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In the Brazilian Amazon, forest conservation has relied on the presence of 'traditional communities' and Indigenous peoples to secure legally demarcated protected areas from deforestation and biodiversity degradation. Facing pressures for land-use change from a rapidly encroaching frontier of resource extraction and commodity production, there is no guarantee that Indigenous peoples or traditional communities will continue to occupy these forests or continue to fulfill the role of forest protectors except under certain conditions. In this article, we detail the case of the extractive reserves of the Terra do Meio and consider what conditions would be needed for traditional communities to continue to occupy and protect protected areas. Employing an agrarian political ecology approach, we draw on years of ethnographic research in this area to argue that forest peasant livelihoods, which revolve around the forest areas of use, produce both ecological and cultural diversity in the forest. We term this socio-ecological arrangement the productive system of the colocação, the system and geographies of forest peasant livelihoods that upholds and is upheld by diverse socio-ecological relationships. Contemporary forest conservation regimes, however, have largely failed to incentivize and value these forest peasant livelihoods in ways that would sustain them in the face of commoditizing frontier pressures. Any mechanisms that pay for forest conservation should remunerate communities for their entire socio-ecological relationships, those relationships that are upheld through forest peasant livelihoods, not simply their products. We propose an approach to valuing forest communities' socio-environmental services, and we argue that such valuation would be more effective for conservation and cultural/ecological diversity than existing proposals for payments for ecosystem services (PES).

Water management has a direct impact on plant development, and under deficit conditions, it often results in reduced yields. Silicon (Si), however, has the potential to alleviate stress and enhance plant performance under unfavorable conditions. This study aimed to analyze the performance of tomato plants cultivated under different water replacement depths and forms of silicon application. The experiment was laid out in a completely randomized design with a 2 × 4 factorial arrangement represented by two water replacement depths (60% and 100% of crop evapotranspiration - ETc) and four forms of silicon application (without application, soil application - full dose, soil application - split dose, and foliar applications). Four replications were used. The plants were cultivated in a protected environment using drip irrigation for water replacement, and silicon oxide served as the source of the element. The analyzed parameters included daily evapotranspiration, leaf spectral reflectance, mass accumulation (root, stem, and leaf), yield indices (fruit weight, plant yield, and defective fruits), water productivity, and post-harvest fruit weight loss. The imposition of water deficit (60% of ETc) in tomato leads to reduced crop development and yield, with the effects partially mitigated by the application of silicon. Conversely, under conditions of adequate water replacement (100% of ETc), silicon application contributes to increased development and yield of tomato. The application of silicon in the soil, whether in a full or split dose, demonstrates a more favorable response in vegetative indices and yield for tomato.

ABSTRACT Soybean and corn succession system widely adopt in different agricultural regions from Brazil. However, different species incorporation, especially in the autumn/winter season, can influence the soybeans profitability in succession system and farm economic return, providing benefits for the agricultural sector. The objective this work was to analyze the development of different species in the autumn-winter crop and the influence on soybean yield and the economic return of farm in Midwest of Paraná, Brazil. The study was conducted during 2019/2020 and 2020/2021 crop. A completely randomized design adopted, with eight treatments (autumn/winter season) and four replications. In autumn/winter season were composed of five crops in single system (black oat, brachiaria ruziziensis, oilseed radish, corn and wheat), two in intercropped systems (black oat with oilseed radish and corn with brachiaria) and fallow area (spontaneous plants). In the spring/summer season, soybean was cultivated. The biomass produced in the autumn/winter season varies with the species and cultivation system adopted. Soybean yield is higher when cultivated in succession to brachiaria, while the worst performance is obtained in succession to spontaneous plants. The cultivation of wheat in the winter and soybeans in the summer presents superior economic performance.

Seaweed extracts have several functions in agriculture due to their composition that is rich in nutrients, plant hormones, and bioactive substances. It is a natural product used as a biostimulant especially to promote the growth and development of plants and their tolerance to environmental stresses. The objective of this study was to analyze the response to a biostimulant containing seaweed extract derived from Ascophyllum nodosum in the cultivation of tomato and eggplant seedlings, analyzing the growth and physiological parameters in two different regions of Brazil. Cherry tomato and eggplant were cultivated in polyethylene trays for 30 days. In each crop, five treatments were tested, comparing the use of a commercial seaweed extract in application doses and forms, which were the control (without seaweed application); 0.1%, 0.2%, and 0.3% of the seaweed extract applied by irrigation water; and treatment with 0.2% of the seaweed extract by foliar application. This study confirms the efficacy of incorporating seaweed extract from Ascophyllum nodosum as a bio-input into the production phase of Solanaceae seedlings. The seedlings which received the seaweed extract significantly increased some morphological parameters, mainly regarding the biomass and length of leaves, stems, and roots. In general, applying both methods through irrigation water and foliar application were effective in providing benefits compared to the control treatment. The intermediate dose (0.2%) was the most effective in promoting improvement in the analyzed parameters. This underscores the importance of obtaining quality seedlings for subsequent planting in the field, potentially leading to better acclimatization and initial adaptation.

ABSTRACT The application of silicon (Si) in plants benefits the performance of several species. However, the dynamics of the element, mainly in non-accumulating species such as tomatoes, are rarely analyzed. This study investigated the dynamics of Si in tomato plants cultivated under different forms of application and water conditions. The experiment was carried out in a completely randomized design with four replications, using a factorial scheme 2 x 4: two water conditions (60 and 100% of the evapotranspiration of the crop - ETc), and four forms of silicon application (without application, full dose applied at soil, split dose applied at soil, and foliar application). Si content in the soil and in the different plant organs were analyzed. Si content in the soil increased after the crop cycle depending on the application form (full or split doses). The dynamics of Si accumulation and extraction by tomato are influenced by the application form (higher in soil application) and water management, with fruits and leaves having the higher values. Si application, mainly in the soil, increased the rate of Si accumulation and extraction by tomatoes cultivated in different water conditions.

Growing conditions such as water supply and soil fertility influence oregano morphological development and physiological responses. Our study aimed to analyse the physiological responses of oregano plants grown under different water conditions and bokashi application rates. The experiment was carried out in a greenhouse under a randomized block design and a 3 x 4 factorial scheme. Treatments encompassed three water replacement levels (60, 80, and 100% crop evapotranspiration - ETc) and four bokashi rates (0, 100, 200, and 300 g m-2), with five replications each. Oregano seedlings were transplanted and grown in a spacing of 0.3 m between plants and 1 m between bed rows. After 60 days, treatments were evaluated for photosynthetic rate (A), stomatal conductance (Gs), internal CO2 rate (Ci), transpiration (E), and water-use efficiency (WUE). Data underwent variance analysis by F-teste, multivariate analysis, and Pearson's linear correlation. Oregano physiological responses were significantly influenced by water replacement level and the application rate of fermented bokashi compost. The multivariate analysis allowed us to analyse the interaction effect between water replacement level and bokashi rate on photosynthesis, stomatal conductance, internal CO2, and transpiration.

Deficit irrigation is applied to several agricultural crops as a water-saving irrigation strategy. The tomato plant is sensitive to water stress; however, integration with biostimulant applications, based on seaweed extracts, could be a strategy for plants adapting to this abiotic condition. The objective of this study was to evaluate agronomic and quality aspects of tomato cultivated under deficit irrigation combined with Ascophyllum nodosum extract (ANE) application. The experiment was conducted using a completely randomized design with two water replacement levels, 70 and 100% of crop evapotranspiration (ETc), and five doses of ANE (0, 0.1, 0.2, 0.3 and 0.4%) applied via soil drench. The interaction between ANE and ETc was significant (p < 0.05) in terms of plant growth, physiological parameters, fruit yield, yield components and fruit quality. Results indicated that when the tomato plant is under deficit irrigation, a higher ANE dose is required to achieve better development when compared to the 100% ETc condition, where the dose is lower. Under deficit irrigation, the largest fruit yield was obtained with 0.3 and 0.4% ANE, and with 100% ETc, the largest fruit yield was obtained with 0.2% ANE. ANE applications were also effective in increasing plant height, stem diameter, plant biomass, leaf area, chlorophyll and relative water content. In addition, tomato quality was also favored under deficit irrigation and seaweed extract application. We conclude that ANE applications attenuate water deficit effects in tomato plants and provide a strategy to ameliorate tomato yield, tomato quality and water use in agriculture.

A clorofila, molécula responsável pela atividade fotossintética das plantas, pode ser quantificada por métodos diretos e indiretos. O objetivo do estudo foi relacionar os resultados do conteúdo de clorofila obtidos por diferentes métodos de determinação em folhas de quiabo. Foi estimado o conteúdo de clorofila através do índice SPAD (não-destrutivo) e da extração dos pigmentos foliares com acetona (destrutivo). As análises foram realizadas em folhas de quiabo (cultivar Santa Cruz 47) do terço médio de plantas no estágio reprodutivo com coloração variando de amarela a verde escuro, em condição de sequeiro. Determinações pelo método não destrutivo foram realizadas com equipamento SPAD-502 e as determinações por método destrutivo foram realizadas por espectrometria, utilizando acetona como extrator. Foi realizada análise descritiva, correlação e regressão nos dados. O índice SPAD variou de 20,93 a 49,03, e apresentou correlação linear com o conteúdo de pigmentos foliares. O índice SPAD apresentou correlação positiva com os teores de clorofila b e clorofila total, entretanto para o conteúdo de clorofila a foi observado relação negativa. A variação do conteúdo de carotenoides não apresentou relação direta com o índice SPAD. A estimativa do conteúdo de clorofila por método não destrutivo apresenta relação direta com o conteúdo absoluto em folhas de quiabo.

The size of the tray in seedling production has a direct influence on the area of ​​root development and availability of resources, such as water as well as nutrients, with a potential impact on the seedling final quality. The objective of this work was to analyse the impact of the tray size on the development of cucumber seedlings. As such, this study was developed in two experiments: in the first, seedlings produced in trays with 50 and 128 cells were compared, while in the second, trays with 50, 98, and 128 cells were considered. For that, polyethylene trays and commercial substrate were used. The trays were kept in a greenhouse, and evaluations were carried out at 21 days after sowing. Morphological development and SPAD index were analysed. The data were submitted to ANOVA and the means compared by the Tukey test (0.05). Linear correlation was performed between the analysed variables. The best development of cucumber seedlings was obtained by adopting trays with 50 cells. Cucumber seedlings produced in trays with a higher number of cells show reduced development, mass accumulation and lower photosynthetic activity.

The objective of the study was to analyze the increase of silicon in commercial substrate on the development of seedlings of Brassica oleracea var. botrytis. The experiment carried out in randomized blocks, with five amounts of silicon (0, 25, 50, 75 and 100 g kg-1 of substrate) and four replications. Silicon oxide (98% SiO2) used, mixed with the substrate with subsequent filling of the polyethylene trays (128 cells) and seeding. The trays kept in a greenhouse. At 30 days after sowing, the height of seedlings, number of leaves, fresh weight of leaves and stem, dry weight of leaves, stem and root evaluated. The data subjected to analysis of variance by the F test and regression analysis. Seedling height increased with the increase of silicon up to the dose of 75 g kg-1. Other variables showed increases up to a dose of 50 g kg-1. The increase of silicon in the substrate was efficient in the development of seedlings of Brassica oleracea var. botrytis in an amount of up to 50 g kg-1 of substrate.

The technological quality of cotton fiber is a fundamental criterion for determining the commercial value of the product, being influenced by the conditions of cultivation. The study aimed to analyze irrigated and non-irrigated cultivation systems and the management of silicon fertilization on cotton fiber characteristics. The experiment was carried out in the field in Selvíria-MS. It was adopted a randomized block design, in a 2x6 factorial scheme, with two cultivation conditions (irrigated and rainfed) and six doses of Si (0, 50, 100, 150, 200 and 400 g ha-1), with four replications per treatment. Seeds of the genotype TMG 11 WS were used. Irrigation was carried out with sprinklers spaced at 6x6 m. The application of Si via leaf was carried out at 50 and 70 days after emergence. From the cotton fiber, the characteristics of length, micronaire, strength, uniformity, elongation, reflectance, yellowing, degree of leaves, impurity and impurity particles were analyzed. The data submitted to analysis of variance by the F test, the means compared by the Tukey test (p

This study aimed to evaluate the benefits of irrigation with magnetically-treated water and replacement depths based on ETc, in plant growth and development of bell pepper grown in a protected environment in two cultivation seasons. The experiment was carried out in a protected environment, in the Centro Técnico de Irrigação (CTI), at Universidade Estadual de Maringá (UEM), in Maringá - PR. Two experiments were performed: summer (2017-2018) and winter-spring (2018). The experimental design adopted was randomized blocks in factorial scheme 3 x 2 (six treatments) with four replications in the summer season and 2 x 2 (four treatments) with six replications in the winter-spring season. The first factor consisted of water replacement depths (50, 75 and 100% of the evapotranspiration of culture (ETc) in the summer season, and 75 and 100% ETc in the winter-spring season. The second factor was the application of water with and without magnetic treatment. Characteristics of growth (plant height, stem diameter, leaf area, and dry matter of stem, leaf, total, and root) and development (first flower and first fruit) were evaluated. Results showed that there was no significant interaction between the factors for the summer season. There were only isolated effects of replacement depths, and the 100% ETc had the highest values for the growth variables, independent of water treatment. The application of magnetically-treated water provided higher accumulation of dry matter (stem, total, and root) when irrigated with 75% ETc for the winter-spring season.

The work aimed to evaluate the effect of irrigation with magnetically treated water on development, growth, and yield of the scarlet eggplant (Solanum gilo Raddi) cv. Morro Grande, in two growing seasons (autumn and spring). A completely randomized design in a 3x2 factorial scheme with three replications for the first growing season and 2x2 with five replications for the second growing season was used. Each experimental unit consisted of four plants spaced 0.75 m between plants and 1.00 m between rows. Factors consisted of irrigation using magnetically treated water, untreated water, three replacement of the crop evapotranspiration (50%, 75%, and 100% ETc) for the first growing season and two replacement of the crop evapotranspiration (75% and 100% ETc) for the second growing season. Stem diameter (millimeters), plant height (centimeters), shoot dry matter (grams), first flower and fruit (accumulated degree-days), number of fruits, fruit yield per plant (grams), and average fruit mass (grams) were evaluated. The water with magnetic treatment provided better results for the development variables, first flower, and first fruit in the second growing season. However, for the variables, stem diameter, plant height, shoot dry matter, fruit yield, and number of fruits, only the replacement irrigation depth factor obtained higher values for the 100% ETc than water-deficit treatments.

O estudo teve como objetivo analisar o efeito do envelhecimento acelerado sobre a germinação de sementes de plantas daninhas. O experimento foi conduzido em laboratório, com delineamento inteiramente casualizado em esquema fatorial 4x5, sendo sementes quatro espécies (capim-carrapicho ( C. echinatus ), capim-colchão ( D. horizontalis ), caruru ( A. viridis ) e corda-de viola ( I. grandifolia)) cinco períodos de envelhecimento (0, 24, 36, 48 e 72 horas), e cinco repetições. As sementes foram envelhecidas à temperatura constante de 42±2°C. Foi analisado a condutividade elétrica, germinação e índice de velocidade de germinação. Os resultados foram descobertos uma análise de variância, análise de regressão e correlação. Houve incremento na condutividade elétrica pelo tempo de envelhecimento acelerado para capim-colchão, caruru e corda-de-viola. A germinação e o de velocidade de germinação índice mudanças expressivas para caruru e corda-de-viola. O tempo de envelhecimento acelerado reduz a germinação de caruru e eleva a germinação de corda-de-viola.

Os teores de pigmentos foliares estão diretamente relacionados com as condições de desenvolvimento da planta, sendo a determinação realizada por métodos diretos e indiretos. O trabalho teve como objetivo relacionar os valores do índice SPAD com o conteúdo de pigmentos foliares na cultura da ervilha. A determinação foi realizada em folhas de plantas em estágio reprodutivo, apresentando coloração variando de amarelada para verde escuro. A determinação indireta foi realizada com o equipamento SPAD 502 e a determinação direta por espectrometria utilizando acetona pura como extrator. Foi realizada análise descritiva, correlação e de regressão nos dados. O índice SPAD obtido variou entre 8,2 e 42,2. O teor absoluto de clorofila é elevado em valores de SPAD superiores, ajustado por modelos quadráticos. Foi obtido elevada correlação entre índice SPAD e pigmentos foliares (clorofilas a, b e totais) em folhas de ervilha.

Crop biomass plays an important role, especially in tropical and subtropical crops that adopt the no-tillage system, whose decomposition is related to material composition and environmental conditions. The objective of this work was to analyze the decomposition of straw remaining from autumn/winter crops in the development of soybean in succession in the Midwest region of Paraná. The experiment was conducted between 2019 and 2021 in a completely randomized design, with eight treatments (spontaneous, black oat, brachiaria, corn, wheat, oilseed radish, corn + brachiaria, and black oat + oilseed radish) and four replications. After autumn/winter cultivation, biomass samples were dried and placed in nylon bags, returning to the original plot during soybean sowing. The decomposition bags were collected in seven periods over 120 days, coinciding with the soybean cycle. The decomposition rate was analyzed by regression. The regression equations and the amount of biomass remaining from the autumn/winter seasons were determinate the half-file and the remaining mass on the soil surface at sowing and at 30, 60, 90, and 120 days after sowing. Biomass production and decomposition rate varied with the season, depending on environmental conditions. Wheat had the lowest decomposition rate with a half-life greater than 100 days. Intercropping crops reduce the decomposition rate.

Evapotranspiration and the estimation of crop coefficient (Kc) are essential information for irrigation management, contributing to increase the water use efficiency and optimizing resources, mainly using local data. This study aimed to determine the water consumption and the crop coefficient of cauliflower (Barcelona hybrid) in the northwestern region of Paraná. The experiment was conducted in a greenhouse at the Technical Irrigation Center belonging to the State University of Maringá, in Maringá - PR. The crop evapotranspiration was determined using constant water table lysimeters, and the reference evapotranspiration was estimated by the Penman-Monteith method (FAO), using climatological data collected in an automatic meteorological station. The cultivation was carried out from April to July. The total water consumption by the cauliflower was 215.11 mm, a higher value than that available in the FAO recommendations. The crop coefficient (Kc) recommended values for local conditions are 0.74 for the initial stage, 1.86 for the intermediate stage, and 1.50 for the final stage.

The application of magnetically treated water is a valuable technique for crop irrigation to enhance the yield and quality of agricultural products. This study aims to evaluate the effect of irrigation water depths and the application of water with and without magnetic treatment on the yield and quality of bell pepper fruits in a controlled environment, verifying the effect of magnetically treated water on soil water retention. Two experiments were conducted in the Irrigation Technical Center of the Universidade Estadual de Maringá, Maringá/PR; the first on Summer 2017-2018, and the second on Winter-Spring 2018. A randomized block design with a factorial scheme 3 x 2 with four repetitions was used for the first experiment and a 2 x 2 scheme with six repetitions for the second. The first factor was the water replacement levels (based on the crop evapotranspiration), and the second the irrigation water treatment, with or without magnetic treatment. The yield and number of fruits were determined after six and four harvests in the first and second experiments. Quality characteristics (soluble solids level, pH, and titratable acidity) were evaluated from three fruits of each plant. The data was submitted to the Tukey test (p ≤ 0.05). It was verified that the application of magnetically treated water did not influence yield. However, it increased the levels of soluble solids and pH. To evaluate the effect of applying magnetically treated water on soil retention, 12 pots filled with soil and without plants were used. An increase in the gravimetric soil moisture using magnetically treated water was perceived, demonstrating higher water retention when using the irrigation method.

Public databases for glaucoma studies contain color images of the retina, emphasizing the optic papilla. These databases are intended for research and standardized automated methodologies such as those using deep learning techniques. These techniques are used to solve complex problems in medical imaging, particularly in the automated screening of glaucomatous disease. The development of deep learning techniques has demonstrated potential for implementing protocols for large-scale glaucoma screening in the population, eliminating possible diagnostic doubts among specialists, and benefiting early treatment to delay the onset of blindness. However, the images are obtained by different cameras, in distinct locations, and from various population groups and are centered on multiple parts of the retina. We can also cite the small number of data, the lack of segmentation of the optic papillae, and the excavation. This work is intended to offer contributions to the structure and presentation of public databases used in the automated screening of glaucomatous papillae, adding relevant information from a medical point of view. The gold standard public databases present images with segmentations of the disc and cupping made by experts and division between training and test groups, serving as a reference for use in deep learning architectures. However, the data offered are not interchangeable. The quality and presentation of images are heterogeneous. Moreover, the databases use different criteria for binary classification with and without glaucoma, do not offer simultaneous pictures of the two eyes, and do not contain elements for early diagnosis.

The water deficit or excess may cause undesirable changes in yield and physiological aspects of irrigated crops. Considering the analysis of experimental data, the use of classical statistical methods may not be sufficient to detect morphological and physiological effects resulting from the conditions employed, being interesting the use of new procedures, such as the Bayesian inference. This study aimed to evaluate the gas exchanges in the bell pepper crop under irrigation depths and different irrigation times, in a protected environment, by applying the parametric and Bayesian methods. The experiment was conducted in a completely randomized design, arranged in a 5 x 2 factorial scheme, with five irrigation depths (60, 80, 100, 120 and 140 % of the crop evapotranspiration) and two irrigation times (8 a.m. and 2 p.m.), with five replications. The stomatal conductance, transpiration rate, photosynthetic rate, intrinsic water-use efficiency, ratio between the photosynthetic rate and the transpiration rate, and total dry matter were evaluated. The gas exchanges were affected by water replacement depths, with little interference from the irrigation times. The linear regression models, according to the irrigation depths, for transpiration rate, stomatal conductance and total dry matter were significant for both the statistical methods, suggesting that the results are similar and even coincident, especially when a priori information are not provided in the Bayesian analysis. Differences in the photosynthetic rate were observed only with the Bayesian method, adjusting linear models according to the irrigation depths,in both the irrigation times.

Water deficit in cauliflower cultivation may impair its development and yield. This study aimed to analyze the agronomic performance of cauliflower grown in a protected environment, under different water conditions and silicon (Si) doses. The experiment was arranged in a randomized block design, in a 3 x 4 factorial scheme, with three levels of water replacement [40, 70 and 100 % of the evapotranspiration (ETc)] and four Si doses (0, 50, 100 and 150 kg ha-1), with four replications. Leaf (SPAD index, area, fresh and dry weight), stem (diameter, height, fresh and dry weight) and inflorescence (diameter, fresh weight, dry weight, water content and commercial classification) characteristics were evaluated. The replacement of 40 % of the ETc showed lower results for the SPAD index in the phases II and III, leaf area, leaf and stem fresh weight and inflorescence diameter. The 70 % replacement cultivation showed a yield similar to that of the 100 % of the ETc. The use of Si was beneficial for the productive performance of the cauliflower at all levels of water replacement.

ABSTRACT The ability of antioxidant compounds in vegetables to prevent disease is important for the pharmaceutical and food industries. In addition, water stress can enhance the existing antioxidant capacity of plants. As such, this study aimed to assess the effect of different irrigation depths and selenium application on the postharvest characteristics of cauliflower. A randomized block design was used in a 3 x 2 factorial scheme, with four repetitions. The first factor consisted of three irrigation depths with regulated deficit irrigation (RDI): severe (50% ETc) and moderate RDI (75% ETc) and complete irrigation (100% ETc), performed after inflorescence initiation, and the second of foliar spraying of selenium (with and without the element). Selenium application increased cauliflower yield under moderate RDI and no water/drought stress. Moderate RDI was the most effective strategy for maintaining yield and increasing the antioxidant capacity and phenolic compound content of cauliflower. Foliar spraying of selenium raised total polyphenol content under drought stress. Severe RDI extended the shelf life of cauliflower florets.

ABSTRACT The gelatin industry wastewater has nutrients in its composition, allowing its use in agriculture as an alternative to disposal and recycling of this residue. However, high application rates can cause the accumulation of elements such as sodium in the soil, and generate negative impacts on the environment. This study aimed to evaluate the effects of the application of rates up to 600 m3ha-1 of gelatin industry wastewater in soil columns, on soil chemical attributes in five depths. The experiment was conducted in a greenhouse, in PVC tube columns (0.20 m diameter) filled with distroferric Red Nitosol soil, of very clayey texture. The treatments consisted of increasing rates of wastewater equivalent to 0, 150, 300, 450 and 600 m3 ha-1, with a single application, at the soil surface and without incorporation. The application of the gelatin industry wastewater resulted no negative effects on soil chemical properties to a depth of 60 cm. The application of the levels of wastewater increased the concentration of sodium in the soil, but without causing problems with sodicity.

After rain or irrigation, the soil pores may present a low oxygen content (hypoxia). Soil aeration after irrigation has been used to overcome hypoxia-based problems. This study aimed to investigate the effect of four aeration levels (0, 0.5, 1.0 and 1.5 times the standard volume) applied after irrigation, using a subsurface drip system, at two soil depths (0.15 m and 0.30 m). A randomized block design was used, in a 4 x 2 factorial scheme, with six replications. The yield characteristics assessed were: total fruit mass per plant, average fruit mass and number of fruits per plant. The growth characteristics were root and stem dry mass. The water-use efficiency was also calculated. The results indicated that the highest aeration level, at a depth of 0.30 m, increased the yield by 41.2 %, when compared with plants that received only irrigation, at the same depth. The water-use efficiency was influenced by the soil aeration after irrigation only at the depth of 0.30 m.

The netted melon requires special growing conditions, including a protected environment, an adequate staking system and proper water and nutrient management. This study aimed to assess the effect of irrigation levels and silicon doses on the yield and quality of Sunrise hybrid melons, in a greenhouse. A randomized block design was used, with a 5 x 3 factorial scheme and four replications. The first factor consisted of five silicon doses (0 kg ha-1, 50 kg ha-1, 100 kg ha-1, 150 kg ha-1 and 200 kg ha-1) and the second of three irrigation levels (40 %, 70 % and 100 % of the ETc). The results demonstrated that the applied irrigation levels and silicon doses have no influence on the yield traits of melon plants. The irrigation level corresponding to 100 % of the ETc promotes higher values for soluble solids (9.86 ºBrix) and maturation index (114.9) on fruits. The increase of silicon doses up to 200 kg ha-1 also increases the maturation index in the treatment with the greatest irrigation level and reduces this index at the shallowest level applied.

Bell pepper is a vegetable-fruit of great economic importance in Brazil. Crop production demands adequate water supply, nutrients, and light. The objective of this study was to evaluate gas exchange (net photosynthesis, stomatal conductance, transpiration, internal carbon concentration and instantaneous carboxylation efficiency) and dry mass accumulation in leaves and roots under fertigation with nitrogen and potassium. The experiment was conducted in a completely randomized design in a factorial scheme (4 × 4) with four replications and a total of 64 experimental units. Treatments consisted of a combination of four nitrogen doses (0; 73.4; 146.8 and 293.6 kg ha-1 of N) with four doses of potassium (0; 53.3; 106.7 and 213.4 kg ha-1 of K). An infrared gas analyzer (IRGA) coupled with a light source (irradiation of 600 µmol m-2 s-1) was used for the evaluation of gas exchange. There was a significant interactive effect of N and K on net photosynthesis and leaf and root dry mass. Root dry mass was the variable that best expressed this interaction. Physiological variables measured were more responsive to nitrogen fertilization than to K fertilization. The optimum values of stomatal conductance, transpiration, internal carbon concentration and carboxylation efficiency were obtained with the application of nitrogen doses between 147 and 294 kg ha-1.

Fertilization is important for the optimization of plant growth and yield, which are necessary for agronomic activities. Soil fertilization should increase net earnings that depend on nutrient use efficiency. The aim of this study was to evaluate the agronomic efficiency of eggplant under different doses of potassium (K) and nitrogen (N). Four levels of K (0, 54, 108, and 216 kg ha-1) and four levels of N (0, 67, 134, and 268 kg ha-1) were applied weekly by fertigation. The highest plant and the largest stem diameter were found with 165-175 kg ha-1 of N. Leaf area was more influenced by N than by K. Isolated application of different K doses did not statistically influence height plant, stem diameter, or leaf dry matter. The agronomic efficiency of nitrogen is reduced with increasing levels of N and K.

Adequate crop fertilization is one of the challenges for agriculture. Measuring gas exchange and biomass accumulation may be used to adjust crop management. The effect of fertigation with potassium (0 kg ha-1, 54 kg ha-1, 108 kg ha-1 and 216 kg ha-1) and nitrogen (0 kg ha-1, 67 kg ha-1, 134 kg ha-1 and 268 kg ha-1) on gas exchange and biomass accumulation in eggplant was assessed under greenhouse conditions. The net photosynthesis, stomatal conductance, transpiration, internal CO2 concentration, instantaneous carboxylation efficiency, water-use efficiency and total dry weight were evaluated. With the exception of K for water-use efficiency and N for internal CO2 concentration, all the other gas exchange parameters were significantly affected by the K and N doses. There was an interaction between N and K doses for net photosynthesis, stomatal conductance, transpiration and instantaneous carboxylation efficiency. The highest values for net photosynthesis, stomatal conductance, transpiration rate, carboxylation instantaneous efficiency and total dry weight were found in the range of 125-185 kg ha-1 of K and 215-268 kg ha-1 of N.

Different irrigation times result in variable transpiration rates, due to the water availability and its interaction with the evapotranspiration demand. The vapor pressure deficit is an accurate indicator of the atmosfere evaporative capacity and can affect plants because of the movement of water in the soil-plant-atmosphere continuum system. This study aimed to evaluate the plant growth, yield and water-use efficiency of bell peppers under irrigation times (8 a.m. and 2 p.m.) and water replacement levels (60 %, 80 %, 100 %, 120 % and 140 % of the crop water requirement - ETc) based on the evapotranspiration demand. The increase in the irrigation levels could be fit to linear models for the variables number of fruits per plant, mean and total fruit weight per plant, fruit length, and root, stem and total dry weight. Irrigation at 2 p.m. increased the total and mean fruit weight and number of fruits per plant, as well as fruit length, if compared to the irrigation at 8 a.m., besides increasing the yield by 50.82 % (2,343.0 g plant-1 to 3,533.6 g plant-1) and the water-use efficiency by 55.64 %. In areas subjected to water shortages, establishing irrigation times based on irrigation management practices can increase the water-use efficiency and yield for bell peppers.

As reservas extrativistas, um dos legados do movimento organizado dos seringueiros do qual Chico Mendes foi um dos grandes protagonistas, foram idealizadas como proposta de desenvolvimento para Amazônia e para os povos da floresta, alternativa ao modelo estatal hegemônico, de características ambientalmente predatórias e socialmente excludentes. Desde o assassinato de Chico Mendes em 1988 foram criadas 88 reservas extrativistas (sendo 62 federais e 26 estaduais). Três dessas reservas extrativistas federais foram criadas nos anos 2000 na Bacia do Xingu, na região conhecida como Terra do Meio. O presente artigo relata a experiência de organização e gestão dessas reservas, defendendo que o modelo das reservas extrativistas pode realizar os objetivos presentes na idealização de sua proposta pelo movimento de Chico Mendes e demais seringueiros mediante a observação de certas condições, incluídas aí o estabelecimento de parcerias e alianças nos diversos setores da sociedade. Escrevemos da perspectiva de membros do Instituto Socioambiental, organização não governamental parceira e assessora das associações dos moradores das Resex da Terra do Meio, há mais de 25 anos instituição importante em questões socioambientais da Bacia do Xingu. Desse ponto de vista, descreveremos as estratégias que têm sido adotadas pelas famílias e seus parceiros em busca de um desenvolvimento ambientalmente viável e socialmente digno e justo.

O pimentão é uma hortaliça-fruto de grande importância econômica no país. Em seu processo de produção a cultura demanda água, nutrientes e luz em quantidades adequadas. Este trabalho teve por objetivo avaliar as trocas gasosas (fotossíntese líquida, condutância estomática, transpiração, concentração interna de carbono e eficiência instantânea de carboxilação) e o acúmulo de massa seca das folhas e de raiz na cultura do pimentão fertirrigado com nitrogênio e potássio. O experimento foi conduzido em ambiente protegido em delineamento inteiramente casualizado com esquema fatorial (4x4) com quatro repetições, totalizando 64 unidades experimentais. Os tratamentos consistiram na combinação de quatro doses de nitrogênio (0; 73,4; 146,8 e 293,6 kg ha-1 de N) com quatro doses de potássio (0; 53,3; 106,7 e 213,4 kg ha-1 de K). Um analisador de gás infravermelho (IRGA) com fonte de luz acoplada (irradiação de 600 µmol m-2 s-1) foi utilizado para avaliar as trocas gasosas. Houve interação na aplicação de N e K para fotossíntese líquida, massa seca das folhas e de raiz, sendo a massa seca de raiz a variável que expressa melhor essa interação. As alterações fisiológicas são mais responsivas à adubação nitrogenada quando comparada à adubação potássica. Os valores mais expressivos de condutância estomática, transpiração, concentração interna de carbono e eficiência de carboxilação foram obtidos com a aplicação de doses de nitrogênio entre 147 e 294 kg ha-1.

The objective of this study was to evaluate the effect of nitrogen and potassium silicate on the productive and commercial aspects of curly lettuce, Vera cultivar. The experimental design was completely randomized (CRD), with ten treatments and three replications. The treatments, arranged in a factorial design according to the Plan Puebla III matrix (Turrent & Laird, 1975), consisted of the combination of five doses of nitrogen (9; 54; 90; 126 and 171 kg ha-1) and five doses of potassium silicate (1.15; 6.90; 11.50; 16.10 and 21.85 kg ha-1). A control treatment without application of nitrogen and potassium silicate was also inserted. The crop was grown in a greenhouse and the doses were applied as sidedressing using drip micro-irrigation system. Total fresh matter, commercial fresh matter, non-commercial fresh matter, number of leaves and commercial trade index were evaluated. The commercial fresh matter and the number of commercial leaves per plant were affected only by nitrogen fertigation and increased linearly with the increase in the nitrogen dose of N, with the best responses observed at the highest dose of this element (171 kg ha-1). Potassium silicate had effect only in non-commercial fresh matter, not influencing the other characteristics.

O girassol (Helianthus annuus L.), que é comumente cultivado para produção de sementes e óleo, também apresenta potencial de uso como planta ornamental. Entretanto, seu porte elevado dificulta essa utilização, principalmente como flor em vaso. Objetivou-se neste experimento avaliar os efeitos do regulador de crescimento paclobutrazol sobre o crescimento de plantas de girassol em vaso, cultivadas em sistema hidropônico, dentro de estufa, em vasos preenchidos com sílica moída. Os dois genótipos de girassol utilizados foram BRS Oásis, com capítulo marrom e altura média de 1,85 m, e Helio 358, com capítulo amarelo e altura média de 1,45 m. As doses de paclobutrazol avaliadas foram 0; 0,5; 1; 2; 4; e 6 mg L-1 , aplicadas diretamente no substrato de sílica moída. A solução nutritiva utilizada foi a de Hoagland, e as plantas foram mantidas sob aeração constante. O delineamento experimental foi o de blocos casualizados, em esquema fatorial com cinco repetições, totalizando 60 parcelas. Avaliaram-se a altura das plantas e a massa de matéria seca de raiz, caule, folhas e de capítulos. Houve efeito do paclobutrazol sobre o crescimento das plantas. O uso do paclobutrazol na dose de 2mgL-1 reduz a altura do girassol, porém não afeta a qualidade da inflorescência, o que pode viabilizar o seu uso na produção de flores de girassol como ornamentais. A sensibilidade ao paclobutrazol é maior para o genótipo Helio 358 em relação ao genótipo BRS Oásis.

The experiment objectified to evaluate the effects of water regimes (irrigation and no irrigation) and fertigation, combined with fertilizer doses for N, P and K, during the initial growth phase of two coffee cultivars, Obatã and IAPAR-59, in the north-western region of the state of Paraná, Brazil. The experimental design was the completely randomized in a split-plot arrangement. The main plots were represented by fertilizer doses, corresponding to 15, 30, 45 and 60 g m-1, for N and K, and to 3, 6, 9 and 12 g m-1, for P, which are equivalent, respectively, to percentages of 50%, 100%, 150% and 200% of the dose recommended for each nutrient. The sub-plots were constituted by lines of plants that received the water regimes. Were evaluated stalk diameter, length of the first plagiotropic branch and its number of inter-knots. The treatments were analyzed separately for each cultivar of coffee. Fertigation and irrigation favored the initial growth of both coffee cultivars. For the IAPAR-59 cultivar, the number of inter-knots was upper only with fertigation. The number of inter-knots increased with irrigation and decreased in no irrigation regime, linearly, for IAPAR-59 and Obatã, respectively, in function of the NPK doses increasing. In fertigation, it was observed reduction of stalk diameter at doses higher than the lowest dose tested, for IAPAR-59, while the largest number of inter-knots was obtained with the highest dose used, for Obatã.

This study was conducted at the Agronomic Institute of Paraná (IAPAR) in Londrina, State of Paraná (PR), Brazil (latitude 23º18'S, longitude 51º09'W and average altitude of 585 m). The local climate, according to the classification of Köeppen, is Cfa type, i.e., humid subtropical climate, with rain in all seasons and can occur dry seasons during the winter. It was determined soil evaporation (E) under different coverage densities with residue from the wheat crop. The treatments were installed in weighting lysimeters of 2.66 m² and 1.3 m deep, which allows to determine E by the mass difference with measuring precision of 0.1mm at one hour intervals. Treatments consisted of 0; 2.5; 5 and 10 t ha-1 of wheat crop residues, placed evenly over each lysimeter. In the first cycle (September 22nd to October 20th, 2008), the reduction of E, as compared to a bare soil, was 4; 15 and 24%, while in the second cycle (December 1st to 30th, 2008), the reduction was of 15; 22 and 25%, respectively, for the treatments of 2.5; 5 and 10 t ha-1.O presente estudo foi realizado no Instituto Agronômico do Paraná (IAPAR), em Londrina, Estado do Paraná (latitude de 23º18'S, longitude de 51º09'W e altitude média de 585 m). O clima local, segundo a classificação do Köppen, é do tipo Cfa, ou seja, subtropical úmido, com chuvas em todas as estações, podendo ocorrer secas no período de inverno. Determinou-se a evaporação (E) da água do solo sob diferentes densidades de cobertura com resíduo da cultura de trigo. Os tratamentos foram instalados em lisímetros de pesagem de 2,66 m² e 1,3 m de profundidade, que permitem determinar E por diferença de massa com precisão equivalente a 0,1 mm em intervalos de uma hora. Os tratamentos consistiram em 0; 2,5; 5 e 10 t ha-1 de resíduos da cultura do trigo, colocadas de forma homogênea em cada lisímetro. No primeiro ciclo (22/09 a 20/10/2008), a redução de E em relação ao solo descoberto foi de 4; 15 e 24%, enquanto no segundo ciclo (01/12 a 30/12/2008), a redução foi de 15; 22 e 25%, respectivamente, para os tratamentos 2,5; 5 e 10 t ha-1.

The performance of the CROPGRO-Drybean model for the prediction ofsoil water balance, as well as growth components and bean crop yield, was assessed using data from two field experiments conducted at the State University of Maringá Iirrigation Technical Center, Paraná, Brazil, (latitude 23º27'S, longitude 51º57' and altitude 542 m)during the 2005 and 2006 growing seasons. This assessment aimed to analyze growth components, evapotranspiration and bean crop yield for the edaphoclimatic conditions of the area as simulated by the CROPGRO-Drybean model. This is a model for legumes, and it is grouped in a Decision Support System for Agrotechnology Transference (DSSAT).The model simulates growth, development and yield components of beans as a function of daily climatologic elements for each soil’s specific conditions. It is possible to affirm that water deficit during flowering caused the model to penalize yield severely. It showeddiscrepant values in leaf area index simulation, and also accentuated discrepancies between measured and simulated values of soil moisture on the day following rainfall. Correlations between measured and simulated values of soil moisture exceeded 70% in both experiments. Yield was underestimated by the model in both experiments.O presente trabalho foi realizado no Centro Técnico de Irrigação da Universidade Estadual de Maringá, localizada em Maringá, Estado do Paraná (lat. 23º 25' S, long. de 51º 57' O, alt. de 542 m). Foram realizados dois experimentos no campo, com a cultura do feijão, conduzidos nos anos agrícolas de 2005 e 2006. Objetivou-se neste trabalho em avaliar os componentes de crescimento, a evapotranspiração e a produção da cultura do feijão para as condiçõesedafoclimáticas da região, simuladas pelo modelo CROPGRO-Drybean. O modelo de foi desenvolvido para a cultura do feijão, está inserido no Sistema de Suporte à Decisão para Transferência de Agrotecnologia (DSSAT). O modelo simula os componentes do crescimento, desenvolvimento e produtividade do feijoeiro em função de elementosclimatológicos diários, para as condições específicas de cada solo. Pode-se afirmar que o déficit hídrico, na fase de florescimento, faz com que o modelo penalize severamente a produtividade, apresentou valores discrepantes na simulação do índice de área foliar, mostrou que há discrepância acentuada nos valores medidos e simulados de umidade do solo, no dia posterior à ocorrência de uma precipitação, apresentando correlações entre os valores medidos e simulados de umidade do solo foram superiores a 70% nos dois experimentos. A produtividade foi subestimada pelo modelo nos dois experimentos.

The aim was to verify if the fungigation via drip irrigation is an alternative to the conventional method of spraying on tomato for controlling early blight. Tomato plants (variety Santa Clara) were grown in pots inside a greenhouse. Fifty days after transplanting, the plants were inoculated with Alternaria solani and treated with four different fungicides: azoxystrobin (8 g 100 L-1), difeconazole (50 mL 100 L-1), metiram+piraclostrobin (200 g 100 L-1) and tebuconazole (100 mL 100 L-1) using two applications methods: conventional spraying and fungigation dripping. The control plants did not receive fungicide application. To assess the severity of the disease, we used a rating scale expressed as the area under the disease progress curve (AUDPC) and production factors, such as number, weight and average diameter of the fruit and its productivity. The experimental design was completely randomized in factorial scheme 4 x 2 + 1 with eight replicates. Each plot had one plant in one pot. A 27% reduction in disease severity was observed when compared with the control plants, with no significant difference noted regarding the application method. The number of fruits did not statistically differ between the treatments. The average weight and diameter of the fruits were superior in the plants that had fungicide application compared to the control plant, reflecting an increase inproductivity. Fungigation through water dripping is an alternative to the conventional method of spraying cultured tomatoes.O objetivo foi verificar se a fungigação via gotejamento é uma alternativa ao método convencinal de pulverização no controle da pinta-preta do tomate. Plantas de tomate (var Santa Clara) foramcultivadas em vasos instalados no interior de uma casa-de-vegetação. Aos 50 dias após o transplantio, foram inoculadas com Alternaria solani e tratadas com quatro diferentes fungicidas: azoxystrobina (8 g 100 L-1), difeconazole (50 mL 100 L-1), metiram+piraclostrobin (200 g 100 L-1) e tebuconazole (100 mL 100 L-1), em duas formas de aplicação: pulverização convencional e fungigação por gotejamento. Uma testemunha não recebeu aplicação de fungicidas. Avaliou-se aseveridade da doença através de escala de notas expressa em área abaixo da curva de progresso da doença (AACPD) e fatores de produção, como número, peso e diâmetro médio dos frutos e produtividade. O delineamento experimental foi 4 x 2 + 1, com oito repetições. Cada parcela constou de uma planta em um vaso. Houve redução da severidade da doença de 27% em comparação com a testemunha. Não houve diferença significativa entre os métodos de aplicação. O número de frutos não diferiu estatisticamente entre os tratamentos. O peso médio e diâmetrodos frutos foram maiores nos tratamentos com fungicidas em comparação a testemunha, o que refletiu no aumento da produtividade. A fungigação por gotejamento é alternativa de aplicação de fungicida sistêmico por pulverização na cultura do tomate.

Este experimento foi conduzido em uma área do Centro Técnico de Irrigação (CTI) da Universidade Estadual de Maringá (UEM) com o objetivo de avaliar o efeito da aplicação de porcentagens de doses para NPK, no número de ramos plagiotrópicos e na produtividade das cultivares de cafeeiro Obatã e IAPAR - 59 em diferentes cultivos (não irrigado, irrigado e fertirrigado). As mudas foram plantadas em espaçamento de 2,0 metros entre linhas e 1,0 metro entre plantas, caracterizando sistema adensado. Utilizou-se o sistema de irrigação localizada por gotejamento. O experimento foi esquematizado em delineamento inteiramente casualizado em parcelas subdivididas com quatro repetições. As parcelas e subparcelas foram compostas pelas porcentagens de doses de NPK e pelos cultivos, respectivamente. A interação entre estes fatores influenciou significativamente a produtividade e o número de ramos plagiotrópicos, permitindo concluir qual a dose de fertilizante mais indicada para cada cultivo. A produtividade máxima para a cultivar Obatã foi conseguida com as doses de NPK de percentual 119,5%, 151,25%, e 154,17% para os cultivos não irrigados, irrigados e fertirrigados, respectivamente. A máxima produtividade da cultivar IAPAR - 59 nos cultivos não irrigados, irrigados e fertirrigados foi alcançada com os percentuais de 137,83%, 162% e 151,75%, respectivamente. Em relação ao número de ramos plagiotrópicos, a melhor dose para a cultivar Obatã, nos cultivos irrigados e fertirrigados, correspondeu a dose de 200%, enquanto que a dose de 150% foi a mais adequada para as plantas irrigadas da cultivar IAPAR - 59. Os melhores desempenhos produtivos foram obtidos nos cultivos fertirrigados.This experiment was conducted in an area of the Technical Center of Irrigation (CTI) of the State University of Maringá (UEM) with the objective of evaluating the effect of the application of different percentages of doses of NPK (50%; 100%; 150%; 200%) in the number of plagiotropic branches and in the productivity of the cultivars of coffee Obatã and IAPAR - 59. The seedlings were planted in the spacing of 2.0 meters between lines and 1.0 meter within lines, characterizing a dense system. In this experiment was used the system of localized irrigation by dripping. The experiment followed a design completely randomized in split plots with four replications. The plots and subplots were composed by percentages of doses of NPK and crops, respectively. The interaction between those factors influenced significantly the productivity and the number of plagiotropic branches allowing concluding which dose of fertilizer is indicated for each cultivation. The maximum yield to grow Obatã was achieved with doses of NPK percentages of 119.5%, 151.25% and 154.17% for non-irrigated crops, irrigated and fertilized, respectively. The maximum yield for IAPAR - 59 in nonirrigated crops, irrigated and fertilized was achieved with doses of NPK percentages of 137.83%, 162% and 151.75% respectively. Regarding the number of primary branches the best dose for cultivating crops in irrigated and Obatã fertirrigated corresponded to a percentage of 200%, while the percentage dose of 150% showed the most suitable for IAPAR - 59 for the irrigated crops. The best productive was obtained for the fertirrigated cultivations.

O experimento foi conduzido no Centro Técnico de Irrigação (CTI), Universidade Estadual de Maringá (UEM), tendo como objetivo avaliar os efeitos de diferentes regimes hídricos (irrigado e não irrigado) e fertirrigação, combinados com diferentes doses de adubo para N (15; 30; 45 e 60 g m-1), P (3; 6; 9 e 12 g m-1) e K (15; 30; 45 e 60 g m-1), na fase de crescimento inicial de duas cultivares de café, na região noroeste do Paraná. Foram avaliadas as seguintes variáveis de crescimento da cultura: diâmetro de copa, altura de planta e número de ramos plagiotrópicos totais. Observou-se que a fertirrigação e a irrigação influenciaram no desenvolvimento inicial do cafeeiro, aumentando os valores de todas as variáveis avaliadas. A interação entre regimes hídricos e fertirrigação versus doses de NPK foi significativa para algumas variáveis de crescimento, porém esses resultados não apresentaram tendência comum, que permitisse constatar qual a dose mais indicada para cada regime hídrico na fase de crescimento inicial do cafeeiro.The experiment was conducted at the Technical Center for Irrigation, Maringá State University. The objective was to evaluate the effects of different water regimes (irrigation and no irrigation) and fertilization-irrigation, combined with different manure doses for N (15; 30; 45 and 60 g m-1), P (3; 6; 9 and 12 g m-1) and K (15; 30; 45 and 60 g m-1), during the initial growth phase of two coffee cultivars, in the north-western region of the state of Paraná. The following culture growth variables were evaluated: top diameter, height of plant and number of total plagiotropic branches. Fertilization-irrigation and irrigation affected the initial development of coffee, increasing the values of all evaluated variables. Interaction between water regimes and fertilization-irrigation with NPK doses was significant for certain growth variables, however results didn't present a common trend, that would indicate which dose was adequate for each water regime during the initial growth phase of the coffee shrub.

Objetivou-se, neste trabalho, estudar os efeitos de diferentes soluções nutritivas aplicadas em duas vazões na produção hidropônica da alface (Lactuca sativa), cultivada pelo sistema NFT (Nutritive Film Technique). O experimento foi conduzido em casa de vegetação, na unidade de pesquisa em agricultura irrigada da Universidade Estadual de Maringá. Os tratamentos constaram de três soluções nutritivas com concentrações diferentes (S1=0,8 dS/m, S2=1,2 dS/m e S3=2,5 dS/m), combinadas com duas vazões de aplicação (V1=0,8 L.min-1 e V2=1,2 L.min-1 ) nos canais de cultivo em esquema fatorial 3 x 2. Para avaliar o efeito dos tratamentos no desenvolvimento da cultura os dados foram submetidos à análise de variância (teste F), e os resultados avaliados através de teste de média de Tukey (5%). A análise dos resultados permitiu concluir que os fatores solução e vazão não apresentaram interação significativa e que os maiores valores avaliados de biomassa fresca e diâmetro do caule foram obtidos no tratamento solução 2 (CE= 1,2 dS/m).The porpose of this work was to study the effect of different nutrient solutions applied in two outflow in the hidroponic yeld of lettuce (Lactuca sativa). This research was accomplished at greenhouse through hydroponic system NFT in Maringá State University. The treatments consisted of three nutrient solutions (S1=0,8 dS/m, S2=1,2 dS/m e S3=2,5 dS/m) combined with two flows of application (V1=0,8 L.min-1 e V2=1,2 L.min-1 ) in the growing channels of cultivation. The flows of application of the solutions were 0,8 L.min-1 (V1) and 1,2 L.min-1 (V2), placed alternately in the growing channels in a 3 x 2 factorial scheme. To evaluate the effect of treatments on the culture development the data were submitted to the variance analysis (Test F), and the results were evaluated through Tukey (5%) average test. The analysis of the results allowed to conclude that the factories nutrient solution and flow did not show significant interaction. The greater values evaluated of biomass fresh and diameter of stem by plant were obtained in treatment solution 2 (EC= 1,2 dS/m).

O presente estudo foi realizado para a localidade de Palotina, Estado do Paraná, (latitude de 24º17'S, longitude de 53º50'30'' e altitude de 333 metros), onde se utilizou o modelo de simulação de crescimento e desenvolvimento da cultura da soja (Glycine max L. Merril), CROPGRO-soybean, o qual foi calibrado para as cultivares de soja CD 202, CD204, CD 206 e CD 210, cultivados na região de Palotina, Estado do Paraná. Após a calibração, realizou-se a simulação da produtividade da soja para cinco datas de semeadura e em 25 safras, compreendidas entre o período de 1974 a 1999. Com as produtividades simuladas determinaram-se diferentes níveis de probabilidade de ocorrência destas produtividades, para as cinco datas de semeadura simuladas. Em 1º de outubro, observaramse maiores produtividades, porém, nesta data também foram encontradas as menores produtividades; em 15 de outubro e 1º de novembro considerou-se a melhor data de semeadura da cultura da soja; estas apresentaram médias das quatro cultivares nas 25simulações de 2.450 kg ha-1, e 2.303 kg ha-1, respectivamente. Em nível de 50% de probabilidade de rendimentos é uma ótima ferramenta para o agricultor, no auxílio à tomada de decisão quanto à época de semeadura da cultura da soja na região. Somente a semeadura realizada em 1º de dezembro apresentou produtividade inferior a 2.000 kg ha-1neste nível.This study was carried out in the region of Palotina, state of Paraná (latitude 24º17’S, longitude 53º50’30”, altitude 333 m), using the growth and development simulation model for soybean crop (Glycine Max (L.) Merrill), CROPGRO-Soybean, which was calibrated to the soybean cultivars CD 202, CD 204, CD 206 and CD 210, grown in the region ofPalotina, state of Paraná. After calibration, the simulation of soybean yield was carried out for five different sowing dates and in 25 harvest periods, from 1974 to 1999. From the analysis carried out in the simulations, varying probability levels were determined for theactual occurrence of these productivities, for each of the simulated sowing times. From the five simulated sowing dates, October 1st presented the highest yields, but also the lowest. October 15th and November 1st were considered the best dates for soybean sowing,presenting an average for the four cultivars in the 25 simulations of 2,450 kg ha-1 and 2,303 kg ha-1, respectively. The yield probability analysis proved to be a great tool in decisionmaking as for the time of sowing of soybean. Well into the 50% level of yield probability is a good number for the farmer, in assisting in the decision of when to sow soybean in the region. Only the sowing time of December 1st presented productivity inferior to 2,000 kg ha-1 with probability levels of 50%.

Este trabalho reporta aos resultados de um experimento sobre perda de carga e fator de atrito em tubos de polietileno de pequenos diâmetros. Utilizaram-se cinco tubos com os seguintes diâmetros internos: 10,0 mm, 12,9 mm, 16,1 mm, 17,4 mm e 19,7 mm. Oexperimento foi conduzido para números de Reynolds, no intervalo de 6000 a 72000, obtidos pela variação da vazão nos tubos, a uma temperatura média da água de 20oC. Os resultados foram analisados e, de acordo com as condições experimentais, o fator de atrito fda equação de Darcy-Weisbach pode ser estimado com c = 0,300 e m = 0,25. A equação de Blasius (c = 0,316 e m = 0,25) superestimou os valores do fator de atrito para todos os tubos analisados, porém esse fato não constitui limitação para sua utilização em projetos demicroirrigação. As análises mostraram que as duas equações proporcionam estimativas do fator de atrito com pequeno desvio-médio (5,1%).On this paper, the results of an experimental study on the hydraulic friction loss for small-diameter polyethylene pipes are reported. The experiment was carried out using a range of Reynolds number between 6000 to 72000, obtained by varying discharge at 20oC water temperature, with internal pipe diameters of 10.0 mm, 12.9 mm, 16.1 mm, 17.4 mm and 19.7 mm. According to the analysis results and experimental conditions, the friction factor (f) of theDarcy-Weisbach equation can be estimated with c = 0.300 and m = 0.25. The Blasius equation (c = 0.316 and m = 0.25) gives an overestimate of friction loss, although this fact is non-restrictive for micro-irrigation system designs. The analysis shows that both the Blasiusand the adjusted equation parameters allow for accurate friction factor estimates, characterized by low mean error (5.1%).

Em decorrência da atual pressão econômica sobre os agricultores, da crescente competição pelo uso da água e dos impactos ambientais, deverá ocorrer uma mudança de paradigma no manejo da irrigação, enfocando-se mais a eficiência econômica do que a exigência de água pela cultura. Desta forma, considerando a importância sócio-econômicaque o feijão tem no Brasil, associado ao fato de tratar-se de uma cultura de elevado padrão de risco devido à grande sensibilidade tanto ao déficit hídrico quanto ao excesso de água, a realização de trabalhos utilizando-se técnicas de otimização no manejo da irrigação de feijão torna-se cada vez mais necessário. Neste trabalho objetivou-se propor um método para determinar a quantidade ótima de irrigação, considerando diferentes combinações entre receita líquida esperada para a cultura do feijoeiro e nível de risco, obtendo uma relação entre a receita líquida esperada, associada a um certo grau de risco econômico, e as lâminas de irrigação, quando o único fator limitante à produção é a disponibilidade hídrica.Nowadays, the rising competition for the use of water and environmental resources with consequent restrictions for farmers should change the paradigm in terms of irrigation concepts, or rather, in order to attain economical efficiency other than to supply water requirement for the crop. Therefore, taking into account the social and economical role of bean activity in Brazil, as well as the risk inherent to crop due to its high sensibility to both deficit and excessive water, the optimization methods regarding to irrigation management have become more interesting and essential. This study intends to present a way to determine the optimal water supply, considering different combinations between desired bean yield and level of risk, bringing as a result a graph with the former associated with the latter, depending on different water depths.

Objetivou-se neste trabalho estudar os efeitos de um regulador de crescimento (paclobutrazol) sobre o crescimento e a produção de flores de girassol em vasos, crescidos sob sistema hidropônico. Foram utilizados dois genótipos de girassol (BRS Oásis e Helio 358), combinados com seis doses de paclobutrazol (0;0,5;1;2;4 e 6 mg.L-1) e substrato inerte de sílica moída. A solução nutritiva foi a de Hoagland modificada (EPSTEIN & BLOOM, 2004) e as plantas foram mantidas sob aeração constante. Para avaliar os efeitos do paclobutrazol sobre o crescimento das plantas (altura final e diâmetro de capítulo), as variáveis foram submetidas à análise de variação (teste F), utilizando-se rotinas do sistema SAS/STAT , aplicando-se, para os valores significativos a 5% de probabilidade e a regressão linear e não linear para a análise dos parâmetros aferidos, em função das doses do regulador de crescimento. A análise dos dados permitiu concluir que há efeito do paclobutrazol sobre o crescimento e sobre a produção de flores de girassol, reduzindo a altura final das plantas e o diâmetro dos capítulos, sendo que doses elevadas causaram deformações nas plantas e má formação nas flores. Helio 358 apresentou-se mais adequado para a produção ornamental, sendo melhor dose entre 1 e 2 mgL-1de paclobutrazol.This work had the aim of studying the effects of a growth regulator (paclobutrazol) on the growth and the production of sunflowers in vases, with hidroponic solution. Two sunflower genotipes were used (BRS Oásis and Helio 358), combined with sixpaclobutrazol doses (0;0,5;1;2;4 and 6 mg.L-1) and inert substratum of silex ground. The nutritious solution was a Hoagland modified (EPSTEIN & BLOOM, 2004) and the plants were maintained under constant aeration. To evaluate the effects of the paclobutrazol on the growth of the plants (final height and head diameter), the variables were submitted to the variation analysis (F tests) , being used routines of the system SAS/STAT, being applied, for the significant values at 5% of probability and the lineal and not lineal regression for the analysis of the parameters checked, in function of the growth regulator doses. The analysis of the data allowed to conclude that there is effect of the paclobutrazol on the growth and on the production of sunflowers, reducing the final height of the plants and head diameter, and the high doses caused deformations in the plants and bad formation in the flowers. Helio 358 presented to be more adequate for the ornamental production, being the best dose between 1 and 2 mgL-1de paclobutrazol.

Em decorrência da atual pressão econômica sobre os agricultores, da crescente competição pelo uso da água e dos impactos ambientais, deverá ocorrer uma mudança de paradigma no manejo da irrigação, enfocando-se mais a eficiência econômica do que a exigência de água pela cultura. Dessa forma, considerando a importância socioeconômicaque o feijão tem no Brasil, tendo em vista o fato de sua cultura apresentar elevado padrão de risco, devido à grande sensibilidade tanto ao déficit hídrico quanto ao excesso de água, a realização de trabalhos utilizando técnicas de otimização no manejo da irrigação de feijão torna-se cada vez mais interessante. O presente estudo procurou identificar uma forma de determinar a quantidade ótima de água aplicada, considerando diferentes combinações entre receita líquida esperada para feijão e nível de risco, obtendo como resultado a receita líquida esperada, associada a um certo grau de risco, em função de diferentes lâminas de água.Nowadays, the rising competition for use of water and environmentalresources with consequent restrictions on farmers should change the paradigm in terms of irrigation concepts. or rather, in order to attain economical efficiency other than to supply water requirement for the crop. Therefore, taking into consideration the social andeconomical role of bean activity in Brazil, as well as the risk inherent to crop due to its high sensibility to both deficit and excessive water, the optimization methods regarding to irrigation management have become more interesting and essential. This study intends to present a way to determine the optimal water supply, considering different combinations between desired bean yield and level of risk, bringing as a result a graph with the formerassociated with the latter, depending on different water depths.

Com o objetivo de comparar a uniformidade de lâminas aplicadas, uniformidade de umidades no solo e produtividade da cultura do feijoeiro, conduziu-se um experimento utilizando a cultivar de feijão IAPAR 57. Foram feitas aplicações de água na superfície do solo, com quatro valores de uniformidades, aplicando-se a mesma lâmina, utilizando-se de quatro espaçamentos entre aspersores: 12 x 12 m; 18 x 18 m; 18 x 24 m, e 24 x 24 m. Foram feitas análises das distribuições dos dados de lâmina aplicada, de umidade do solo e de rendimento de grãos, no espaço. Para isso, foram usadas técnicas de análise exploratória que consistiram principalmente em gráficos tipo "box-plot" simplificados, nos quais são apresentados apenas os valores de mediana, máximo e mínimo das distribuições. Verificou-se que a qualidade da irrigação interferiu na uniformidade da umidade do solo e influenciou nas variáveis de produção da cultura de feijão. Uniformidade máxima não implicou maior produtividade de grãos.Aiming to evaluate the effect of irrigation depth and soil moisture uniformity on dry bean yield, an experiment was conducted with the cultivar IAPAR 57. Water was applied on soil surface at four uniformity levels with the same irrigation depth, imposed by four sprinklers spaced at 12 x 12 m; 18 x 18 m; 18 x 24 m, and 24 x 24 m. Spatial distribution analyses of the irrigation depth, soil moisture and grain yield data were proceeded with exploratory data analysis techniques based on simplified box-plot graphics, which only represent the median, minimal, and maximal values. It was verified that the quality of irrigation affected the soil moisture uniformity, causing effect also on dry bean yield. The maximum uniformity of water distribution did not relate with the highest yield.

O experimento foi conduzido em ambiente protegido, na unidade de pesquisa em agricultura irrigada da Universidade Estadual de Maringá, Estado do Paraná. O objetivo deste trabalho foi estudar os efeitos de diferentes soluções nutritivas aplicadas em duas vazões na produção hidropônica da alface (Lactuca sativa L.), cultivada pelo sistema NFT(Nutrient Film Technique). O delineamento experimental foi o de inteiramente casualizado, em esquema fatorial 3x2 e com três repetições. Os tratamentos constaram de três soluções nutritivas com concentrações diferentes (S1=1,2 dS m-1, S2=2,5 dS m-1 e S3=0,8 dS m-1), combinadas com duas vazões de aplicação (V1=1,2 L min-1 e V2=0,8 L min-1 ), nos canais de cultivo. Para avaliar o efeito dos tratamentos no desenvolvimento da cultura os dados foram submetidos à análise de variância (Teste F). Os resultados avaliados por meio de teste de média de Tukey (5%). A análise dos resultados permitiu concluir que a interação dos fatores solução e vazão não foi significativa e o tratamento S1 (CE= 1,2 dS m-1) mostrou maior biomassa fresca e diâmetro do caule e menor biomassa seca de raiz.The experiment was conducted in protected environment, within a research unit in irrigated agriculture of the State University of Maringá, state of Paraná. The purpose was to study the effect of different nutrient solutions applied on two outflows in the hidroponic production of lettuce (Lactuca sativa). The experimental design was entirely randomized, in factorial scheme 3x2 and with 3 replications. The treatments consisted of three nutrients solutions combined with two outflows of application in the canals of cultivation. In order to evaluate the effect of the treatments on crop growing, data were submitted to a variance analysis (Test F), and the results were evaluated through Tukey (5%) average test. The analysis of the results allowed to conclude that the interaction between the factors solution and the outflows was not significant andtreatment S1 (CE = 1.2 dS m-1) showed higher fresh biomass, larger diameter of the stem and lower dry biomass of root.

O experimento foi conduzido em casa de vegetação, na unidade de pesquisa em agricultura irrigada da Universidade Estadual de Maringá, Estado do Paraná, com o objetivo de estudar o efeito de três soluções nutritivas com condutividades elétricas distintas, aplicadas em duas vazões diferentes, na cultura da alface, analisando as seguintes variáveis de produção: número de folhas aproveitáveis, número de folhas não aproveitáveis e comprimento de caule. Os tratamentos consistiram na combinação fatorial de três soluções nutritivas com concentrações diferentes (S1=1,2 mS cm-1, S2=2,5 mS cm-1 e S3=0,8 mScm-1) e duas vazões de aplicação (V1=1,2 L min-1 e V2=0,8 L min-1) nos canais de cultivo, em delineamento inteiramente ao acaso com 3 repetições. Assim, foram compostos os seguintes tratamentos: S1V1 - Solução nutritiva 1 aplicada na vazão 1, S1V2 - Solução nutritiva 1 aplicada na vazão 2, S2V1 - Solução nutritiva 2 aplicada na vazão 1, S2V2 - Solução nutritiva 2 aplicada na vazão 2, S3V1 - Solução nutritiva 3 aplicada na vazão 1, S3V2 - Solução nutritiva 3 aplicada na vazão 2. O aumento na concentração de nutrientes com vazões diferentes das soluções não promoveram aumento significativo no número de folhas aproveitáveis. No entanto, analisando o tratamento solução isoladamente, houve diferenças significativas no número de folhas não aproveitáveis entre as soluções I e II, em relação àsolução III. A solução 1 (CE = 1,8 mS cm-1) proporcionou o maior comprimento do caule de forma significativamente diferente das demais soluções. This experiment was carried out in a vegetation environment at the irrigated agriculture unit of the State University of Maringá, State of Paraná in order to study the effect of three nutritious solutions with distinct electrical conductivities, applied to two different outflows, on the lettuce cultivation. The following production variables were analyzed: number of useful leaves, number of non-useful leaves, and length of the stem. The treatments consisted of a factorial combination of three nutritious solutions with different concentrations (S1=1.2 mS cm-1, S2=2.5 mS cm-1, and S3=0.8 mS cm-1) and two application outflows (O1=1.2 L min-1 and O2=0.8 L min-1) in the cultivation channels. The delineation was performed at random with 3 replications. Thus, the following treatments were used: S1O1 - nutritious solution 1 applied to outflow 1, S1O2 - nutritious solution 1 applied to outflow 2, S2O1 - nutritious solution 2 applied to outflow 1, S2O2 - nutritious solution 2 applied to outflow 2, S3O1 - nutritious solution 3 applied to outflow 1, S3O2 - nutritious 3 applied to outflow 2. The increase in the concentration of the nutrients with different outflows of the solutions did not provide a significant increase in the number of useful leaves. However, when analyzing the solution treatment separately, there were significant differences in the number of non-useful leaves between solutions I and II, in relation to solution III. Solution 1 (CE = 1.8 mS cm-1) provided the longest length of the stem, which was significantly different from the other solutions.

Calibrou-se o modelo de simulação do crescimento e do desenvolvimento da cultura de soja (Glycine Max (L) Merrill), Cropgro-soybean, para os cultivares de soja CD 202, CD 204, CD 206 e CD 210, cultivados na região de Palotina, Estado do Paraná, (latitude de 24º17'S, longitude de 53º50'30'' e altitude de 333 m). Após a calibração, o modelo Cropgro foi usado para estimar a produtividade de soja para cinco datas de semeadura, durante 25 safras (1974 a 1999). Análises de sensibilidade realizadas revelaram alta resposta do modelo àvariação dos coeficientes genéticos dos cultivares estudados. Das cinco datas de semeadura simuladas, a que apresentou as maiores produtividades foi a de 1 de outubro, porém foi a que também apresentou as menores produtividades. As melhores épocas de semeadura foram consideradas 15 de outubro e 1.º de novembro, por apresentarem médias dos quatro cultivares de 2.450 kg ha-1 e de 2.303 kg ha-1, respectivamente.The model Cropgro-soybean was calibrated for cultivars CD 202, CD 204, CD 206 and CD 210 in the municipality of Palotina, State ofParaná, Brazil (24º17'S latitude, 53º50'30'' longitude and 333 m altitude). After calibrated, the model Cropgro was used to estimate soybean yield for five planting times, during 25 years (1974 to 1999). Sensitivity analysis of the model showed high response due to changes in genetic coefficients of the cultivars in this study. The highest crop yield was simulated for October 1, but it also gave the lowest estimates. The best planting dates were found to be October 15 and November 1, with mean yields of 2.450 kg ha-1 and 2.303 kg ha-1,respectively.

A utilização de hidrogel na agricultura brasileira, principalmente na silvicultura e fruticultura, está cada dia mais consolidado pela capacidade que ele possui de armazenar e disponibilizar água para as plantas. Este trabalho teve por objetivo estudar a capacidade deretenção de solução nutritiva pelo hidrogel quando submetido em diferentes soluções nutritivas de diferentes fertilizantes. Este estudo foi realizado no laboratório do Centro Técnico de Irrigação da Universidade Estadual de Maringá, Maringá, Estado do Paraná. Oexperimento constou de 26 tratamentos e 4 repetições, disposto em um esquema fatorial (5 x 5) mais um tratamento testemunha comum a todos os tratamentos, em um delineamento inteiramente casualizado. Os resultados mostraram que tanto as condutividades elétricas quanto as diferentes soluções de sulfatos interferiram na capacidade de retenção de solução nutritiva do hidrogel.The hydrogel use in the brazilian agriculture, mainly in the forestation, fruits field, and growth media, is being consolidated by its capacity of holding and release water (nutrient solution) to plants. This work aimed to study the holding capacity of nutrient solutions by hydrogel when submitted into differents solutions from sulphates. This study was conducted out the Irrigation Technical Center of Universidade Estadual de Maringá, Maringá, Paraná State. Itwas conducted in a 5 x 5 factorial way (with 26 treatments and 04 replications) and the randomized design. It was used as treatments 05 fertilizers sulphates base (ferrous sulphate, ammonium sulphate, zinc sulphate, copper sulphate, and magnesium sulphate) and 05 doses (0.4; 0.8; 1.2; 1.6, and 2.0 g to each 500 g of distilled water). The distilled water treatment and hydrogel were used as control treatment. The hydrogel was hydrated for 24 hours for a later measure of holding capacity of nutrient solution. We noticed that besidesthe electric conductivity of nutrient solution the different fertilizer interfered with the holding capacity of nutrient solution.