced records on alien mammal species of which around 96% correspond to occurrence data on 77 species belonging to eight orders and 26 families. Data cover 26 continental countries in the Neotropics, ranging from Mexico and its frontier regions (southern Florida and coastal-central Florida in the southeast United States) to Argentina, Paraguay, Chile, and Uruguay, and the 13 countries of Caribbean islands. Our data set also includes neotropical species (e.g., Callithrix sp., Myocastor coypus, Nasua nasua) considered alien in particular areas of Neotropics. The most numerous species in terms of records are from Bos sp. (n = 37,782), Sus scrofa (n = 6,730), and Canis familiaris (n = 10,084); 17 species were represented by only one record (e.g., Syncerus caffer, Cervus timorensis, Cervus unicolor, Canis latrans). Primates have the highest number of species in the data set (n = 20 species), partly because of uncertainties regarding taxonomic identification of the genera Callithrix, which includes the species Callithrix aurita, Callithrix flaviceps, Callithrix geoffroyi, Callithrix jacchus, Callithrix kuhlii, Callithrix penicillata, and their hybrids. This unique data set will be a valuable source of information on invasion risk assessments, biodiversity redistribution and conservation-related research. There are no copyright restrictions. Please cite this data paper when using the data in publications. We also request that researchers and teachers inform us on how they are using the data