Efectos de plaguicidas y bioestimulantes vegetales sobre la germinación de clamidosporas y el desarrollo in vitro del hongo nematófago Pochonia chlamydosporia / Effects of pesticides and plant bio-stimulants on the germination of chlamydospores and in vitro development of the nematophagous fungus Pochonia chlamydosporia

Antecedentes. Se desconocen los efectos que sobre el hongo Pochonia chlamydosporia pueden causar los plaguicidas y bioestimulantes vegetales que son usados en sistemas protegidos de producción de hortalizas. Objetivos. La efectividad de P. chlamydosporia frente a Meloidogyne spp. podría verse afectada por productos usados en sistemas protegidos de producción de hortalizas. Con el fin de evaluar cualquier potencial efecto sobre el hongo, se realizaron dos ensayos in vitro.Métodos. El efecto en la germinación de clamidosporas se evaluó en un primer ensayo, y el crecimiento micelial y la producción de clamidosporas en un segundo. Con estos resultados se determinó la compatibilidad de cada producto con el hongo. Resultados. La germinación de clamidosporas fue superior al 50% con los tratamientos control, FitoMas E, Biobras-16 y Amidor; se registraron valores menores con otros productos y algunos incluso la inhibieron completamente. El crecimiento fúngico se potenció con Biobras-16 al 106,23%, lo promovieron entre un 50-100% el control, FitoMas E y Cuproflow, y el resto de productos generó un crecimiento inferior al 50%. La producción de clamidosporas se estimuló con Cipermetrina, Benomilo, Zineb, Mitigan, Karate, FitoMas E y Amidor; con Cuproflow fue menor al 50%, y el resto la inhibió totalmente. De los productos evaluados, el 54% fueron compatibles con P. chlamydosporia, el 8% resultaron tóxicos, y el 38%, muy tóxicos. Conclusiones. Fueron compatibles con P. chlamydosporia Cipermetrina, Karate, Amidor, Benomilo, Zineb, Mitigan y FitoMas E. De ser necesaria la utilización del resto de los productos para el manejo integrado de plagas en sistemas protegidos de producción de hortalizas, se recomienda evitar el contacto directo con P. chlamydosporia (AU)

Background. The effects of pesticides and plant bio-stimulants used in protected vegetable production systems on the fungus Pochonia chlamydosporia are unknown. Aims. The effectiveness of P. chlamydosporia against Meloidogyne spp. could be affected by products used in protected vegetable production systems. Two in vitro assays were carried out to evaluate any potential effect that pesticides and bio-stimulants often used in these systems could have on the fungus. Methods. The effect on chlamydospore germination was evaluated in a first assay, and mycelia growth and sporulation in a second. With these results, the compatibility of each product with the fungus was determined. Results. Chlamydospores germination was over 50% with the control, FitoMas E, Biobras-16 and Amidor. Lower results were observed with other products, with some of them even inhibiting germination completely. Fungal growth was potentiated by Biobras-16 to 106.23%, promoted up to 50-100% by the control, FitoMas E and Cuproflow, and was below 50% with the rest of the products.Cipermetrina, Benomilo, Zineb, Mitigan, Karate, FitoMas E and Amidor promoted fungal sporulation, which was below 50% with Cuproflow and completely inhibited by the other products. Fifty-four percent of the products evaluated were compatible with P. chlamydosporia, while 8% were toxic and 38%, very toxic. Conclusions. Cipermetrina, Karate, Amidor, Benomilo, Zineb, Mitigan and FitoMas E were compatible with P. chlamydosporia. If it is necessary to use any of the other products for integrated pest management in protected vegetable production systems, it is recommended to avoid direct contact with P. chlamydosporia (AU)

Calagem e adubação orgânica na produção de biomassa e óleo essencial em Lippia citriodora (Kunth) / Liming and organic fertilization on Lippia citriodora (Kunth) phytomass and essential oil production

O presente trabalho objetivou avaliar a calagem e adubação orgânica na produção de biomassa e óleo essencial em Lippia citriodora Kunth. O delineamento experimental utilizado constou de fatorial 7 x 2, sendo sete tratamentos (testemunha; adição de sulfato de Ca e Mg; calcário dolomítico; silicato de Ca e Mg; sulfato de Ca e Mg + esterco de curral; calcário dolomítico + esterco de curral; silicato de Ca e Mg + esterco de curral) e duas épocas de colheita, com quatro repetições, inteiramente casualizado (DIC). Verificou-se que a correção do solo mostrou-se prática necessária para o desenvolvimento da Lippia citriodora. Independentemente da época de colheita, a produção de massa fresca e seca foi maior com a aplicação do esterco de curral (32 t ha-1), no entanto, isso não refletiu em maior rendimento de óleo essencial.

The present work aimed to evaluate the effect of liming and bovine fertilization on Lippia citriodora Kunth phytomass and essential oil production. The experimental design was completely randomized with seven treatments (control; Ca and Mg sulfate; limestone; Ca and Mg silicate; Ca and Mg sulfate + manure; limestone + manure; Ca and Mg silicate + manure) and two harvest seasons, with four replicates. Soil adjustment showed to be a necessary procedure for Lippia citriodora development. Independently of the harvest season, fresh and dry matter yields were higher under treatments with bovine manure (32 t ha-1); however, no effect of treatments was observed on essential oil concentration.