Effect of plant growth promoting rhizobacteria, humic fertilizer, vermicompost and essential oil from pennyroyal on tomato leaf miner population

Mohamadi, Poune (2017) Effect of plant growth promoting rhizobacteria, humic fertilizer, vermicompost and essential oil from pennyroyal on tomato leaf miner population. Doctoral thesis, university of Mohaghegh Ardabili.

Text (تأثیر ریزوباکتری¬های محرک رشد گیاه، کود هیومیک، ورمی¬کمپوست و اسانس گیاه پونه روی جمعیت شب¬پره مینوز گوجه¬فرنگی) Poune Mohamadi.pdf Download (590kB)

Abstract

The tomato leafminer, Tuta absoluta (Meyrick) is a devastating pest of tomato worldwide. In this study, effects of tomato plants treated with vermicompost (20, 40 and 60%), humic fertilizer (2, 4 and 6 g/Kg soil), plant growth promoting rhizobacteria (Pseudomonas fluorescens and Bacillus subtilis) and control were investigated on the life table parameters of T. absoluta in a growth chamber at 25 ± 1° C, 65 ± 5% RH, and 16:8 (L: D) h. The lowest values of net reproductive rate (R0), intrinsic rate of natural increase (rm) and finite rate of increase (λ) were obtained on 2 g/Kg humic fertilizer and 40% vermicompost. Furthermore, T. absoluta had the longest mean generation time (T) and doubling time (DT) on 2 g/Kg humic fertilizer treatment. Results showed that humic fertilizer (2 g/Kg) and vermicompost (40%) treatments reduced T. absoluta populations on tomato plants as well as, improved growth parameters of tomato seedlings. Therefore further experiments were conducted to determine life table parameters of Trichogramma brassicae Bezdenko on T. absoluta eggs reared in tomato plant with vermicompost (40%), humic fertilizer (2 g/kg) and control treatments. Significant differences were found for immature life period and total fecundity of T. brassicae on the treatments. The highest values of R0, rm and λ were recorded for T. brassicae developed on T. absoluta eggs on 2 g/kg humic fertilizer. Furthermore, T. brassicae had the shortest T and DT on 2 g/kg humic fertilizer and 40% vermicompost treatments. Humic fertilizer and vermicompost positively affected population growth parameters of T. brassicae on eggs of T. absoluta. In the other experiments, fumigant toxicity of essential oil extracted from Mentha pulegium was tested against the eggs and second-instar larvae of T. absoluta. Results showed that essential oil from M. pulegium was very toxic towards T. absoluta. Mortality of eggs at different tested doses (0.02 to 0.1 µl/L air) was found to be 12% to 92%. The doses of 0.02 to 0.3 µl/L air caused 11.36% to 93.18% mortality of larvae. The LC50 was 0.044 and 0.066 and LC90 was 0.099 and 0.274 µl/L air for eggs and larvae of T. absoluta, respectively.

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