Açaí production in the municipality of São Miguel do Guamá, Pará: perspective of açaí beaters

The pulp of the açaí fruit is a staple food for a large part of the population of Pará. Nonetheless, despite the significance of açaí product for the regional economy, there is a gap in the literature on the market potential for processing this fruit. Thus, the objective of this study was to identify the challenges and opportunities of açaí beaters in the development of the activity in the municipality of São Miguel do Guamá, state of Pará, Brazil. This investigation is characterized as applied research, composed of qualitative and quantitative approaches. Data collection was based on interviews with açaí beaters and with linked production chains: middlemen, waste loaders, financial support institutions, and support institutions. The results were submitted to SWOT analysis to determine the risk factors of the internal-external matrix. As an internal risk factor, it was observed the difficulty to maintain income during the harvest period, given the decrease in the availability of raw materials and the drop in the price of the product. Externally, the risk is due to the lack of strengthening of collective organizations. It was also observed that there is a great distance between the açaí beaters and the public actors of the support institutions. The SWOT analysis was effective in identifying the activity that faces severe threats and weaknesses, internally and externally, which serves as a warning to the municipality, institutions, and actors regarding the greater attention needed to its production chain, which is evidenced by the lack of investments in this activity.

Graphical analysis to determine the stability and adaptability of yield characteristics of dwarf cashew trees

The cashew culture provides jobs and boosts the economy of the Northeast region and is therefore of great socioeconomic importance. In genetic improvement programs, the existence of an interaction between genotypes and environments has been observed, making studies of adaptability and stability essential for effective selection. Thus, the objective was to study the performance of early dwarf cashew clones using the GGE Biplot in three agricultural years (2016–2018). The experimental design was in randomized blocks with 25 treatments (clones) and three replications. The plot consisted of four plants spaced 8 × 8 m apart. The variables evaluated were nut yield throughout the harvest (PRC), average nut weight (PMC), and percentage of nuts pierced (PCF). The clones most characterized as ideotypes were T25, T14, T7, T8, T2, T10, T15, and T22 for PRC; T12, T1, and T16 for PMC; and T5, T24, T21, and T8 for PCF, with coincidence for T8 in PC and PCF. Clones with values above the general average, with emphasis on stability, were T14 and T2 for PRC; T12, T1, T16, T8, and T22 for PMC; and T5 and T22 for PCF. The years with test characteristics, that is, those with average environmental factors for all years, were 2016 for PRC and 2018 for PCF, with no test year for PMC; the every years were more discriminating to PCF, with the exception of 2016 for PRC.

Introduction of special rice genotypes under upland conditions

Although widely consumed as white rice, there are special rice cultivars that contain aromas, colors and nutrients that reach special market niches, and constitute alternatives to vary the Brazilian menu and the farmer’s income. Most genotypes of special rice have nutritional characteristics superior to those of white rice, with call for better health, which is a growing concern of the general population. Based Based on these assumptions, the objective was to evaluate the productivity of special rice genotypes in rainfed cultivation conditions, in two seasons (2016/2017 and 2017/2018), in the city of Lavras/MG The treatments consisted of the following accessions: YIN LU 31, Japanese, CMG 1164, Formoso, Aromatic, IAC 400, IAC 300, IAC 600, IAC 500, BRSMG Relâmpago, BRSMG Caçula, BRSMG Caravera, SCS119 Ruby, SCS120 Onyx. After analysis of variance, the adaptability analysis and stability was performed by the Annichiaric method. The Aromatic and IAC 300 genotypes, by evaluated under rainfed conditions, showed high productivity (greater than 3,000 kg.ha-1), higher than the state average (867 kg ha-1), and low incidence of diseases in the conditions of high lands. These special rice genotypes grown in upland and compared to cultivars of rice indicated for this cultivation condition demonstrated that it is possible to produce rice from quality and develop genotypes more adaptable to rainfed conditions, which can be excellent option of cultivation to conventional rice and thus increase the diversity of the agricultural property.

Influence of agroforestry system modalities on maize (Zea mays) yield in an Amazon ecosystem

Corn is among the short-cycle annual species used in agroforestry systems due to its adaptation to intercropping. Thus, this study aimed to evaluate the corn yield, cultivar BIO Z 2365, in two types of agroforestry systems. The experiment was carried out in a forestry agroforestry system in two treatments: mechanized with mineral fertilizer and semi-mechanized with organic fertilizer. The experiment was carried out in a forestry agroforestry system (AFSs), with two treatments, mechanized with mineral fertilizers (MEC) and semi-mechanized with organic fertilizers (SMEC). Each treatment was composed of four crop strips (4 x 24 m) distributed with plants arranged at a distance of 0.50 m between lines, totaling four plots per treatment. A random collection of 20 plants per strip was used, and different variables related to production were evaluated. The productivity was estimated using the EMATER and Reetz methods and by estimating the direct yield. The t-test was adopted to verify the difference between treatments. The mechanized system was superior for all the variables evaluated, obtaining average yield of 41.6 bags ha-1. In the semi-mechanized system, the average yield was 29.2 bags ha-1. The performance of cultivar BIO Z 2365 was better in the mechanized system. However, the results revealed that the cultivation of short-cycle crops, despite technological restrictions in the experimental area, can mean an increase in income for small producers or act in reducing the costs of the implementation and maintenance in agroforestry systems; operating as an agent of economic sustainability.

Bioactive compounds and descriptors analysis of six cultivars of Capsicum spp.

Although peppers have a specific niche of use, due to their use in gastronomy, studies on morphoagronomic characterization and their nutritional qualities are scarce. The objective of this work was to evaluate the main descripts and to quantify bioactive compounds of the most cultivated pepper cultivars (Capsicum spp.) and consumed in the state of Roraima, Brazil. The experimental design was in randomized blocks with three replications, and the following peppers were evaluated: ‘Malagueta’, ‘Mesa’, ‘Cheiro’, ‘Canaimé’, ‘Olho de peixe’ and ‘Muripi’. Each plot consisted of seven seedlings. The following descriptors were analyzed: canopy diameter, plant height, stem color, stem diameter, height of the 1st bifurcation, and leaf length. The following bioactive and other compounds were also evaluated: calories, capsaicin, total anthocyanins, carotenoids, titratable acidity, pH, total and soluble fibers, total and reducing sugars, humidity, ashes, lipids, carbohydrates, soluble solids, proteins, antioxidant activity by ORAC and DPPH methods, phenolic compounds and vitamin C. It was observed that the cultivars Mesa, Malagueta, Olho de Peixe and Cheiro presented the best results regarding height, stem diameter, cup diameter, favorable to field cultivation. It was also verified that the best cultivar for consumption was Malagueta, since it presented higher indices of physicalchemical analyzes, higher levels of bioactive compounds and the highest antioxidant activity.

Efficiency of essential oils to control Colletotrichum theobromicola in vitro

Essential oils promote the inhibitory control of several fungi, including those within the genus Colletotrichum, the causal agent of Anthracnose, a disease which may occur at any stage of development in various crops, reducing up to 70% of crop production in some cases. Thus, the use of alternative products constitutes an important strategy for the integrated management, promoting less persistent molecules in the environment and lower toxicity rates, providing health benefits to producers and consumers of agricultural products. In this context, the present study evaluated the in vitro fungitoxic effect of essential oils from Java citronella (Cymbopogon winterianus), clove (Syzygium aromaticum), eucalyptus (Eucalyptus globulus) and rose pepper (Schinus terebinthifolius) on the mycelial growth of Colletotrichum theobromicola. The experiment was performed under completely randomized design, in a 4x5 factorial scheme (4 essential oils x 5 concentrations), with five replications, and the experimental unit consisting of a Petri dish. The treatments were generated by combining the concentrations (0, 5, 10, 15, 25 and 50 μL mL-1) of essential oils (citronella, clove, eucalyptus and rose pepper). The plates were inoculated with the pathogen C. theobromicola and incubated for seven days at 25 ± 2 °C. To verify the difference between treatments, the percentage of mycelial growth inhibition (PGI) was estimated. The mycelial growth of C. theobromicola was significantly reduced with increasing concentrations of essential oils. At a concentration of 50 μL mL-1, the essential oil from S. terebinthifolius showed the best result inhibiting 54.57% of mycelial growth, followed by the oil from S. aromaticum (49.26%), C. winterianus (23.70%) and E. globulus (17.90%). All the studied oils showed antifungal activity.

How thinning in a seasonally dry tropical forest contributes towards root biomass, carbon stock and aggregate size in a Vertisol

Forest management activities influence fine root development, total soil carbon (TSC) and size of aggregates. A field experiment was carried out in Vertisols of two adjacent catchments in a seasonally dry tropical forest (SDTF) to investigate the thinning on fine-root biomass, stock of the total soil carbon and aggregate size. The catchments are located in the State of Ceará, Brazil. The control catchment of 2.1 ha has been under regenerating vegetation for 35 years (RC35), while the second catchment (1.1 ha) was subjected to thinning (TC5) in December of 2008. The analysed variables were: fine-root biomass in the 0-10, 10-20 and 20-30 cm soil layers, TSC and mean weight diameter of the soil aggregates in the 0-20, 20-40 e 40-60 cm layers. The data were submitted to Pearson correlation analysis and compared by paired t-test (P < 0.05). The 0-10 cm layer of the TC5 management stored double the average amount of fine-roots found in the RC35. Under the TC5 management, stocks of soil TSC increased by 237 and 151% in the 20-40 and 40-60 cm layers, respectively, when compared with RC35. Aggregates 2.15 times greater than those found under RC35 management were obtained in the topsoil (0-20 cm) under the TC5 management. The implementation of thinning in a Vertisol of a SDTF emerges as an alternative management to be considered in projects for sustainability in the semi-arid region, contributing to an improvement in soil structure as well as an increase in the stocks of total carbon.

Cowpea subjected to organic fertilization and management of the natural vegetation of the savannah of Roraima

Cowpea (Vigna unguiculata (L.) Walp.) is one of the main sources of nutrients for a large part of the population. To increase your income, there is a need for proper management. This study aimed to evaluate yield components of the cowpea cultivar Aracê subjected to two levels of organic fertilization and three management of the natural vegetation of the savannah of Roraima. The experiment was set up in the experimental area of CCA/UFRR, in Boa Vista, Roraima. The experimental design was a randomized block design in a 3×2 factorial scheme, with four replications. The first factor consisted of the management of the natural vegetation: glyphosate application and cutting or not of the natural vegetation. The second factor consisted of the application or not of cattle manure. Yield components were plant height, number of trifoliate leaves, percentage of normal pods, pod length, number of grains per pod, 100-grain weight, sample grain index, total grain index, and final stand. Organic fertilization with 2 L m-2 of manure increased cowpea production. The management with vegetation cutting in areas with organic fertilization increased the final stand of cowpea plants. The desiccation of natural vegetation with glyphosate was the management that had the highest cowpea production.

Genetic variability and genetic progress in seed traits in breeding the physic nut

Determining the chemical composition of seeds of the physic nut (Jatropha curcas L.) is of great importance for the species due to the oil content of the seeds (the principal trait of interest). Identifying promising genotypes with selectable seed traits is one of the strategies adopted in breeding the physic nut in order to increase the yield and quality of the oil. Therefore, the aim of this study was to determine the chemical composition of seed traits in ten half-sibling progeny of the physic nut, and to identify which progeny have good genetic performance for transmission to the offspring. The experimental design was completely randomised, with ten treatments and four replications. The treatments were represented by seeds from half-sibling progeny in which the carbohydrate, protein and lipid content, and the composition of the fatty acids were evaluated. The genetic parameters and the gains from their selection were predicted for the principal seed traits using mixed-model analysis, including REML (restricted maximum likelihood) and BLUP (best linear unbiased prediction). The physic-nut seeds showed an average dry matter (DM) concentration of 60 mg g-1 carbohydrates, 42 mg g-1 protein and 142 mg g-1 total lipids. Unsaturated fatty acids represented more than 85% of the total fatty acid composition, with the oil classified as oleic-linoleic. Considering the predictions of the genetic parameters, the lipid traits can be selected for the purpose of breeding, resulting in genetic progress in the yield and quality of physic-nut oil.

Initial growth of zucchini irrigated with saline water in soil with biofertilizers

Zucchini culture is slightly sensitive to salinity and is among the ten vegetables of highest economic value, with characteristics of precocity and easy cultivation. These characteristics are some of the reasons for the expansion of its cultivation among small producers. Thus, the objective was to evaluate the effect of different levels of salinity in the irrigation water and biofertilizer types on the initial growth of the zucchini (Cucurbita pepo L.) culture. The experiment was carried out in the full sunlight in a randomized block design, in a 5x2 factorial arrangement. The treatments consisted of a combination of five types of biofertilizers (quail, sheep, mixed, bovine, and crab) and two salinity levels of the irrigation water (0.8 and 2.5 dS m-1), with five replicates. At 30 days after transplanting, the following variables were evaluated: electrical conductivity of the substrate, plant height, number of leaves, roots length, stem diameter, leaf area, chlorophyll content, dry mass of the aerial part, root dry mass, and total dry mass. Salt stress negatively interferes with the accumulation of zucchini plant biomass. Quail, bovine, and sheep biofertilizers are more efficient about plant height, number of leaves, and stem diameter. The sheep biofertilizer attenuates the salt stress for the dry mass of the aerial part, the root, and the total dry mass.