Resumo em Inglês:

ABSTRACT The objective of this work was to determine the use and efficiency of energy and to quantify the greenhouse gas (GHG) emissions, per hectare, for the cultivation of pepper, Capsicum anuum L., hybrid MIRELLA F1, using plastic mulch in the open-field. The assays were performed in a farm of Puerto La Boca (1° 20’ 51” S and 80° 43’ 51” W), the precinct of the Puerto Cayo parish of Jipijapa Municipality, Manabí province, Ecuador. The data was collected through field research, between March and September 2021, under observation and timing techniques. There was evidence of energy consumption and production (in the form of pepper berries) of 18,442.29 and 27,702.74 MJ ha-1, respectively, and a total GHG emission of 3,058.90 kg CO2-eq ha-1. The energy efficiency was determined at 1.50, the energy productivity 1.88 kg MJ-1, the specific energy 0.53 MJ kg-1, and the net energy 8,858.46 MJ ha-1. The quotas of direct and indirect energies were calculated at 9,513.15 and 8,929.15 MJ ha-1, respectively, and the proportion of renewable and non-renewable energies at 12,994.03 and 5,448.27 MJ ha-1, respectively. The GHG index per kg of MIRELLA F1 pepper yield was 0.088.

Resumo em Inglês:

ABSTRACT The objective, in this research, was to evaluate the agricultural productivity and the financial performance of levels of irrigation in the cassava. For this, experiment was carried out, under a randomized block design, with six irrigation levels, as a function of crop evapotranspiration (L0 = 0% (rainfed), L1 = 40%, L2 = 80%, L3 = 120%, L4 = 160% and L5 = 200% of ETC) and four repetitions. Was evaluated: length and mass of roots, productivity of maximum physical and economic efficiency of roots and productivity of the aerial part. The irrigation level L5 or total useful water of 1,023 mm, got greatest productivity of the aerial part, 57 Mg ha-1. With a total useful water of 926 mm, this irrigation level, generated the greatest length and mass of roots per plant and the maximum physical productivity, 94 Mg ha-1. As well as the root yield of maximum economic efficiency, which is achieved with a total usable water, 914 mm. Among the irrigation levels studied, L3 (963 mm) is the one that provides the greatest productivity of roots, 90 Mg ha-1, and gross revenue 167% higher than in areas cultivated under rainfed conditions. Therefore, irrigation of cassava is economically viable.

Resumo em Inglês:

ABSTRACT Straw management associated with furrow opener mechanisms under a no-tillage system can enable better yields in the corn crop. Thus, this study aimed to evaluate corn productivity under a no-tillage system as a function of furrowing mechanisms and oat straw management. This research was conducted in the 2019/2020 growing season in Pato Branco, Paraná, Brazil, in a factorial scheme consisting of furrow opener mechanisms (shank and double disk) and oat straw management (rolled, desiccated, and crushed), with four replications. Oat dry matter, furrow depth, furrow width, tilled soil area, emergence rate index, initial and final plant stand, initial and final plant height, initial and final stem diameter, ear insertion height, number of rows per ear, number of grains per row, ear length, ear diameter, thousand-grain weight, and productivity were evaluated. The results were subjected to analysis of variance by the F-test at a significance 5% probability and the means were compared by Tukey’s test. Corn development, yield, and productivity were more influenced by the furrow opener mechanisms, standing out the use of a shank compared to the double disk.

Resumo em Inglês:

ABSTRACT Chickpea is a winter legume with prospects for worldwide consumption growth, mainly demanded by Asian countries. Thus, studies on its growth, such as the leaf area (LA), are important to determine proper management practices for its cultivation. The objective of this work was to determine a mathematical model able to estimate the leaf area (LA) of chickpea in a non-destructive method. For this, a field experiment was carried out in the county of Santa Maria (RS), with five cultivars available in the national market. Several leaves of each cultivar were collected, and their greatest width (W) and longest length (L) were measured. With the aid of a scanner, these leaves were photocopied, and their LA (cm2) was determined using software. With the power model, models relating to LA and its dimensions were determined. These models were tested using various statistics, with independent data. The results indicate that for the cultivars BRS Aleppo, BRS Kalifa, Jamu, and BRS Toro the best model is LA= 0,0940.(L)1.8483 and for the cultivar BRS Cícero the best model is LA = 0,1092.L2.1815.

Resumo em Inglês:

ABSTRACT Digitaria insularis (L.) Fedde stands out for its resistance to glyphosate and this characteristic may have a relationship with structural alterations. In such context, this research aimed at the characterization of the foliar anatomical structure of two populations of D. insularis (glyphosate-resistant and glyphosate-susceptible biotypes) collected in agricultural areas of Paraná, a Brazilian state. The experiment was conducted at the Laboratory of Botany of the Universidade Estadual do Oeste do Paraná – Unioeste, Brazil. The resistant biotypes of D. insularis differ from the susceptible ones in several structural parameters. Among them, the Mesophyll Thickness in the interveinal region was 7.3% thicker in the resistant biotype, which was also observed in the thickness of the keel, in the percentage of 11.3%, and in the thickness of cuticles in the adaxial surface (TCad), which was 53.8% thicker in the resistant biotype. In this way, we concluded that the resistant biotypes of D. insularis differ from the susceptible ones in several anatomical foliar characteristics, therefore, they present possible mechanisms of resistance to glyphosate.

Resumo em Inglês:

ABSTRACT The phytonematodes seriously harm plants worldwide, reducing agricultural productivity, especially root-knot nematodes, genus Meloidogyne. An alternative form of control for this pathogen is the use of essential oils, which have a complex mixture of compounds with potential nematicidal activity. The objective of this work was to identify the chemical compounds present in the essential oil of pequi and to verify the efficiency of the oil in the control of Meloidogyne javanica. The identification of chemical compounds was performed by comparing the mass spectra obtained with the spectra present in the equipment library, Nist08. Eighty-second stage juveniles (J2) were incubated in the following treatments: control 0 (2 mL of distilled water) 2, 4, 8 and 16 mg L-1 of pequi essential oil (PEO). The results obtained in the experiment were significant, with a high percentage of mortality of J2 in the treatment T5 (16 mg L-1) of 82% and T3 (4 mg L-1) 66%, respectively. Among the compounds identified, 58.3% are esters, highlight for ethyl hexanoate, and 25.0% are monoterpenes, and all are nematicidal compounds. Pequi essential oil has the potential to be used in the control of M. javanica.

Resumo em Inglês:

ABSTRACT Sequential crops may be affected by herbicide residuals in the soil. In corn crop there are reports of problems when the crop is sown soon after application of ACCase-inhibiting herbicides. The aim of this study was to evaluate safety intervals for the application of ACCase-inhibiting herbicides before sowing corn in different soils. Two experiments were conducted in a greenhouse, and in the field conditions. In both, the experimental design were completely randomized in factorial scheme 6x4+1 (6 periods of application x 4 herbicides + 1 control) with five replications. The treatments were: haloxyfop-P-methyl (124.7 g ha-1), clethodim – formulation 1 (192 g ha-1), quizalofop-P-ethyl (100 g ha-1) and clethodim formulation 2 (192 g ha-1) in applications at 15, 10, 5, 3, 1 and 0 days before sowing in sandy and clayey soil. In the greenhouse, formulations based on clethodim were more safety in both types of soils, and safety intervals for clethodim-based herbicides were 5 days and greater than 15 days for quizalofop-P-ethyl and haloxyfop. Haloxyfop should not be applied on day of sowing in clay soil. In the field none of the treatments compromised the development and yield of the crop, even when applied on the day of sowing.

Resumo em Inglês:

ABSTRACT The objectives were to estimate the potential of S2 corn progenies for forage-related traits, and use of AMMI analysis to evaluate topcrosses compared to the classic analyzes. Progenies were crosses with four different testers: LG 6030, 2B688, 9.H3.33 and 53F.P37. Topcross hybrids were evaluated in four 9 x 9 simple square lattice design, during the 2017/18 season at Maringa, Parana State. Grain yield, forage fresh matter yield, and forage dry matter yield were measured. Classical approach was composed by variance components, general and specific combining ability, whereas AMMI analysis was performed for progenies x testers interaction, considering additive main effects and multiplicative effects. Considering the classical approach, testers LG 6030 and 2B688 better expressed the genetic variability between progenies for grain yield. AMMI analysis allowed the partitioning of the sum of squares in additive main effects and multiplicative effects, being a complementary result for the classical approach. Progeny 14 was selected due to higher general combining ability for grain yield, forage fresh matter and forage dry matter yield. Topcrosses 14x9.H3.33 and 14x2B688 were selected due to their higher specific combining ability, additive and multiplicative effects. The AMMI analysis was effective and helped in the interpretation of the results.

Resumo em Inglês:

ABSTRACT Popularly known as araçá-una, Psidium myrtoides is an endemic tree species in Brazil, with fruits much appreciated by the fauna. It is indicated for the composition of reforestation and for enriching the vegetation of degraded areas. This work aimed to evaluate the effects of drought, heat, and the interaction of both in the physiological attributes of Psidium myrtoides plants. Monitored fluorescence, gas exchange, and chlorophyll index in araçá-una plants induced by drought, heat, and the combination of both during 1, 3, and 7 days after treatment induction (DAT). After, the plants were returned to their initial condition, and their recovery was evaluated at 15 DAT. The results indicate that Psidium myrtoides plants reduce photosynthetic activity in the absence of water, contrary to what has been shown in other studies; in addition, they are not potentiated by the combination with heat. Therefore, we conclude that this species has a potential tolerance to heat (Tmean 30.3 °C). However, if water is available in the soil, it maintains photosynthetic activity at normal levels.

Resumo em Inglês:

ABSTRACT Pecan crops has been expanding in recent years, mainly in southern Brazil. Genotypes that compose Brazilian orchards come from the USA and from selections of plants made by Brazilian producers. This study aimed to characterize with microsatellite markers pecan cultivars registered for cultivation in Brazil, including some selections made in the country. It is important to know the genetic variability of the pecan tree, as it facilitates the identification of possible phytotechnical deficiencies due to the genetic similarity between the plants, in addition to helping in the conservation of the species, among other. Thirty-four, out of forty collected accessions, were genotyped with 11 selected SSR (Simple Sequence Repeats) loci. Twenty-four polymorphic alleles were identified. The genetic similarity matrix, based on the Jaccard coefficient, ranged from 0.125 to 1.0; general mean of similarity was 0.46. The cluster analysis, which was carried out by the Unweighted Pair Group Method with Arithmetic Mean (UPGMA), classified pecan accessions into four main groups. Results showed that there is high genetic variability in germplasm evaluated, although some accessions may be duplicates.

Resumo em Inglês:

ABSTRACT Basil (Ocimum gratissimum - Lamiaceae), is a sub-shrub plant species with great economic importance for several regions, and studies on its growth, physiology, and reproduction become needed. The aimed research was to obtain a regression equation to estimate leaf area of O. gratissimum. 250 basil leaves were collected and the linear dimensions (length and width) and real leaf area of each leaf were measured. From these data, the products between length and width, length and length were calculated. Equations were obtained using regression models: linear, linear without intercept, quadratic, cubic, power, and exponential. The best equation was selected based on determination coefficient, Pearson’s correlation coefficient, Willmott’s agreement index and CS index, Akaike information criterion, mean absolute error and root mean square error. All equations proposed using the product between length and width (LW) can be used to predict the leaf area of O. gratissimum. However, the equation LA=0.54*LW1.03 (power model) is the most recommended to estimate the leaf area of this species.

Resumo em Inglês:

ABSTRACT Hop (Humulus lupulus L.) is one of the most important raw materials of beer production. Despite being the third-largest producer and consumer of beer worldwide, Brazil imports almost all hops for production. Nitrogen is an essential macronutrient for hop development and its behavior under different doses is still unknown for Brazilian conditions. Our goal was to evaluate the dry matter and essential oil yields of the Chinook hop fertilized with five N rates during three harvests. Leaves, branches, and cones were sampled to determine their dry matter production, and cones were also analyzed for essential oil contents, extracted by hydrodistillation. Cone number per plant, cone, branch, and leaf dry matter yields, as well as total essential oil yield per plant, increased linearly as nitrogen rates were raised. The production of DM of cones obtained ranged between 245.8 (N:0) and 386.7 kg ha-1 (N:250 kg N ha-1). Yield differences were also noted between harvest years due to weather conditions. Therefore, we can conclude that increasing N rates and climatic conditions affect N contents in hop leaves, as well as hops overall and oil yields, due to the higher cone dry matter. However, essential oil contents in cone dry matter did not change.

Resumo em Inglês:

ABSTRACT The most important viruses infecting potato in Colombia are PVY, PLRV, PVS, PYVV, PVV, PVX, PMTV, and PVB. Unfortunately, recent investigations on the health status of uncertified and certified seed-tubers of Solanum tuberosum cv. Diacol Capiro and Solanum phureja cv. Criolla Colombia used by farmers in eastern Antioquia (Colombia) have revealed alarming levels of infection by these viruses in all types of seeds distributed in the region. A similar study on northern Antioquia, testing all these eight viruses has not been performed. To close this gap, we present a complementary study on the prevalence of viruses in seed-tubers distributed and commercialized in this region using a combination of RT-qPCR and high-throughput sequencing. Our results further confirm the poor quality of seed-tubers used in Colombia and suggests infection by tobacco necrosis virus D (TNV-D), which is the first report for this virus in Colombia.

Resumo em Inglês:

ABSTRACT Studies have shown the synergism of co-inoculation with symbiotic and non-symbiotic N2-fixing bacteria, efficiently contribute to plant development. However, for crops such as forage legumes, data on the use of co-inoculation are still incipient, requiring studies to identify the contribution of this technique for application in pasture areas, thus ensuring greater sustainability. The objective of this study was to evaluate the effects of co-inoculation of Azospirillum brasilense (Ab-V5) and native rhizobia isolated from two forage legumes, Crotalaria spectabilis and Lupinus albus. Two experiments were installed in pots with 8dm3. Both were conducted in a randomized block design (DBC) with four replications and an 8 x 2 factorial scheme with six bacterial strains and two control treatments without inoculation (with presence or absence of mineral nitrogen), co-inoculated or not with the Ab-V5 strain. Plants were cultivated until the time of flowering when shoot (SDM) and root dry matter (RDM), number (NN) and nodule dry matter (NDM), and relative symbiotic efficiency (RSE) were evaluated. Isolates 05-21 and 06-03, for C. spectabilis and L. albus, respectively, indicated higher potential to promote plant growth when co-inoculated with Ab-V5, showing potential to act as substitutes for nitrogenous chemical fertilizers, reducing costs and increasing the sustainability of production.

Resumo em Inglês:

ABSTRACT The pre-harvest application of the bioprotective agent Cladosporium cladosporioides is an alternative to inhibit these fermentative processes that might occur in coffee beans that were either their storing bag or exposed to simulated rain, because a controlled amount of water was applied to the coffee. The objective of this study was to evaluate the effect of Cladosporium cladosporioides (Fresen) de Vries in the physical-chemical and sensory of the coffee beans. The study was conducted in an arabica coffee plantation, in the municipality of Inconfidentes, state of Minas Gerais, Brazil. In this study used four different doses of the bioprotector and three different pos-harvest conditions. The sour defective coffee beans, electrical conductivity, total titratable acidity, soluble solids, color and it was determined the general quality of coffee of both the left-in-bag and rainfall-exposed variants were positively influenced by the bioprotector. The bioprotector promoted an increase in the quality of the physical and chemical composition and sensory quality of rainfall and left-in-bag coffees compared to coffee beans without bioprotector. The bioprotector also maintained quality in rainfall and left-in-bag coffee when compared with the yard-grown variant. The sensory quality of the yard-grown coffeed was not influenced by the bioprotector.

Resumo em Inglês:

ABSTRACT The flaxseed is little explored under Brazilian cultivation conditions, generating a gap in information about the appropriate management of the crop, in the country. Hence, the objective was to find the appropriate dose of nitrogen for the development of the variables: technical length, yield length, main stem diameter, number of grains per pod, plant grain yield, and plant dry mass of two flaxseed varieties, brown and golden, in places with subtropical and tropical climate in Brazil. The treatments consisted of a two-factor 2 x 6 experiment, consisting of two flax varieties (brown and golden) and six nitrogen doses (0; 30; 60; 90; 120 and 150 kg ha-1), in randomized blocks with four repetitions and three different environments: Santa Maria and Frederico Westphalen, in the state of Rio Grande do Sul, and Viçosa, in the state of Minas Gerais. The brown variety obtained greater technical and yield length compared to the golden variety, on the other hand, the golden variety showed a higher number of grains per capsule and higher plant grain yield compared to the brown variety, in the three environments. The plant dry mass increased linearly and proportionally to the increase in nitrogen doses in Santa Maria and Frederico Westphalen environments. Therefore, flaxseed responds differently to nitrogen supplementation according to the cultivation environment, showing wide variability. The different doses of nitrogen influenced the variables analyzed and the varieties of flaxseed differently, depending on the environment.

Resumo em Inglês:

ABSTRACT Cedro-rosa (Cedrela fissilis) is native to Brazil with great potential for seedling production. However, soil correction is necessary to improve its performance, due to the edaphoclimatic conditions in Brazil, where soils have a high weathering degree and large amounts of Fe and Al oxides. Here, we evaluated the combined effect of soil acidity correction by liming and phosphate fertilization using single superphosphate on the growth and development of cedro-rosa seedlings cultivated in Amazonian soil. The study was carried out in a greenhouse at the Universidade Federal Rural da Amazônia (UFRA) – Campus Capitão Poço, between July and December 2019. Different levels of base saturation (V%) showed no influence on the variables analyzed. On the other hand, phosphorus (P), calcium (Ca), and sulfur (S) supplied by single superphosphate significantly influenced growth and development of cedro-rosa seedlings. The optimum P levels for stem diameter (SD), leaves number (LN), root dry matter (RDM), stem dry matter (StDM), leaf dry matter (LDM), total dry matter (TDM) were 405, 286, 385, 421.87, 393.75, 445 mg dm-3 of P, respectively. Seedling quality (DQI) showed a positive linear response to levels of P, Ca, and S in single superphosphate. Thus, fertilization with P was necessary at the nursery stage for the cultivation of the species in soil of low chemical fertility. For better quality of cedro-rosa seedlings grown in pots, the application of 400 mg dm-3 of P is recommended.

Resumo em Inglês:

ABSTRACT This study aimed to evaluate the effect of the application of Siliceous Rocks Powder as a source of K (phonolite and verdete) in natura and calcined at temperatures of 300, 600, 800 and 1000° C, pure and in consortium with dolomitic limestone and coffee husk to corn crop (Zea mays L.). The analyses of the phenological variables, stem diameter, number of shoots, leaves, plants height, weight of dry biomass of the aerial part and the contents of N, P and K, accumulated in the aerial part of the plants were performed. The range of calcination temperature between 300 °C and 600 °C, being the treatments that become K more available to the plants. The treatment that produced the highest biomass was the rocks in mixture (m/m) with coffee husk. The calcination temperatures influenced the biomass production and the content of macronutrients accumulated in the dry biomass of the aerial part. The least efficient treatment in the production of biomass was associated with the rocks in mixture with dolomitic limestone.

Resumo em Inglês:

ABSTRACT The objective of this study was to evaluate the influence of a commercial product, a soil bioactivator, on the establishment and efficiency of symbiosis between rhizobia and Arachis pintoi (forage peanut). The experiment was conducted in a greenhouse in 8 dm3 pots and 12 treatments were used, ten inoculated with different strains of rhizobia and two without inoculation (presence or absence of mineral nitrogen), associated or not with the application of soil bioactivator. The experimental design used was a randomized block design with four repetitions. The experiment was conducted until the time of flowering, when the agronomic characteristics referring to the shoot dry matter (SDM) and root (RDM), relative symbiotic efficiency (RS), number (NN) and nodule dry matter (NMS) and the bromatological characteristics, given by the content of crude protein (CP), neutral detergent fiber (NDF) and acid (ADF) were evaluated. The use of soil bioactivator did not influence the bromatological characteristics, but potentiated the inoculation with rhizobia strains, UNIFENAS 03-16, UNIFENAS 03-31 and UNIFENAS 03-36, effectively contributing to increases in the values of SDM, RS and NN, thus constituting a sustainable alternative for the production of A. pintoi.

Resumo em Inglês:

ABSTRACT Off-season crops diversification and gypsum under minimal tillage can improve soil fertility and reduce soil compaction. The objective of this work was to evaluate changes on soil physical and chemical properties and soybean yield grown over off-season crops in combination with gypsum and chiseling. Treatments consisted of gypsum application (0 and 3,5 t ha-1), two tillage systems (no tillage [NT] and minimal tillage [MT] with chiseling) and four soybean off-season crop successions: maize (M); maize+brachiaria (M+B); millet+crotalaria/wheat (Mi+C/W) and maize+black oats (M+O). Gypsum application reduced resistance to penetration (PR) by 12% in M+B system (1.12 kPa), when compared to the same treatment without gypsum. Gypsum increased surface soil Ca contents, mainly in M/O (from 3.81 to 5.66 cmolc dm-3). MT decreased PR in M+B, Mi+C/W and M/O, from 1.28 kPa in NT to 0.98 kPa. MT lowered total soil porosity from 66.9 to 63.1%, but reduced Ca contents compared to NT. Cultivation of crotalaria in the off-season reduced Al levels on the soil surface and grasses increased K and P in depth. Despite the improvements in the soil properties, crop rotations, chiseling and gypsum were not able to increase soybean yields in this 18-month experiment, averaging 3904 kg ha-1.