Natural abundance analysis of the role played by 15 N as indicator for the certification of organic-system deriving food.

BACKGROUND: The natural abundance of stable isotope 15 N (δ15 N) in production systems has emerged as an alternative to distinguish organic products from conventional ones. This study evaluated the use of δ15 N values recorded for nitrogen fertilizers, soil and plant tissue in order to set the differences between organic and conventional agricultural production systems applied to rice, potatoes, apple and banana crops. RESULTS: Values of δ15 N recorded for N sources ranged from +5.58‰ to +18.27‰ and from -3.55‰ to +3.19‰ in organic and synthetic fertilizers, respectively. Values recorded for δ15 N in food from organic rice, potatoes and banana farms were higher than values recorded for δ15 N in conventional farms; the same was observed for values recorded for δ15 N in leaves from the four crops. CONCLUSION: Results have allowed for differentiation between production systems due to values of δ15 N recorded in leaves of all crops and food, for rice, potatoes and banana trees. © 2021 Society of Chemical Industry.

Feature-specific nutrient management of onion (Allium cepa) using machine learning and compositional methods.

While onion cultivars, irrigation and soil and crop management have been given much attention in Brazil to boost onion yields, nutrient management at field scale is still challenging due to large dosage uncertainty. Our objective was to develop an accurate feature-based fertilization model for onion crops. We assembled climatic, edaphic, and managerial features as well as tissue tests into a database of 1182 observations from multi-environment fertilizer trials conducted during 13 years in southern Brazil. The complexity of onion cropping systems was captured by machine learning (ML) methods. The RReliefF ranking algorithm showed that the split-N dosage and soil tests for micronutrients and S were the most relevant features to predict bulb yield. The decision-tree random forest and extreme gradient boosting models were accurate to predict bulb yield from the relevant predictors (R2 > 90%). As shown by the gain ratio, foliar nutrient standards for nutritionally balanced and high-yielding specimens producing > 50 Mg bulb ha-1 set apart by the ML classification models differed among cultivars. Cultivar × environment interactions support documenting local nutrient diagnosis. The split-N dosage was the most relevant controllable feature to run future universality tests set to assess models' ability to generalize to growers' fields.

Garlic (Allium sativum) feature-specific nutrient dosage based on using machine learning models.

Brazil presents large yield gaps in garlic crops partly due to nutrient mismanagement at local scale. Machine learning (ML) provides powerful tools to handle numerous combinations of yield-impacting factors that help reducing the number of assumptions about nutrient management. The aim of the current study is to customize fertilizer recommendations to reach high garlic marketable yield at local scale in a pilot study. Thus, collected 15 nitrogen (N), 24 phosphorus (P), and 27 potassium (K) field experiments conducted during the 2015 to 2017 period in Santa Catarina state, Brazil. In addition, 61 growers' observational data were collected in the same region in 2018 and 2019. The data set was split into 979 experimental and observational data for model calibration and into 45 experimental data (2016) to test ML models and compare the results to state recommendations. Random Forest (RF) was the most accurate ML to predict marketable yield after cropping system (cultivar, preceding crops), climatic indices, soil test and fertilization were included features as predictor (R2 = 0.886). Random Forest remained the most accurate ML model (R2 = 0.882) after excluding cultivar and climatic features from the prediction-making process. The model suggested the application of 200 kg N ha-1 to reach maximum marketable yield in a test site in comparison to the 300 kg N ha-1 set as state recommendation. P and K fertilization also seemed to be excessive, and it highlights the great potential to reduce production costs and environmental footprint without agronomic loss. Garlic root colonization by arbuscular mycorrhizal fungi likely contributed to P and K uptake. Well-documented data sets and machine learning models could support technology transfer, reduce costs with fertilizers and yield gaps, and sustain the Brazilian garlic production.

Prediction of Nitrogen Dosage in 'Alicante Bouschet' Vineyards with Machine Learning Models.

Vineyard soils normally do not provide the amount of nitrogen (N) necessary for red wine production. Traditionally, the N concentration in leaves guides the N fertilization of vineyards to reach high grape yields and chemical composition under the ceteris paribus assumption. Moreover, the carryover effects of nutrients and carbohydrates stored by perennials such as grapevines are neglected. Where a well-documented database is assembled, machine learning (ML) methods can account for key site-specific features and carryover effects, impacting the performance of grapevines. The aim of this study was to predict, using ML tools, N management from local features to reach high berry yield and quality in 'Alicante Bouschet' vineyards. The 5-year (2015-2019) fertilizer trial comprised six N doses (0-20-40-60-80-100 kg N ha-1) and three regimes of irrigation. Model features included N dosage, climatic indices, foliar N application, and stem diameter of the preceding season, all of which were indices of the carryover effects. Accuracy of ML models was the highest with a yield cutoff of 14 t ha-1 and a total anthocyanin content (TAC) of 3900 mg L-1. Regression models were more accurate for total soluble solids (TSS), total titratable acidity (TTA), pH, TAC, and total phenolic content (TPC) in the marketable grape yield. The tissue N ranges differed between high marketable yield and TAC, indicating a trade-off about 24 g N kg-1 in the diagnostic leaf. The N dosage predicted varied from 0 to 40 kg N ha-1 depending on target variable, this was calculated from local features and carryover effects but excluded climatic indices. The dataset can increase in size and diversity with the collaboration of growers, which can help to cross over the numerous combinations of features found in vineyards. This research contributes to the rational use of N fertilizers, but with the guarantee that obtaining high productivity must be with adequate composition.

Earthworm species in Musa spp. plantations in Brazil and worldwide.

Bananas and plantains are major commodity/food crops that represent an important habitat for earthworms, although so far, no review is available on earthworm communities associated with banana/plantain crops worldwide. The Vale do Ribeira region is among the largest banana producing areas in Brazil, but little is known of the earthworms living there. Hence, the present study assessed earthworm populations and species in three banana plantations and adjacent Atlantic forest fragments along the Ribeira de Iguape River using standard (hand sorting) methodologies. Furthermore, we review earthworm populations reported in banana/plantain plantations worldwide. Only two species (Pontoscolex corethrurus, Amynthas gracilis) belonging to two families (Rhinodrilidae, Megascolecidae) were found in the Ribeira River valley, occurring concurrently. Abundance was low (< 13 indiv. m-2) compared with other banana plantations worldwide, that frequently surpassed 100 indiv. m-2. More than 70 studies reported earthworms from >200 banana plantations in 28 countries, and mean species richness was 2.7 per site, ranging from 1 to 10 species. Exotics predominated in most sites and P. corethrurus was the most prevalent species encountered. Overall, more than 104 species from 10 families were reported, with around 61 native and 43 exotic widespread species, mainly of the Megascolecidae, Lumbricidae and Acanthodrilidae families. Richness was highest in India (27 spp.) and the Canary Islands (25 spp.), but native species dominated only in a few countries and sites, while exotics were prevalent especially in island countries and Brazil. Lower-input practices appear to be important for earthworm communities and banana plantations can have large earthworm populations in some cases, which may be contributing to soil processes and plant production, topics that deserve further attention. However, many important banana-producing countries have not yet been evaluated, so further work is warranted, both in terms of applied ecology and biodiversity.

Plant ionome diagnosis using sound balances: case study with mango (Mangifera Indica).

Plant ionomes and soil nutrients are commonly diagnosed in agronomy using concentration and nutrient ratio ranges. However, both diagnoses are biased by redundancy of information, subcompositional incoherence and non-normal distribution inherent to compositional data, potentially leading to conflicting results and wrong inferences. Our objective was to present an unbiased statistical approach of plant nutrient diagnosis using a balance concept and mango (Mangifera indica) as test crop. We collected foliar samples at flowering stage in 175 mango orchards. The ionomes comprised 11 nutrients (S, N, P, K, Ca, Mg, B, Cu, Zn, Mn, Fe). Traditional multivariate methods were found to be biased. Ionomes were thus represented by unbiased balances computed as isometric log ratios (ilr). Soil fertility attributes (pH and bioavailable nutrients) were transformed into balances to conduct discriminant analysis. The orchards differed more from genotype than soil nutrient signatures. A customized receiver operating characteristic (ROC) iterative procedure was developed to classify tissue ionomes between balanced/misbalanced and high/low-yielders. The ROC partitioning procedure showed that the critical Mahalanobis distance of 4.08 separating balanced from imbalanced specimens about yield cut-off of 128.5 kg fruit tree(-1) proved to be a fairly informative test (area under curve = 0.84-0.92). The [P | N,S] and [Mn | Cu,Zn] balances were found to be potential sources of misbalance in the less productive orchards, and should thus be further investigated in field experiments. We propose using a coherent pan balance diagnostic method with median ilr values of top yielders centered at fulcrums of a mobile and the critical Mahalanobis distance as a guide for global nutrient balance. Nutrient concentrations in weighing pans assisted appreciating nutrients as relative shortage, adequacy or excess in balances.

The plant ionome revisited by the nutrient balance concept.

Tissue analysis is commonly used in ecology and agronomy to portray plant nutrient signatures. Nutrient concentration data, or ionomes, belongs to the compositional data class, i.e., multivariate data that are proportions of some whole, hence carrying important numerical properties. Statistics computed across raw or ordinary log-transformed nutrient data are intrinsically biased, hence possibly leading to wrong inferences. Our objective was to present a sound and robust approach based on a novel nutrient balance concept to classify plant ionomes. We analyzed leaf N, P, K, Ca, and Mg of two wild and six domesticated fruit species from Canada, Brazil, and New Zealand sampled during reproductive stages. Nutrient concentrations were (1) analyzed without transformation, (2) ordinary log-transformed as commonly but incorrectly applied in practice, (3) additive log-ratio (alr) transformed as surrogate to stoichiometric rules, and (4) converted to isometric log-ratios (ilr) arranged as sound nutrient balance variables. Raw concentration and ordinary log transformation both led to biased multivariate analysis due to redundancy between interacting nutrients. The alr- and ilr-transformed data provided unbiased discriminant analyses of plant ionomes, where wild and domesticated species formed distinct groups and the ionomes of species and cultivars were differentiated without numerical bias. The ilr nutrient balance concept is preferable to alr, because the ilr technique projects the most important interactions between nutrients into a convenient Euclidean space. This novel numerical approach allows rectifying historical biases and supervising phenotypic plasticity in plant nutrition studies.

DRIS standard and normal ranges of foliar nutrients for the culture of ‘Thompson’ atemoya / Norma DRIS e faixas normais de nutrientes foliares para a cultura da atemoia ‘Thompson’

ABSTRACT: Atemoya, an interspecific hybrid belonging to Annonaceae family, is the outcome of a cross between cherimoya (Annona cherimola Mill.) and Custard apple (Annona squamosa L.). In light of the current shortage of scientific data on the nutritional management techniques for this fruit, the need to develop and apply a specific methodology becomes crucial. From the variety of plant diagnostic tools available, the DRIS method was selected, for use in the commercial cultivation of the ‘Thompson’ cultivar of atemoya located in the São Paulo State, municipalities of Itapetininga, Piedade, Pilar do Sul and Salto de Pirapora. Normal nutrient ranges were determined to interpret the levels of N, P, K, Ca, Mg, S, B, Cu, Fe, Mn and Zn in the culture through statistical regression analysis and samples of leaf dry matter, with their respective DRIS indices. Although the general index of the nutritional balance of DRIS disallowed establishing a link with productivity, this study achieved it based on the standard of determining normal ranges for cognate macronutrients to the ones cited in the literature.

RESUMO: A atemoia é um híbrido interespecífico, da família da Annonaceae, obtido pelo cruzamento da cherimoia (Annona cherimola Mill.) e a fruta-pinha (Annona squamosa L.). Devido a falta de informações científicas disponíveis para a fruta sobre os procedimentos de manejo nutricional, o desenvolvimento e a aplicação de uma metodologia específica são de grande importância. Dentre as ferramentas disponíveis para a realização da diagnose de plantas temos o método DRIS. Este foi empregado em talhões comerciais de atemoia do cultivar ‘Thompson’ nos municípios do estado de São Paulo: Itapetininga, Piedade, Pilar do Sul e Salto de Pirapora. A determinação das faixas normais de nutrientes para a interpretação dos níveis de N, P, K, Ca, Mg, S, B, Cu, Fe, Mn e Zn na cultura foram obtidas pela análise estatística de regressão relacionando os seus teores, presentes nas matérias secas das amostras foliares com seus respectivos índices DRIS. Embora o índice geral de balanço nutricional do DRIS não tenha permitido estabelecer uma relação com a produtividade, foi possível, com base na norma, determinar faixas normais para macronutrientes semelhantes aos encontrados na literatura.

Norma DRIS e faixas normais de nutrientes foliares para a cultura da atemoia Thompson / DRIS standard and normal ranges of foliar nutrients for the culture of Thompson atemoya

Atemoya, an interspecific hybrid belonging to Annonaceae family, is the outcome of a cross between cherimoya (Annona cherimola Mill.) and Custard apple (Annona squamosa L.). In light of the current shortage of scientific data on the nutritional management techniques for this fruit, the need to develop and apply a specific methodology becomes crucial. From the variety of plant diagnostic tools available, the DRIS method was selected, for use in the commercial cultivation of the Thompson cultivar of atemoya located in the São Paulo State, municipalities of Itapetininga, Piedade, Pilar do Sul and Salto de Pirapora. Normal nutrient ranges were determined to interpret the levels of N, P, K, Ca, Mg, S, B, Cu, Fe, Mn and Zn in the culture through statistical regression analysis and samples of leaf dry matter, with their respective DRIS indices. Although the general index of the nutritional balance of DRIS disallowed establishing a link with productivity, this study achieved it based on the standard of determining normal ranges for cognate macronutrients to the ones cited in the literature.(AU)

A atemoia é um híbrido interespecífico, da família da Annonaceae, obtido pelo cruzamento da cherimoia (Annona cherimola Mill.) e a fruta-pinha (Annona squamosa L.). Devido a falta de informações científicas disponíveis para a fruta sobre os procedimentos de manejo nutricional, o desenvolvimento e a aplicação de uma metodologia específica são de grande importância. Dentre as ferramentas disponíveis para a realização da diagnose de plantas temos o método DRIS. Este foi empregado em talhões comerciais de atemoia do cultivar Thompson nos municípios do estado de São Paulo: Itapetininga, Piedade, Pilar do Sul e Salto de Pirapora. A determinação das faixas normais de nutrientes para a interpretação dos níveis de N, P, K, Ca, Mg, S, B, Cu, Fe, Mn e Zn na cultura foram obtidas pela análise estatística de regressão relacionando os seus teores, presentes nas matérias secas das amostras foliares com seus respectivos índices DRIS. Embora o índice geral de balanço nutricional do DRIS não tenha permitido estabelecer uma relação com a produtividade, foi possível, com base na norma, determinar faixas normais para macronutrientes semelhantes aos encontrados na literatura.(AU)

Norma DRIS e faixas normais de nutrientes foliares para a cultura da atemoia Thompson / DRIS standard and normal ranges of foliar nutrients for the culture of Thompson atemoya

Atemoya, an interspecific hybrid belonging to Annonaceae family, is the outcome of a cross between cherimoya (Annona cherimola Mill.) and Custard apple (Annona squamosa L.). In light of the current shortage of scientific data on the nutritional management techniques for this fruit, the need to develop and apply a specific methodology becomes crucial. From the variety of plant diagnostic tools available, the DRIS method was selected, for use in the commercial cultivation of the Thompson cultivar of atemoya located in the São Paulo State, municipalities of Itapetininga, Piedade, Pilar do Sul and Salto de Pirapora. Normal nutrient ranges were determined to interpret the levels of N, P, K, Ca, Mg, S, B, Cu, Fe, Mn and Zn in the culture through statistical regression analysis and samples of leaf dry matter, with their respective DRIS indices. Although the general index of the nutritional balance of DRIS disallowed establishing a link with productivity, this study achieved it based on the standard of determining normal ranges for cognate macronutrients to the ones cited in the literature.

A atemoia é um híbrido interespecífico, da família da Annonaceae, obtido pelo cruzamento da cherimoia (Annona cherimola Mill.) e a fruta-pinha (Annona squamosa L.). Devido a falta de informações científicas disponíveis para a fruta sobre os procedimentos de manejo nutricional, o desenvolvimento e a aplicação de uma metodologia específica são de grande importância. Dentre as ferramentas disponíveis para a realização da diagnose de plantas temos o método DRIS. Este foi empregado em talhões comerciais de atemoia do cultivar Thompson nos municípios do estado de São Paulo: Itapetininga, Piedade, Pilar do Sul e Salto de Pirapora. A determinação das faixas normais de nutrientes para a interpretação dos níveis de N, P, K, Ca, Mg, S, B, Cu, Fe, Mn e Zn na cultura foram obtidas pela análise estatística de regressão relacionando os seus teores, presentes nas matérias secas das amostras foliares com seus respectivos índices DRIS. Embora o índice geral de balanço nutricional do DRIS não tenha permitido estabelecer uma relação com a produtividade, foi possível, com base na norma, determinar faixas normais para macronutrientes semelhantes aos encontrados na literatura.

Simulation of defoliation caused by Black Sigatoka in the yield and quality of banana "Nanica" fruits / Simulação da desfolha causada pela Sigatoka Negra na produção e a qualidade de frutos da bananeira Nanica

Defoliation caused by Black Sigatoka in yield and quality of banana "Nanica" was stimulated in this study. A completely randomized 2x8 factorial design with six repetitions was used, in which period of bunch formation and number of leaves at flowering were established as factors. Plants for defoliation were selected on 04/05/2013 (Period 1), and on 07/01/2014 (Period 2). Six to to 13 leaves remained per plant by removing those with more than 50% of blade with injury or senescence. More appropriate climatic conditions before and after flowering, promoted greater mass accumulation in the bunch in Period 2. The increased number of leaves at flowering increased the length of the fruit and the mass of 4th hand, as well as the bunch mass and postharvest period. Defoliation is suggested only for non-functional leaves as well as the maintenance of at least 10 leaves per plant, independent of the period of bunch formation.(AU)

Simulou-se o efeito da desfolha causada pela Sigatoka Negra na produção e qualidade dos frutos da bananeira "Nanica". Adotou-se o delineamento inteiramente casualizado, em esquema fatorial 2x8, com seis repetições, no qual o período de formação do cacho e o número de folhas na floração foram estabelecidos como fatores. No Período 1, a seleção de plantas para desfolha foi realizada em 04/05/2013 e, no Período 2, em 07/01/2014. Mantiveram-se 6 a 13 folhas por planta, removendo as folhas com mais 50% do limbo com injúria ou senescência. Condições climáticas mais apropriadas antes e depois da floração promoveram maior acumulação de massa no cacho, no Período 2. O aumento do número de folhas na floração aumentou o comprimento do fruto e a massa da 4a penca, bem como a massa do cacho e período pós-colheita. Sugere-se a desfolha apenas para folhas não-funcionais e a manutenção de pelo menos 10 folhas por planta, independente do período de formação do cacho.(AU)

Simulation of defoliation caused by Black Sigatoka in the yield and quality of banana "Nanica" fruits / Simulação da desfolha causada pela Sigatoka Negra na produção e a qualidade de frutos da bananeira Nanica

Defoliation caused by Black Sigatoka in yield and quality of banana "Nanica" was stimulated in this study. A completely randomized 2x8 factorial design with six repetitions was used, in which period of bunch formation and number of leaves at flowering were established as factors. Plants for defoliation were selected on 04/05/2013 (Period 1), and on 07/01/2014 (Period 2). Six to to 13 leaves remained per plant by removing those with more than 50% of blade with injury or senescence. More appropriate climatic conditions before and after flowering, promoted greater mass accumulation in the bunch in Period 2. The increased number of leaves at flowering increased the length of the fruit and the mass of 4th hand, as well as the bunch mass and postharvest period. Defoliation is suggested only for non-functional leaves as well as the maintenance of at least 10 leaves per plant, independent of the period of bunch formation.

Simulou-se o efeito da desfolha causada pela Sigatoka Negra na produção e qualidade dos frutos da bananeira "Nanica". Adotou-se o delineamento inteiramente casualizado, em esquema fatorial 2x8, com seis repetições, no qual o período de formação do cacho e o número de folhas na floração foram estabelecidos como fatores. No Período 1, a seleção de plantas para desfolha foi realizada em 04/05/2013 e, no Período 2, em 07/01/2014. Mantiveram-se 6 a 13 folhas por planta, removendo as folhas com mais 50% do limbo com injúria ou senescência. Condições climáticas mais apropriadas antes e depois da floração promoveram maior acumulação de massa no cacho, no Período 2. O aumento do número de folhas na floração aumentou o comprimento do fruto e a massa da 4a penca, bem como a massa do cacho e período pós-colheita. Sugere-se a desfolha apenas para folhas não-funcionais e a manutenção de pelo menos 10 folhas por planta, independente do período de formação do cacho.

Growth and yield of anthurium in response to sawdust mulching / Crescimento e produção de antúrio em resposta a cobertura do solo com serragem de madeira

ABSTRACT: The objectives of the study were to analyze the effect of sawdust mulch on the: (1) soil characteristics; (2) growth and flower yield of the anthurium cv. 'Apalai'. Assay was conducted in a totally randomized design in subdivided plots, with five treatments and eight replications. The treatment consisted of five volumes of sawdust 0, 20, 40, 60 and 80L m-2, distributed over the bed, every three months. Soil, plants and flower stalks were evaluated during two years. Soil temperature, moisture, organic matter, bulk density and water retention conditions were improved, while the leaf area of plants and the yield of flower stalks were increased when the soil were mulched with sawdust. In addition to increasing soil organic matter, however, no change occurred in the level of nutrients in plants. Sawdust also improved the dimension of flower stalks. Application of 40L m-2 of sawdust every three months is recommended.

RESUMO: Objetivou-se analisar o efeito da serragem de madeira: (1) nas características do solo; (2) no crescimento e produção de hastes florais de anthurium cv. 'Apalai'. O ensaio foi conduzido em delineamento inteiramente casualizado em parcelas subdivididas, com cinco tratamentos e oito repetições. Os tratamentos consistiram em cinco volumes de serragem 0, 20, 40, 60 e 80L m-2, distribuídos sobre os canteiros, a cada três meses. O solo, as plantas e hastes florais foram avaliados por dois anos. A temperatura, a umidade, o teor de matéria orgânica, a densidade e a retenção de água do solo melhoraram, enquanto a área foliar e a produção de hastes florais aumentaram quando o solo foi coberto com serragem. Apesar do aumento do teor de matéria orgânica, não ocorreram modificações no teor de nutrientes nas plantas. A serragem também melhorou as dimensões das hastes florais. Recomenda-se aplicação de 40L m-2 de serragem a cada três meses.

Growth and yield of anthurium in response to sawdust mulching / Crescimento e produção de antúrio em resposta a cobertura do solo com serragem de madeira

The objectives of the study were to analyze the effect of sawdust mulch on the: (1) soil characteristics; (2) growth and flower yield of the anthurium cv. 'Apalai'. Assay was conducted in a totally randomized design in subdivided plots, with five treatments and eight replications. The treatment consisted of five volumes of sawdust 0, 20, 40, 60 and 80L m-2, distributed over the bed, every three months. Soil, plants and flower stalks were evaluated during two years. Soil temperature, moisture, organic matter, bulk density and water retention conditions were improved, while the leaf area of plants and the yield of flower stalks were increased when the soil were mulched with sawdust. In addition to increasing soil organic matter, however, no change occurred in the level of nutrients in plants. Sawdust also improved the dimension of flower stalks. Application of 40L m-2 of sawdust every three months is recommended.

Objetivou-se analisar o efeito da serragem de madeira: (1) nas características do solo; (2) no crescimento e produção de hastes florais de anthurium cv. 'Apalai'. O ensaio foi conduzido em delineamento inteiramente casualizado em parcelas subdivididas, com cinco tratamentos e oito repetições. Os tratamentos consistiram em cinco volumes de serragem 0, 20, 40, 60 e 80L m-2, distribuídos sobre os canteiros, a cada três meses. O solo, as plantas e hastes florais foram avaliados por dois anos. A temperatura, a umidade, o teor de matéria orgânica, a densidade e a retenção de água do solo melhoraram, enquanto a área foliar e a produção de hastes florais aumentaram quando o solo foi coberto com serragem. Apesar do aumento do teor de matéria orgânica, não ocorreram modificações no teor de nutrientes nas plantas. A serragem também melhorou as dimensões das hastes florais. Recomenda-se aplicação de 40L m-2 de serragem a cada três meses.

Growth and yield of anthurium in response to sawdust mulching / Crescimento e produção de antúrio em resposta a cobertura do solo com serragem de madeira

The objectives of the study were to analyze the effect of sawdust mulch on the: (1) soil characteristics; (2) growth and flower yield of the anthurium cv. 'Apalai'. Assay was conducted in a totally randomized design in subdivided plots, with five treatments and eight replications. The treatment consisted of five volumes of sawdust 0, 20, 40, 60 and 80L m-2, distributed over the bed, every three months. Soil, plants and flower stalks were evaluated during two years. Soil temperature, moisture, organic matter, bulk density and water retention conditions were improved, while the leaf area of plants and the yield of flower stalks were increased when the soil were mulched with sawdust. In addition to increasing soil organic matter, however, no change occurred in the level of nutrients in plants. Sawdust also improved the dimension of flower stalks. Application of 40L m-2 of sawdust every three months is recommended.(AU)

Objetivou-se analisar o efeito da serragem de madeira: (1) nas características do solo; (2) no crescimento e produção de hastes florais de anthurium cv. 'Apalai'. O ensaio foi conduzido em delineamento inteiramente casualizado em parcelas subdivididas, com cinco tratamentos e oito repetições. Os tratamentos consistiram em cinco volumes de serragem 0, 20, 40, 60 e 80L m-2, distribuídos sobre os canteiros, a cada três meses. O solo, as plantas e hastes florais foram avaliados por dois anos. A temperatura, a umidade, o teor de matéria orgânica, a densidade e a retenção de água do solo melhoraram, enquanto a área foliar e a produção de hastes florais aumentaram quando o solo foi coberto com serragem. Apesar do aumento do teor de matéria orgânica, não ocorreram modificações no teor de nutrientes nas plantas. A serragem também melhorou as dimensões das hastes florais. Recomenda-se aplicação de 40L m-2 de serragem a cada três meses.(AU)

Período de formação do cacho e biorreguladores na produção e qualidade da banana 'Grande Naine' / Period of bunch formation and growth regulators on yield and quality of banana 'Grande Naine'

Objetivou-se determinar o efeito do período de formação do cacho e dos biorreguladores na produção e qualidade da banana 'Grande Naine'. O experimento foi realizado em delineamento inteiramente casualizado em parcelas subdivididas, com seis repetições. Consideram-se, nas parcelas, os períodos de formação do cacho, verão e outono, e nas subparcelas, os biorreguladores: duas aplicações com água, giberelina (AG3, 200mg L-1), auxina (2,4 D; 10mg L-1), citocinina (TDZ, 150mg L-1) e a mistura de giberelina, auxina e citocinina (AG3, 56,3mg L-1; AIB, 56,3mg L-1 e ZEA, 101,3mg L-1). Os períodos de formação do cacho influenciam o número de pencas, o tamanho, a vida pós-colheita, o pH, a acidez titulável, a razão sólidos solúveis e acidez titulável e a firmeza do fruto. A mistura de biorreguladores eleva o peso do cacho e da 4ª penca em cachos formados no verão.

The objectives of this study were to determine the effect of climatic conditions during the period of bunch formation and growth regulators on yield and quality of banana 'Grande Naine'. The experiment was conducted in a completely randomized split plot with six replications. It was considered the plots, and the periods of bunch formation, summer and autumn. In the subplots it was considered the growth regulators: two applications were made with water, gibberellin (GA3, 200mg L-1), auxin (2.4-D, 10mg L-1), cytokinin (TDZ, 150mg L-1) and a mixture of gibberellin, auxin and cytokinin (AG3, 56.3mg L-1; AIB, 56.3mg L-1 and ZEA, 101.3mg L-1). Periods of bunch formation influence the number of hands, the size, shelf life, pH, titratable acidity, soluble solids and titratable acidity ratio and the firmness of the fruit. The mixture of growth regulators increase the weight of the bunch and the 4th hand bunches formed in the summer.

Período de formação do cacho e biorreguladores na produção e qualidade da banana Grande Naine / Period of bunch formation and growth regulators on yield and quality of banana Grande Naine

Objetivou-se determinar o efeito do período de formação do cacho e dos biorreguladores na produção e qualidade da banana 'Grande Naine'. O experimento foi realizado em delineamento inteiramente casualizado em parcelas subdivididas, com seis repetições. Consideram-se, nas parcelas, os períodos de formação do cacho, verão e outono, e nas subparcelas, os biorreguladores: duas aplicações com água, giberelina (AG3, 200mg L-1), auxina (2,4 D; 10mg L-1), citocinina (TDZ, 150mg L-1) e a mistura de giberelina, auxina e citocinina (AG3, 56,3mg L-1; AIB, 56,3mg L-1 e ZEA, 101,3mg L-1). Os períodos de formação do cacho influenciam o número de pencas, o tamanho, a vida pós-colheita, o pH, a acidez titulável, a razão sólidos solúveis e acidez titulável e a firmeza do fruto. A mistura de biorreguladores eleva o peso do cacho e da 4ª penca em cachos formados no verão.(AU)

The objectives of this study were to determine the effect of climatic conditions during the period of bunch formation and growth regulators on yield and quality of banana 'Grande Naine'. The experiment was conducted in a completely randomized split plot with six replications. It was considered the plots, and the periods of bunch formation, summer and autumn. In the subplots it was considered the growth regulators: two applications were made with water, gibberellin (GA3, 200mg L-1), auxin (2.4-D, 10mg L-1), cytokinin (TDZ, 150mg L-1) and a mixture of gibberellin, auxin and cytokinin (AG3, 56.3mg L-1; AIB, 56.3mg L-1 and ZEA, 101.3mg L-1). Periods of bunch formation influence the number of hands, the size, shelf life, pH, titratable acidity, soluble solids and titratable acidity ratio and the firmness of the fruit. The mixture of growth regulators increase the weight of the bunch and the 4th hand bunches formed in the summer.(AU)

Ciclagem de nutrientes em mangueira / Nutrient cycling in mango trees

A estimativa das quantidades de nutrientes que saem e que devem ser adicionados para a manutenção da produtividade das frutíferas requer estudos sobre a dinâmica dos elementos nos vários compartimentos do ecossistema, o que compõe, em termos gerais, a ciclagem de nutrientes. Assim, objetivou-se com este estudo avaliar a ciclagem bioquímica de nutrientes em um pomar de mangueiras, variedade Palmer. Foram determinados os teores de macronutrientes (N, P, K, Ca, Mg e S) em folhas em diferentes estádios: folhas novas, folhas maduras, folhas senescentes e folhas do folhedo. Inicialmente, aplicou-se a análise exploratória de componentes principais que preserva a estrutura multivariada contida nos dados. Verificou-se a associação das folhas novas com N, P, K, Mg e S; folhas senescentes e do folhedo com Ca e folhas maduras com K. Em complemento, considerando as variáveis independentes, o teste de Tukey (p?0,01) mostrou que as médias de N, P e Ca diferem entre as folhas novas e maduras, a média de Mg das folhas novas difere das demais e que o S não difere entre os estádios. Foi observada a retranslocação de 41, 63 e 57% de N, P e K, respectivamente, quando se comparou os teores dos elementos em folhas maduras e em folhas do folhedo, indicando que a ciclagem bioquímica é importante para a cultura da manga.(AU)

Estimates of nutrient amounts both shedding and demanding replacement in the maintenance of productivity of fruit trees require studies on element dynamics within the many ecosystem components generally made up of nutrient cycling. Thus, it was the objective of this study to evaluate the nutrient biochemical cycling in a mango tree (Mangifera indica L.) orchard, Palmer variety. Macronutrients [nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sulfur (S)] had their contents evaluated in leaves at different stages: new, mature, senescent, and litter. First exploratory analysis was performed for main components which preserve the multivariate structure shown by the data. It was possible to observe the association of new leaves with N, P, K, Mg, and S; senescent leaves and the leaves from the litter were associated to Ca, while mature leaves, to K. As a complement, taking the independent variables into consideration, Tukey test (p≤0.01) showed that the averages of N, P, and Ca differ between the new and the mature leaves; average of Mg in new leaves differs from the others, and S does not differ along the stages. Also observed was the re-translocation of 41%, 63% and 57% of N, P, and K, respectively, when comparison was made among the contents of the elements in mature leaves as well as in litter, which indicates that the biochemical cycling is important for the mango tree cultivation.(AU)

The numbers of sample design for evaluation of the soil fertility / Dimensionamento do número de amostras para avaliação da fertilidade do solo

The determination of the amount of sample units that will compose the sample express the optimization of the workforce, and reduce errors inherent in the report of recommendation and evaluation of soil fertility. This study aimed to determine in three systems use and soil management, the numbers of units samples design, needed to form the composed sample, for evaluation of soil fertility. It was concluded that the number of sample units needed to compose the composed sample to determination the attributes of organic matter, pH, P, K, Ca, Mg, Al and H+Al and base saturation of soil vary by use and soil management and error acceptable to the mean estimate. For the same depth of collected, increasing the number of sample units, reduced the percentage error in estimating the average, allowing the recommendation of 14, 14 and 11 sample in management with native vegetation, pasture cultivation and corn, respectively, for a error 20% on the mean estimate.

A determinação da quantidade de unidades amostrais que irão compor a amostra exprimirá a otimização da mão-de-obra, além de diminuir erros inerentes ao laudo de recomendação e avaliação da fertilidade do solo. Com este trabalho se objetivou determinar em três sistemas de uso e manejo do solo, o dimensionamento do número de unidades amostrais, necessárias a formar a amostra composta, para avaliação da fertilidade do solo. Concluiu-se que o número de unidades amostrais necessário a compor a amostra composta para determinação dos atributos de matéria orgânica, pH, P, K, Ca, Mg, H+Al e saturação por bases do solo variam conforme o uso e manejo do solo e o erro aceitável para a estimativa da média. Para uma mesma profundidade de coleta, o aumento do número de unidades amostrais, reduziu o erro porcentual na estimativa da média, permitindo a recomendação de 14, 14 e 11 unidades amostrais no manejo com mata nativa, pastagem e milho, respectivamente, para um erro de 20% na estimativa da média.

Marcha de absorção de nutrientes e crescimento de mudas de caramboleira enxertada com a cultivar nota-10 / Growth and uptake of nutrients curves in star fruit plants budded with nota 10 cultivar

O adequado estado nutricional das mudas de caramboleira permite o sucesso da implantação de um pomar. O objetivo deste trabalho foi determinar a marcha de absorção de nutrientes e o crescimento de mudas enxertadas de caramboleira 'Nota 10' produzida em solução nutritiva. O delineamento experimental utilizado foi o inteiramente casualizado, com seis tratamentos e quatro repetições. Os tratamentos foram constituídos pelos tempos de coleta (25; 50; 75; 100; 125 e 150 dias após o início da brotação das borbulhas). As plantas foram avaliadas quanto a: altura, diâmetro do enxerto e do porta-enxerto, área foliar e massa da matéria seca (folhas, caule e raízes). Nos diferentes órgãos das mudas, determinou-se o acúmulo de macronutrientes. O acúmulo de massa seca das mudas de caramboleira apresentou ajuste sigmoidal, enquanto o acúmulo de nutrientes apresentou incremento quadrático, exceto Mg, P e Cu, que foi sigmoidal, obedecendo à seguinte sequência: N>K>Ca>P>S>Mg>Fe>Mn>Zn>B>Cu, sendo maior nas folhas para todos os nutrientes, à exceção do P, Zn, Fe e Cu. O período de maior exigência de nutrientes foi entre 90 ­ 150 dias após o transplantio.

The nutritional state of star fruit seedlings must be adequate for a successful field implementation. The objective of the present work was to study the growth and uptake of macro e micronutrients curves by star fruit plants budded with Nota 10 cultivar in nutrient solution conditions. The experimental design was randomized complete blocks, with four replications and six treatments, which were consisted by the times of collects during the 150 days of the experiment (each 25 days). In each collection, the plant growth was evaluated by the division of the plants in root, stem and leaves in order to obtain the height, diameter of the stem, leave area and the dry matter. The accumulation of dry matter followed sigmoidal adjustment, while the uptake of nutrients followed quadratic adjustment, except Mg, P, and Cu that followed sigmoidal adjustment. The accumulation of nutrients by star fruit seedlings 'nota 10' followed the sequence: N