ABSTRACT Iodine is essential to human metabolism, being fundamental in the production of the thyroid hormones. The consumption of biofortified foods can contribute to the increase of its intake. The objective of this study was to increase the iodine concentration in lettuce, also evaluating its effects on plant growth and production. The experiment was conducted in a greenhouse, in a hydroponic system of aerated static solution. A completely randomized design was used, in a 2 x 5 factorial scheme (variety x iodine dose), with three repetitions. Two lettuce varieties were used, the iceberg lettuce and the crispy leaf lettuce, submitted to five doses of iodine (0, 10, 20, 30 and 40 µmol L-1), having as source potassium iodide. At 40 days after transplantation, both cultivars were collected and evaluated for the weight of fresh and dry matter, iodine content and levels in the leaves and the root volume. With increased doses, the plants showed symptoms of phytotoxicity, resulting in lower productivity. However, all doses promoted elevations in the total iodine levels of plants. Therefore, it is possible to increase the iodine content in lettuce leaves, being necessary to adjust the doses to be used.

Resumo: Tecnologias baseadas em radiação eletromagnética, como a técnica de raios X, contribuíram para estabelecer novas e promissoras metodologias para avaliar a qualidade de sementes. Nesse sentido, este estudo teve como objetivo relacionar parâmetros baseados na análise semiautomatizada de radiografias de sementes de crambe à sua qualidade fisiológica. Imagens radiográficas de sementes pertencentes a 10 lotes da cultivar FMS Brilhante foram analisadas de forma semiautomatizada por meio do software ImageJ®. Foram obtidas medidas de características morfométricas e integridade tecidual das sementes, bem como individualmente para o embrião das sementes. Após o teste de raio-X, as sementes foram submetidas ao teste de germinação e crescimento de plântulas. Foi possível visualizar as estruturas internas das sementes nas radiografias. Houve diferenças nos parâmetros físicos obtidos pela análise semiautomática das radiografias entre os lotes de sementes. Além disso, os lotes diferiram quanto à qualidade fisiológica das sementes. Características morfométricas e de integridade tecidual, especialmente para o embrião, apresentaram alta correlação com a qualidade fisiológica. Assim, este trabalho apresenta uma abordagem eficiente para avaliar de forma rápida e não destrutiva a qualidade de sementes de crambe.

Abstract: Technologies based on electromagnetic radiation, such as the X-ray technique, has contributed to the establishment of new and promising methodologies for evaluating seed quality. This study aimed to relate parameters based on semi-automated analysis of radiographs of crambe seeds to their physiological quality. Radiographic images of seeds from 10 seed lots of cultivar FMS Brilhante were semi-automatically analyzed using ImageJ® software. Measurements of morphometric characteristics and tissue integrity were obtained for the seeds, as well as individually for the seed embryo. Following X-ray test, the seeds were subject to germination and seedling growth test. It was possible to visualize the internal structures of the seeds in the radiographs. There were differences in the physical parameters obtained by the semi-automated analysis of the radiographs between the seed lots. Also, the lots differed regarding the physiological quality of the seeds. Morphometric characteristics and tissue integrity, especially for the seed embryo, showed high correlation with the seed physiological quality. Therefore, this work presents an efficient approach to rapid and non-destructively assess the quality of crambe seeds.

Abstract Studies evaluating the influence of nutrients on plant anatomy are very important because nutritional deficiencies can alter the thickness and shape of certain tissues, compromising their functionality what can explain the reduction of productivity. The aim of this study was to characterize the anatomical changes in cherry tomato plants subjected to calcium (Ca) and magnesium (Mg) deficiencies. The experiment was conducted in nutrient solution and the plants subjected to three treatments: complete solution (Control), Ca restriction (1 mmol L-1 of Ca) and Mg omission (without Mg). The experimental design was completely randomized, with three repetitions. Sixty days after seedling transplanting leaves and stem were collected and submitted to anatomical evaluations. Ca or Mg deficiency promotes most evident anatomical changes in chlorophyllous and vascular tissues of the leaves, rather than in the stems. Leaves of ‘Sindy’ tomato plants with a concentration of 1.7 g kg-1 of Mg and visual symptoms of Mg deficiency present hyperplasia of both tissues, phloem and xylem. This deficiency also promotes increases in the thickness of mesophyll, spongy parenchyma and palisade parenchyma, and consequently of leaf thickness. The midrib of the leaves with a concentration of 10 g kg-1 of Ca, without visual symptoms of deficiency presented phloem hypertrophy and hyperplasia.

RESUMO A obtenção de frutos de boa qualidade e com alta produtividade é um dos principais desafios da cultura do tomateiro. Com o adensamento de cultivo, há redução na massa fresca de frutos e aumento na produtividade por área; porém, a comercialização considera o número e a massa fresca de frutos. Objetivou-se avaliar a produtividade e a qualidade de frutos de tomateiro híbrido de crescimento indeterminado (Rebeca), cultivado em sistema hidropônico, com diferentes densidades de plantio e número de cachos por planta. O experimento foi conduzido em casa-de-vegetação, em sistema de subirrigação contendo argila expandida como substrato. O delineamento foi em blocos ao acaso, com parcelas subdivididas e três repetições. Nas parcelas, foram alocadas quatro densidades de plantio (11,1 plantas m-2; 8,3 plantas m-2; 6,6 plantas m-2; e 5,5 plantas m-2) e, nas subparcelas, o número de cachos por planta (um ou dois). A produtividade total foi influenciada pela interação densidade de plantio x número de cachos por planta. O tratamento que possibilitou maior produção foi o de 11,1 plantas m-2 com dois cachos, com 22,61 kg m-2 ou 226,1 t ha-1, em um ciclo de cultivo de 134 dias. As variações observadas para os teores de nutrientes minerais nas folhas e frutos do tomateiro com um ou dois cachos, em densidades de 5,5-11,1 plantas m-2, não comprometem a qualidade dos frutos e nem influenciam na produção de frutos comercializáveis, no cultivo hidropônico.

ABSTRACT Obtaining a high yield of good quality fruits is one of the main challenges of the tomato crop. The enhancement in plant density promotes a reduction in the fruit fresh mass and an increase the yield per area. On the other hand, commercialization parameters take into account number and fresh mass of fruits. This study aimed at evaluating the yield and fruit quality of indeterminate growth hybrid tomato (Rebeca), cultivated in a hydroponic system, with different planting densities and number of bunches per plant. The experiment was conducted under greenhouse conditions, in a sub-irrigation system containing expanded clay as substrate. A split-plot randomized block design, with three replications, was used. In the plots, four planting densities (11.1 plants m-2, 8.3 plants m-2, 6.6 plants m-2 and 5.5 plants m-2) were allocated and, in the subplots, the number of bunches per plant (one or two). The total yield was influenced by the interaction planting density x number of bunches per plant. The treatment that allowed the highest yield was 11.1 plants m-2 with two bunches, with 22.61 kg m-2 or 226.1 t ha-1, in a crop cycle of 134 days. The observed variations for the nutrient contents of leaves and fruits of tomato plants with one or two bunches, at densities of 5.5-11.1 plants m-2, do not compromise the fruit quality nor influence the production of tradable fruits, using the hydroponic system.

RESUMO A utilização de índices constitui ferramenta prática e importante para o manejo da adubação nitrogenada, na cultura da batata e, ainda, pode prognosticar a produtividade de tubérculos. Assim, objetivou-se avaliar o efeito do parcelamento do fertilizante nitrogenado sobre índices de nitrogênio (N) em plantas de batata, bem como estabelecer um modelo para o prognóstico da produtividade de tubérculos. Foram utilizados os cultivares Ágata e Asterix em dois experimentos independentes. Os tratamentos foram: T1 - controle, sem adubação nitrogenada, T2- 50% da dose no plantio + 50% aos 22 dias após a emergência (DAE) e T3 - dose única no plantio. Foi utilizada a ureia como fonte de N e a dose total aplicada foi de 220 kg ha-1 de N. Os índices avaliados foram: clorofila (CHL), flavonóis (FLV), balanço de N (NBI), determinados, com o Dualex e SPAD, na quarta folha completamente desenvolvida, aos 10, 21, 34, 48, 62 e 76 DAE. As doses e o parcelamento do N interferiram nos índices avaliados, sendo que os valores de SPAD, CHL e NBI decresceram com a idade da planta, enquanto houve aumento dos valores de FLV, para ambos os cultivares. O índice CHL é o mais indicado para estimar indiretamente o teor de nitrato na seiva do pecíolo, o teor de N na matéria seca e a quantidade de N acumulada na quarta folha. Tanto o índice SPAD quanto o índice CHL podem prognosticar a produtividade final de tubérculos de batata e foi estabelecido um modelo utilizando esses índices.

ABSTRACT The use of indexes is a practical and important tool for the nitrogen fertilization management on potato crop, and can be used to prognosis the yield of tubers. Thus, this study aimed to determine the effect of splitting nitrogen fertilizer on nitrogen indexes, as well as to establish a model for the prognosis of tuber yield. The Agate and Asterix cultivars were used in two independent experiments. The treatments consisted of: T1 - control without N fertilization; T2 - 50% of N dose at planting and 50% of N dose at 22 days after plant emergence (DAE); and T3 - 100% of N dose at planting. Urea was used as source of N and the total dose applied was 220 kg ha-1 of N. The indexes evaluated were: chlorophyll (CHL), Flavonol (FLV), nitrogen balance (NBI), evaluated with Dualex, and SPAD, determined in the fourth fully developed leaf, at 10, 21, 34, 48, 62 and 76 DAE. Dose and N splitting interfered on the evaluated indexes and the values of SPAD, CHL and NBI decreased with increasing in plant age, while the FLV increased for both cultivars. The CHL index was the most suitable to indirectly estimate the petiole sap nitrate content, the N content in the dry matter and the N accumulated in the fourth leaf. Both indexes, SPAD and CHL, can be used to prognosis the final potato tuber yield and a model was established using these indexes.

O pinhão manso (Jatropha curcas L.) tem grande potencial para ser utilizado na produção de biodiesel, pelo elevado teor de óleo de suas sementes. A colheita das sementes em momento adequado é fundamental para se obter sementes de elevada qualidade. Foi conduzido um experimento de campo para monitorar o processo de maturação das sementes de pinhão e estabelecer o ponto ideal para a colheita das sementes com base na coloração dos frutos. Para isso, foram colhidos frutos em diferentes estádios de maturação com base na coloração externa: verde, verde-amarelo, amarelo, amarelo-marrom e marrom. As sementes foram extraídas manualmente e, após secagem natural, foram submetidas aos seguintes testes e determinações: grau de umidade e massa seca, germinação, primeira contagem de germinação, emergência de plântulas, crescimento de plântulas, envelhecimento acelerado, condutividade elétrica, peso de mil sementes e teor de óleo. Utilizou-se o delineamento inteiramente casualizado, com quatro repetições. Os dados foram submetidos à análise de variância e, para cada teste, as médias dos tratamentos foram comparadas pelo teste de Tukey (p < 0.05). Sementes de pinhão manso de alta qualidade fisiológica são obtidas de frutos amarelos e amarelo-marrons. Sementes obtidas de frutos verdes têm menor conteúdo de massa seca, de óleo e qualidade fisiológica inferior às dos demais estádios de maturação. As sementes obtidas de frutos marrons possuem elevado potencial de germinação, no entanto apresentam menor vigor em relação às dos estádios amarelo e amarelo-marrom.

The physic nut (Jatropha curcas L.) has great potential for use in biodiesel production due to the high oil content of its seeds. Production of high quality seeds depends upon the appropriate time of harvest. A field experiment was carried out to monitor the maturation process of physic nut seeds and to establish the ideal harvest time of the seeds based on external fruit color. Fruits were collected at different maturation stages based on the external color: green, yellow-green, yellow, yellow-brown and brown. Seeds were extracted manually and, after natural drying, were submitted to the following tests and determinations: moisture content and dry matter, germination, first count seedling emergence, seedling growth, accelerated aging, electrical conductivity, the weight of thousand seeds and oil content. A randomized design was used with four replications. Data were subjected to analysis of variance and, for each test, treatment means were compared by Tukey test at 5% probability. Physic nut seeds with high physiological quality are obtained from yellow and yellow-brown fruits. Seeds from green fruits have lower physiological quality, dry matter and oil content than the other maturation stages. The seeds obtained from brown fruits have a high germination potential, but have low vigor in relation to yellow and yellow-brown stages.