ABSTRACT: Vale do Ribeira is one of the largest banana producing regions in Brazil. However, information on soil fertility and nutrient status that could limit fruit production remains scarce. Thus, the present study diagnosed the most limiting nutrient parameters for the Nanica and Prata banana cultivars, in Vale do Ribeira, São Paulo State, based on soil and leaf chemical analyses. The data assessed included samples from commercial plantations in the municipalities of Eldorado, Cajati, Jacupiranga, Pariquera-açú, Registro and Sete Barras, between 2012 and 2020. The results of soil (pH, V, P, K, Ca, Mg, S, B, Cu, Fe, Mn and Zn) and leaf chemical analyses (N, P, K, Ca, Mg, S, B, Cu, Fe, Mn and Zn) were interpreted according to literature values and their maximums, minimums, means, coefficients of variation (CV), and confidence intervals (CI) were calculated at P < 0.05. Parameter classes were assessed according to their frequency distribution. A large part of the samples exhibited pH and V values similar to those recommended for banana plants. Although, average soil nutrient concentrations were considered high, soil K, Mg and S levels did not provide adequate banana plant nutrition, since these nutrients were deficient in the plants.

RESUMO: O Vale do Ribeira é uma das maiores regiões produtoras de banana do Brasil. Contudo, ainda são escassas informações sobre a fertilidade do solo e o estado nutricional das plantas que possam limitar a produção da fruta na região. Deste modo, o presente trabalho objetivou diagnosticar os parâmetros nutricionais mais limitantes para as cultivares de bananeira, Nanica e Prata, no Vale do Ribeira - SP, a partir de laudos de análises químicas de solo e folha. Os dados avaliados compreenderam amostragens realizadas em pomares comerciais, nos municípios de Eldorado, Cajati, Jacupiranga, Pariquera-açú, Registro e Sete Barras entre os anos 2012 e 2020. Os resultados das análises químicas de solo (pH, V, P, K, Ca, Mg, S, B, Cu, Fe, Mn e Zn) e folha (N, P, K, Ca, Mg, S, B, Cu, Fe, Mn e Zn) foram interpretados de acordo com valores disponíveis na literatura e calculados seus valores máximos, mínimos, médias, coeficientes de variação (CV) e intervalos de confiança (IC) a P < 0.05. As classes de interpretação dos parâmetros foram avaliadas de acordo com sua distribuição de frequência. Grande parte das amostras apresentaram valores de pH e V próximos aos indicados para a bananeira. As concentrações de nutrientes no solo, em média, foram consideradas altas, no entanto, para K, Mg e S, a concentração no solo não refletiu em adequada nutrição da bananeira, estando esses nutrientes deficientes na planta.

Abstract The rational use of correctives and fertilizers in banana orchards depends on reliable standards for interpreting soil fertility. The study aimed to establish critical levels (CL) for phosphorus (P) and potassium (K) in the soil of banana plantations in Santa Catarina, using the Boundary Line (BL) method. A database with information of soil chemical analysis and fruit yield obtained from orchards in producing regions was used. Scatter plots were obtained relating P and K concentration in the soil extracted by the Mehlich-1 method with the relative productivity of fruits and then the pairs of data in the upper border were selected and used to establish a mathematical model. The model was derived and obtained the concentrations of P and K in the soil that provided the maximum physical productivity (100 %) and maximum economic productivity (90% of the maximum production), corresponding to the CL in the soil. It is proposed that the update of critical levels of P and K for banana cultivation in Santa Catarina to be 85 and 229 mg/dm3, respectively. The banana grower will be able to suppress the P and K doses in a punctual and temporary way in areas of built fertility with the proper monitoring of productivity, soil and leaf analysis.

Resumo O uso racional de corretivos e de fertilizantes em pomares de bananeira depende de padrões confiáveis de interpretação da fertilidade do solo. O trabalho objetivou estabelecer níveis críticos (NC) para fósforo (P) e potássio (K) no solo, em bananais de Santa Catarina, usando o método de Linha de Fronteira (LF). Foi utilizado um banco de dados com informações de análises químicas do solo e da produtividade de frutos, coletados em pomares de regiões produtoras. Gráficos de dispersão foram obtidos relacionando os teores de P e K no solo extraídos pelo método Mehlich-1, com a produtividade relativa de frutos, e, em seguida, os pares de dados da fronteira superior foram selecionados e usados para estabelecer modelos matemáticos. Os modelos foram derivados, e obtidos os teores de P e K no solo, que proporcionaram a máxima produtividade física (100 %) e a máxima produtividade econômica (90 % da produção máxima), correspondente ao NC no solo. É proposto que a atualização dos níveis críticos de P e K no solo, para a bananicultura em Santa Catarina, seja de 85 e 229 mg/dm3, respectivamente. O bananicultor poderá suprimir as doses de P e K de forma pontual e temporária, em áreas de fertilidade construída com o devido monitoramento da produtividade, das análises de solo e de folha.

Resumo A caramboleira é uma frutífera exótica, originária das regiões topicais da Ásia, que encontrou no Brasil condições climáticas adequadas ao seu desenvolvimento, tornando- se uma espécie promissora para o cultivo em todo o País. Entretanto, apesar do clima favorável, nas regiões tropicais, os solos, em geral, são ácidos e de baixa fertilidade natural. Soma-se a isso, o fato de que, devido à condição perene da caramboleira, suas raízes permanecem por vários anos explorando praticamente o mesmo volume de solo, o que requer o monitoramento constate da fertilidade do solo e do estado nutricional das plantas. Os resultados de pesquisas têm comprovado que a caramboleira é responsiva à calagem e à aplicação de fertilizantes, com ganhos de produtividade e com melhorias na qualidade dos frutos. Entretanto, para garantir respostas positivas e sucesso na atividade agrícola, é necessário que os corretivos da acidez do solo e os adubos sejam aplicados de forma técnica e eficiente, com base no uso de ferramentas agronômicas já consagradas, como a análise de solo e de folhas. Esta revisão tem como objetivo reunir informações de pesquisas, principalmente as realizadas no Brasil, sobre as exigências nutricionais da caramboleira, sugerindo as melhores práticas agronômicas na área de fertilidade do solo e de nutrição dessa frutífera

Abstract Star fruit is an exotic fruit, originally from the topical regions of Asia, which found in Brazil adequate climatic conditions for its development, making it a promising species for cultivation throughout the country. However, despite the favorable climate, soils in tropical regions are generally acidic and have low natural fertility. In addition, due to the perennial condition of the star fruit tree, its roots remain for several years exploring practically the same soil volume, which requires constant monitoring of soil fertility and the nutritional status of plants. Research results have proven that the star fruit tree is responsive to liming and fertilizer application, with productivity gains and improvements in fruit quality. However, to ensure positive responses and success in agricultural activity, it is necessary that soil acidity correctors and fertilizers are applied in a technical and efficient manner based on the use of well-established agronomic tools, such as soil and leaf analysis. This review aims to gather information from studies, mainly those carried out in Brazil, on the nutritional requirements of star fruit trees, suggesting the best agronomic practices of soil fertility and nutrition of this fruit tree.

ABSTRACT The search for techniques that maximize the use of water is becoming necessary for the sustainability of agriculture in semi-arid areas. In this sense, the present work aimed to evaluate the effects of soil protection against water loss and the use of bovine biofertilizer on fruit production and chlorophyll content in bell pepper plants. The experiment was conducted in the municipal district of Nova Floresta in the semi-arid region of the State of Paraíba during the period of August 2010 to February 2011. The experimental design was a randomized block design with four repetitions in a 2 × 2 × 2 factorial scheme, corresponding to soil without and with bovine biofertilizer, without and with mulch, and without and with side coating of the grooves with polyethylene film, to reduce water loss through evaporation and lateral movement of water. The results showed that the use of side coatings of the grooves led to greater production, generating productivity gains in bell pepper cultivation. The association between side coating of the grooves and mulching of the soil resulted in increased levels of chlorophyll, but the bovine biofertilizer × side coating × mulch interaction inhibited the production of chlorophyll in the plants.

ABSTRACT The adoption of more productive and nutrient-demanding genotypes, in addition soils with low availability of nutrients of soils under forest plantations, lead high fertilizer demand and justify research that seeks to rationalize the use of these inputs. Therefore, we aimed with this research to determine classes of interpretation of soil fertility using boundary line (BL) and estimate macronutrient sufficiency ranges for eucalyptus. Fertility classes and sufficiency ranges were obtained using a database of areas cultivated with eucalyptus in the Central-East region of Minas Gerais, Brazil, totaling 689 plots, containing information on yield, leaf contents, and soil chemical properties. Scatter plots were drawn relating the mean annual increment (MAI) in trunk volume (relative) with soil organic matter (OM), phosphorus (P), potassium (K+), calcium (Ca2+), and magnesium (Mg2+) of the 0.00-0.20 m layer. Those graphs and equations were used to estimate soil fertility classes. Leaf contents of N, P, K, Ca, and Mg were plotted with soil contents of OM, P, K+, Ca2+, and Mg2+. Using the Quadrant Diagram of the plant-soil Relationship (QDpsR) method, horizontal and vertical lines were drawn separating the cloud of points in four quadrants. With the points at the quadrants III and I, regression equations were fitted. To obtain foliar sufficiency ranges, soil values of critical and optimal levels of OM, P, K+, Ca2+, and Mg2+, obtained by BL, were substituted in the equations generated by the QDpsR method. The appropriate soil content ranges determined by BL for productivity of 47.7 m3 ha-1 yr-1 were: 24.75-38.28 g kg-1 of OM, 8.5-14.6 mg dm-3 of P, 100.0-150.35 mg dm-3 of K+, 0.77-1.47 cmolc dm-3 of Ca2+, and 0.25-0.43 cmolc dm-3 of Mg2+. Leaf content ranges determined by QDpsR are: 19.4-21.3 g kg-1 of N, 1.0-1.2 g kg-1 of P, 8.5-10.6 g kg-1 of K, 4.8-6.1 g kg-1 of Ca, and 1.9-2.4 g kg-1 of Mg. The critical levels of nutrients in the soil, obtained by the BL method, and the leaf sufficiency ranges, obtained using the QDpsR method, are similar to those existing in the literature. This indicates that this methodology is reliable in establishing standards and that the critical levels obtained can be used to improve the recommendation of fertilizers for eucalyptus.

Resumo O adequado manejo nutricional de qualquer espécie vegetal requer quantificar os nutrientes acumulados na planta e conhecer sua alocação nos diferentes órgãos. O trabalho teve como objetivo avaliar a partição, o conteúdo, a exportação de macronutrientes e a eficiência nutricional de plantas de bananeira-Prata fertirrigadas. Realizou-se um levantamento histórico de produtividade anual de frutos em 66 talhões de bananeira-Prata, selecionando-se quatro que atendessem às classes de produtividade anual (< 30,0; 30,0 = 37,5; 37,5 = 45,0 e > 45,0 t ha-1). Utilizando-se da massa de matéria seca dos diferentes órgãos da planta-mãe e da planta-filha, bem como dos respectivos teores de macronutrientes, estimaramu-se o conteúdo, a partição, a exportação, a sequência de acúmulo dos macronutrientes e a eficiência nutricional por meio do coeficiente de utilização biológica (CUB). A partição do conteúdo de macronutrientes variou com a classe de produtividade e o órgão da planta. A distribuição média de nutrientes na planta-mãe e na planta-filha apresentou amplitudes de 67,5 a 82,8 % e de 17,2 a 32,5 %, respectivamente. As exportações de macronutrientes por tonelada de cacho foram 4,334; 1,660; 0,361; 0,224; 0,148 e 0,119 kg t-1 para K, N, P, Mg, S e Ca, respectivamente. A bananeira possui padrão de partição de nutrientes para diferentes rendimentos, ou seja, o trabalho traz evidências de que existe uma “compartimentalização ideal” que promove maiores produtividades; entretanto, há necessidade de mais pesquisas para suportar essa afirmação. Os nutrientes mais exportados por tonelada de cacho foram K e N. A ordem decrescente de acúmulo foi: K > N > Ca Mg > P > S. Observou-se que os CUBs de N e P foram menos sensíveis às variações de produtividade, enquanto Ca e Mg foram os mais sensíveis.

Abstract Adequate nutritional management of any plant species requires quantifying the nutrients accumulated in the plant and knowing their allocation in the different organs. The objective of this study was to evaluate the partitioning, accumulation, export of macronutrients and the nutritional efficiency of fertigated Prata banana plants. A historical survey of annual fruit productivity was conducted in 66 plots of Prata banana, selecting four that met the annual productivity classes (< 30.0; 30.0 = 37.5; 37.5 = 45.0 and > 45.0 t ha-1). The dry matter weights of the different organs of parent plant and follower, as well as the respective contents of macronutrients, were used to estimate the accumulation, partitioning, export, sequence of accumulation of macronutrients and nutritional efficiency using the coefficient of biological utilization (CBU). The partitioning of macronutrient accumulation varied with productivity class and plant organ. The average distribution of nutrients in the parent plant and in the follower ranged from 67.5 to 82.8 % and from 17.2 to 32.5 %, respectively. Macronutrient exports per ton of bunch were 4.334, 1.660, 0.361, 0.224, 0.148 and 0.119 kg t-1 for K, N, P, Mg, S and Ca, respectively. Banana mats have a nutrient partitioning pattern for different yields, that is, this work provides evidence that there is an “ideal compartmentalization” that promotes higher productivity; however, more research is needed to support this statement. The most exported nutrients per ton of bunch were K and N. The descending order of accumulation was: K > N > Ca > Mg > P > S. It was observed that the CBUs of N and P were less sensitive to productivity variations, while those of Ca and Mg were the most sensitive.

RESUMO A goiabeira é uma frutífera cultivada mundialmente, destacando-se pela grande aceitação no mercado consumidor. Entretanto, para que a cultura explore o seu máximo potencial produtivo e mantenha a qualidade dos frutos, é necessária a adequada adubação mineral para elevar a disponibilidade de nutrientes no solo e aumentar sua absorção pelas plantas. Objetivou-se, com este trabalho, avaliar os efeitos da adubação com doses de potássio, na presença e na ausência de cálcio, no estado nutricional e na produção da goiabeira 'Paluma'. O experimento foi desenvolvido de agosto de 2015 a maio de 2016, no município de Remígio, Paraíba. As variáveis analisadas foram: teores foliares de macro e de micronutrientes, número de frutos por planta, massa média de frutos, produção de frutos por planta e produtividade. As plantas da goiabeira estavam adequadamente supridas em nitrogênio, fósforo, potássio, cálcio, magnésio, boro, ferro, manganês e deficientes em enxofre, cobre e zinco. A adubação com cálcio incrementou os teores foliares de P, K, Ca, S, B, Mn e Zn e reduziu o número de frutos por planta e a produtividade da goiabeira 'Paluma'. A adubação potássica sem adição de cálcio, nas doses entre 101 e 143 g planta-1 ano-1 de K2O, aos 16 meses de idade, proporcionou a maior produtividade da goiabeira 'Paluma'.

ABSTRACT The guava is a fruit cultivated worldwide, distinguished by the great acceptance in the consumer market. However, so that the crop exploits its maximum productive potential and maintains the quality of the fruits it is necessary an adequate mineral fertilization to raise the availability of nutrients in the soil and to increase the absorption by plants. The objective of the work was to evaluate the effects of fertilization with potassium doses, in the presence and absence of calcium, on the nutritional status and on the production of 'Paluma' guava. The experiment was carried out from August 2015 to May 2016, in the municipality of Remígio-PB, Brazil. The variables analyzed were: macro and micronutrient leaf contents, number of fruits per plant, average fruit mass, fruit yield per plant and productivity. Guava plants were adequately supplied with nitrogen, phosphorus, potassium, calcium, magnesium, boron, iron and manganese, and deficient in sulfur, copper and zinc. Calcium fertilization increased the leaf content of P, K, Ca, S, B, Mn and Zn, but reduced the number of fruits per plant and the yield of 'Paluma' guava. Potassium fertilization without calcium addition at doses between 101 and 143 g plant-1 year-1 K2O at 16 months of age provides the highest productivity of 'Paluma' guava.

Abstract Noni is a fruit species cultivated around the world, including Brazil however, scientific information about its nutritional status are scarce, thus justifying the need for more research on this topic to enhance its productive yield. This study aim is to evaluate both the mineral foliar composition and the productivity of noni plants cultivated in soil with cattle manure and potassium (K). The experiment was conducted from July 2012 to November 2013 at the Universidade Federal da Paraíba, Municipality of Bananeiras, Paraíba State. Treatments were organised according to a 5 × 2 factorial design involving five doses of KCl (0; 13.2; 37.5; 61.5; and 69.6 g plant-1) in soil without cattle manure and with 4 kg plant-1, in randomized blocks, with four repetitions and three plants per plot. The number of noni fruits harvested by plants fertilized with cattle manure increased from 51 to 70 fruits plant-1. Compared to coffee trees, noni plants were adequately supplied with nitrogen, phosphorus, potassium, calcium, magnesium, sulphur, iron and zinc, but they were deficient in boron and manganese. The application of cattle manure to soil promoted contents of phosphorus and potassium in foliar samples, positively affecting the fruit formation and the production of noni plants.

Abstract: Phosphorus is important to plant growth due to its storage and energy transference processes and its involvement in the active absorption of other nutrients. The aim of this study was to evaluate the nutritional status of yellow passion fruit plants under fertilization from different P2O5 sources and rates. Treatments were distributed in randomized blocks in a 2 × 5 factorial design, with two phosphorus sources (simple and triple superphosphate) and five P2O5 doses of 0, 12, 18, 24 and 30 g hole-1. A total of two applications were performed at 60 and 120 days after seedling transplanting; P2O5 doses of 0, 24, 36, 48 and 60 g hole-1 were equivalent to 0, 27, 40, 53 and 67 kg hole-1 of P2O5 from each superphosphate source, respectively. When the orchard was in fructification, 150 days after seedling transplanting, individual leaf samples were harvested from the median branches of the plants in each parcel in order to evaluate N, P, K, Ca, Mg, S, B, Cu, Fe, Mn, Zn and Na contents. The phosphate fertilization promoted adequate nutrition for passion fruit plants of N, P, K, Mg and S, independent of the source provided, but adequate Ca only for doses up to 36 g hole-1 of P2O5. Plants were impaired in B, Cu, Fe and Mn, except for Fe in those not fertilized with P2O5 and those treated with 24 and 36 g hole-1 of P2O5 in simple superphosphate form. Considering the adequate nutritional value of passion fruit, it is recommended to fertilize with 36 g hole-1 year-1 of P2O5, whether simple or triple superphosphate.

Resumo A importância da nutrição mineral para as diversas espécies de plantas é reconhecida há muitos anos. Por estarem diretamente ligados aos processos fisiológicos e metabólicos, os nutrientes favorecem o crescimento de porta-enxertos e mudas, contribuindo para a formação de pomares mais produtivos. Em razão da carência de informações técnicas para a maioria das frutíferas, a fertilização em viveiros ainda é feita de forma empírica, por vezes subestimando ou superestimando as exigências nutricionais e comprometendo a qualidade das plantas produzidas. Tendo em vista a importância da nutrição mineral na formação de mudas com qualidade, bem como a escassez de informações científicas, a presente revisão objetiva despertar o interesse para novas pesquisas, além de contribuir para a produção de mudas de frutíferas nutricionalmente equilibradas.

Abstract The importance of mineral nutrition to the various plant species has been recognized for many years. Since nutrients are directly linked to physiological and metabolic processes, they promote the growth of rootstocks and seedlings, contributing to the formation of more productive orchards. As a consequence of the lack of technical information for most fruit trees, fertilization in nurseries has still been carried out empirically, sometimes underestimating or overestimating nutritional requirements and compromising the quality of plants produced. Given the importance of mineral nutrition in the formation of high-quality seedlings and the lack of scientific information on the topic, the aim of the present review was to raise interest in further research, and contribute to produce nutritionally balanced fruit seedlings.

RESUMO A utilização de água com teor salino elevado está se tornando uma alternativa à produção agrícola mundial, mas, para isso, há necessidade de tecnologias que reduzam os impactos no solo e no rendimento das culturas, como o emprego de lixiviação dos sais do solo ou o uso de espécies tolerantes à salinidade. Nessa direção, o objetivo do trabalho foi avaliar o crescimento de plantas de noni (Morinda citrifolia L.) submetidas à irrigação e lavagem do solo com águas de salinidade crescente. O experimento foi desenvolvido em ambiente telado do Centro de Ciência Agrárias, Universidade Federal da Paraíba em Areia, PB, em blocos casualizados, com quatros repetições e duas plantas por parcela, usando o arranjo fatorial 5×2, referente a cinco valores de condutividade elétrica das águas de irrigação (0,5; 1,5; 3,0; 4,5; 6,0 dS m-1), combinados com presença e ausência de drenagem para a lavagem do solo e lixiviação dos sais. O aumento da condutividade elétrica das águas de irrigação elevou o caráter salino do solo para valores que comprometeram o crescimento biométrico e a produção de biomassa total das plantas de noni, independentemente da ausência ou presença de lixiviação dos sais, mas, com maior severidade, em todas as variáveis, no solo sem drenagem. As plantas do solo sem lixiviação dos sais não sobreviveram à irrigação com água de salinidade estimada de 5,28 dS m-1, não cresceram adequadamente em altura, diâmetro caulinar, emissão de folhas e área foliar e produziram baixos níveis de biomassa sob irrigação com água de condutividade elétrica 4,5 dS m-1.

ABSTRACT The use of water with a high salt content is seen as an alternative in global agricultural production; but there is a need for technologies that reduce the impact on soil and crop yields, such as employing leaching of salts from the soil or the use of salt-tolerant species. With this in mind, the aim of this work was to evaluate the growth of the noni plant (Morinda citrifolia L.) when submitted to irrigation and washing the soil with water of increasing salinity. The experiment was carried out in a greenhouse environment of the Centre for Agricultural Science, at the Federal University of Paraiba in Areia, in the State of Paraiba, Brazil. The design was of randomised blocks, with four replications and two plants per lot, using a 5×2 factorial arrangement, representing the five values for electrical conductivity of the irrigation water (0.5, 1.5, 3.0, 4.5, 6.0 dS m-1), with and without drainage for washing the soil and leaching the salts. Increases in the electrical conductivity of the irrigation water raised the saline character of the soil to values that compromised biometric growth and the total biomass production of the noni plants, whether with or without the leaching of salts; this was more severe for all variables in the soil with no drainage. The plants in soil where there was no leaching, did not survive irrigation with water at an estimated salinity of 5.28 dS m-1, displayed less than adequate growth in height, stem diameter, leaf emission and leaf area, and produced low levels of biomass under irrigation with water at an electrical conductivity of 4.5 dS m-1.

RESUMO Apesar de ser amplamente cultivada no Estado de São Paulo, na literatura, há poucas informações sobre os efeitos da adubação e da nutrição em porta-enxertos de caramboleira. O trabalho teve como objetivo avaliar o crescimento das plantas e o acúmulo de Zn em porta-enxertos de caramboleira, submetidos a diferentes doses de zinco. O trabalho foi desenvolvido entre os meses de setembro de 2012 e fevereiro de 2013, em viveiro comercial de produção de mudas, localizado em Taquaritinga-SP. O delineamento foi em blocos casualizados, com cinco doses de zinco: zero; 2,0; 4,0; 6,0 e 8,0 mg dm-3 de Zn, quatro repetições e três plantas por parcela. Os porta-enxertos empregados no experimento estavam com um ano e dois meses de idade e foram cultivados em sacos de polietileno, com casca de pínus como substrato. Aos 170 dias após a aplicação do zinco, avaliaram-se: altura das plantas, diâmetro do caule, número de folhas, massa seca da parte aérea, das raízes e total. A concentração de zinco nas raízes e na parte aérea foi determinada e, em seguida, calculou-se o acúmulo de Zn nas diferentes partes da planta. O zinco influenciou na altura de plantas, diâmetro caulinar, emissão de folhas, acúmulo de massa seca da parte aérea, raízes e total. O maior desenvolvimento dos porta-enxertos de caramboleira esteve associado à dose entre 3,1 e 3,8 mg dm-3 de Zn. Doses elevadas de zinco prejudicam o crescimento e o acúmulo do micronutriente nos porta-enxertos de caramboleira.

ABSTRACT Even though the star fruit is widely grown throughout the state of Sao Paulo, it is lacking information on nutrition and fertilization effects on rootstocks star fruit in literature. The study aimed to evaluate plant growth and how much Zn accumulates in star fruit rootstocks subjected to different doses of zinc. The study was conducted between the months of September 2012 and February 2013, on a commercial seedling production nursery, located in Taquaritinga, SP. A randomized block experimental design was used consisting of five doses of zinc: zero, 2.0; 4.0; 6.0 and 8.0 mg dm-3 of Zn. There were four repetitions and three plants per plot. The age of the rootstocks used in the experiment were one year and two months old and were grown in polyethylene bags, with pine bark as substrate. At 170 days after administering the zinc, the plant height, stem diameter, number of leaves, the dry weight of the shoot, roots and total dry weight were recorded. The zinc content in the roots and shoots was determined, following a calculation of the accumulation of Zn in different parts of the plant. Zinc influenced the plant height, stem diameter, leaf emergence and accumulation of dry matter of shoots, roots and total. Found that the greatest development of star fruit rootstocks was associated with the dose between 3.1 and 3.8 mg dm-3 of Zn. High doses of zinc impair the growth and accumulation of the micronutrient in star fruit rootstocks.

Um experimento foi conduzido a céu aberto no município de Remígio, PB, para se avaliar as respostas do maracujazeiro amarelo relacionadas à eficiência fotossintética e trocas gasosas. O delineamento experimental utilizado foi em blocos casualizados, no esquema fatorial 2 x 2 x 2, referente à irrigação com água não salina (0,5 dS m-1) e salina (4,5 dS m-1), sem e com biofertilizante bovino, sem e com cobertura morta, com três repetições e três plantas por parcela, em recipientes plásticos circulares utilizados como lisímetros de pressão, com 130 dm³ de volume e drenos na parte inferior para a lixiviação do excesso de sais. A irrigação com água de baixa salinidade e aplicação de biofertilizante bovino comum estimularam a eficiência fotossintética das plantas. O uso simultâneo de água de alta salinidade, biofertilizante e cobertura morta reduziram a condutância estomática do maracujazeiro amarelo. As plantas sob estresse salino apresentaram atividade fotoquímica do fotossistema II e fotossíntese líquida inibida.

The experiment was conducted in Remigio, Paraiba State, to evaluate the responses of yellow passion fruit (Passiflora edulis Sims f. flavicarpa Degener) related to photosynthetic efficiency and gás exchange, mineral nutrition, water consumption yield and water use efficiency by plants. The experimental design was randomized blocks in a 2 x 2 x 2 factorial, related to irrigation with not saline (0.5 dS m-1) and saline water (4.5 dS m-1), soil with and without biofertilizer, with and without mulch, in three replications. Three plants were maintained in plastic containers used as pressure circular lysimeters with 130 dm³ volume and drains to the leaching of salts excess. Irrigation water with low salinity and application of biofertilizer common stimulated photosynthetic efficiency of plants. Simultaneous use of high salinity water, fertilizer and mulch to reduced stomatal conductance of yellow passion fruit. Plants under salt stress have photochemical activity of photosystem II and inhibited net photosynthesis.