Enhanced white rot control in garlic bulbil using organic-inorganic hybrid materials as coating membranes.

Organic-inorganic hybrid materials have a range of applications due to their unique properties. Their application in agriculture brings alternatives for the controlled release of nutrients in the soil, the seed coating, the transport of herbicides, and the treatment of plant diseases. The present study aimed to investigate the use of fungicides incorporated into hybrid membranes formed by synthetic hectorite (LAPONITE®) and polymers in the pre-treatment of garlic bulbils exposed to the pathogen Stromatinia cepivora, which causes white rot. The coatings were selected by a germination test, based on the bulbil sprouting index, and by a mycelial growth inhibition test, based on the percentage of mycelial growth inhibition. The chosen membranes were used to coat the bulbils for bioassays conducted in a biochemical oxygen demand incubator at 17 °C. The coated bulbils were planted in soil samples containing three different densities of Stromatinia cepivora: 0.1 g, 1.0 g, and 10 g of sclerotium per L of soil. Membranes containing 2% carboxymethyl cellulose and 2% LAPONITE® incorporated with (i) the fungicide tebuconazole (36 mg L-1) and (ii) the combination of the actives tebuconazole (36 mg L-1) and triadimenol (62 mg L-1) showed the total rate of sprouting and null indices of incidence of symptoms and mortality in its repetitions. The hybrid membranes were characterized employing several techniques, including X-ray diffraction, infrared and Raman spectroscopy, thermogravimetric analysis and differential scanning calorimetry coupled to mass spectrometry, and optical microscopy. Characterization data confirmed the presence of fungicides incorporated into the membranes. Some concentrations of fungicides were low enough not to be detected in all analyses performed, although they guaranteed a protective character to the bulbils about the fungus S. cepivora present in the soil, with a possibility of antifungal pre-treatment with a potential reduction in the concentration used.

Distribution of Dalbulus maidis (DeLong) (Hemiptera: Cicadellidae) and incidence of maize rayado fino virus and Candidatus Phytoplasma asteris in corn succession planting systems.

BACKGROUND: Corn is one of the main crops grown globally to produce food for human consumption and animal feed, including raw materials for bioenergy. Effective pest management is critical for the economic viability of corn production. The leafhopper Dalbulus maidis and the diseases transmitted by it have become relevant to corn production. Our study aimed to determine environmental parameters that affect D. maidis populations and the impacts of pathogen dispersion on corn productivity under different rotation systems and sowing seasons. RESULTS: The population density of leafhoppers found in the studied crops was low but capable of establishing the diseases and spreading them widely in the crops. The leafhopper's highest occurrence was in the corn vegetative development stage, and its population peaks were earlier in the corn off-season. The incidence of maize rayado fino virus and maize bushy stunt phytoplasma were higher in corn off-season than in the growing season. The incidence of diseases was higher in the final stages of the cultivation cycle. Yield losses were significantly higher for maize bushy stunt phytoplasma and not significant for maize rayado fino virus. CONCLUSION: Our study observed that corn's physiological stage was the main factor influencing D. maidis dynamics. The occurrence of D. maidis at low densities was sufficient to ensure the efficient transmission and dissemination of maize rayado fino virus and maize bushy stunt phytoplasma, which had a higher incidence in the reproductive stage and the corn sowed off-season. © 2023 Society of Chemical Industry.

Extracts and purified substances of Cabralea canjerana inhibit hatching and extracts of Schinus terebinthifolius kill juveniles of meloidogyne incognita

Nematicidal substances have been identified from plants and are potentially useful for the management of plant-parasitic nematodes. Cabralea canjerana, (Meliaceae) and Schinus terebinthifolius (Anacardiaceae) produce bioactive compounds during their secondary metabolism and little is known about the effect of such substances on plant-parasitic nematodes. In the present study, we assessed the effect of aqueous and ethanolic extracts of C. canjerana and S. terebinthifolius at 1% (m:v) and purified substances from C. canjerana (gedunin, ocotillone, cabraleadiol, a mixture of ocotillone + cabraleadiol and a mixture of shoreic acid + eichlerianic acid) on hatching and mortality of Meloidogyne incognita juveniles. Aqueous extracts of C. canjerana fruits and seeds reduced hatching by 70.3 to 95.7%. Aqueous extracts of S. terebinthifolius fruits killed 42.8 to 77.1% of juveniles. The purified substances of C. canjerana inhibited the hatching of M. incognita from 57 to 90% and did not increase the mortality of juveniles. Therefore, C. canjerana extracts and its purified substances reduce M. incognita hatching and aqueous extracts of S. terebinthifolius kill J2 of this nematode.

Exogenous application of salicylic acid to control coffee rust

The exogenous application of salicylic acid can induce plant resistance against pathogens. However, little is known about the potential uses of this bioregulator for controlling coffee diseases. In this study, we assessed the effect of applying salicylic acid (SA – 150 mg L-1) on the management of coffee rust (Hemileia vastatrix) in a 7-year-old coffee plantation with low crop load (651.6 kg ha-1 in 2017). For comparison, plants were sprayed with protectant fungicide (copper hydroxide – CH) and standard fungicides (SF) used by local farmers (boscalid, pyraclostrobin + epoxiconazole, and copper hydroxide). Non-treated plants were included as a negative control. Five monthly applications were performed from November 2016 to March 2017. Rust incidence and severity, defoliation, and growth of plagiotropic branches were evaluated monthly. The activity of catalase (CAT), ascorbate peroxidase (APX), superoxide dismutase (SOD) and total proteins was assessed one day after the first, third, and fifth product applications. Compared to untreated plants, SA reduced the severity and incidence of rust from 36.3 to 54.7%, while CH and SF reduced disease from 31.8 to 54.6% and from 83.8 to 88%, respectively. SA reduced defoliation by 54.1%. SA increased the concentration of CAT, APX, and SOD after the first application. However, this effect was not observed after subsequent applications. Foliar application of SA reduces the severity and incidence of coffee rust and defoliation in plants with a low crop load.

Distribution of Meloidogyne species in carrot in Brazil / Distribuição de espécies de Meloidogyne em cenoura no Brasil

ABSTRACT: Root-knot nematodes (RKN - Meloidogyne spp.) are one of the most serious threats to carrot production worldwide. In Brazil, carrots are grown throughout the year, and economic losses due to RKN are reported. Since little is known on the distribution of RKN species in carrot fields in Brazil, we collected plant and soil samples from 35 fields across six states. Based on the morphology of perineal patterns, esterase phenotypes and species-specific PCR, three Meloidogyne species were identified: 60% of the fields were infested with Meloidogyne incognita, M. javanica was reported in 42.9% of the areas, whereas M. hapla was detected in 17.1% of carrot fields. Mixed populations were reported in 20% of the areas with a predominance of M. incognita + M. javanica. The combination of morphological, biochemical, and molecular techniques is a useful approach to identify RKN species.

RESUMO: Os nematoides-das-galhas (RKN - Meloidogyne spp.) são uma das mais sérias ameaças à produção de cenoura no mundo. No Brasil, as cenouras são cultivadas ao longo do ano, e as perdas econômicas devido à RKN são frequentemente relatadas. Como pouco se sabe sobre a distribuição de espécies RKN em campos de cenoura no Brasil, coletamos amostras de plantas e solo de 35 campos em seis estados. Baseado na morfologia do padrão perineal, fenótipos de esterase e/ou PCR espécie-específica, três espécies de Meloidogyne foram identificadas: 60% dos campos estavam infestados por Meloidogyne incognita, M. javanica foi encontrada em 42,9% das áreas, enquanto M. hapla foi detectada em 17,1% dos campos de cenoura. Populações mistas foram encontradas em 20% das áreas, com predominância de M. incognita + M. javanica. A combinação de técnicas morfológicas, bioquímicas e moleculares é uma abordagem útil para identificar espécies de RKN.

Nematicidal potential of essential oils of Ageratum fastigiatum, Callistemon viminalis and Schinus terebinthifolius / Potencial nematicida de óleos essenciais de Ageratum fastigiatum, Callistemon viminalis e Schinus terebinthifolius

Some essential oils are rich in nematicidal compounds and can be used for the management of plant-parasitic nematodes. Laboratory and field studies aiming to evaluate the efficiency of this compounds are necessary. The objective of this research was to assess the nematicidal potential of essential oils from leaves of Ageratum fastigiatum and Callistemon viminalis, and green and mature fruits of Schinus terebinthifolius on the root-knot nematode Meloidogyne javanica. In laboratory, the essential oil of S. terebinthifolius green fruits reduced hatching by more than 80% and increased juvenile mortality by 300% when compared to Tween 20 + water. In the field, none of the essential oils controlled M. javanica in lettuce. In conclusion, the essential oil of S. terebinthifolius green fruits reduces the egg hatching and kills J2 of M. javanica in laboratory. In an infested field with an average of 555 J2/100 cm3 of soil, the application of the essential oils of S. terebinthifolius, C. viminalis and A. fastigiatum does not control M. javanica in lettuce.

Alguns óleos essenciais são ricos em compostos nematicidas e poderiam ser usados no manejo de fitonematoides. Estudos laboratoriais e de campo que visam avaliar a eficiência desses compostos são necessários. O objetivo desta pesquisa foi avaliar o potencial nematicida de óleos essenciais de folhas de Ageratum fastigiatum e Callistemon viminalis e frutos verdes e maduros de Schinus terebinthifolius sobre o nematoide de galhas Meloidogyne javanica. Em laboratório, o óleo essencial de frutos verdes de S. terebinthifolius reduziu mais de 80% a eclosão e aumentou em 300% a mortalidade de juvenis em comparação com Tween 20 + água. No campo, nenhum óleo essencial controlou M. javanica em alface. Em conclusão, o óleo de frutos verdes de S. terebinthifolius reduz a eclosão e mata J2 de M. javanica em laboratório. Em campo com infestação média de 555 J2/100 cm3 de solo, a aplicação dos óleos essenciais de S. terebinthifolius, C. viminalis e A. fastigiatum não controla M. javanica em alface.

Diagnostic methods for identification of root-knot nematodes species from Brazil / Métodos diagnósticos usados na identificação de espécies do nematoide das galhas do Brasil

ABSTRACT: The accurate identification of root-knot nematode (RKN) species (Meloidogyne spp.) is essential for implementing management strategies. Methods based on the morphology of adults, isozymes phenotypes and DNA analysis can be used for the diagnosis of RKN. Traditionally, RKN species are identified by the analysis of the perineal patterns and esterase phenotypes. For both procedures, mature females are required. Over the last few decades, accurate and rapid molecular techniques have been validated for RKN diagnosis, including eggs, juveniles and adults as DNA sources. Here, we emphasized the methods used for diagnosis of RKN, including emerging molecular techniques, focusing on the major species reported in Brazil.

RESUMO: A identificação acurada de espécies do nematoide das galhas (NG) (Meloidogyne spp.) é essencial para a implementação de estratégias de manejo. Métodos baseados na morfologia de adultos, fenótipos de isoenzimas e análise de DNA podem ser usados para a diagnose do NG. Tradicionalmente, as espécies de NG são identificadas pela análise do padrão perineal e fenótipos de esterase. Em ambos os procedimentos, fêmeas maduras são necessárias. Nas últimas décadas, técnicas moleculares acuradas e rápidas têm sido validadas para a diagnose de NG, incluindo ovos, juvenis e adultos como fontes de DNA. Aqui, nós destacamos os métodos usados para a diagnose de NG, incluindo técnicas moleculares emergentes, focando nas principais espécies encontradas no Brasil.

Survival of Pochonia chlamydosporia on the soil surface after different exposure intervals at ambient conditions / Supervivencia de Pochonia chlamydosporia en la superficie del suelo después de diferentes intervalos de exposición a condiciones ambientales

Background. Exposure of the nematophagous fungus Pochonia chlamydosporia to solar radiation and elevated temperatures before being incorporated into the soil can reduce its survival and efficiency as biocontrol agent. Aims. A field experiment was carried out to assess the effect of the exposure period on the viability of P. chlamydosporia applied on the soil surface. Methods. A commercial bionematicide based on P. chlamydosporia was sprayed on soil, and soil samples were collected before and at 0, 30, 60, 90, 120, and 150 min after fungal application. Relative humidity (RH), the irradiance (IR), air temperature (AT), and soil temperature (ST) were recorded. The number of P. chlamydosporia colony forming units (CFUs) was evaluated after 20 days of incubation. Results. P. chlamydosporia survival decreased over the time of exposure on the soil surface. Overall, the number of CFUs decreased by more than 90% at 150min after application. Exposure to RH ≥61%, ST and AT between 25-35°C and 19-29°C, and IR between 1172 and 2126μmol of photons m−2s−1 induced a negative exponential effect on the survival of the fungus over the time. Conclusions. Exposure to climatic conditions on the soil surface reduces P. chlamydosporia viability (AU)

Antecedentes. La exposición del hongo nematófago Pochonia chlamydosporia a la radiación solar y la temperatura elevada antes de ser incorporado al suelo puede reducir su supervivencia y eficiencia como agente de biocontrol. Objetivos. Se realizó un experimento de campo para evaluar el efecto del período de exposición a condiciones ambientales sobre la viabilidad de P. chlamydosporia en la superficie del suelo. Métodos. Se pulverizó sobre el suelo un bionematicida comercial hecho a base de P. chlamydosporia y se recogieron muestras de suelo antes y después de 0, 30, 60, 90, 120 y 150min tras la aplicación del hongo. Se registraron la humedad relativa (HR), la irradiación (IR), la temperatura del aire (TA) y la temperatura del suelo (TS). Se evaluó el número de unidades formadoras de colonias (UFC) de P. chlamydosporia después de 20 días de incubación. Resultados. La supervivencia de P. chlamydosporia disminuyó durante el tiempo de exposición en la superficie del suelo. En general, el número de UFC disminuyó en más de un 90% a los 150min después de la aplicación. La exposición a HR≥61%, TS y TA entre 25-35°C y 19-29°C, e IR entre 1.172 y 2.126μmol de fotones m−2 s−1 indujo un efecto exponencial negativo en la supervivencia del hongo. Conclusiones. La exposición a las condiciones climáticas en la superficie del suelo reduce la viabilidad de P. chlamydosporia (AU)

Survival of Pochonia chlamydosporia on the soil surface after different exposure intervals at ambient conditions.

BACKGROUND: Exposure of the nematophagous fungus Pochonia chlamydosporia to solar radiation and elevated temperatures before being incorporated into the soil can reduce its survival and efficiency as biocontrol agent. AIMS: A field experiment was carried out to assess the effect of the exposure period on the viability of P. chlamydosporia applied on the soil surface. METHODS: A commercial bionematicide based on P. chlamydosporia was sprayed on soil, and soil samples were collected before and at 0, 30, 60, 90, 120, and 150min after fungal application. Relative humidity (RH), the irradiance (IR), air temperature (AT), and soil temperature (ST) were recorded. The number of P. chlamydosporia colony forming units (CFUs) was evaluated after 20 days of incubation. RESULTS: P. chlamydosporia survival decreased over the time of exposure on the soil surface. Overall, the number of CFUs decreased by more than 90% at 150min after application. Exposure to RH ≥61%, ST and AT between 25-35°C and 19-29°C, and IR between 1172 and 2126µmol of photons m-2s-1 induced a negative exponential effect on the survival of the fungus over the time. CONCLUSIONS: Exposure to climatic conditions on the soil surface reduces P. chlamydosporia viability.

Incorporação ao solo de substrato contendo micélio e conídios de Pochonia chlamydosporia para o manejo de Meloidogyne javanica / Soil amendment with substrate containing mycelium and conidia of Pochonia chlamydosporia for the management of Meloidogyne javanica

Os clamidósporos são os principais propágulos utilizados como fonte de inóculo de Pochonia chlamydosporia em experimentos envolvendo o biocontrole do nematoide das galhas. O presente trabalho teve por objetivo avaliar o controle de Meloidogyne javanica em tomateiro por meio da aplicação ao solo de grãos de arroz colonizados pelo fungo contendo apenas micélio e conídio, sem a presença de clamidósporos. O isolado de P. chlamydosporia Pc-10 foi cultivado por 15 dias a 26°C em arroz previamente esterilizado em forno microondas. Dois experimentos foram conduzidos simultaneamente em casa de vegetação. No experimento 1, vasos de 2L de capacidade foram preenchidos com mistura solo:areia (1:1, v:v), contendo 3g kg-1 de solo de grãos de arroz colonizados pelo antagonista. No experimento 2, o fungo foi adicionado ao solo de vasos de 0,5L nas doses de 1, 5, 10, 15, 20, 25 ou 30g kg-1 de solo. Em seguida, o substrato de cada vaso foi infestado com 4.000 ovos de M. javanica e, após 15 dias, uma plântula de tomate foi transplantada. No experimento 1, a aplicação do fungo ao solo reduziu o número de galhas e de ovos do nematoide em 40% e 72,83%, respectivamente. No experimento 2, houve redução do número de ovos a partir de doses de 5g kg 1 de solo e no número de galhas, principalmente, nas doses de 25 e 30g kg-1 de solo. Conclui-se que P. chlamydosporia Pc-10 controlou M. javanica em tomateiro, mesmo quando aplicado ao solo na forma de grãos de arroz colonizados e sem a presença de clamidósporos.

Chlamydospores are the main propagules used as source of inoculum of Pochonia chlamydosporia in biocontrol experiments of root-knot nematodes. The objective of this study was to evaluate the control of Meloidogyne javanica on tomato plants by the soil application of rice grains colonized by Pochonia chlamydosporia containing just mycelium and conidia, without chlamydospores. The fungus (isolate Pc-10) was grown for 15 days at 26°C on grains of rice, previously sterilized in microwave oven. Two experiments were simultaneously carried out under greenhouse conditions. In the experiment 1, 2-L pots were filled with a soil:sand mixture (1:1, v:v) containing 3g kg-1 of soil of rice grains colonized by the antagonist. In the experiment 2, the fungus was added into the soil of 0.5L pots at the doses of 5, 10, 15, 20, 25 or 30g kg-1 of soil. The soil of each pot was infested with 4,000 eggs of M. javanica and one tomato seedling was transplanted in each pot after fifteen days. In the experiment 1, the application of the fungus into the soil reduced the number of galls and eggs of the nematode by 40% and 72.83%, respectively. In the experiment 2, it was observed the reduction of the number of eggs from the dose of 5 g kg-1 of soil and of the number of galls, particularly at the doses of 25 and 30g kg-1 of soil. As a conclusion, P. chlamydosporia controlled M. javanica on tomato plants even when applied into the soil as colonized-rice grains and without chlamydospores.

Pochonia chlamydosporia e Bacillus subtilis no controle de Meloidogyne incognita e M. javanica em mudas de tomateiro / Pochonia chlamydosporia and Bacillus subtilis on the control of Meloidogyne incognita and M. javanica in tomato seedlings

O objetivo deste estudo foi avaliar o efeito da aplicação de Pochonia chlamydosporia no solo e a microbiolização de sementes de tomateiro com Bacillus subtilis no controle de Meloidogyne incognita e M. javanica em condições de casa de vegetação. Os tratamentos foram constituídos pela incorporação no solo de 20g de milho triturado colonizado ou não pelo fungo, com ou sem microbiolização das sementes com a suspensão bacteriana (DO540 = 0,5) por 24 h. O solo dos vasos foi infestado com 5.000 ovos de M. javanica ou M. incognita. Nenhum tratamento alterou a massa da parte aérea e das raízes dos tomateiros em ambos os experimentos, tampouco reduziu o número de galhas dos nematoides aos 45 dias após o transplantio das mudas e infestação do solo. A microbiolização das sementes de tomateiro com B. subtilis reduziu em 62,6% o número de ovos de M. incognita, quando comparado com as sementes não tratadas, independentemente da aplicação do fungo. A combinação entre microbiolização de sementes com B. subtilis e a aplicação de P. chlamydosporia reduziu em mais de 80% o número de ovos de M. javanica em comparação com a adoção de apenas um dos tratamentos isoladamente.

The aim of this study was to evaluate the effect of the application of Pochonia chlamydosporia into the soil and tomato seeds soaked in Bacillus subtilis cell suspension on the control of Meloidogyne incognita and M. javanica under greenhouse conditions. The treatments were incorporation into the soil of milled corn (20 g) colonized or not by the fungus, with or without seeds treatment with bacterial suspension (OD540 = 0,5) for 24 h. The soil of each pot was infested with 5,000 eggs of M. javanica or M. incognita. Neither the biomass of tomato plants nor the number of galls were influenced by the treatments 45 days after seedlings transplanting and soil infestation in both the experiments. Seed microbiolization with B. subtilis reduced the number of eggs of M. incognita by 62.6%, in comparison to non-treated seeds, regardless of the application of the fungus. The combination of seed microbiolization with B. subtilis and application of P. chlamydosporia reduced more than 80% the number of eggs of M. javanica, when compared to each separate treatment.

Controle de Meloidogyne javanica com Pochonia chlamydosporia e esterco bovino / Control of Meloidogyne javanica with Pochonia chlamydosporia and cow manure

A aplicação conjunta de agentes de controle biológico e matéria orgânica pode potencializar o controle do nematoide das galhas em hortaliças. Desta forma, o objetivo deste estudo foi avaliar o efeito da aplicação de Pochonia chlamydosporia (Hypocreales: Clavicipitaceae) (PC) e esterco bovino na redução populacional de Meloidogyne javanica (Tylenchida: Heteroderidae) em tomateiro. Os tratamentos foram constituídos da incorporação ao solo de 20g de canjiquinha colonizada pelo fungo (PC), 20g de canjiquinha não-colonizada (CNC), 70g de esterco bovino + 20g de canjiquinha colonizada (EBPC) e apenas 70g de esterco bovino (EB). Ao solo de cada vaso foi adicionado o respectivo tratamento e 5.000 ovos de M. javanica, seguido pelo transplantio das mudas. A incorporação ao solo de EBPC, seguido de EB, aumentou a biomassa da parte aérea e das raízes de tomateiros. A maior redução no número de galhas e de ovos de M. javanica foi observada após a aplicação de EB, seguido por EBPC. Não houve diferença significativa na aplicação apenas do fungo em relação à testemunha considerando a avaliação do número de galhas e de ovos.

Concomitant application of biological control agents and organic amendment can enhance the control of the root-knot nematode on vegetables. Thus, the objective of this study was to evaluate the effect of the application of Pochonia chlamydosporia (Hypocreales: Clavicipitaceae) (PC) and cow manure on the reduction of the Meloidogyne javanica (Tylenchida: Heteroderidae) on tomato. The treatments were: 20 g of milled corn colonized by the fungus (PC), 20 g of non-colonized milled corn (NCMC), 70g of cow manure + 20g of PC-colonized milled corn (CMPC) and 70g of cow manure alone (CM). Into the soil of each pot was added the respective treatment and 5,000 eggs of M. incognita and M. javanica, separately, followed by the transplanting of the seedlings. Soil amendment with CMPC, followed by CM, increased the tomato aboveground and root system biomass. Highest reduction on the number of galls and eggs was observed after soil amendment with CM, followed by CMPC. No significant reduction on the number of galls and eggs was observed by the application of PC.

Soil amendment with chopped or ground dry leaves of six species of plants for the control of Meloidogyne javanica in tomato under greenhouse conditions / Incorporação ao solo de folhas secas picadas ou moídas de seis espécies de plantas para o controle de Meloidogyne javanica em tomateiro em casa de vegetação

Greenhouse experiments were conducted to evaluate the effect of soil amendment with chopped (1cm²) or ground (1mm sieve) dry leaves of assa-peixe (Vernonia polyanthes), lemon-grass (Cymbopogon citratus), eucalyptus (Eucalyptus citriodora), castor (Ricinus communis), mango (Mangifera indica) or neem (Azadirachta indica) for the control Meloidogyne javanica. Into the soil (Yellow red oxisol) of each pot were added leaves (5g kg-1 of soil) and 5,000 eggs of the nematode. After seven days, one tomato seedling "Santa Cruz Kada" was transplanted to each pot. The tomato root weight, galls and eggs/root system were determined 60 days after transplant. None of the soil amendments reduced gall or eggs, when applied as leaf pieces. However, all tested plant species reduced the gall number, when they were incorporated into the soil as powder, and maximum nematode suppression occurred in soil amended with neem leaves (61 percent). The amendment with ground leaves of castor, neem, eucalyptus and lemon-grass reduced the number of eggs, with maximum reduction occurring in soil amended with ground castor leaves (69 percent), evidencing that these organic amendments can be an alternative for M. javanica control in tomato. Further studies are required under field conditions to confirm the potential of these organic amendments on the control of M. javanica.

Experimentos em casa de vegetação foram conduzidos com o objetivo de avaliar o efeito da adição ao solo de folhas secas picadas (1cm²) ou trituradas (peneira de 1mm) de assa-peixe (Vernonia polyanthes), capim-limão (Cymbopogon citratus), eucalipto (Eucalyptus citriodora), mamona (Ricinus communis), manga (Mangifera indica) ou nim (Azadirachta indica) para o controle de Meloidogyne javanica. Ao solo de cada vaso (latossolo vermelho-amarelo), foram adicionadas folhas (5g kg-1 de solo) e 5.000 ovos do nematoide. Após sete dias, uma muda de tomateiro "Santa Cruz Kada" foi transplantada em cada vaso. O peso das raízes e os números de galhas e de ovos foram avaliados 60 dias após o transplantio. As folhas picadas de nenhuma planta reduziram o número de galhas e de ovos. Entretanto, as folhas de todas as plantas estudadas reduziram o número de galhas quando foram incorporadas ao solo na forma de pó e a máxima supressão foi obtida com as folhas de nim (61 por cento). A adição ao solo de folhas trituradas de mamona, nim, eucalipto e capim-cidreira reduziu o número de ovos, com redução máxima após aplicação de folhas de mamona (69 por cento), indicando que esses materiais orgânicos podem ser uma alternativa de controle de M. javanica em tomateiro. Novos estudos devem ser realizados em condições de campo para confirmar o potencial desses materiais orgânicos no controle de M. javanica.