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This study investigated the survival of Xanthomonas campestris pv. campestris (Xcc) in the soil, under field and controlled conditions, and associated with cauliflower crop debris. Under field conditions, the soil temperature influenced the survival of Xcc, and the bacterium survived from 4 to 7 days. Under controlled conditions, the soil type and temperature influenced Xcc survival. Depending on the texture, pH and organic matter content of the soil, the bacterium survived from 10 to 24 days. Xcc survived in the soil for 14 days at 20 °C, and for 4 days when incubated at 30 °C. The soil moisture did not influence Xcc survival of 14 days at the three moisture contents evaluated. Similar behaviour was observed regarding the survival of four Xcc strains in the soil. The longest period of Xcc survival associated with cauliflower debris was 255 days. Our results suggest that the soil is not an important source of inoculum for Xcc. Considering the survival periods of Xcc in cauliflower crop residues under the Brazilian conditions studied, we recommend crop rotation with non-host species of Xcc for 1 year. This information may also be useful for the management of black rot in other brassica-producing countries.

Abstract Galls by Leptocybe invasa Fisher & La Salle (Hymenoptera: Eulophidae) reduce the productivity of Eucalyptus spp. plantations and Quadrastichus mendeli Kim & La Salle (Hymenoptera: Eulophidae) parasitizes this pest. This study aimed to evaluate, under laboratory conditions, two biological control strategies against Leptocybe invasa using the parasitoid Quadrastichus mendeli: (i) inundative biological control (referred to here as applied biological control), consisting of the release of five mated females per seedling, and (ii) natural biological control, representing the action of naturally occurring populations of the parasitoid already established in the environment. Ninety-day-old seedlings of the clone 3025 (Eucalyptus grandis × E. camaldulensis), naturally infested by L. invasa, were placed individually in cages under controlled conditions (25 ± 2 °C; 70 ± 10% RH; 12 h photoperiod) in a completely randomized design with 22 replicates per treatment. The number of insects was adjusted using zero-inflated mixed nonlinear regression models. The emergence of L. invasa adults (p>0.05) was similar between treatments, but that of Q. mendeli greater with the release of five females of this natural enemy per seedling compared to the applied biological control. The controlled release of Q. mendeli reduced L. invasa damage on Eucalyptus seedlings, increasing the importance of applied biological control to manage this pest in cultivated forests. Resumo Galhas formadas por Leptocybe invasa Fisher & La Salle (Hymenoptera: Eulophidae) reduzem a produtividade de plantações de Eucalyptus spp., e Quadrastichus mendeli Kim & La Salle (Hymenoptera: Eulophidae) parasita essa praga. Este estudo teve como objetivo avaliar, em condições laboratoriais, duas estratégias de controle biológico contra Leptocybe invasa utilizando o parasitoide Quadrastichus mendeli: (i) controle biológico inundativo (denominado aqui como controle biológico aplicado), consistindo na liberação de cinco fêmeas acasaladas por muda, e (ii) controle biológico clássico, representando a ação de populações naturalmente ocorrentes do parasitoide já estabelecidas no ambiente. Mudas com 90 dias de idade do clone 3025 (Eucalyptus grandis × E. camaldulensis), naturalmente infestadas por L. invasa, foram colocadas individualmente em gaiolas sob condições controladas (25 ± 2 °C; 70 ± 10% UR; fotoperíodo de 12 h) em delineamento inteiramente casualizado, com 22 repetições por tratamento. O número de insetos foi ajustado por meio de modelos de regressão não linear mistos com inflação de zeros. A emergência de adultos de L. invasa (p>0,05) foi semelhante entre os tratamentos, mas a de Q. mendeli foi maior com a liberação de cinco fêmeas desse inimigo natural por muda, em comparação ao controle biológico aplicado. A liberação controlada de Q. mendeli reduziu os danos causados por L. invasa em mudas de Eucalyptus, ressaltando a importância do controle biológico aplicado para o manejo dessa praga em florestas cultivadas.

Abstract The growing demand for sustainable pest control has intensified the need for large-scale biopesticide production. Beauveria bassiana and Metarhizium anisopliae are widely used in Integrated Pest Management (IPM), but their production still requires more efficient, scalable methods. This study is the first to evaluate the simultaneous cultivation of B. bassiana (IBCB227) and M. anisopliae (IBCB425) in the JKI-Solid Fermenter System (JKI-SFs) under different temperatures and novel substrate combinations, including rice-barley mixes. Solid-state fermentation was conducted at 15, 20, 25, 30, and 37 °C on parboiled rice, barley, and a rice-barley mix (4:1). Optimal conidia yields were achieved at 25 °C for B. bassiana and 25-30 °C for M. anisopliae, with no sporulation at 37 °C. The rice-barley matrix enhanced production: a 194% increase in conidia yield was observed for B. bassiana and 5.8% for M. anisopliae compared to rice alone. The JKI-SFs bioreactor enabled yields up to 6.0 × 109 conidia/g dry mass without contamination and with better handling. These findings demonstrate the potential of JKI-SFs as an efficient, scalable, and contamination-free system for biopesticide production using optimized substrate strategies. Resumo A crescente demanda por controle sustentável de pragas intensificou a necessidade de produção de biopesticidas em larga escala. Beauveria bassiana e Metarhizium anisopliae são amplamente utilizadas no Manejo Integrado de Pragas (MIP), mas sua produção ainda requer métodos mais eficientes e escaláveis. Este estudo é o primeiro a avaliar o cultivo simultâneo de B. bassiana (IBCB227) e M. anisopliae (IBCB425) no Sistema JKI-Fermentador Sólido (JKI-SFs) sob diferentes temperaturas e novas combinações de substratos, incluindo misturas de arroz e cevada. A fermentação em estado sólido foi conduzida a 15, 20, 25, 30 e 37 °C em arroz parboilizado, cevada e uma mistura de arroz e cevada (4:1). Rendimentos ótimos de conídios foram alcançados a 25 °C para B. bassiana e 25-30 °C para M. anisopliae, sem esporulação a 37 °C. A matriz arroz-cevada aumentou a produção: observou-se um aumento de 194% na produção de conídios para B. bassiana e 5,8% para M. anisopliae em comparação com o arroz isolado. O biorreator JKI-SFs permitiu rendimentos de até 6,0×109 conídios/g de massa seca sem contaminação e com melhor manuseio. Esses resultados demonstram o potencial dos JKI-SFs como um sistema eficiente, escalável e livre de contaminação para a produção de biopesticidas, utilizando estratégias otimizadas de substrato.

This study determined the mobility of sulfentrazone in soils used for reforestation (Haplic Planosol, Ultisol, Humic Cambisol, and Regolithic Neosol) in the south of Brazil. To form the soil columns, previously prepared PVC tubes (10-cm diameter and 50-cm long) were filled with soil samples. Sulfentrazone was applied on top of the columns, which contained soil with moisture close to the field capacity. Subsequently, simulated 60-mm rainfall was applied to the columns. After draining the water, the columns were opened, and soil samples of each segment of 5.0 cm of the columns were taken for analysis of sulfentrazone by high-performance liquid chromatography. The herbicide was extracted from the soils by the solid–liquid extraction method with low temperature partition (SLE-LTP), which was adapted and validated. Sulfentrazone showed high mobility in the four soils analyzed, but presented lower mobility in the Humic Cambisol due to its lower rate of desorption. In this soil, the herbicide remained in the upper layers of the column, while in the other soils the herbicide was distributed throughout the columns. The soil that held the highest concentration of the compound in the first two segments of the column (0–5 and 5–10 cm) was the one with the highest clay content. Thus, it was concluded that the sulfentrazone leaching process in the soils analyzed is dependent on the chemical and physical characteristics of the soils, particularly, the contents of clay, sand, and organic matter.

Herbicides with long residual period may increase the risk of environmental contamination. Adequate management of forage can reduce the half-life of the picloram, one of the most herbicides used in weed control. This study aims to determine the half-life of picloram, using high-performance liquid chromatography in a cultivated soil with Brachiaria brizantha trimmed or not. Brachiaria brizantha was cultivated in 60 pots filled with samples of oxisol, and 30 others were kept uncultivated with this forage. This plant was cut off close to the ground, after 60 days of emergency on 30 vessels. Picloram was applied in all of the plots. Soil samples were collected at 2, 16, 30, 44, 58, 72, 86, 120, 150, and 180 days after the application of this herbicide. These samples were air-dried and stored at − 20 °C. Picloram was extracted by HPLC/UV-Vis detector. Half-life of this herbicide was calculated using kinetics models. The mere presence of roots in treatment with signalgrass cutoff did not reduce the concentrations of this herbicide, except when the emergence of new leaves occurred. The absence of B. brizantha cultivation in areas with application of picloram increases the risk of environmental contamination and successive crops due to the half-life of this herbicide. Brachiaria brizantha reduced half-life picloram and environmental risk in pastures. The validation method is suitable for determining picloram in low concentrations in soil.

In pastures, the application of limestone is often performed after removal of the animals for proper development and establishment of regrowth. Together with this practice, the use of picloram in high concentrations for dicotyledonous weeds is common. Therefore, the evaluation of the behavior of this herbicide in these conditions is critical. The objective of this study was to determine the leaching of the picloram, in the soil with different pH and cultivated with Urochloa brizantha (signalgrass) trimmed or not. The experiment was plotted in a subdivided plot with four repetitions, where the plots were constituted by factors pH (5.3 and 6.4) and Urochloa brizantha managements (trimmed and no trimmed). The subplots were composed by depths (0 to 50 cm). The picloram was applied to the top of the columns after 65 days after emergency. A rain of intensity of 60 mm was simulated 12 h after the herbicide application. Picloram concentration was quantified by the high-performance liquid chromatography. Besides that, a control treatment was added without the presence of the signalgrass, for each substrate. The picloram was not detected in the percolated water through the columns. Picloram leached to deeper layers in the soil with pH 6.4, independently of the signalgrass management. The signalgrass reduced the leaching of the picloram, and those no-trimmed demonstrate a higher capacity to retain the herbicide in superficial layers. The liming of the soil increases the pH and reduces the amount of organic matter in the soil, which favors the leaching of picloram to the layer of 30–35 cm. Trimming of Urochloa brizantha reduces the capacity of this forage to reduce the leaching of picloram.

Author family name to be read as Silva Júnior.

Background Anaphes nitens (Girault, 1928) (Hymenoptera: Mymaridae) is an egg parasitoid used for the biological control of Gonipterus spp. in regions where this pest is present. Cold storage of host eggs is a crucial strategy in biological control programs. This study aimed to evaluate the effects of cold storage on G. platensis eggs for laboratory rearing of both the host and its parasitoid, A. nitens. Methods Gonipterus platensis eggs, aged 1 and 3 days, were stored in a refrigerator at 7 ± 1 °C for 5, 10, 20, 30, 40, and 50 days in complete darkness. After each storage period, the eggs were transferred to a biochemical oxygen demand (BOD) chamber at 25 °C and hatching rates and larval survival were assessed. To evaluate parasitoid reproduction, fresh host eggs were stored at 7 ± 1 °C for 5, 10, 15, 20, and 25 days under dark conditions and subsequently exposed to A. nitens. Parasitism rate, sex ratio, and offspring longevity were recorded. Results Results showed that 1- and 3-day-old G. platensis eggs maintained the highest viability within the first 10 days of storage, with hatching rates exceeding 50% up to 20 days post-storage. A 20-day storage period was the longest duration that did not differ significantly from the non-stored eggs (control) considering A. nitens parasitism and progeny longevity when stored host eggs were offered. Conclusion Therefore, storing host eggs for this period effectively supports colony maintenance while simultaneously facilitating parasitoid propagation.

The mycelium growth kinetics and vigor of shiitake (Lentinula edodes (Berk.) Pegler) strains LE 96/17, LE 98/51, LE 98/53, and LE 98/56 were studied under different agar medium compositions. The strains were from the mycological collection of the Módulo de Cogumelos, Faculdade de Ciências Agronômicas, Unesp-Botucatu, Brazil. Mycelium fragments from stock cultures were transferred to Petri dishes with Sawdust extract-Dextrose-Agar medium. The area of growth and vigor (density) of the mycelia were daily recorded with a digital camera, during incubation, until the complete colonization of the Petri dish. The images were analyzed by the freeware UTHSCSA ImageTool, v. 2.0, developed by the University of Texas Health Science Center, San Antonio. The kinetics of mycelium growth, as measured by the mycelium area (mm²), has as a deterministic component an exponential function of Gompertz. The vigor, as evaluated by mycelium color in gray scale, was similar for all strains, reached a maximal value between the 4th and 5th day of incubation and decreased further on. The velocity of growth of L. edodes strains was lower in enriched culture media, while vigor was higher. Digital monitoring permits a objective evaluation of the growth kinetics of L. edodes in vitro. Avaliou-se o crescimento e vigor das linhagens LE 96/17, LE 98/51, LE 98/53 e LE 98/56 de Lentinula edodes (Berk) Pegler em diferentes composições de meio de cultura. As linhagens foram provenientes da Micoteca do Módulo de Cogumelos da Faculdade de Ciências Agronômicas, Unesp, Campus de Botucatu. Os isolados foram obtidos por propagação vegetativa, pela transferência asséptica do micélio para o meio de cultura de extrato de serragem-dextrose-ágar. O crescimento e vigor do micélio foi fotografado diariamente com uma câmera digital, durante a incubação, até a colonização total da placa de Petri. As imagens foram analisadas pelo programa UTHSCSA ImageTool (freeware), versão 2.0, desenvolvido pela University of Texas Health Science Center, San Antonio, Texas. O modelo estatístico que melhor explicou a cinética de crescimento miceliano em área (mm²), das linhagens de cogumelos L. edodes, tem como componente determinístico a exponencial de uma função Gompertz. O vigor, avaliado através da cor do micélio (em escala de tons do cinza), revelou um comportamento similar entre as linhagens, com valor máximo entre o 4º e 5º dia e, em seguida apresentou declínio. Em meios de cultura mais enriquecidos, a velocidade de crescimento das linhagens de L. edodes foi menor e o vigor maior. O monitoramento digital permite uma avaliação objetiva do crescimento e vigor do L. edodes in vitro.