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 Soybeans are among the world’s main crops because they are excellent sources of proteins, micronutrients, and oil. Considering that abiotic stress affects agribusiness, resulting in losses, the grain yield of the crop must be maintained even at high temperatures. In this context, the objective of this study was to select markers related to soybean yield assessed under high temperatures, using associative mapping. The mapping population included 80 soybean PIs and 15 controls. For phenotyping, genotypes were evaluated at high temperatures in an experiment conducted in Teresina (in the state of Piauí) and four characters of interest for agronomy were evaluated: height of the plant when mature, agronomic value, 100-seed weight, and grain yield. Genotyping was carried out using the Affymetrix Platform (180 K Axiom® Soybean Genotyping Array), and the imbalance in the connection between pairs of markers was calculated through the coefficient of determination using the fast permutation test. The analysis of the association between markers and the phenotype of interest was carried out using a generalized linear model approach, including phenotyping data, SNP markers, and information on population structure. The results revealed that 34.06% of loci showed a significant linkage disequilibrium (p < 0.001), and 16 significant associations were found for the four characters related to heat tolerance. These associations can aid breeders that aim to incorporate high temperature tolerance in programs of soybean genetic improvement via selection assisted by markers.

ABSTRACT Fusarium wilt, caused by the fungus Fusarium oxysporum f. sp. passiflorae (Fop) is the main fungal disease in passion fruit crops. Chlamydospores, which are structures of resistance produced by Fop, allow the fungus survival in the soil for several years and have saprophytic activity. Biofumigation with incorporation of cabbage and bitter cassava has been a viable alternative, among management methods, for the control of soil pathogens. The objective of this work was to evaluate the effect of different plant debris (plant residues) on survival of Fop under laboratory conditions. In vitro tests were carried out with incorporation of leaves of yellow passion fruit, cabbage, bitter cassava, and sweet cassava plants into substrates infested with different Fop isolates. Mycelial growth and chlamydospore production and germination were evaluated. The incorporation of cabbage and bitter cassava debris had a fungistatic effect on Fop, with decreases in mycelial growth and chlamydospore production. The incorporation of cabbage into the substrate totally inhibited the chlamydospore germination in 78% of the evaluated isolates and decreased the germination percentage in the others.

ABSTRACT An experiment was carried out aiming to evaluate the effect of phosphorus rates on beet, in an Oxisol with high phosphorus (P) content, in Jaboticabal city, São Paulo, Brazil. The treatments were arranged in a factorial scheme, in a randomized block experimental design with four replicates. The factors evaluated were P rates (0, 120, 240, 360 and 480 kg ha-1 P2O5) and cultivar ('Early Wonder' and 'Kestrel'). At 50 days after transplanting the seedlings, foliar nitrogen (N), P, potassium (K) and boron (B) contents were evaluated, and there was no effect of the interaction between factors on foliar nutrient contents. The accumulation of these four nutrients was evaluated at harvest. All evaluated nutrients accumulated to higher levels in ‘Early Wonder’ than in 'Kestrel' both in the shoots and tuberous root. N, P and B accumulated more in the tuberous root whilst K accumulated more in the shoots. P dose did not influence the yield. Therefore, phosphate fertilization is not recommended for beet crop when cultivated in an Oxisol with a high content (88 mg dm-3) of available P.

ABSTRACT Pochonia chlamydosporia (Pc) is a nematophagous fungus with saprotrophic activity. However, little is known about the interaction between Pc and green manure. This study aimed to investigate the interaction effects of different green manures and Pc on the control of Meloidogyne javanica in soybean. Two greenhouse experiments were conducted in different periods using a 6 × 2 factorial design, with six replicates. The first factor was green manure application (oat, brachiaria, crotalaria, millet, buckwheat, and untreated control) and the second factor was treatment with Pc (in-furrow application and untreated control). Cover crops were grown separately and applied to pots as green manure 15 days before soybean sowing. At 5 days after sowing, soybean was inoculated with 2 000 eggs and juveniles of M. javanica. At 60 days after inoculation, nematode and vegetative variables were determined. All green manures reduced nematode population levels, especially oat, crotalaria, and buckwheat. Pc treatment did not influence nematode population levels. Soybean plants treated with oat or crotalaria green manure had greater height than untreated plants in both experiments. The effects of factors on shoot fresh and dry weights differed between experiments, and green manure application did not affect root development. The findings confirmed the potential of plant residues to control M. javanica.

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 South American fruit fly, Anastrepha fraterculus (Diptera: Tephritidae) is the most important insect pest in pear tree crops in Southern Brazil. Several studies pointed to the controversial efficacy of some food lures used for capture and monitoring this species in various fruit species. This study aimed to evaluate the efficacy of food lures available in the Brazilian market in capturing and monitoring A. fraterculus in relation to grape juice. The experiment was conducted during the 2014/2015 and 2015/2016 crop seasons in an Asian pear (Pyrus spp.) orchard located in Caçador, State of Santa Catarina, Brazil. The food lures evaluated were CeraTrap®, BioAnastrepha®, Torula®, Isca Mosca®, BioFruit®, and grape juice (a standard food lure in Southern Brazil). For each attractant substance, population fluctuations of A. fraterculus were recorded as well as the average number of female and male specimens captured, the FTD (fly/trap/day) rate of capture, the number of control indications, and mean weekly evaporation. The first A. fraterculus adults were captured in November, and in both crop seasons the population peak was found in January. CeraTrap® was more effective in capturing females and males and indicated a higher number of control indications compared to the other food lures. Grape juice presented lower effectiveness compared to CeraTrap®, including the evaporation parameter. It was concluded that CeraTrap® is the most effective food attractant in capturing adults of A. fraterculus and more accurate in detecting its population levels in Asian pear orchards, therefore, it is recommended rather than the usual grape juice.

ABSTRACT Technologies that use rhizobacteria to promote plant growth are increasing in agriculture, results have shown improvements in soil quality, increases in productivity, and decreases in the use of synthetic inputs, The objective of work was to characterize bacterial isolates regarding their biological activity and growth promotion of soybean plants grown in a controlled environment. Fifteen bacteria were isolated from soils with continuous use of biological fertilizer. They were evaluated for enzymes production (amylase and protease), nitrogen fixation, antagonistic activity to phytopathogenic fungi, and indoleacetic acid (IAA) production, Soybean seeds were inoculated with bacterial isolates in a greenhouse and evaluated for plant development and soil chemical attributes. The results showed that 8 of the 15 isolates presented production of amylase, protease, or both and 4 isolates presented nitrogen-fixing capacity. The percentage of isolates with high or moderate inhibitory action against the fungi Sclerotinia sclerotiorum, Macrophomina phaseolina, and Fusarium solani were 73.3%, 66.6%, and 73.3%, respectively. The IAA production varied from 8.56 to 31.33 µg mL-1 (5 isolates had low, 6 had moderate, and 4 had high production). The soybean development was significantly higher in 80% of the treatments with inoculation with bacterial isolates. Five bacterial isolates effectively present all characteristics for use as inoculant (biofertilizer) to promote the development of soybean plants.