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Abstract The root system distribution of coffee, especially Coffea canephora cv. Robusta, remains poorly characterized. The aim of this study were: (i) to analyze the distribution of the root system in various genotypes of C. canephora cv. Robusta cultivated in the Amazon region; (ii) to evaluate genetic variability based on root traits; and (iii) to test the correlation between root traits, aboveground part, and production capacity. Roots were collected up to a depth of 60 cm and 30 cm away from the stems. The roots were washed, scanned, and processed to quantify root volume (mm3 cm−3), surface area (mm2 cm−3), diameter (mm), and length (mm cm−3). The variations in root systems reveled phenotypic variability among different genotypes of C. canephora cv. Robusta. Most roots were concentrated in the surface layer of the soil (0–30 cm), with LB015 standing out. At a depth of 50–60 cm, AS10, AS4, A106, and GJ08 had more roots than other genotypes, suggesting a promising capacity to avoid drought. There were significant negative correlations between root traits, aboveground part, and production capacity. This study provides valuable information for the selection of genotypes with desirable root traits for different environmental conditions, contributing to the improvement of management practices and breeding programs for Robusta coffee.

Abstract: Papaya seeds have natural barriers (phenolic compounds, seed structure and genetic factors) that make their germination difficult. And the use of seeds is the main means of propagating the species, whether for commercial cultivation, maintenance of germplasm or selection of genetic materials. Thus, the use of seeds with physiological quality (germination, normal seedlings and germination speed) is fundamental to the production of vigorous plants. However, few studies have been developed with the aim of evaluating and improving seed quality. From this perspective, the study aims to evaluate the quality of seeds in genetic materials widely used to obtain new genotypes, in order to identify superior materials and possible crosses between those that have high physiological seed quality. For this purpose, 44 genotypes were analyzed by molecular characterization, via microsatellite markers (observed and expected heterozygosity, number of alleles, information index, fixation index, inbreeding coefficient, genetic structure and genetic dissimilarity via UPGMA grouping), as well as determining physiological quality of the seed (germination speed index, percentage of germination and abnormal seedlings). Among the genotypes, 10 have germination above 60%, a high rate of germination speed and a low percentage of abnormal seedlings, and can be used in crosses to improve seed quality. The dissimilarity analysis was able to highlight the dissimilarity between the accessions of the Solo and Formosa groups. The use of the dissimilarity coefficient and the number of shared alleles made it possible to identify 18 possible crosses promising to improve the quality of papaya seeds.

Currently, 130 species of the genus Coffea have been identified [...]

ABSTRACT This study was developed to carry out selection, estimate genetic parameters and predict individual genetic values of 55 genotypes from S2 families as well as estimate genetic dissimilarity based on physiological seed attributes. All S2 genotypes evaluated were obtained from self-pollination of S1 genotypes from the guava breeding program. The experiment was laid out in blocks with 55 S2 genotypes and four blocks. Genetic parameters were estimated and the best genotypes were selected based on the genetic value, using the statistical method of mixed models. In addition, genetic divergence was estimated based on the mean Euclidean distance. Although heritability values were considered medium to high magnitude for germination (0.22) and germination speed index (0.35), genetic gains were obtained for all traits. Based on the evaluation of individual BLUPs, the S2 genotypes that contributed to most of the evaluated traits were: 5, 31, 85, 214, 369, 393, 398, 442, 443, 444, 449 and 529, suggesting potential to generate vigorous. Through genetic dissimilarity, it was possible to verify the formation of five distinct groups. Therefore, the selection of divergent genotypes with high average for germination is recommended for the advancement of generation in the guava breeding plant.

Low rainfall rates are becoming increasingly frequent because of climate change, causing droughts and threatening world food security. For popcorn, drought is the most limiting abiotic factor for plant’s growth and development. Thus, the water deficit directly impacts for crop productivity. Based on knowledge of the genetic basis of traits involved in stages of popcorn germination and seedling development under water stress, genotypes with potential for adaptation to adverse growing conditions can be selected early. Therefore, data on genetic effects and combining ability of 10 popcorn parents were compiled to propose breeding strategies for the development of cultivars with greater adaptation to water stress in the early stages. Forty-five diallel hybrids were evaluated under two different water regimes, that is, water stress and full irrigation. This corresponded to a water retention capacity of 25% and 70% of the germination paper. The plants were watered daily as needed for seven days. A range of factors were evaluated, that is, germination traits including the germination speed index and germination on the seventh day; shoot traits including length and dry weight; and root system including length, dry weight, root-to-shoot ratio, maximum root number, root network area, specific and root network length, and root volume. Breeding for drought adaption in the early stages of popcorn development can be successful when hybrids are used, because of the genetic effects of dominance (ϕs). These control the traits evaluated at the seedling stage. The combinations L61 x P2 and L71 x P3 were recommended, in view of the more successful performance estimated for traits related to the shoot and root system.

Coffee genotypes cultivated in the Amazonian region have been gaining increasing prominence in Brazilian plantations. This study aimed to quantify nutrient accumulation in the fruits, grains, and husks of Robusta coffee genotypes cultivated in the Brazilian Amazon and estimate genetic diversity. The experiment was conducted in Alta Floresta D’Oeste—Rondônia, Brazil. To assess nutrient accumulation, fresh fruits were collected. These were dried, processed, separated into grains and husks, and subjected to chemical analysis. Nutrient accumulation in fruits, grains, and husks, as well as the grain/husk ratio, underwent analysis of variance through the F-test (p < 0.01. For each evaluated trait, the experimental coefficient of 337 variation (CVe), genetic coefficient of variation (CVg), and genotypic determination coefficient (H2) were also estimated. Variability was observed among Robusta coffee genotypes, with VP06, AS4, and AS10 being the most dissimilar. LB080 had the lowest dry fruit weight and the lowest percentage of grains in relation to husks. ZD156 accumulated more K in the grains, while VP06 and AS10 were the genotypes that accumulated more nutrients in the husks. Nutrients N, K, Ca, and P are accumulated in larger quantities, necessitating the calibration of mineral fertilization dosages and distribution.

This research studied growth and yield of Syagrus schizophylla, an extinction-endangered ornamental palm, grown under five light gradients. The treatments were: G1 - PAR=1234.10 μmol photons m-2 s-1, G2 - PAR=913.16 μmol photons m-2 s-1, G3 - PAR=666.34 μmol photons m-2 s-1, G4 - PAR=419.56 μmol photons m-2 s-1 and G5 - PAR=534.77 μmol photons m-2s-1. Before the experiment and at three, five and seven months of treatment, growth (plant height, collar diameter, number of leaves, petiole length, leaf length and width), gas exchange, chlorophyll a, and leaf green color intensity were assessed. The highest net photosynthetic rates were observed in plants under G2, G3 and G4. Values of maximum quantum efficiency (Fv/Fm) over 0.75 were observed under G2. At seven months, estimated SPAD values were 36 in G2 plants and 32 in G1 plants. According to the Dickson quality index (DQI), presented the highest growth and development rates. We conclude that G2 suits plants to be transplanted into the field, whereas G3 would be best for plants grown under shade environments. Highlights: • Syagrus schizophylla is an extinction endangered ornamental palm. • One layer of Red Chromatinet® 50% should be recommended for the first year of growth of schizophylla plants to be later transplanted to the field. • Two Red Chromatinet® 50% layers would be best for plants meant to grow under shade environments. • The highest net photosynthetic rates were observed in plants under G2, G3 and G4.

Os cafeeiros conilon podem apresentar padrões divergentes para o acúmulo de matéria seca e desenvolvimento de frutos, sejam eles resultantes de fatores genéticos ou ambientais. O objetivo deste estudo foi quantificar o acúmulo de matéria seca em órgãos aéreos e a produtividade do café conilon cultivado em condições de irrigação ou de sequeiro. O experimento foi realizado no Estado da Bahia (Brasil), localizado no Atlântico, ao longo de dois anos de avaliação. Foi utilizado o delineamento experimental inteiramente casualizado, em parcelas subdivididas, com 14 repetições. Os tratamentos consistiram de dois tipos de cultivo, sendo estes, irrigado e de sequeiro, nas parcelas e o tempo ao longo do ciclo reprodutivo nas sub-parcelas. O crescimento reprodutivo foi avaliado a partir de dez dias após a primeira floração e, em seguida, a cada 28 dias, até a completa maturação dos frutos. O acúmulo de matéria seca nos frutos do café conilon pode ser bem explicado usando modelos sigmoidais; enquanto o número de ramos e o acúmulo de biomassa nas folhas presentes se ajustam a modelos lineares, independentemente do cultivo irrigado ou de sequeiro. A magnitude e intensidade do acúmulo de biomassa, no entanto, é influenciada pelo uso da irrigação, o que provoca ganhos no acúmulo de biomassa por fruto.

ABSTRACT The seed coating technique adds value to the seeds. This technique allows changing the seed size and shape, facilitating sowing, and also the application of essential nutrients to the good development of the plant in the post-germination phases. Therefore, the objective of this work was to evaluate the physical and physiological characteristics of Stylosanthes capitata/macrocephala coated with different materials. For the coating procedure, a N10 Newpack bench seed coating machine was used. The experimental design was completely randomized, with four replications and 50 seeds per plot distributed in 10 treatments. The different materials and their respective mixtures significantly altered the physical characteristics, the weight of a thousand seeds (WTS), water content (SWC), maximum diameter (DMA), and minimum diameter (DMI) of the seeds. Among the different materials, the sand coated seeds had the highest germination percentage (%G), germination velocity index (GSI), and first germination count (FGC). The maintenance of physiological attributes was observed in sand coated seeds (0.25 mm). Therefore, it is an alternative application of nutrients via seeds, due to the inert character of the sand. The mixing of the materials used in this work is not recommended.

Phoenix roebelenii is a palm species widely used in Brazil due to its exuberant leaves and adaptability to different climatic variations. For proper propagation, detailed information about seed viability, vigor and longevity subjected to dehydration and storage is yet to be obtained. For this purpose, the present research comprised two stages. The first one aimed at evaluating the response of seeds to desiccation and storage based on formal protocols. In the second stage, seeds were desiccated to 33, 30, 25, 23, 20, 18, 16, 12, 10 and 7% of water content by monitoring water loss in a convection oven at 35±2°C. After reaching each established water content, the seeds were subjected to germination tests. At 65 days after sowing, root length, root area, volume and diameter, shoot and eophyll length, and total seedling fresh and dry weights, were measured. Significant increases in germination and eophyll length were observed for lower seed water contents. Aversely, collar diameter decreased with seed desiccation. Highlights: • Phoenix roebelenii seeds are orthodox. • Reduced seed water content increased the percentage of germination, the germination speed index, and eophyll length of Phoenix roebelenii seedlings. • Significant increases in germination and eophyll length were observed for lower seed water contents. • Aversely, collar diameter decreased with seed desiccation.

Sorghum (Sorghum bicolor) is highly sensitive to zinc deficiency in soils, which results in decreased productivity and low-quality agricultural products. Our objective was to evaluate the effects of different zinc doses, applied to seeds, on the physiological quality and initial performance of sorghum plants. Six doses (0, 3.5, 7.0, 14.0, 21.0, and 28.0 g kg-1 seeds) were used and an uncoated control. The Zn coating process used dolomitic limestone as the filler and glue. Laboratory tests were conducted in a completely randomized design and greenhouse experiments were conducted in a randomized block design. The control means were 8, 9, and 14% lower than the maximum, minimum, and total seed area of treatments, respectively, relative to that of treatments. The control differed from other treatments by 10.47 in the speed index of emergence. Zinc at a dose of 28 g kg-1 seeds provided greater production of aerial dry matter, with nutrient content of 75.85 mg kg-1. Zinc on sorghum seeds affected length and dry matter production of aerial parts and roots but did not affect physical characteristics, germination, or emergence time. Applied zinc accumulated mainly in the roots, and promotes changes in Ca and Mg in seeds and other plant parts.

ABSTRACT Molybdenum (Mo) availability is strongly affected by soil pH, which determines the dynamics of electrical charges and the adsorption of molybdate. This study evaluated the effects of nitrogen (N) and Mo application on the chemical properties of a Latossolo Amarelo (Oxisol) and in Coffea canephora nutrition and productivity throughout two productive cycles under field conditions. The experiment was conducted from June 2018 to May 2020. The experimental design used was in randomized blocks, in a 2 × 5 factorial scheme, the first factor being the absence and presence (4 kg ha-1 yr-1) of molybdic fertilization and the second factor was the N dose (300, 500, 700, 900, and 1,100 kg ha-1 yr-1). At the end of each production cycle, soil samples were collected to evaluate the pH(H2O), pH(KCl), exchangeable aluminum, potential acidity, organic matter, and Mo, at layers of 0.00-0.20 and 0.20-0.40 m. Leaves were sampled from the coffee tree to determine Mo and N contents and the coffee beans were harvested to evaluate the yield of processed coffee. The results showed that urea has a high potential for soil acidification, influencing the values of exchangeable aluminum, potential acidity, and ∆pH, at layers of 0.00-0.20 and 0.20-0.40 m. The decrease in pH caused by increasing doses of N increased the density of positive electrical charges of the soil and reduced Mo content in the leaves of C. canephora by 67 %. The application of sodium molybdate via soil was efficient in providing Mo to Conilon coffee and provided a 3.7 % increase in the yield of processed coffee. Nevertheless, molybdic fertilization did not influence the Mo content in the soil in the evaluations carried out at the end of each production cycle.

Boron (B) deficiency is commonly found in tropical crops, among which sorghum stands out for its limited yield under B shortage. However, as a micronutrient, the range between its adequate and toxic levels is narrow, thus fertilization should be cautiously applied. Our goal was to evaluate the physiological and physical quality, as well as early performance, of grain sorghum seedlings under different B doses applied via seeds. Treatments consisted of six doses of boric acid (0.0, 2.5, 5.0, 7.5, 10.0, and 12.5 g Kg-1 seeds) plus a control (uncoated seeds). Boron doses were applied to seeds by coating, in which dolomitic limestone and glue were used for pellet formation. Coated seeds were assessed for physical, physiological, and nutritional characteristics in the laboratory, and early seedling performance was evaluated in a greenhouse. Seed tests were carried out in a fully randomized design, while seedling evaluations were carried out in a randomized block design. Boron application to seeds had no significant effect on seed physical characteristics, despite increases in coated seed sizes. Boron doses had a negative effect on the length and dry mass accumulation of both plant shoot and root. Seed-applied B accumulated mainly in roots and significantly interfered with Ca and Mg accumulations in sorghum seeds, shoots, and roots.

The search for productive germplasm adapted to adverse conditions is an important action to mitigate the harmful effects of climate change. The aim was to identify the yield potential of 50 popcorn inbred lines grown in field conditions, in two crop seasons (CS), and under contrasting water conditions (WC). Morphoagronomic, physiological, and root system traits were evaluated. Joint and individual analyses of variance were performed, in addition to the multivariate GT bip-lot analysis. Expressive reductions between WC were observed in 100-grain weight (100 GW), popping expansion (PE), grain yield (GY), expanded popcorn volume per ha (EPV), row number per ear (RNE), plant height (PH), relative chlorophyll content (SPAD), and nitrogen balance index (NBI). It was found that the SPAD, 100 GW, GY, PE, and grain number per ear (GNE) traits had the most significant impact on the selection of genotypes. Regardless of WC and CS, the ideal lines were L294 and L688 for PE; L691 and L480 for GY; and L291 and L292 for both traits. SPAD, 100 GW, and GNE can contribute to the indirect selection. Our work contributes to understanding the damage caused by drought and the integration of traits for the indirect selection of drought-tolerant popcorn genotypes.

This study aimed to identify the genetic control of morphological, water status, and root traits in four inbred lines and their pre-selected hybrid combinations of popcorn, and to identify the best parents and hybrids. The plants were grown under greenhouse conditions, and with two water conditions—water-stressed (WS) and well-watered (WW). We evaluated shoot biomass (SB), whole plant leaf area (WPLA), chlorophyll content, carbon isotope discrimination, net CO2 assimilation rate, the stomatal conductance, transpiration, cumulative plant transpiration, and root weight density in three sections. The reductions in SB and WPLA are attributed to stomatal causes, given the maintenance of water condition values in water-stressed plants. In fact, the stomata were closed for long periods during plant growth under the water-stressed condition, as indicated by the more negative carbon isotope discrimination values. The root weight density, regardless of soil depth and water conditions, was higher in hybrids. There was a preponderance of non-additive effects in the control of morphological and root traits, especially in the WS condition, and heterosis was shown to be the fundamental strategy for obtaining superior hybrids. For water status traits, it is essential to choose the female parent in the crossing block, given the maternal effect expressed by net CO2 assimilation rate, stomatal conductance, and transpiration.

Sclerotium rolfsii a fungus widespread in tropical and subtropical regions, is a phytopathogen that affects a large number of cultivated and wild plants"”e.g. Brachiaria species"”, causing damping-off. Current disease control strategies include chemical treatment of seeds, genetic resistance and crop rotation. Compared to synthetic agrochemicals, silicon may act as an element inducing plant resistance. This study examined the efficiency of calcium silicate in the coating of Brachiaria seeds on the incidence of the disease during plant germination and establishment. The experiment consisted of six Brachiaria brizantha seed-coating treatments involving different proportions of calcium silicate and sand, plus two controls. The fungus was inoculated at three different times in relation to seed sowing, namely, inoculation along with sowing (IN0); inoculation 10 days after sowing (IN10); inoculation 20 days after sowing (IN20); and no inoculation (control). Radicle emergence, germination, abnormal seedlings, damped-off seedlings and dead seeds were evaluated. There was an increase in the germination rate of B. brizantha cv. MG5 seeds coated with calcium silicate, which showed a protective effect against the incidence of S. rolfsii, directly reflecting in a lower of percentage of damping-off. Highlights According to the results obtained, it is convenient to use seeds coated with calcium silicate increases and inoculated with rolfsii. Seed coating with calcium silicate decreased damping-off in plants. Silicon can contribute to increase crop yield and disease resistance, given the benefits demonstrated in the current experiment.

Abstract Guava is an important fruit in Brazil and worldwide. However, research has yet to advance on its breeding and seed technology, an essential factor for the development of productive genotypes with germination potential which would support the continuity of breeding programs. In search of a methodology for routine analysis testing of guava seeds under genetic control, this study examined the effect of temperature and substrate on the germination of guava seeds from full-sib families. The experiment was laid out in a completely randomized design with a 5 × 4 factorial arrangement consisting of the combination of five temperatures (25, 30, 35, 20-30 and 25-35 °C) and four substrates (paper roll, on-paper, in-sand and on-sand), with eight replicates of 50 seeds. Germination, germination speed index and live ungerminated seeds were evaluated. The alternating temperatures of 20-30 and 25-35 °C and the paper roll, on-paper and in-sand substrates are adequate conditions for germination tests with guava seeds.

Plathymenia reticulata Benth, popularly known as "˜vinhático"™, is a tree species with potential for the production of high-quality timber that is used in luxury furniture and construction. Seed coating ensures an adequate stand, vigorous plants, delayed onset of epidemics, and increased yield. The present study was carried out to investigate different types of seed-coating materials and their effects on the physical and physiological characteristics of Plathymenia reticulata Benth and define the best coating material. The coatings were made with sand, silicate, limestone, sand + silicate, sand + limestone and uncoated seeds as a control. The experiment was set up as a completely randomized design with six treatments tested in four replicates with 50 seeds each. Sand + limestone coating reduced GSI and ESI but did not influence the seedling germination or emergence rates. The best material for coating Plathymenia reticulata Benth was the sand + limestone mixture.

ABSTRACT Fertilization is not a common management practice at pasture establishment in Brazil. Seed coating technology can be a useful approach to ensure the availability of nutrients to plants during the early stages of development. Thus, the objective of this work was to investigate the incorporation of liquid fertilizer in seeds of Stylosanthes and to evaluate the effect of this technology on seed quality. Mastermins® fertilizer was applied to the last layer of the binder material coating on the seed and Polyseed 76F polymer adhesive was thereafter applied onto the fertilizer. Physiological and biometric analyses of the seeds were carried out. Six fertilizer doses (0, 10, 20, 30, 40, and 50 mL.100 g seeds-1) were tested, with and without adhesive. The control group comprised of uncoated seeds. The method provided a significant increase in the concentration of mineral nutrients supplemented to the seeds, and the use of the adhesive polymer further increased the concentration of minerals. The liquid fertilizer had no effect on seed emergence and emergence speed but influenced germination and germination speed. The results also showed that fertilizer doses higher than 10 mL.100 g seeds-1 did not provide higher dry mass accumulation in Campo Grande Stylosanthes.

ABSTRACT: The binder materials used in seed coating provide adherence of the filler materials onto the seeds. Adequate concentrations of the binder promote good physical characteristics of coating while not impairing seed physiological characteristics. Thus, the objective of this study was to evaluate the type and the concentration of binder materials that allow the best physical and physiological characteristics in coated seeds of Campo Grande Stylosanthes. Seed coating was carried out in a coating pan, using sand as the filling material. The treatments consisted of 2 types of binders mixed in 3 ratios (PVA glue and gum arabic glue, diluted in water, 3:1, 2:1, and 1:1), and uncoated seeds as control. The coated seeds were evaluated for physical and physiological characteristics. The laboratory and greenhouse experiments were arranged in a completely randomized design. Results showed that at the different concentrations used this study, neither the PVA glue nor the gum arabic glue had any effect on the physiological quality of Campo Grande Stylosanthes seeds. However, PVA glue in the ratio of 2:1 provided the greatest surface area, maximum diameter, minimum diameter, and sphericity to coated seeds.

ABSTRACT The cycle pruning programmed is a reinvigoration technique widely employed in Conilon coffee. This strategy may also be adopted for Arabica coffee to increase its crop longevity and yield. In this scenario, the present study proposes to examine the influence of the cycle pruning programmed on the vegetative and productive development of Arabica coffee. The experiment was developed in the field as a randomized-block design with four replicates. Treatments were tested in a 4 × 2 factorial arrangement consisting of four stem densities (4000, 8000, 12000 or 16000 stems ha-1) and two management strategies for the removal of plagiotropic branches (annual or biennial removal of branches which had reached 70% or more of their production capacity). For some variables, the treatments were organized as a 4 × 2 × 2 factorial arrangement in which the last factor corresponded to two regions of data collection in the plant (upper or lower). For all factorial arrangements, an additional treatment (control) was employed corresponding to traditional pruning (recepa). Annual or biennial removal of plagiotropic branches which had attained 70% or more of their production capacity can be adopted with no losses to crop yield. The cycle pruning programmed improves the distribution of branches, increases canopy area and prevents the occurrence of the “naked neck” phenomenon, observed in control treatment. Additionally, it provides better agronomic and productive performance; therefore, it can be used as a substitute for recepa.

Abstract: Perennial soybean (Neonotonia wightii) is a Fabaceae with potential to be used in consortium with Poaceae plants to improve pasture quality. In order to add value to perennial soybean seeds and improve their seed distribution, seeds coated with different materials in coating machine were characterized by digital image analysis and physical attributes related to physiological attributes in order to define the ideal amount and material to be used in the coating. Different material quantities were tested, 150 g, 200 g and 250 g, divided into layers, namely: sand, calcium silicate + sand and limestone + sand. Coating promoted maximum increments of approximately 350% in seed mass and significant increases of up to 230% in area, 154% in maximum diameter, 162% in minimum diameter, 167% in contained diameter and 152% in perimeter. The coating was also efficient in reducing the moisture of the pellets by increasing the layers that cover the seeds. The sand + limestone combination resulted in the largest pellets. The combination of sand + silicate did not interfere with plant speed and formation. Thus, it was considered the appropriate material for the coating of perennial soybean seeds.

The objective of this study was to evaluate nutrient concentrations in the flowers, leaves (pre-flowering and grain-filling period), grains, and husks of Robusta coffee genotypes cultivated in the Amazon region, as well as to identify their genetic diversity. This experiment was carried out in Alta Floresta D’Oeste, Rondônia, Brazil, in randomized blocks with three replications; for the leaves, a factorial experimental design of sampling periods was included. The nutrient concentrations of the different evaluated organs were subjected to analysis of variance by the F test (p < 0.01), and the genetic parameters were estimated. To determine the genetic diversity, the genotypes were grouped by the UPGMA hierarchical method, and to predict it the relative importance of traits was analyzed. Genetic divergence among Coffea canephora genotypes was indicated by the leaf nutrient concentrations. At a maximum dissimilarity threshold of 82% for the genotypes, the UPGMA method formed six groups. Concentrations of nitrogen (N) and phosphorus (P) in the leaf sampling periods of pre-flowering and grain filling were not influenced by genotypes. The leaf and flower iron (Fe) concentrations contributed most to genetic divergence. For a nutritional diagnosis of Robusta coffee, it is important to take into account the comparisons of genetic diversity as well as the nutritional requirements during the flowering and grain-filling periods.

Abstract: The objective of this work was to evaluate the relative contribution of variables related to fruit production and to seed morphophysiological characteristics to the genetic divergence in passion fruit (Passiflora edulis) progenies, aiming at selecting progenies potentially responsive to fertilization. Ten progenies were evaluated under conditions of low (50% of the recommended dose of fertilizers) and high soil fertility (dose 50% higher than the recommended one), regarding variable sets related to production and to the morphological and physiological characteristics of seeds. The association between these sets was determined by the canonical correlation analysis and by the nearest-neighbor clustering method. The nutritional environments interfered in the relative contribution of the variables to the genetic divergence of the progenies. The accelerated aging test of seeds - from the set of seed physiological quality - did not contribute significantly to the selection of genotypes responsive to soil fertilization. The most responsive progenies to the increased availability of nutrients were grouped according to the production variables that were evaluated under high soil fertility. Irrespectively of the evaluated environment, the set of production variables is the one that contributes more expressively to the identification of the genetic divergence of passion fruit progenies.

This study aimed to evaluate the viability of seeds of butterfly pea, stylosanthes cv. Campo Grande, tropical kudzu and archer after passage through the gastrointestinal tract (GIT) of goats; and to evaluate these animals as dispersing agents. Fifty grams of seeds of each plant were mixed with the concentrate and given to 20 goats, whose feces were collected up to 102 hours after ingestion for seed retrieval and subsequent germination test. This was a completely randomized design in a factorial arrangement: 4 Fabaceae plants x 17 sampling times with five replicates. The percentage of seed retrieval ranged from 16.9 to 70.9%; butterfly pea and archer, respectively. The passage through the GIT positively affected the germination of kudzu seeds; which presented the highest germination average (45%), and negatively the seeds of stylosanthes and butterfly pea, which presented respectively, 15 and 13%. The period of highest seed dispersal was 24 - 42 hours, peaking in 36 hours. Under these conditions, goats may be considered as legitimate seed dispersers.

The objective of the present study was to assess the influence of the packaging material (cotton cloth bag, multifolium paper and glass container) and storage environment (laboratory and cold chamber conditions) on fennel seedling growth. Seeds were placed in different packaging materials and exposed to the two environments for twelve months. Assessments were made before storage and at every two months and the following were determined: total emergence, emergence speed index, seedling fresh and dry matter. A completely randomized experimental design was used, with four replications in a 2 x 3 x 6+1 factorial design in split split plots, where the plot was the storage environment (laboratory and cold chamber conditions); the split plot was the storage (cotton cloth bag, multifolium paper and glass container) and the split plot was the storage periods (2, 4, 6, 8, 10 and 12 months) and plus an additional treatment (before storage). The results showed that the fennel seedlings had superior growth when their seeds were placed in the glass packaging material, regardless of the storage environment.

RESUMO Níquel e molibdênio são micronutrientes essenciais que apresentam a capacidade de alterar o crescimento e o desenvolvimento do feijoeiro. O objetivo deste trabalho foi avaliar a produtividade, o crescimento e a composição mineral do feijão Ouro Vermelho em resposta às adubações com molibdênio (Mo) e níquel (Ni). O experimento foi conduzido a campo em Argissolo Acinzentado distrófico, no arranjo fatorial 5 x 2, referente a cinco doses de Ni (0; 15; 30; 45 e 60 g ha-1) e duas de Mo (0 e 80 g ha-1), no delineamento em blocos casualizados, com quatro repetições. A aplicação foliar de Ni e Mo foi feita aos 25 dias após a semeadura, por meio de um pulverizador manual. As características avaliadas foram: estande final, altura, produtividade, número de vagens por planta, número de sementes por vagem, massa de 100 sementes e os teores de N, P, K, Fe, Mo, e Ni. Verificou-se que a adubação molíbdica aumentou o teor de N na folha, reduziu o teor de Fe na semente e, em doses elevadas de Ni, reduziu o teor de Ni nas sementes. As doses de Ni, sem aplicação de Mo, aumentaram o teor de N na folha e, na presença do Mo, aumentaram o teor de Fe na semente. Houve aumento do número de grãos por vagem, com a aplicação de Ni, e da massa seca da parte aérea, com a adubação molíbdica. As adubações com 80 g ha-1 de Mo e 60 g ha-1 de Ni aumentaram em 12,71 e 27,5%, respectivamente, a produtividade do feijoeiro.

ABSTRACT The number of days between anthesis and maturation of conilon coffee berries varies according to the genotype. Thus, it is believed that periods of greater nutrient demand for fruit formation also vary according to the genotype, directly influencing fertilizer management. The goal of this study was to establish accumulation curves for the micronutrients boron, copper, iron, manganese, and zinc in conilon coffee trees with different maturation cycles. The experiment was conducted in Nova Venécia, State of Espírito Santo, Brazil, during the reproductive cycle of the 2010/2011 crop year. Four coffee genotypes with different maturation cycles (early, intermediate, late, and super-late) were studied. A completely randomized experimental design was used with five replications. The treatments correspond to the accumulation of B, Cu, Fe, Mn, and Zn in the berries every 28 days in the period from flowering to harvest. The early, intermediate, and late genotypes accumulated Fe, Cu, and Mn in a similar manner, with sigmoid curves, whereas the super-late genotype accumulated these nutrients exponentially. Zn was accumulated by all four genotypes following a sigmoid curve. The early, intermediate, and late genotypes accumulated B linearly, whereas the super-late genotype accumulated B following a sigmoid curve. The maturation cycle of the genotype must be taken into account to apply the correct rate of micronutrient fertilization in coffee plantations.

The aim of this study was to assess the effect of different coatings on the physiological potential of stylosanthes cv. Campo Grande seeds. The treatments were: uncoated seeds; limestone + PVA glue; limestone + sand + PVA glue; limestone + activated carbon + PVA glue; calcium silicate + PVA glue; calcium silicate + sand + PVA glue; calcium silicate + activated carbon + PVA glue. Posteriorly, the seeds were analyzed for water content (WC), maximum diameter (MAD) and minimum diameter (MID), thousand seed weight (TSW), germination test, germination speed index (GSI), mean germination time (MGT), emergence, emergence speed index (ESI), mean emergence time (MET), shoot and root length, fresh and dry matter of shoot and root. The coating increased the TSW, MAD and MID and decreased its WC. The treatments comprising limestone + PVA glue and limestone + sand + PVA glue increased the germination time, but none of the treatments negatively affected the physiological seed quality. Treatment with calcium silicate + PVA glue was outstanding for germination speed index and fresh and dry matter of shoot and root in the stylosanthes cv. Campo Grande seeds coating.

The objective of this work was to evaluate the influence of intercropping 'Conilon' coffee (Coffea canephora) with rubber trees on coffee tree microclimate, nutrition, growth, and yield. Rubber trees were planted in two double rows 33 m apart, with 4x2.3 m spacing between plants. Treatments consisted of the distances from the coffee plants to the rubber trees: 3, 6, 9, 12, and 15 m. Measurements of atmospheric variables (temperature, irradiance, and relative humidity), leaf nutrient concentration, internode length of plagiotropic and orthotropic branches, individual leaf area, chlorophyll content, and yield were performed. Intercropping promotes changes in the microclimatic conditions of coffee plants close to rubber trees, with reduction of temperature and irradiance level and increase in air relative humidity. The proximity of the coffee tree to the rubber trees promotes the elongation of the plagiotropic and orthotropic branches and increases the individual leaf area; however, it does not affect leaf concentrations of N, K, Mg, Fe, Zn, and B in 'Conilon' coffee and does not have a negative impact on yield.

A cultura do feijoeiro tem grande importância para o Estado de Goiás, Brasil. No entanto, informações relacionadas aos padrões nutricionais para condições irrigadas são carentes na região. Os objetivos deste trabalho foram estabelecer padrões foliares, avaliar o estado nutricional do feijoeiro irrigado na região do Vale do Rio dos Bois, no Estado de Goiás, pelos métodos da faixa de suficiência (FS), da diagnose da composição nutricional (CND) e do sistema integrado de diagnose e recomendação (DRIS), bem como comparar os procedimentos de diagnóstico por meio de padrões nutricionais locais. Avaliaram-se a produtividade e a concentração foliar de 55 lavouras de feijoeiro na região do Vale do Rio dos Bois, entre 2010 e 2012. As amostras foram coletadas no estádio R5 (período de floração) e analisadas quanto aos teores totais de N, P, K, Ca, Mg, S, B, Cu, Fe, Mn e Zn. As 55 amostras foram divididas em dois grupos, sendo o primeiro de baixa produtividade, com rendimento abaixo de 2.700 kg ha-1; e o segundo de alta produtividade, com rendimento igual ou acima de 2.700 kg ha-1, este último originando os padrões nutricionais. Normas CND e DRIS são mais indicadas para avaliação nutricional do feijoeiro irrigado comparativamente a FS estimada neste trabalho. Manganês, P e B são os elementos que mais limitam a produção nas lavouras de baixa produtividade na região do Vale do Rio dos Bois.

O objetivo deste trabalho foi avaliar o efeito da aplicação foliar de níquel (Ni) e molibdênio (Mo) sobre componentes de rendimento, crescimento e composição mineral do feijoeiro comum Ouro Vermelho. O delineamento experimental foi o de blocos casualizados, com quatro repetições e arranjo fatorial 5 x 2, constituído de doses de Ni (0, 15, 30, 45 e 60 g ha-1) e de Mo (0 e 80 g ha-1), aplicadas por via foliar, aos 25 dias após a semeadura, na forma de cloreto de níquel hexaidratado e de molibdato de amônio, respectivamente. As doses de Ni não influenciaram os teores foliares de N, P, K, Fe, Mo e Ni, aumentaram, porém, os teores de N, Ni e de proteína bruta na semente. A aplicação foliar de Mo reduziu os teores foliares de P, Fe e Ni, aumentou, no entanto, o teor foliar de Mo e o teor de N, Mo e de proteína bruta na semente. Observou-se que as doses de Ni e de Mo não afetaram a massa de sementes, o número de sementes por vagem, o número de vagens por planta e a massa seca de raiz do feijoeiro. A aplicação de Mo aumentou em 21,62% o número de nódulos.

The period between anthesis and fruit ripening varies according to the Conilon coffee (Coffea canephora) genotype. Therefore, the time of the nutritional requirements for fruit formation may differ, depending on the formation phase and the genotype, and may directly affect split application of fertilizer. The aim of this study was to quantify the accumulation of dry matter and N, P, K, Ca, Mg and S at several stages in the fruit of the Conilon coffee genotype with different ripening cycles, which may suggest the need for split application of fertilizer in coffee. The experiment was carried out in the municipality of Nova Venecia, Espírito Santo, Brazil, throughout the reproductive cycle. The treatments were composed of four coffee genotypes with different ripening cycles. A completely randomised experimental design was used. with five replicates. Plagiotropic branches were harvested from flowering to fruit ripening at 28-day intervals to determine the dry matter of the fruits and the concentration and accumulation of the nutrients they contained. The behavior of dry matter and macronutrient accumulation during the study period was similar and increasing, but it differed among genotypes sampled in the same season. Early genotypes exhibited a higher speed of dry matter and nutrient accumulation. Split application of fertilizer should differ among coffee genotypes with different ripening cycles (early, intermediate, late and very late).

The failure to obtain the ideal stand is one of the causes of decreased crop yields, in this sense it is important to investigate the genetic effects related to seed quality. The aim of this study was to measure the general combining ability (GCA), the specific combining ability (SCA) and the reciprocal effects (RE) for popcorn seed quality in addition to evaluate the association between germination and vigor tests with field emergencein order to identify hybrids with better germination and vigour. Ten inbred lines were evaluated using a complete diallel cross with reciprocals. Seed quality was measured by germination tests (GT) and by modified cold vigour tests (MCV). In the GT, the numbers of strong normal seedlings (SNS), weak normal (WNS), abnormal (AS) and ungerminated seeds (UGS) were counted. In the MCV, the numbers of normal seedlings (NPC), abnormal (ASC) and ungerminated seeds (UGSC) were counted, and the plants' dry matter (DM) was measured. Analysis of variance for GCA, SCA and RE were significant for all variables. The quadratic components for SCA were higher than those for GCA for the SNS, AS, UGS, ASC and UGSC traits, which indicates higher significance for the non-additive effects. The most favourable GCA estimates, were found in lines P3 and L70. The best hybrids were P1xL70, P3xP6 and P8xL70. The RE results showed that L70 and P3 should be used as the female parent in the P1xL70 and P3xP6 hybrid crosses, respectively. The MCV was the test that was most strongly correlated with field emergence, with a magnitude of 0.667.

O objetivo deste trabalho foi avaliar a adequação de medidas instrumentais de textura como índice de qualidade de raízes da mandioca de mesa e sua correlação com o tempo de cozimento. Quinze raízes de mandioca foram colhidas no 11.º mês de cultivo na região noroeste fluminense. Pedaços de raízes foram cozidos em água, sendo o tempo de cozimento determinado, em triplicata, quando se observou pouca resistência à penetração do garfo. A resistência ao corte foi realizada nas polpas cruas e cozidas, em cinco a nove repetições, operando o texturômetro TA. XT Plus Texture Analyser com probe Warner-Bratzler Blade HDP/BSW, velocidades de pré-teste de 0,2 cm/s, de pós-teste e de teste de 0,5 cm/s, e distância de 5 cm. Os dados foram analisados por ANOVA e teste de média Tukey (tempo de cozimento); GLM, LSMEANS e PDIFF (resistência ao corte) e análise de correlação de Pearson (p < 0,05). A variedade Viçosa Martinha destacou-se por apresentar o menor tempo de cozimento (18 minutos) e menores valores de resistência ao corte das polpas crua (10,6 N) e cozida (0,7 N). Com exceção das variedades Aipim Pretinho, IAC Espeto e IAC 13, todas as demais podem ser consideradas adequadas como mandiocas de mesa por apresentarem tempos de cozimento iguais ou inferiores a 30 minutos. Verificou-se correlação significativa entre a resistência ao corte da polpa cozida e o tempo de cozimento (0,62), porém moderada, em razão dos altos valores de coeficiente de variação observados para as medidas de textura, evidenciando a heterogeneidade das raízes. Portanto, a determinação do tempo de cozimento, nas condições deste experimento, é mais adequada como índice da qualidade de raízes de mandioca associado à textura.

In recent years, several new coffee cultivars recommended for different regions have been released. However, the performance of these varieties in many traditionally producing regions is unknown. Difference of climate and soil may jeopardize the productivity of the new cultivars and cause losses to farmers. The objective of this study is to evaluate the vegetative growth and productive genotypes of C. arabica in the conditions of the Northwestern Rio de Janeiro State, Brazil. The experiment was settled in 2007, in Panorama 1 Farm, located in the municipality of Varre Sai, RJ. Twenty-five genotypes of C. arabica were planted in a spacing of 2.5 × 0.8 m, using a completely randomized design with five replications and eight plants per plot. There were eight measurements of vegetative growth represented by plant height, stem diameter and number of plagiotropic branches. Assessments of productivity were also performed in years 2009 and 2010. There was a positive phenotypic correlation among vegetative characteristics and between vegetative characteristics and yield in the first harvest, while in the second harvest only the number of plagiotropic branches was positively correlated with yield. Up to date, the genotypes Catucaí amarelo 2 SL, Catiguá MG 02, Acauã, Palma II, Sabiá 398, IPR 103/ Iapar, IPR 100/Iapar, H 419-10-6-2-12-1, Catucaí amarelo 24 / 137, Iapar 59, Catucaí amarelo 20/15, H 419-10-6-2-5-10-1 and H 419-10-6-2-5-1 had the highest average yield after two harvests.

O presente trabalho teve como objetivo avaliar o efeito de alguns aspectos do manejo da cultura do mamoeiro como espaçamento e nível de adubação NPK, sobre alguns atributos de qualidade dos frutos do híbrido do grupo 'Formosa' UENF/CALIMAN-01(UC01). O experimento foi conduzido na fazenda Caliman Agrícola S.A., em Linhares-ES. Utilizou-se o delineamento estatístico experimental em blocos casualizados, com esquema fatorial, com três espaçamentos de plantio entre plantas (E1 = 1,80 m; E2 = 2,25 m, e E3 = 2,70 m), cinco níveis de adubação NPK convencional (A1 = 80% do padrão da empresa (PE); A2 = 100% PE; A3 = 120% PE; A4 = 140% PE, e A5 = 160% PE), e três períodos de avaliação (junho, agosto e outubro de 2007). O padrão de adubação NPK da empresa (PE) consiste em 350; 105 e 660 kg ha-1ano-1 de sulfato de amônio (20% de N), superfosfato simples (18% de P2O5) e cloreto de potássio (60% de K2O), respectivamente. Foram analisados a firmeza do fruto e da polpa, a concentração de sólidos solúveis (SS), o pH, a acidez titulável (AT) e a razão SS/AT da polpa. Os dados foram submetidos à análise de variância e teste de médias. Os resultados mostram que, entre as condições de espaçamento e níveis de adubação NPK testados, o melhor desempenho foi obtido pelas combinações E1A1 ou E2A1, os quais devem ser adotadas para o manejo do híbrido UC01. Os tratamentos resultaram em frutos com atributos de qualidade superiores, além de proporcionar redução nos gastos com adubação NPK e menor impacto ambiental em função da aplicação excessiva de adubo no solo.

Notwithstanding its relevance, studies regarding nutrient cycling and biological dinitrogen fixation in Conilon coffee (Coffee canephora cv. Conilon) associated with cover plants are very scarce. Aiming to evaluate the contribution of cover crops for organic conilon production, a field experiment was carried out consisting of Pennisetum glaucum, and legume species Canavalia ensiformis, Mucuna deeringiana and Cajanus cajan (inoculated and non inoculated) cultivated between coffee trees, and spontaneous vegetation as cover crops. The experiment was carried out in Espírito Santo State- Brazil, in a 6.5 years old coffee crop production system. Chemical analyses of soil and vegetative parts of spontaneous and cover crops, as well as coffee leaf nutrients concentration were performed. Biological Nitrogen Fixation (BNF) was determined by the natural abundance method. BNF contributed with about 80% of the nitrogen accumulated by the leguminous plants, corresponding to 27 - 35 kg of N ha-1. Concentration and accumulation of nutrients varied among cover crops. Rhizobium inoculation did not influence nutrient cycling or BNF. Legume plants partially supplied the nitrogen requirements of Conilon coffee. No significant effect of the treatments was observed on the nutrient concentration of Conilon coffee or on plant growth.Apesar de sua relevância, estudos sobre a ciclagem de nutrientes e fixação biológica do nitrogênio (FBN) em café Conilon (Coffea canephora cv. Conilon), associadas com plantas de cobertura, são escassos. Objetivou-se, com este trabalho avaliar a ciclagem de nutrientes, a FBN e o efeito que plantas de cobertura podem causar em lavoura de C. canephora cv. Conilon, sob manejo orgânico. O experimento foi conduzido no Estado do Espírito Santo - Brasil, em uma lavoura de café sob manejo orgânico, com 6,5 anos. Os tratamentos consistiram de testemunha (ausência de plantas de cobertura), Pennisetum glaucum e as leguminosas Canavalia ensiformis, Mucuna deeringiana e Cajanus cajan, com e sem inoculação de rizóbio específico. Efetuaram-se análises químicas de solo e da parte aérea das plantas espontâneas e de cobertura, bem como as concentrações foliares de nutrientes do cafeeiro. A contribuição da FBN foi determinada pela técnica da abundância natural. A FBN contribuiu com cerca de 80% do N acumulado pelas leguminosas, correspondendo a 27 - 35 kg N ha-1. A concentração e acúmulo de nutrientes variaram entre as plantas de cobertura. A inoculação com rizóbio não influenciou ciclagem de nutrientes e a FBN. As leguminosas forneceram parte do N necessário para o cafeeiro. Não houve efeito significativo dos tratamentos sobre a concentração de nutrientes e o crescimento do cafeeiro.

A casca do fruto da mamoneira (CFM) é um resíduo gerado, em grande quantidade, no beneficiamento da mamona. O objetivo desta pesquisa foi avaliar as características físicas e químicas da CFM e seu efeito, como substrato, para plantas. A avaliação das características da CFM foi realizada em um experimento fatorial (2x3), constituído da combinação de dois tipos de casca (CFM in natura e compostada) e três granulometrias (peneiras 3, 5 e 10 mm de malha), em delineamento de blocos ao acaso. Os teores de macro e micronutrientes, condutividade elétrica (CE), pH, densidade seca (DS), densidade úmida (DU), porosidade total (PT) e espaço de aeração (EA) foram avaliados. A avaliação da CFM como substrato para plantas foi realizada, utilizando-se mudas de tomateiro (Lycopersicon esculentum Mill.) e estacas de pingo-de-ouro (Duranta repens L.) como espécies indicadoras. Para o cultivo de mudas de tomateiro, a CFM, na granulometria de 3 mm, in natura, ou compostada, foi misturada com Plantmax® em cinco proporções [0:100; 25:75; 50:50; 75:25; 100:0 (v/v)]. Para o enraizamentode pingo-de-ouro, estacas foram plantadas em CFM, in natura, ou compostada, de três granulometrias (3, 5 e 10 mm). A CFM compostada, na granulometria de 3 mm, apresentou as características físicas mais adequadas. A CFM in natura apresentou efeitos negativos, sendo inadequada como substrato. A CFM compostada permitiu obter 100% de germinação e mudas normais de tomateiro, bem como estacas enraizadas de pingo- de- ouro, podendo, portanto, ser utilizada como substrato, pura, ou em misturas.

To evaluate the effect of different types of packages and environmental conditions on the physiologicalquality of maize seeds variety “Aliança”, during 214 days, the following packages were used: PET bottles, Tetra Paktype and cotton bags, in a cold environment and at room temperature in Campos dos Goytacazes, RJ, Brazil. Theexperimental design was a completely randomized block, with three replications, in split plot, where the plot was thestorage environment, and the subplot made by a 3 x 4 factorial, packaging and storage. In addition to the germinationtests, electrical conductivity and cold tests were performed. Assessments were made at 61, 122, 183 and 214 days ofstorage. It was found that the seeds packed in PET bottles maintained the germination rate and seed vigor, and wasconsidered the best container, over the 214 days of storage, regardless of the storage environment. The seeds stored atcold temperature outperformed with respect to those stored in the natural environment.

Avaliou-se o efeito da aplicação de doses de nitrogênio associado ao potássio, em quatro idades de rebrota, sobre o índice de área foliar (IAF), produção de matéria seca (MS), teores de proteína bruta (PB) e fibra em detergente neutro (FDN) e relação folha/colmo (F/C) de Brachiaria humidicola (Rendle) Schweick. Foram testadas as seguintes doses de nitrogênio (N), na forma de uréia agrícola, e de potássio (K2O), na forma de cloreto de K, em kg/ha/ano: 0 de N + 100 de K2O; 100 de N + 100 de K2O; 200 de N + 200 de K2O e 400 de N + 400 de K2O. As aplicações foram feitas em quantidades equivalentes a 1/6 do total anual (parceladas em 6 vezes), para melhorar a eficiência da fertilização. Os resultados demonstraram efeito significativo para as idades de rebrota e adubação na produção de MS. Não foi observado efeito (P>0,05) sobre os teores de FDN em resposta aos tratamentos estudados. As variáveis relação F/C, PB e IAF foram influenciadas (PThe effect of levels of nitrogen (N) fertilization associated with potassium (K2O) and four growth intervals on the dry matter (DM) production, levels of crude protein (CP) and neutral detergent fiber (NDF), leaf/stem (L/S) ratio and leaf area index (LAI) of Brachiaria humidicola (Rendle) Schweick were studied. The following doses of N were tested, as agricultural urea, and K2O, as potassium chloride, in kg/ha/year: 0 of N + 100 of K2O; 100 of N + 100 of K2O; 200 of N + 200 of K2O and 400 of N + 400 of K2O. The applications were in equivalent amounts of 1/6 of the annual total (in 6 parcels) to improve the efficiency of fertilization. We observed a significant effect of the fertilization levels and cutting ages on DM production. The effect of fertilization rates and growth intervals did not affect the NDF content of the grass (P>0.05), but CP content, LAI and L/S ratio were influenced by growth intervals (P

Weeds can bring benefits to agriculture, but when incorrectly managed they can compete with commercial crops for resources. The objective of this work was to evaluate the effect that cover crops, associated with Coffea canephora cv. Conilon, imposes to the weed community. Cover crops were planted between the rows of a 6.5 years old organic coffee plantation spaced 2.0 x 1.5 m. The experiment was arranged in a complete randomized block design, with four replications, in a factorial scheme with the following treatments: control, Pennisetum glaucum and the legume plants: Canavalia ensiformis, Mucuna deeringiana and Cajanus cajan, with and without Rizobium inoculation. Cover crops dry weight and nutrient contents on coffee trees were determined. Weeds density, frequency, relative abundance, importance value index and plant similarity index were also determined. Twenty seven weed species were identified, with special emphasis on Bidens subalternans and Commelina benghalensis. Cover crops promote modifications on the succession dynamics of weeds and do not interfere with the development of the coffee trees. Canavalia ensiformis, Mucuna deeringiana and Pennisetum glaucum help on weed control.As plantas espontâneas competem com as culturas por recursos escassos, quando mal manejadas. No entanto, podem trazer benefícios à agricultura. O objetivo desse trabalho foi avaliar o efeito que plantas de cobertura, consorciadas com Coffea canephora cv. Conilon, impõem à comunidade de plantas espontâneas. Plantas de cobertura foram semeadas nas entrelinhas de um cafezal de 6,5 anos conduzido sob manejo orgânico, com espaçamento de 2,0 x 1,5 m. O delineamento experimental foi de blocos ao acaso, com quatro repetições, num arranjo fatorial com tratamentos adicionais: testemunha, milheto – Pennisetum glaucum, e as leguminosas feijão-de-porco – Canavalia ensiformis, mucuna-anã – Mucuna deeringiana, e feijão-guandu – Cajanus cajan, com e sem inoculação com rizóbio. Foram determinados a matéria seca das plantas de cobertura e as concentrações de nutrientes no cafeeiro. Determinou-se ainda a densidade, frequência e abundância relativas, assim como o índice de valor de importância e de similaridade das plantas espontâneas. Foram identificadas 27 espécies, destacando-se Bidens subalternans e Commelina benghalensis. As espécies de cobertura promovem modificações na população de plantas espontâneas e não prejudicam o cafeeiro. Feijão-de-porco, mucuna-anã e milheto auxiliam na supressão de plantas espontâneas.

The seasonal pattern of vegetative growth is an important feature for evaluation of crop status and its management. The aim of this work was to evaluate the seasonality of vegetative growth of Conilon coffee tree (Coffea canephora Pierre) and its relation with climate variables. The evaluation of vegetative growth rates of three groups of plagiotropic branches and one group of orthotropic branches was performed along one year, in Rio Janeiro state, Brazil. The vegetative growth rates of the branches varied along the period of evaluation, and it seems to be related to the minimum air temperature (in the low growth phase). Higher growth rates were observed when the average of minimum air temperatures was higher than 17ºC and the average of the maximum temperatures lower than 31.5ºC. Below 17ºC the growth rate declined. The branches’ growth patterns appeared to be similar, but the plagiotropic branches of different ages presented different rates in the same period of the year, indicating that seasonal growth studies should not be based on a single branch group with the same age.O padrão do crescimento sazonal do cafeeiro é um importante auxiliar na avaliação do estado fisiológico e no manejo da cultura. O objetivo do estudo foi avaliar o crescimento vegetativo em Coffea canephora Pierre cv. Conilon e relacionar com fatores climáticos, tendo por base o crescimento de ramos ortotrópicos e plagiotrópicos com diferentes idades. Marcaram-se três grupos de ramos plagiotrópicos e um de ramos ortotrópicos, cuja avaliação de taxa de crescimento foi efetuada durante um ano no Estado do Rio de Janeiro. A taxa de crescimento varia ao longo do ano, o que parece estar relacionado com a temperatura mínima do ar (na fase de baixo crescimento). Foi observada taxa mais elevada quando a média da temperatura mínima do ar foi superior a 17ºC e a média das temperaturas máximas inferior a 31,5ºC. Abaixo de 17ºC a taxa de crescimento dos ramos diminuiu. O padrão sazonal de crescimento dos ramos é semelhante, contudo, os ramos plagiotrópicos de diferentes idades apresentam taxas de crescimento diferentes no mesmo período do ano. Assim, estudos sobre o crescimento vegetativo sazonal dos ramos não deve se basear apenas num grupo de ramos com idades similares.

Avaliou-se a erradicação de escleródios de Sclerotium rolfsii em diferentes temperaturas e umidades do substrato. Testaram-se umidades de 5, 6, 9 e 11 (equivalentes a -5, -3, -1 e -1/3 Bar) e mais 0 e 18% de umidade. As temperaturas testadas foram 40, 48, 52 e 58oC, no tempo de 30 min., seguidos de resfriamento em balcão, em condições de laboratório. Avaliou-se a germinação em meio BDA salino. A 0% de umidade do substrato, nenhuma temperatura foi eficiente na inativação dos escleródios. Para todas as outras umidades testadas, porém, os escleródios foram erradicados em temperaturas acima de 52oC. De todas as quatro temperaturas testadas, apenas a menor (40oC) não inativou os escleródios do patógeno. A 48oC, a erradicação dos escleródios variou entre 80 e 100% para os níveis de umidade de 5 a 18%. O calorúmido foi eficiente na erradicação de escleródios de S. rolfsii.Thermal eradication of Sclerotium rolfsii in vitro was evaluated underdifferent substrate temperatures and humidity. Humidity levels of 5, 6, 9 and 11% (equivalent to -5, -3, -1 and -1/3 Bar) and 0 and 18% were tested. Temperatures tested were 40, 48, 52 and 58ºC. After substrate treatment, germination in saline BDA medium was evaluated. At 0% humidity, the temperature was not efficient in sclerotia eradication. For all other values of humidity tested, sclerotia were eradicated in temperatures over 52 ºC. From all temperatures tested, only the lowest (40ºC) did not eradicate pathogen sclerotia. Soiltreatment at 40ºC/30 min. stimulated sclerotia germination as the level of substrate humidity was increased. At temperatures of 52 and 58 ºC, and at humidity levels of 5, 6, 9, 11 and 18%, a 30 min. treatment was efficient for eradication of the pathogen. At 48ºC,sclerotia eradication reached 80 to 100% for humidity levels of 5 to 18%. S. rolfsii was eradicated with humidity heat.

The present research aimed to characterize some biochemical responses of Coffea canephora (clones 02 and 153) and C. arabica (Catucaí IPR 102) genotypes subjected to low positive temperatures, helping to elucidate the mechanisms involved in cold tolerance. For that, one year old plants were subjected successively to 1) a temperature decrease (0.5°C a day) from 25/20°C to 13/8°C (acclimation period), 2) a three day chilling cycle (3x13/4°C) and to 3) a recovery period of 14 days (25/20°C). In Catucaí (less cold sensitive when compared to clone 02) there was an increased activity in the respiratory enzymes malate dehydrogenase and pyruvate kinase. Furthermore, Catucaí showed significant increases along the cold imposition and the higher absolute values after chilling exposure of the soluble sugars (sucrose, glucose, fructose, raffinose, arabinose and mannitol) that are frequently involved in osmoregulation and membrane stabilization/protection. The analysis of respiratory enzymes and of soluble sugar balance may give valuable information about the cold acclimation/tolerance mechanisms, contributing to a correct selection and breeding of Coffea sp. genotypes.A pesquisa teve por objetivo caracterizar respostas bioquímicas de genótipos de Coffea canephora (clones 02 and 153) e C. arabica (Catucaí IPR 102) submetidos a baixas temperaturas positivas, ajudando a elucidar os mecanismos envolvidos na tolerância ao frio. Plantas com um ano de idade foram submetidas sucessivamente a 1) decréscimo da temperatura (0,5°C por dia) desde 25/20°C até 13/8°C (período de aclimatização), 2) um ciclo de três dias a 13/4°C e 3) 14 dias de recuperação (25/20°C). Em Catucaí, genótipo menos sensível ao frio quando comparado com o clone 02, observou-se um aumento das atividades das enzimas malato desidrogenase e piruvate cinase, relacionadas com a respiração. Nesse genótipo, os níveis de açúcares solúveis sacarose, glucose, frutose, rafinose, arabinose e manitol (frequentemente envolvidos em processos de regulação osmótica e estabilização/proteção de membranas) aumentam significativamente durante a imposição de baixas temperaturas, mostrando ainda os valores absolutos mais elevados depois de exposição a 4°C. Portanto, a análise de enzimas respiratórias e do balanço de açúcares solúveis pode fornecer informação importante sobre mecanismos de aclimatização/tolerância ao frio, contribuindo para seleção e melhoramento de genótipos de Coffea sp.

The objective of this work was to evaluate photoprotective mechanisms related to low positive temperatures in Coffea canephora (Conilon clones 02 and 153) and C. arabica ('Catucaí' IPR 102) genotypes, involved in cold temperature tolerance. To accomplish this, one-year-old plants were successively submitted to: temperature decrease of 0.5ºC day-1, from 25/20ºC to 13/8ºC; a three-day chilling cycle at 13/4ºC; and a recovery period of 14 days (25/20ºC). During the experiment, leaf gas exchange, chlorophyll a fluorescence and leaf photosynthetic pigment content were evaluated. Total activity of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and ribulose-5-phosphate kinase (Ru5PK) were quantified to measure the activity of photosynthesis key enzymes. All genotypes showed low temperature sensitivity, but displayed diverse cold impact and recovery capabilities regarding the photosynthetic-related parameters studied. Catucaí IPR 102 cultivar showed better ability to cope with cold stress than the Conilon clones, especially Conilon 02, and had full recovery of leaf gas exchange, fluorescence parameters, enzymatic activity, and higher contents of the photoprotective pigments zeaxanthin and lutein.O objetivo deste trabalho foi avaliar mecanismos de fotoproteção relacionados a temperaturas baixas positivas em genótipos de Coffea canephora (clones Conilon 02 e 153) e C. arabica ('Catucaí' IPR 102), envolvidos na tolerância a baixas temperaturas. Para tal, plantas com um ano de idade foram expostas sucessivamente a: decréscimo da temperatura (0,5ºC dia-1), de 25/20ºC até 13/8ºC; um ciclo de três dias a 13/4ºC; e a 14 dias de recuperação (25/20ºC). Durante o experimento, foram avaliadas as trocas gasosas, a fluorescência da clorofila a e os teores de pigmentos fotossintéticos foliares. Foram quantificadas a atividade total da ribulose-1,5-bisfosfato carboxilase/oxigenase (Rubisco) e da ribulose-5-fosfato quinase (Ru5PK), para medir a atividade de enzimas-chave da fotossíntese. Todos os genótipos mostraram sensibilidade a baixas temperaturas, mas tolerância e capacidade de recuperação diferentes no que respeita aos diversos parâmetros fotossintéticos estudados. A cultivar Catucaí IPR 102 apresenta maior capacidade de suportar o estresse do frio que os clones de Conilon, em particular o Conilon 02, com completa recuperação dos parâmetros de trocas gasosas foliares, de fluorescência e das atividades enzimáticas, e teores mais elevados dos pigmentos fotoprotetores zeaxantina e luteína.

O cultivo de café orgânico utiliza fontes não solúveis de fósforo e grande quantidade e variedade de material orgânico em seu manejo. Assim, o objetivo do trabalho foi avaliar as frações que compõem a matéria orgânica e distribuição do fósforo no solo de cafeeiros Coffea canephora da cultivar 'Conilon' cultivados sob diferentes sistemas de manejos de produção orgânica. O solo foi coletado na projeção da copa do cafeeiro, na camada de 0 a 20cm. Determinaram-se as características químicas e granulométricas do solo em procedimentos de rotina e as frações de fósforo e da material orgânica. Na maioria das lavouras, o fósforo orgânico constituiu a maior parte do fósforo lábil, e a fração humina constituiu a maior parte da matéria orgânica. Houve maior presença de fósforo inorgânico nos solos das lavouras com maiores concentrações de fósforo total e lábil. O conteúdo total de Pi + Po nos solos avaliados apresentou valores elevados, variando de 426,9 até 910,4mg dm-3 de solo. A fração humina constituiu a maior parte da matéria orgânica. As frações que compõem a distribuição do fósforo no solo apresentaram discrepâncias entre os sistemas de manejos de produção orgânica.The organic management in coffee uses insoluble phosphorus sources and a large quantity and variety of organic material. Thus, the objective of this research was to evaluate organic matter composition and phosphorus distribution on soils from Coffea canephora cv. 'Conilon' crops, under different organic management production systems. Soil under the coffee tree canopy was collected from 0 to 20cm depth. Chemical and soil texture characteristics were determined by routine analysis as well as phosphorus and organic matter constitution. On the average crops organic phosphorus was the main part of the labile phosphorus and carbon humine. There was a higher content of inorganic phosphorus on soils from the crops with the highest concentrations of total and labile phosphorus. The total content of Pi + Po in the evaluated soils showed high and variation from 426.9 to 910.4mg dm-3 of soil. The humin fraction formed the bulk of organic matter. The fractions that make up the phosphorus distribution in the soil showed discrepanncies between the organic management production systems.

Durante a germinação e o desenvolvimento pós-germinativo de milho, o fluxo metabólico é intenso, ocorrendo síntese e degradação de açúcares (glicose, frutose e sacarose) e hidrólise de amido, além da redução da concentração do ácido abscísico (ABA). Acredita-se que altas concentrações de glicose exógena, promovam acúmulo de ABA, proporcionando atraso na germinação e desenvolvimento de plântulas. Concentrações menores, por outro lado, podem ocasionar estímulo na germinação e desenvolvimento. Neste trabalho, foi observado que a glicose (800 µM) estimulou a germinação e o desenvolvimento inicial de genótipo de milho comum e retardou, severa ou brandamente, genótipos de milho doce (su1), provavelmente devido às diferentes concentrações endógenas de glicose de cada genótipo. Foi visto, também, que a concentração de 1,2 ηM de insulina foi capaz de estimular o maior desenvolvimento de genótipos de milho comum (UENF 506-8) e doce H43IN e nula para o genótipo doce HDC. Quando adicionada insulina e glicose ao meio, foi obtido efeito aditivo para o desenvolvimento. Esses resultados sugerem que a insulina e glicose apresentam forte influência na germinação e no desenvolvimento de sementes de milho.During germination and development of corn seeds the metabolic flow is intense, the synthesis and degradation of sugars (glucose, fructose and sucrose) and hydrolysis of starch, besides to the decrease in abscisic acid (ABA) concentration are some of the major events. High concentrations of exogenous glucose are believed to promote accumulation of ABA, causing delay in the germination and development of seedlings, while lower concentrations stimulated the germination and development. In our studies it was verified that 800 µM glucose stimulated the germination and initial development of the common corn genotype and delayed severely or softly for sweet corn (su1) genotypes, probably due to different glucose endogenous concentrations of each genotype. It was also verified that 1.2 ηM insulin was capable to stimulate the development for the common corn and sweet H43IN genotypes and did not affect HDC sweet genotype development. These events may have happened due to metabolic differences in the mutants. When insulin and glucose were added to the medium, addictive effects on the development were observed. These results suggest that both insulin and glucose have strong influence on germination and development of corn seeds.

Os ácidos húmicos podem atuar no aumento da população de bactérias diazotróficas introduzidas no interior da planta e, consequentemente, no incremento dos efeitos benéficos sobre a planta hospedeira. Com este trabalho, objetivou-se avaliar o efeito dos ácidos húmicos na inoculação de bactérias diazotróficas endofíticas, em sementes de milho. Foi utilizada a estirpe Herbaspirillum seropedicae Z67 BR 11175. A inoculação das sementes com as bactérias e a adição de ácidos húmicos foram realizadas pelo recobrimento das sementes de milho UENF 506-8, com a mistura de calcário, meio de cultura semisólido, água e cimentante. As sementes recobertas foram semeadas em vasos Leonard. Aos 40 dias após a semeadura, as plântulas foram coletadas, e foi realizada a contagem de bactérias nas raízes pela técnica do Número Mais Provável. Os resultados deste trabalho mostram que os ácidos húmicos não interferem negativamente no crescimento das bactérias e estimulam a colonização da microbiota nativa. No entanto, nas condições avaliadas, a aplicação conjunta de bactérias + ácidos húmicos não estimulou o crescimento da população de bactérias inoculadas nas plântulas de milho.The objective of this research was to evaluate the effect of the humic acids in the inoculation of endophytic diazotrophic bacteria in corn seeds. It was used the bacteria Herbaspirillum seropedicae Z67 BR 11175. The inoculation of the seeds with the bacteria and the addition of humic acids were accomplished by the coating of the corn seeds UENF 506-8. The coating was accomplished with a mixture of lime, semi-solid middle culture, water and cement. The seeds covered were sown in Leonard vases. Forty days after sowing the plants were collected and the bacteria couting was accomplished in the roots by the Most probable Number technique. The results showed that the humic acids doesn't interfere negatively in the bacteria growth of and they stimulate the colonization of the native microbiota. However, in the appraised conditions, the united application of bacteria + humic acids didn't stimulate the growth of the bacteria population inoculated in the corn seedling.

Conduziu-se este trabalho com o objetivo de avaliar a qualidade fisiológica das sementes recobertas com diferentes misturas e armazenadas, assim como a sobrevivência das células bacterianas no recobrimento destas. Utilizou-se neste estudo a estirpe H. seropedicae Z67 BR 11175. O recobrimento das sementes de milho 'UENF 506-8' foi realizado com a mistura de calcário, meio de cultura semi-sólido, água e cimentante. As sementes foram acondicionadas durante três meses, em sacos de papel multifoliado e armazenadas em duas condições: ambiente de laboratório (temperatura média de 26,2 ºC e UR média de 61,5%) e câmara BOD. A cada 30 dias de armazenamento, foram efetuadas determinações do teor de água, contagem de bactérias e avaliações da qualidade fisiológica das sementes. O recobrimento das sementes não altera a perda natural da qualidade fisiológica das sementes durante o armazenamento. Dentre as condições de armazenamento estudadas, a mais adequada para a manutenção das sementes foi a temperatura média de 26,4 ºC e UR média de 61,5 %. As células bacterianas foram observadas nas raízes das plântulas oriundas de sementes revestidas com bactéria, armazenadas por até 60 dias independente da condição de armazenamento.The aim of this study was to evaluate the physiological quality of stored seeds covered with different mixtures and the period of survival of the bacterial cells in the seed coatings. H. seropedicae Z67 BR 11175 was used in this study. The 'UENF 506-8' corn seeds were coated with a mixture preparation consisting of lime, JNFb semi-solid medium, water and cement. The seeds were conditioned for three months in paper bags and stored under two conditions: laboratory (at a temperature of 26.2 ºC and 61.5% relative humidity) and BOD chamber. Every 30 days of storage determinations of the water content, counting of bacteria, and evaluations of the physiologic quality of the seeds were performed. The coating of the seeds did not modify the natural loss of physiological quality of the seeds during the storage. Among the storage conditions studied, the most appropriate for the maintenance of the seeds was the 26.2 ºC and 61.5% of relative humidity. Bacterial cells were detected in the roots of plants originated from coated seeds inoculated with bacterial and stored up to 60 days independently the of storage conditions.