Tavakkoli-Korghond, G. (2022) Biological effects of nano-metal oxides on saffron corm mite Rhizoglyphus robini (Astigmata: Acaridae) and their side effects on predator mite Gaeolaelaps sp. Doctoral thesis, university of zabol.
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Biological effects of nano-metal oxides on saffron corm mite Rhizoglyphus robini Astigmata Acaridae and their side effects on predator mite Gaeolaelaps sp.pdf Download (171kB) | Preview |
Abstract
The saffron corm mite, commonly found in all the cultivated saffron producing areas could decrease saffron economic value. Newly, Metal oxide Nanoparticles have been introduced as novel pesticides Due to the capability and versatility, they are important in reducing the use of pesticides. This study was conducted as an effective and environmentally-friendly method to control the growth of saffron corm mite. The lethal and sublethal effects of metal oxide nanoparticles (MNPs) including Copper Oxides (CuO), Magnesium Oxide (MgO), Zinc Oxide (ZnO), Titanium dioxide (TiO2), and Iron Oxide (Fe3O4) which their lethal concentrations ranged between 159.2 and 1036.4 mg L-1 were studied on R. robini adult females. The contact effect of the tested MNPs was evaluated using the corm dip bioassay method. Bioassays showed that the LC50 contact toxicity of the CuO treatment (229.1 mg L-1) was higher than other MNPs. To assess the sublethal effects of the MNPs, adult females were exposed to the LC25 concentration of MNPs, and life-table parameters of the surviving bulb mite were investigated. The exposure to sublethal concentrations of the tested MNPs prolonged the egg duration, larval period, and nymphal period significantly when compared to the control mites (P<0.05). Compared to other MNPs or control mite, nano-MgO and nano-TiO2 led to the longest duration of the total immature stages (11.32 and 11.32, respectively). The net reproductive rate (R0), the intrinsic rate of increase (r), the finite rate of increase (λ), and the generation time (T) were significantly different between control and MNP treatments. The population exposed to ZnO, MgO, and TiO2 had a much lower r value (0.164, 0.164, and 0.171 d-1, respectively) compared to the control population (0.231 d-1) and those exposed to Fe3O4- and CuO (0.180 and 0.176 d-1, respectively). Also, discover simple and low-cost innovative mass rearing techniques and use the capacities of Gaeolaelaps aculeifer to control soil pests have highly importance. For mass production of this predatory soil mite, three growth environments were evaluated. Saffron corms and layered potatoes and the mixture of “cocopeat+perlite and saffron chaff” was used. The results showed that the G. aculeifer population was increased within 30 days, up to 27-fold gradually. This method gives saffron growers the choice to improve biological control of bulb mites in saffron fields. Our findings in evaluation of the sublethal effects of ZnO-NPs (313.9 mg L-1) and CuO-NPs (229.1 mg L-1) on the life table and predation rate of G. aculeifer, showed that the treatments significantly prolonged the duration of G. aculeifer immature stages. Relative to the control, exposure to ZnO-NPs increased the longevity of female adults by 3.7 days (P<0.05). However, we observed that CuO-NP and ZnO-NP had no significant effect on the GRR, R0, r, and λ, but ZnO-NP caused a significant increase in the mean generation time (T) (P<0.05). In comparison to control predators, there was a significant reduction in the predation rate when G. aculeifer was offered prey previously exposed to ZnO-NPs and CuO-NPs. We concluded that ZnO-NP and CuO-NP are marginally compatible with the use of G. aculeifer in the integrated management programs against R. robini.
| Item Type: | Thesis (Doctoral) |
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| Uncontrolled Keywords: | Fecundity, Integrated pest management, Saffron, Nanopesticides, Toxicity, Bulb Mite |
| Subjects: | S Agriculture > SB Plant culture |
| Depositing User: | Mrs najmeh khajeh |
| Date Deposited: | 26 Sep 2023 05:24 |
| Last Modified: | 26 Sep 2023 05:24 |
| URI: | http://eprints.uoz.ac.ir/id/eprint/3379 |
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