ABSTRACT Macrophomina (Botryosphaeriaceae) is one of the main genera of soilborne phytopathogenic fungi, which causes root and seed rot in more than 800 host plants worldwide. Recent phylogenetic studies identified the species M. phaseolina and M. pseudophaseolina in Trianthema portulacastrum and Boerhavia diffusa in melon and watermelon production areas in northeastern Brazil. Therefore, the objective of this study was: i) to verify the effect of temperature and salinity on the mycelial growth of M. phaseolina, M. pseudophaseolina and M. euphorbiicola, ii) to assess their pathogenicity on melon and watermelon seedlings, and iii) to determine their sensitivity to the fungicide carbendazim. The optimal temperature for mycelial growth rate (MGR) for Macrophomina spp. ranged from 27.18 ºC (CMM4771 – M. pseudophaseolina) to 31.80 ºC (CMM4763 – M. phaseolina). For the effect of salinity on mycelial growth of Macrophomina isolates, the EC50 ranged from 103.76 (CMM4868 – M. euphorbiicola) to 315.25 mM (CMM4801 – M. pseudophaseolina). The pathogenicity test demonstrated that M. phaseolina, M. pseudophaseolina and M. euphorbiicola are pathogenic on melon with M. phaseolina exhibiting a higher level of virulence. Macrophomina euphorbiicola isolates did not cause disease in watermelon. The most sensitive isolates to the fungicide carbendazim were CMM4868, CMM4867 (M. euphorbiicola) and CMM1531 (M. phaseolina) with EC50 of 0.003, 0.012 and 0.012 mg.L-1 a.i., respectively. All Macrophomina spp. used in these experiments were pathogenic to the tested melon and watermelon cultivars with the exception of the M. euphorbiicola isolate that did not cause damage to watermelon.

ABSTRACT Understanding the behaviour of herbicides in the soil can contribute to adapting the correct dose for efficient weed control with less environmental impact. In this study, we sought to evaluate the factors involved in the sorption, desorption, half-life and leaching processes of sulfometuron-methyl in three soil classes: Cambissolo Háplico (CX) (Inceptisol), Latossolo Vermelho (LV) (Oxisol) and Neossolo Quartzarênico (RQ) (Entisol). The sorption and desorption tests were performed using the “batch equilibrium" method. The studies of degradation and formation of metabolites were estimated from the half-life at the end of 180 days. Leaching potential was estimated by testing PVC columns filled with soil. Analyses were performed by ultra-performance liquid chromatography coupled to a mass spectrometer for herbicide quantification. The higher sorption of sulfometuron-methyl in LV (2.81) is related to the low pH (4.7) and mineralogical composition, mainly due to the higher concentration of Fe and Al oxides in this soil, influencing the lower desorption of the herbicide in LV (0.59). This result contributed to more remarkable herbicide persistence in this soil, reducing the molecules available in the solution for degradation. These results contributed to the longer half-life (19 days) in LV compared to the other soils. Among the studied soils, RQ had the highest risk of transport of sulfometuron-methyl based on the GUS Index (2.2) due to its greater desorption (0.34). The results showed that the studied processes are dependent on the physical, chemical and mineralogical attributes of the different classes of soils.

ABSTRACT Given the lack of information on the use of spontaneous plants from the Caatinga biome as green manure to produce green grains, the present work aimed to agronomically and economically optimize cowpea production for green grains and their components when fertilized with equitable biomass amounts of hairy woodrose (Merremia aegyptia L.) and roostertree (Calotropis procera Ait.) in two cropping seasons in a semi-arid environment. The experiment used a randomized complete block design, with five treatments and five replicates. The treatments consisted of equitable amounts of dry M. aegyptia and C. procera biomass of 16, 29, 42, 55 and 68 t ha-1. In each experiment, an additional treatment was planted with cowpea without fertilizer (absolute control), and another was fertilized with mineral fertilizer for the purpose of comparison with the treatment of maximum physical or economic efficiency. The maximum optimized physical (agronomic) efficiencies of cowpea green pods and grain production were reached in the productivity of green pods at 3.90 t ha-1 and green grains at 4.06 t ha-1, with incorporation into the soil of 45.07 and 50.48 t ha-1 of green manure, respectively. The maximum economic efficiency of cowpea green grain production was reached at a net income of R$5826.12 ha-1 and at a rate of return of 1.29 reals for each real invested with application to the soil of 38.74 and 37.85 t ha-1 of the tested green manure biomass.

ABSTRACT Chalcididae is a family of parasitoids with wide distribution and great richness, with almost 1,500 described species. Its diversity might be greater than that known today, mainly due to the few existing studies and its taxonomic complexity. Studies in semiarid regions are scarce and necessary to contribute to the biogeographic knowledge of the neotropical fauna. Therefore, the objective of this work was to record Chalcididae species that occur in the municipality of Barra do Choça, in the Semiarid region of the state of Bahia, Brazil. Five Malaise traps were distributed in two areas with native vegetation and an area with eucalyptus plantation, which were monitored monthly for two consecutive years. The insects were sorted and specimens of the family Chalcididae were identified at the species level, when possible. A total of 182 specimens from five genera (Aspirrhina Kyrbi, 1883; Brachymeria Westwood, 1829; Conura Spinola, 1837; Dirhinus Dalman, 1818, and Haltichella Spinola, 1811), and 18 species were identified and 32 were morphotyped. The genus Conura was the most abundant and the most diverse, with 12 species identified and 30 potential new species. The native vegetation presented higher abundance and higher taxonomic wealth, mainly in the area at initial stage of succession (capoeira). The eucalyptus area presented low diversity, with predominance of Brachymeria species. The species C. nigricornis presented the highest relative frequency. This study constitutes the first list of Chalcididae species in the Semiarid region of Brazil. The sampling carried out in the state Bahia showed an important diversity of Chalcididae species when compared to other regions of Brazil.

ABSTRACT Vegetables intercropping of results in a better use of natural resources, water, light, and nutrients, when properly managed. The objective of this work was to evaluate the performance of lettuce and radish in single crop and intercropping systems under different irrigation water depths. The experiment was conducted in a protected environment at the State University of Maringá, in Maringá, Paraná, Brazil. A randomized block experimental design was used in a 4×2 factorial arrangement, with four replications. The first factor consisted of four irrigation water depths (60%, 80%, 100%, and 120% ETc), and the second factor consisted of two crop systems (single crop and intercrop). A drip irrigation system was used, consisting of constant water table lysimeters. The variables evaluated were: shoot fresh weight, root dry weight, and leaf area for the lettuce crop; total fresh weight, root fresh weight, and root diameter for the radish crop; and yield, water use efficiency, and land use efficiency index for both crops. Shoot fresh weight, leaf area, and yield of lettuce, and total fresh weight, root fresh weight, and yield of radish increased as the irrigation water depth applied was increased. Total fresh weight, root fresh weight, root diameter, and yield of the radish crop were higher in the intercropping system. The water use efficiency of both crops was higher in the single crop, and the land use efficiency index was higher in the intercropping system.

ABSTRACT Residues from turkey production are often used as fertilizers in pastures near producing regions. These residues can contribute to the increase of carbon and nitrogen stocks in the soil. This study aimed to evaluate the cumulative effects of nine applications of turkey litter rates on C and N fractions and stocks in a Latossolo Vermelho distroférrico (Oxisol) cultivated under rotational grazing. The experimental area was divided into 16 pickets of 0.5 ha each and cultivated with Urochloa decumbens in a rotational grazing system. The treatments consisted of accumulated doses of turkey litter (38.3; 54.8 and 69.2 Mg ha−1), with applications carried out between 2008 and 2017, in addition to a control treatment, without application of this material. After nine years of application, total organic carbon (TOC) and total nitrogen (TN) stocks in the soil increased as turkey litter rates increased, reaching increments in the 0-0.2 m layer of 11.2 Mg ha−1 and 1.03 Mg ha−1, respectively, when compared to the control treatment. In the same 0-0.2 m layer, the maximum increments in carbon stock in particulate organic matter (POC) and nitrogen stock in particulate organic matter (N-POM) were obtained with the estimated total doses of 62 and 66 Mg ha−1, respectively. In addition to increasing the amount, the use of turkey litter improved the quality of the carbon present in the soil, since the carbon management index, in the 0-0.2 m layer, was increased by 124% when using the highest accumulated dose.

ABSTRACT The objective of this study was to evaluate the effect of the conversion of secondary native vegetation (NV) to conventional systems (agriculture and pasture) in soil organic carbon (SOC) and carbon of fractions particulate organic matter (POM) and mineral-associated organic matter (MAOM) in the Brazilian semi-arid region. The study was carried out in the municipalities of Delmiro Gouveia, Inhapi and Pariconha, in Alagoas, Brazil. Soils were collected in the layers of 0-0.1, 0.1-0.2 and 0.2-0.3 m. The treatments analyzed were: agricultural crops with 4, 15 and 30 years and pasture with 10 years. As a reference, the secondary Caatinga was used. The results show that in soils with sandy texture (Neossolos Quartzarênico and Regolítico – Arenosols and Regosols, respectively), there were reductions in SOC levels and carbon in the compartment associated with minerals. The inverse can be observed in the clay-textured Argissolo (Acrisols), with 30 years of cultivation, in which there was an increase in SOC and C in the quantitative fractions of soil organic matter. In addition, despite the sandy texture of the Neossolo Regolítico, POM levels were increased in the pasture system in comparison to native vegetation, but it was not enough to recover the original SOC content of this system.

ABSTRACT Cowpea is a crop of great socioeconomic relevance for the populations of the North and Northeast of the country, and its low yield is commonly related to environmental stresses, especially water. The objective of this study was to evaluate the water stress index of cowpea, cultivar BR3 - Tracuateua, subjected to different irrigation levels (100, 50, 25 and 0% of ETc) in three reproductive phenological stages (R7, R8 and R9) in Castanhal-PA, Brazil. The experimental design was in randomized blocks, with six replications and four treatments corresponding to 100, 50, 25 and 0% of daily replacement of crop evapotranspiration, during the reproductive period, through an irrigation system. The surface temperature readings were made with infrared thermometer, during the reproductive stage. The smallest absolute temperature differences between canopy and air occurred in stages R7 and R8. The highest values of water stress index (CWSI) were verified when the plant was under water deficit, regardless of phenological stages. The effect of water deficit caused reductions in stomatal conductance of 58.82% (R7), 83.57% (R8) and 84.87% (R9), in leaf transpiration of 45.97% (R7), 64.21% (R8) and 65.90% (R9) and in the net photosynthetic rate of 40.75% (R7), 66.92% (R8) and 74% (R9). The CWSI varied with the availability of water, showing the highest value (0.75) in the treatment without irrigation, in the R8 stage. The CWSI proved to be a good indicator of the water status of the plant.

ABSTRACT Sodom apple is a plant species adapted to various ecosystems and has stood out for its economic and ecological importance. We evaluated the amplification profile of 23 ISSR primers and selected polymorphic loci for genetic studies of a natural population of Calotropis procera by collecting and extracting genomic DNA from 33 individuals. Genomic DNA was extracted using the sorbitol protocol and 2% CTAB and the ISSR amplification products were resolved by electrophoresis. Based on the amplification profile, the 23 primers were classified as suitable, moderate, and unsuitable. We described the quality of primers considering the total number of bands, mean bands per primer, percentage of polymorphism, Nei’s genetic diversity (expected heterozygosity – He), assuming Hardy-Weinberg equilibrium and the polymorphic information content (PIC). All ISSR primers showed an amplification profile, which generated 173 bands with an average of 7.5 loci per primer. However, only 18 out of the 23 tested primers allowed visible and high-quality amplification, which were classified as suitable and polymorphic. We also observed a mean of 0.30 and 0.24 for PIC and He estimates, respectively. The DiCA3`RG, TriAGA3`RC, and TriCGC3`RC primers were highly transferable to C. procera (they presented quality for amplification with good reproducibility), with PIC values higher than 0.40, He higher than 0.30, and polymorphism higher than 86%.

Basidiomycete fungi that decompose wood produce substances with promising biological activity for the alternative control of plant diseases. The production of these substances can change according to the climatic conditions and the substrate used for fungal cultivation. The objective of this study was to develop a substrate with sawdust from Eucalyptus sp. and to verify its influence on biomass and cinnabarin production by Pycnoporus sanguineus. Sawdust was used in two particle sizes: less than 500 microns (G1) and between 500–841 microns (G2). Four isolates of P. sanguineus were plated on Petri dishes containing potato broth and agar media added with 0%, 1%, 5%, 10%, and 15% sawdust for each particle size. The largest final diameter of the colony and speed of mycelial growth were observed in the substrate with G1 particle size, with the Ps14 isolate showing the highest averages. For these variables, the sawdust concentration did not influence G1 granulometry and provided the highest values in G2 granulometry. Fresh mycelium mass and cinnabarin production showed the highest values in G2, with the isolated Ps13 and Ps08 showing the highest averages, whereas in G1, Ps14 had the best performance for the analyzed variables. These results indicate that sawdust from Eucalyptus sp., at concentrations of 10% and 15%, is an alternative for the in vitro cultivation of P. sanguineus, and that particle size influences the growth speed, fresh mass production, and cinnabarin content. | Fungos basidiomicetos decompositores de madeira produzem substâncias com atividade biológica promissora para o controle alternativo de doenças de plantas. A produção dessas substâncias é influenciada pela condição climática e substrato utilizado para cultivo do fungo. Dessa forma, objetivou-se desenvolver um substrato com serragem de Eucalyptus sp. para verificar a influência na produção de biomassa e cinabarina por Pycnoporus sanguineus. A serragem foi utilizada em duas granulometrias, inferior a 500 micra (G1) e entre 500 a 841 micra (G2). Quatro isolados de P. sanguineus foram repicados em placas contendo o meio de cultivo caldo de batata e ágar adicionados com zero, 1%, 5%, 10% e 15% de serragem para cada granulometria. O maior diâmetro final da colônia e velocidade de crescimento micelial foi observado no substrato com granulometria G1, sendo o isolado Ps14 com as maiores médias. A concentração de serragem, para essas variáveis, não influenciou na granulometria G1 e proporcionou maiores valores na granulometria G2. Massa fresca do micélio e produção de cinabarina apresentaram os maiores valores em G2, sendo dos isolados Ps13 e Ps08 as maiores médias, já em G1, Ps14 apresentou o melhor desempenho nas variáveis analisadas. A serragem de Eucalyptus sp., nas concentrações de 10% e 15% é uma alternativa para cultivo in vitro de P. sanguineus, e a granulometria influencia na velocidade de crescimento, produção de massa fresca e teor de cinabarina.