Concentrações foliares do porta-enxerto limoeiro 'cravo' em função da adubação N, P, K, Ca e S

A determinação das concentrações foliares representa o estado nutricional das plantas, identifica deficiências e/ou excessos e avalia a necessidade de ajustar as adubações. Este trabalho objetivou determinar a melhor combinação de doses NPKCa e S que proporcione a concentração foliar responsável pela maior quantidade de matéria seca total das plantas de porta-enxerto limoeiro `Cravo', em um experimento fatorial fracionário (¹/25) 5(4), com 25 tratamentos, repartidos em cinco blocos de cinco tratamentos. As mudas do limoeiro `Cravo' (Citrus limonia Osb.) foram transplantadas para recipientes (3,8 dm³) com substrato comercial, em viveiro telado, quando atingiram 10 cm. Os tratamentos consistiram de combinações das seguintes doses (g por planta): N = 0,31; 0,62; 1,25; 2,5 e 5; K = 0,4; 0,62; 1,25; 2,5 e 5; P = 0,35; 1,0; 2,0; 3,0 e 4,0; e Ca = 3,5; 5,0; 6,0; 7,0 e 8,0. O P e o Ca foram misturados ao substrato de uma vez antes do transplantio e o N e o K após o transplantio, divididos em 20 aplicações semanais. As fontes utilizadas para os tratamentos foram superfosfato triplo, gesso, NH4NO3 e KCl. As concentrações foliares aos cinco meses de idade situaram-se na faixa alta, para os nutrientes N, P, K e S, e baixa para Ca e Mg. As doses que proporcionaram a maior produção de matéria seca e melhores concentrações foliares foram N = 3,5; P = 2,7; K = 2,0; e Ca = 6,5 g por planta.Analysis of leaf nutrient contents can demonstrate plant nutritional status, identify symptoms of deficiency and toxicity, and evaluate the need to adjust fertilization programs. This research determined N:P:K:Ca:S rates for optimal nutrition of Rangpur lime - RL (Citrus limonia Osb.) rootstock, in an experiment arranged in a fractional factorial design of the (¹/25) 5(4) type, with 25 treatments distributed within five blocks. Seedlings of RL were transplanted into 3.8-dm³ containers filled with commercial growing media, when plant height = 10 cm, in a nursery. Treatments consisted of the following nutrient rates (g per plant): N = 0.31, 0.62, 1.25, 2.5 and 5; K = 0.4, 0.62, 1.25, 2.5 and 5; P = 0.35, 1.0, 2.0, 3.0 and 4.0; and Ca = 3.5, 5.0, 6.0, 7.0 and 8.0. Phosphorus and Ca were applied to the compost before transplant of seedlings, while N and K were applied later and total amounts were split into 20 weekly applications via fertigation. Nutrient sources were triple super phosphate, gypsum, NH4NO3 and KCl. Leaf nutrient concentrations of five-mo-old plants were high or in excess for N, P, K and S. Calcium and Mg concentrations were low. Greater dry mass of plants were observed at nutrient rates of N = 3.5, P = 2.7, K = 2.0, and Ca = 6.5 g per plant

Potencial produtivo de forrageiras estivais perenes e anuais, no sul do Brasil

A utilização de pastagens para a alimentação de ruminantes auxilia na diminuição dos custos de produção, aumentando a viabilidade da atividade. Com o objetivo de avaliar a potencialidade de produção de matéria seca (MS) e teores de proteína bruta (PB) de pastagens estivais perenes e anuais no sul do Brasil, conduziu-se um experimento fatorial em blocos casualizados, com 5 repetições de quatro forrageiras estivais, duas anuais (Milheto ou Pennisetum glaucum (L.) R. BR. e capim Sudão ou Sorghum bicolor cv. sudanense), e 2 perenes (Jiggs ou Cynodon dactilon sp. cv. Jiggs e Braquiária mulato II ou Brachiaria hibrida cv. Mulato II), totalizando 20 parcelas de 2,25 m2 (1,5 m x 1,5 m), com um metro de espaçamento entre si. Através de um quadrado de 0,25 m² (50 cm x 50 cm), lançado aleatoriamente em cada parcela, foram coletadas através de simulação de pastejo, amostras das cultivares, que foram analisadas quanto a produção de MS e teores de PB. Verificou-se maior potencialidade de produção em MS e teores médios de PB nas pastagens estivais perenes. O Jiggs apresentou uma produção acumulada em 4 cortes de 14.528 Kg de MS/ha e teores médios de PB de 11,35%. A Braquiária mulato II mostrou o melhor rendimento produtivo no segundo corte (4.036 kg de MS/ha) e teores médios de PB (10,28%) maiores que as pastagens estivais anuais, no entanto atingiu sua altura ideal de coleta somente em dois momentos (primeiro e segundo corte)

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Growth and nutritional status of citrus plants as affected by nitrogen, phosphorus, potassium, and calcium fertilization

Foram conduzidos dois experimentos com o objetivo de avaliar a produção de porta-enxerto e de mudas de citros em resposta à adubação com N, P, K e Ca, em ambiente protegido. O primeiro experimento objetivou determinar-se a melhor combinação das doses NPKCa, que proporcionavam uma nutrição adequada do porta-enxerto limoeiro Cravo. Utilizou-se um fatorial fracionario (1/25) 54, com 4 níveis de nutrientes (N, P, K e Ca) e cinco does, num total de com 25 tratamentos, repartidos em 5 blocos de 5 tratamentos. As mudas do limoeiro Cravo foram transplantados com 10 cm, para os vasos (3,8 dm3, ) com substrato rendimax. Os tratamentos (g por planta) foram: N (0,31; 0,62; 1,25; 2,5 e 5), K (0,4; 0,62; 1,25; 2,5 e 5), P (0,35; 1,0; 2,0; 3,0 e 4,0) e Ca (3,5; 5,0; 6,0; 7,0 e 8,0). As fontes utilizadas para os tratamentos foram nitrato de amônio, superfosfato triplo, cloreto de potássio e gesso agrícola. Avaliou-se as produções de produções de material seco das folhas, caule, raízes e total da planta, altura das plantas, volume de raízes, diâmetro do caule, concentração total de nutrientes e de carboidratos solúveis totais nas folhas e o acúmulo de nutrientes. Funções de respostas foram ajustadas aos níveis de nutrientes, para se obter as melhores respostas. Concluiu-se que, para a produção dos porta-enxertos, as doses mais adequadas foram N = 3,5; P = 2,7; K = 2,0 e Ca = 6,5 g por planta. O segundo experimento objetivou determinar-se a melhor combinação das doses NKCa que proporcionavam uma nutrição adequada à laranjeira Pêra. Utilizou-se um fatorial fracionário (1/5) 53, com 25 tratamentos, repartidos em 5 blocos de 5 tratamentos. A laranjeira Pêra foi enxertada sobre o porta-enxerto limoeiro Cravo aos quatro meses após o transplante para vasos (3,8 dm3,) contendo substrato rendimax. Após o pegamento da enxertia iniciou-se a aplicação dos tratamentos. Os tratamentos (g por planta) foram: N (0,37; 0,75; 1,50; 3,0 e 6,0), K (0,37; 0,75; 1,50; 3,0 e 6,0) e Ca (0,6; 1,8; 3,0; 4,2 e 5,4). O P (2,7 g por planta). As fontes utilizadas para os tratamentos foram NH4NO3, KCl e Ca Cl2. Avaliou-se as produções de material seco das folhas, caule, raízes, total da parte aérea e total da planta, volume de raízes, diâmetro de caule, altura, área foliar, teor total de nutrientes nas folhas e acumulação de nutrientes. Coletou-se as plantas aos 6 meses de idade. A concentração de carboidratos solúveis totais nas folhas não tiveram efeito significativo em função dos tratamentos. Concluiu-se que as doses que proporcionaram uma nutrição mais equilibrada para a muda foram N = 5,0; K = 2,0 e Ca = 5,0 g por plantaTwo experiments were conducted with the objective to evaluate the effects of N, P, K, and Ca fertilization on the production of citrus rootstock and nursery plants grown under screenhouse environment. The first study determined rates of N:P:K:Ca to support optimal nutritional status of Rangpur lime rootstock (C. limonia Osbeck). The experiment was arranged in a fractional factorial design of the (1/25) 54 type, with a total of 25 treatments, distributed within 5 blocks. The Rangpur lime seedlings were transplanted when 1 O-cm height into 3.8 dm3 containers filled with a commercial compost of Pinus bark, vermiculite, and perlite. Treatments presented rates of (g per plant): N (0.31, 0.62, 1.25, 2.5 and 5), K (0.4, 0.62, 1.25, 2.5 and 5), P (0.35, 1.0, 2.0, 3.0 and 4.0) and Ca (3.5, 5.0, 6.0, 7.0 and 8.0). Phosphorus and Ca rates were all applied to the compost before transplant of seedlings, while N and K rates were after split into 20 weekly applications via fertigation. Nutrients were applied as ammonium nitrate, triple superphosphate, potassium chloride, and gypsum. We concluded that better response of Rangpur lime rootstock was attained at N = 3.5, P = 2.7, K = 2.0 and Ca = 6.5 g per plant. The second study determined rates of N:K:Ca to support optimal nutritional status of Pêra sweet orange [C. sinensis (L.) Osbeck] nursery plants. The experiment was arranged in a fractional factorial design of the (1/5) 53 type, with a total of 25 treatments, also distributed within 5 blocks. Buds of Pêra were grafted on 4-month-old Rangpur lime seedlings grown in 3.8 dm3 containers filled with compost. After bud take, the rootstock stem was cut off and treatments application were initiated Treatments presented rates of (g per plant): N (0.37, 0.75, 1.50, 3.0 and 6.0), K (0.37, 0.75, 1.50, 3.0 and 6.0) and Ca (0.6, 1.8, 3.0, 4.2 and 5.4). Phosphorus (2.7 g per plant) was applied before rootstock transplant. Rates of N, K, and Ca were split into 24 weekly applications via fertigation. Nutrients were applied as NH4NO3, KCl and CaCl2. Concentration of carbohydrates was not affected by fertilization. Our data suggest that optimum nutritional status of nursery plants are possible at fertilizer rates of N = 5.0, K = 2.0 and Ca = 5.0 g per plant

Nitrate accumulation, nutrient absorption and production in two varieties of hydroponic ally grown lettuce: nitrogen and potassium effects

No Brasil é crescente a utilização de cultivos hidropônicos de alface, sem contudo haver informações mais precisas quanto ao uso de fontes de nutrientes, mais especificamente sobre o efeito da utilização do nitrato de potássio como, fonte de nitrogênio e potássio, sobre o acúmulo de nitrato. O limite máximo de nitrato estabelecido por alguns países da Europa é de 4.000 mg kg-1 no material fresco em folhas de alface cultivadas sob hidroponia, mostrando a grande preocupação com a toxicidade e o acúmulo de nitrato pelo organismo humano, em função da grande utilização de adubos nitrogenados. O fornecimento de N em excesso para a planta causa acúmulo de nitrato nos tecidos vegetais. O objetivo do experimento foi avaliar o comportamento de duas cultivares de alface (Lactuca sativa L.), cultivadas com a técnica do fluxo laminar de solução (NFT Nutrient Film Technique) e submetidas a 4 doses de N e K na solução nutritiva. Todos os nutrientes foram mantidos constantes, exceto o N, que acompanhou o K, em função da utilização de KNO3 comercial. Os tratamentos, com as doses de N e de K em mg L-1 foram os seguintes: 220 e 160; 240 e 220; 260 e 280 e 280 e 340, respectivamente. O delineamento experimental utilizado foi o inteiramente casualizado, com duas cultivares (Vera e Marisa) e quatro doses fixas de N e K, com três repetições por tratamento, num total de 24 canais. As cinco plantas centrais de cada parcela foram coletadas no final do ciclo (17 dias após o transplante), separadas em parte aérea e sistema radicular. Os parâmetros avaliados foram: o consumo de solução nutritiva, o rendimento de material fresco e seco da parte aérea e da planta inteira, a concentração de nitrato na parte aérea, teor e quantidade dos nutrientes absorvidos pela parte aérea e pela planta inteira. Os resultados permitiram concluir que não houve aumentos significativos na quantidade de nitrato na parte aérea em função dos tratamentos. As produções de material seco e de material fresco da parte aérea e da planta inteira das plantas de alface foram influenciadas pelos tratamentos, ajustando-se a um modelo linear para a cultivar Marisa e quadrático para a cultivar Vera. As concentrações de K e de Ca na parte aérea e na planta inteira e de enxofre na parte aérea, tiveram aumentos significativos em função das doses na solução nutritiva, com interação entre doses e cultivares. O Mg teve decréscimos significativos, com interação apenas para doses. As quantidades de N, P, K, Ca e S absorvidos pela parte aérea e pela planta inteira, tiveram aumentos significativos em função das doses de N e de K na solução nutritiva, com interação entre doses e cultivares. A cultivar Vera teve uma melhor eficiência na utilização de N e de K, possibilitando uma economia de fertilizantes na solução nutritiva.The use of hydroponics for lettuce cultivation is a practice which is increasing in Brazil. However, there is a need for more precise information related to the use of nutrient sources, mainly with regard to potassium and nitrate fertilizers, and in addition, with nitrate accumulation. The excessive use of nitrogen fertilization is likely to increase problems due to nitrate accumulation. The maximum for nitrate concentration in plant tissue in some European countries is 4,000 mg kg-1. Our hypothesis is that when N is abundant, nitrate accumulates in the plant. The objective of this experiment was to evaluate the behavior of two cultivars of lettuce grown using a Nutrient Film Technique (NFT) with 4 combinations of K and N doses in the nutrient solution. All the nutrient concentrations were maintained constant, except for N, which accompanied K since we used a common commercial KNO3 source. Nitrogen and K were applied as (mg L--1): 220 and 160; 240 and 220; 260 and 280; and 280 and 340, respectively. The experimental design was randomized with 2 lettuce cultivars (Vera and Marisa) and 4 rates of N and K, with 3 replicates per treatment for a total of 24 flats. Plants were grown in greenhouse in large flats for 17 days. The five central plants of each flat were collected at harvest. Roots and shoots were separated. The following parameters were evaluated: consumption of solution, production of shoot and root fresh and dry weights, total shoot nitrate and the concentration and accumulation of macronutrients absorbed by shoots. The results indicated that there was no significant increase In the amount of shoot nitrate. Dry and fresh weight for lettuce shoots and roots were influenced by the fertilizer addition. Growth increased linearly with N and K addition (cv. Marisa) or in a quadratic fashion (cv. Vera). The K and Ca concentrations, in roots and in shoots increased as a function of N and K additions in the nutrient solution, with an interaction between rates and cultivares. Magnesium decreased significantly with N and K additions, with interactions only with increasing levels of fertilizer. The accumulation of N, P, K, Ca and S in both shoots and roots significantly increased as a function of N and K dose, with interactions between rates and cultivars. The cv. Vera had the best efficiency with regards to N and K utilization, permitting the economy of those fertilizers in the nutrient solution

Nitrate accumulation, nutrient absorption and production in two varieties of hydroponic ally grown lettuce: nitrogen and potassium effects

No Brasil é crescente a utilização de cultivos hidropônicos de alface, sem contudo haver informações mais precisas quanto ao uso de fontes de nutrientes, mais especificamente sobre o efeito da utilização do nitrato de potássio como, fonte de nitrogênio e potássio, sobre o acúmulo de nitrato. O limite máximo de nitrato estabelecido por alguns países da Europa é de 4.000 mg kg-1 no material fresco em folhas de alface cultivadas sob hidroponia, mostrando a grande preocupação com a toxicidade e o acúmulo de nitrato pelo organismo humano, em função da grande utilização de adubos nitrogenados. O fornecimento de N em excesso para a planta causa acúmulo de nitrato nos tecidos vegetais. O objetivo do experimento foi avaliar o comportamento de duas cultivares de alface (Lactuca sativa L.), cultivadas com a técnica do fluxo laminar de solução (NFT Nutrient Film Technique) e submetidas a 4 doses de N e K na solução nutritiva. Todos os nutrientes foram mantidos constantes, exceto o N, que acompanhou o K, em função da utilização de KNO3 comercial. Os tratamentos, com as doses de N e de K em mg L-1 foram os seguintes: 220 e 160; 240 e 220; 260 e 280 e 280 e 340, respectivamente. O delineamento experimental utilizado foi o inteiramente casualizado, com duas cultivares (Vera e Marisa) e quatro doses fixas de N e K, com três repetições por tratamento, num total de 24 canais. As cinco plantas centrais de cada parcela foram coletadas no final do ciclo (17 dias após o transplante), separadas em parte aérea e sistema radicular. Os parâmetros avaliados foram: o consumo de solução nutritiva, o rendimento de material fresco e seco da parte aérea e da planta inteira, a concentração de nitrato na parte aérea, teor e quantidade dos nutrientes absorvidos pela parte aérea e pela planta inteira. Os resultados permitiram concluir que não houve aumentos significativos na quantidade de nitrato na parte aérea em função dos tratamentos. As produções de material seco e de material fresco da parte aérea e da planta inteira das plantas de alface foram influenciadas pelos tratamentos, ajustando-se a um modelo linear para a cultivar Marisa e quadrático para a cultivar Vera. As concentrações de K e de Ca na parte aérea e na planta inteira e de enxofre na parte aérea, tiveram aumentos significativos em função das doses na solução nutritiva, com interação entre doses e cultivares. O Mg teve decréscimos significativos, com interação apenas para doses. As quantidades de N, P, K, Ca e S absorvidos pela parte aérea e pela planta inteira, tiveram aumentos significativos em função das doses de N e de K na solução nutritiva, com interação entre doses e cultivares. A cultivar Vera teve uma melhor eficiência na utilização de N e de K, possibilitando uma economia de fertilizantes na solução nutritiva.The use of hydroponics for lettuce cultivation is a practice which is increasing in Brazil. However, there is a need for more precise information related to the use of nutrient sources, mainly with regard to potassium and nitrate fertilizers, and in addition, with nitrate accumulation. The excessive use of nitrogen fertilization is likely to increase problems due to nitrate accumulation. The maximum for nitrate concentration in plant tissue in some European countries is 4,000 mg kg-1. Our hypothesis is that when N is abundant, nitrate accumulates in the plant. The objective of this experiment was to evaluate the behavior of two cultivars of lettuce grown using a Nutrient Film Technique (NFT) with 4 combinations of K and N doses in the nutrient solution. All the nutrient concentrations were maintained constant, except for N, which accompanied K since we used a common commercial KNO3 source. Nitrogen and K were applied as (mg L--1): 220 and 160; 240 and 220; 260 and 280; and 280 and 340, respectively. The experimental design was randomized with 2 lettuce cultivars (Vera and Marisa) and 4 rates of N and K, with 3 replicates per treatment for a total of 24 flats. Plants were grown in greenhouse in large flats for 17 days. The five central plants of each flat were collected at harvest. Roots and shoots were separated. The following parameters were evaluated: consumption of solution, production of shoot and root fresh and dry weights, total shoot nitrate and the concentration and accumulation of macronutrients absorbed by shoots. The results indicated that there was no significant increase In the amount of shoot nitrate. Dry and fresh weight for lettuce shoots and roots were influenced by the fertilizer addition. Growth increased linearly with N and K addition (cv. Marisa) or in a quadratic fashion (cv. Vera). The K and Ca concentrations, in roots and in shoots increased as a function of N and K additions in the nutrient solution, with an interaction between rates and cultivares. Magnesium decreased significantly with N and K additions, with interactions only with increasing levels of fertilizer. The accumulation of N, P, K, Ca and S in both shoots and roots significantly increased as a function of N and K dose, with interactions between rates and cultivars. The cv. Vera had the best efficiency with regards to N and K utilization, permitting the economy of those fertilizers in the nutrient solution

Growth and nutritional status of citrus plants as affected by nitrogen, phosphorus, potassium, and calcium fertilization

Foram conduzidos dois experimentos com o objetivo de avaliar a produção de porta-enxerto e de mudas de citros em resposta à adubação com N, P, K e Ca, em ambiente protegido. O primeiro experimento objetivou determinar-se a melhor combinação das doses NPKCa, que proporcionavam uma nutrição adequada do porta-enxerto limoeiro Cravo. Utilizou-se um fatorial fracionario (1/25) 54, com 4 níveis de nutrientes (N, P, K e Ca) e cinco does, num total de com 25 tratamentos, repartidos em 5 blocos de 5 tratamentos. As mudas do limoeiro Cravo foram transplantados com 10 cm, para os vasos (3,8 dm3, ) com substrato rendimax. Os tratamentos (g por planta) foram: N (0,31; 0,62; 1,25; 2,5 e 5), K (0,4; 0,62; 1,25; 2,5 e 5), P (0,35; 1,0; 2,0; 3,0 e 4,0) e Ca (3,5; 5,0; 6,0; 7,0 e 8,0). As fontes utilizadas para os tratamentos foram nitrato de amônio, superfosfato triplo, cloreto de potássio e gesso agrícola. Avaliou-se as produções de produções de material seco das folhas, caule, raízes e total da planta, altura das plantas, volume de raízes, diâmetro do caule, concentração total de nutrientes e de carboidratos solúveis totais nas folhas e o acúmulo de nutrientes. Funções de respostas foram ajustadas aos níveis de nutrientes, para se obter as melhores respostas. Concluiu-se que, para a produção dos porta-enxertos, as doses mais adequadas foram N = 3,5; P = 2,7; K = 2,0 e Ca = 6,5 g por planta. O segundo experimento objetivou determinar-se a melhor combinação das doses NKCa que proporcionavam uma nutrição adequada à laranjeira Pêra. Utilizou-se um fatorial fracionário (1/5) 53, com 25 tratamentos, repartidos em 5 blocos de 5 tratamentos. A laranjeira Pêra foi enxertada sobre o porta-enxerto limoeiro Cravo aos quatro meses após o transplante para vasos (3,8 dm3,) contendo substrato rendimax. Após o pegamento da enxertia iniciou-se a aplicação dos tratamentos. Os tratamentos (g por planta) foram: N (0,37; 0,75; 1,50; 3,0 e 6,0), K (0,37; 0,75; 1,50; 3,0 e 6,0) e Ca (0,6; 1,8; 3,0; 4,2 e 5,4). O P (2,7 g por planta). As fontes utilizadas para os tratamentos foram NH4NO3, KCl e Ca Cl2. Avaliou-se as produções de material seco das folhas, caule, raízes, total da parte aérea e total da planta, volume de raízes, diâmetro de caule, altura, área foliar, teor total de nutrientes nas folhas e acumulação de nutrientes. Coletou-se as plantas aos 6 meses de idade. A concentração de carboidratos solúveis totais nas folhas não tiveram efeito significativo em função dos tratamentos. Concluiu-se que as doses que proporcionaram uma nutrição mais equilibrada para a muda foram N = 5,0; K = 2,0 e Ca = 5,0 g por plantaTwo experiments were conducted with the objective to evaluate the effects of N, P, K, and Ca fertilization on the production of citrus rootstock and nursery plants grown under screenhouse environment. The first study determined rates of N:P:K:Ca to support optimal nutritional status of Rangpur lime rootstock (C. limonia Osbeck). The experiment was arranged in a fractional factorial design of the (1/25) 54 type, with a total of 25 treatments, distributed within 5 blocks. The Rangpur lime seedlings were transplanted when 1 O-cm height into 3.8 dm3 containers filled with a commercial compost of Pinus bark, vermiculite, and perlite. Treatments presented rates of (g per plant): N (0.31, 0.62, 1.25, 2.5 and 5), K (0.4, 0.62, 1.25, 2.5 and 5), P (0.35, 1.0, 2.0, 3.0 and 4.0) and Ca (3.5, 5.0, 6.0, 7.0 and 8.0). Phosphorus and Ca rates were all applied to the compost before transplant of seedlings, while N and K rates were after split into 20 weekly applications via fertigation. Nutrients were applied as ammonium nitrate, triple superphosphate, potassium chloride, and gypsum. We concluded that better response of Rangpur lime rootstock was attained at N = 3.5, P = 2.7, K = 2.0 and Ca = 6.5 g per plant. The second study determined rates of N:K:Ca to support optimal nutritional status of Pêra sweet orange [C. sinensis (L.) Osbeck] nursery plants. The experiment was arranged in a fractional factorial design of the (1/5) 53 type, with a total of 25 treatments, also distributed within 5 blocks. Buds of Pêra were grafted on 4-month-old Rangpur lime seedlings grown in 3.8 dm3 containers filled with compost. After bud take, the rootstock stem was cut off and treatments application were initiated Treatments presented rates of (g per plant): N (0.37, 0.75, 1.50, 3.0 and 6.0), K (0.37, 0.75, 1.50, 3.0 and 6.0) and Ca (0.6, 1.8, 3.0, 4.2 and 5.4). Phosphorus (2.7 g per plant) was applied before rootstock transplant. Rates of N, K, and Ca were split into 24 weekly applications via fertigation. Nutrients were applied as NH4NO3, KCl and CaCl2. Concentration of carbohydrates was not affected by fertilization. Our data suggest that optimum nutritional status of nursery plants are possible at fertilizer rates of N = 5.0, K = 2.0 and Ca = 5.0 g per plant

Engaging the Scientific Community, Authors and Publishers in FAIR Taxonomic Data Liberation: An Overview of Training Resources at Plazi

Since 2008, the not-for-profit organization Plazi*1, based in Switzerland, has been supporting and promoting the development of persistent and openly accessible digital taxonomic literature. To achieve this goal, Plazi makes use of in-house software tools for data mining and extraction from taxonomic publications, along with other partner institutions' tools and platforms, to liberate data on animals, plants, fungi, and more. In its mission to make taxonomic data FAIRly (Findable, Accessible, Interoperable and Reusable*2) available to the community, Plazi has developed sets of training material and courses, which enable taxonomists, collection curators, students, technicians and others to participate in the process of taxonomic data liberation. The participation of several different members of the community is critcally important as data requires deep curation, often very specific to a particular field. Most recently, Plazi led a virtual 2-day workshop as part of the COST MOBILISE ACTION*3 (European Cooperation in Science and Technology - Mobilising Data, Policies and Experts in Scientific Collections) in Europe, along with two 4-day in-person workshops in Brazil and South Africa. Participants are issued certificates that entitle them to extract data on their own, thus multiplying the output of FAIR data using Plazi’s workflow. Plazi is also planning a new series of in-person courses for the scientific community in different regions of Brazil as well as courses for specific audiences interested in data reuse. These courses aim not only at training new certificate data liberators and data search platform users, but also at disseminating knowledge about the relevance of FAIR data, increasing the number of authors and publishers rethinking the future of scientific publications