Effects of pesticides and plant bio-stimulants on the germination of chlamydospores and in vitro development of the nematophagous fungus Pochonia chlamydosporia

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. (C) 2013 Revista Iberoamericana de Micologia. Published by Elsevier Espana, S.L.U. All rights reserved.