Effects of organic, non organic fertilizers, and selected novel pesticides on survival of two Entomopathogenic nematodes.

Abstract

In this study, the effect of six macro fertilizers i.e. urea, ammonium sulfate, ammonium nitrate, NPK, NP & DAP, and three micro elements i.e. Zn, Mn, and Fe at different concentrations as well as eight novel pesticides, thiamethoxam, spinetoram, azoxystrobin, chlorfenpyr, chlorantraniliprole, novaluron, lambda-cyhalothrin and avaunt at field recommended rate on two entomopathogenic nematodes (EPNs): Steinernema carpocapsae and Heterorhabditis bacteriophora were determined under laboratory conditions. The obtained results reported that S. carpocapsae was more tolerant to NPK; NP and DAP macro fertilizers than H. bacteriophora, showed the lowest mortality percentages (12.63, 9.47and12.63%), (15.79, 13.68 and 31.58%) and (20.21, 30.85 and 34.04%) at three tested concentrations (1g/liter water, 5g/liter water and10g/liter water), respectively. All tested micro fertilizers (Zn, Mn, and Fe) were lethal for two EPNs and induced 94.85, 100, 100 mortality % after five days of exposure. The morality percent increased as the concentration of fertilizers increased. With respect to tested pesticides, the mortality percentages of two EPN were ranged between 2.67-23.67% for S. carpocapsae and 3.33-18.33% for H. bacteriophora after five days of exposure. The tested macro fertilizers such as DAP, NP and NPK can be used safely at tested concentrations (5-10 g/ liter water) with Steinernema carpocapsae. All tested macro fertilizers cannot be used with Heterorhabditis bacteriophora. All micro fertilizers could be used with two EPNs. All tested pesticides can be successfully used for integrated plant protection systems. EPNs are tolerant to the tested pesticides and the tank-mix application is possible in most compounds except Lambda cyhalothrin which significantly reduced the virulence of tested nematodes.