Compatibility ofSteinernema feltiae(Nematoda: Steinernematidae) with Pesticides and Plant Growth Regulators Used in Glasshouse Plant Production

Abstract

Compatibility of the entomopathogenic nematode, Steinernema feltiae Filipjev with 17 different pesticides and three plant growth regulators, recommended for drench application in glasshouses, was evaluated. The products tested were two biofungicides, Streptomyces griseoviridis (Mycostop) and Trichoderma harzianum (Rootshield), nine chemical fungicides, iprodione (Chipco 26GT), thiophanate-methyl (Fungo Flo 4.5F), azoxystrobin (Heritage), fludioxonil (Medallion), flutolanil (Prostar), mefenoxam (SudDue Maxx 21.3ME), PCNB (Terraclor 400F), triflumizole (Terraguard), and etridiazole (Terrazole), two bioinsecticides, spinosad (Conserve SC) and Bacillus thuringiensis subsp. israelensis (Gnatrol), three chemical insecticides diflubenzuron (Adept IGR), acephate (Orthene), and fenoxycarb (Precision 25WP), one herbicide, clethodim (Envoy) and three plant growth regulators, ancymidol (ARest), paclobutrazol (Bonzi), and uniconazole-P (Sumagic). Infective juvenile nematodes were exposed to each product at the highest recommended concentration in 24-well plates at 228C. Observations on the viability and infectivity of the nematodes were made at 4, 24, and 72 h after exposure. We found that S. feltiae is compatible with the majority of the tested formulations with no loss in viability and infectivity up to 24 h of exposure. The viability of S. feltiae was more than 80% in all the products even after 72 h of exposure. Three pesticide formulations, Prostar (1%), Gnatrol (9%), and Terrazole (10%) decreased the viability of S. feltiae significantly within 24 h compared to the controls. However, during the 24 to 72 hr incubation period, eight pesticides affected the viability of S. feltiae with Gnatrol and Terrazole causing the highest decrease (17% and 15%, respectively). Only Terrazole decreased the infectivity of S. feltiae to Galleria mellonella larvae compared to the control when tested after 24 h exposure. At 72 hr, Orthene and Terrazole caused significant decrease in the infectivity of S. feltiae (10% and 15%, respectively) and Gnatrol caused a significant increase in the infectivity (11%) compared to the Correspondence to: P. S. Grewal. Permanent address of E.A.B. De Nardo: Brazilian Agricultural Corporation Á/ EMBRAPA MEIO AMBIENTE, Rod. SP.-340, Downloaded by [Colorado College] at 17:47 31 March 2015control. Our results suggest that S. feltiae can be tank-mixed and applied in combination with all the tested formulations, except Terrazole.

The influence of insecticides on the viability of entomopathogenic nematodes (Rhabditida: Steinernematidae and Heterorhabditidae) under laboratory conditions

“…EPN were reared and prepared as described elsewhere. , 9a – Six EPN strains were included in the experiment. The commercial preparations Nemasys (a.i.…”

“…These nematodes can be used as biological control agents to suppress a variety of economically important insect pests –. EPN are being used more widely in crop‐protection strategies and are therefore likely to come into contact with chemical pesticides, fertilizers and soil amendments . It is often desirable to know whether a pesticide can be tank‐mixed or applied simultaneously with another pesticide to save time and money and for compatibility with integrated pest management (IPM) and integrated production (IP) systems …”

“…Some research has already been carried out on the effect of pesticides on the EPN , . Work on the combination of EPN and adjuvants shows that even short exposure to some adjuvants can decrease the viability of EPN .…”

“…For convenience, nematodes may also be tank‐mixed with other control agents, that is, combined in the tank of the application equipment, thus increasing the chances of interactions due to the higher concentration of both agents. Nematodes may be combined with other control agents to achieve better control of a single pest through additive or, preferably, synergistic effects on pest mortality , . Nematode–insecticide combinations in tank mixes might offer a cost‐effective alternative to foliar IPM systems.…”

Entomopathogenic Nematodes (Nematoda: Rhabditida) in Slovenia: From Tabula Rasa to Implementation into Crop Production Systems

“…EPN infective juveniles (IJs) can tolerate short-term exposure (2-24 hrs.) to many chemical and biological insecticides, fungicides, herbicides, fertilizers, and growth regulators, and can thus be tank-mixed and applied together (Koppenhöfer et al 2002;De Nardo and Grewal 2003). Nematode-chemicals combinations in tank-mixes could offer a cost-effective alternative to foliar integrated pest management (IPM) systems.…”