Resumen

For protecting potato tubers from the potato tuber moth (PTM) infestation during storage, different concentrations of ten natural plant oils and three commercial monoterpnes were tested, some as fumigants or dusts against adults or dusts against neonate larvae, while others as sprays on the gunny sacks in which potato tubers were stored. Tuber damage indices as well as persistence indices for tested materials were assessed. Vapors of Cymbopogon citratus, Myristica fragrans (nutmag), Mentha citrata and a-Ionone (monoterpene) caused a highly significant reductions in the life span of exposed moths as well as in new adult offsprings. Other tested oils as Cinnamonium zeylanicum, Myristica. fragrans (Mace) and Pelargonium graveolens caused a insignificant effect. There was no significant effect of the tested vapors on egg hatchability, except in case of oils of C. citratus, M. fragrans (nutmag) and M. tragrans(Mace oil) which caused high reduction in egg hatchability. According to the values of damage indices, the most effective oil vapors were arranged ascendingly as follows: Myristica (nutmag) < Cymbopogon < Mentha < a – Ionone. Dusting potato tubers with 1% conc., (mixed with talcum powder) of Myristica, Mentha, Cymbopogons oils and a-Ionone (monoterpene) caused high reduction in egg deposition, adult emergence as well as percentage of penetrated larvae of PTM. According to their damage indices, Cymbopogon and Ü-Ionone were the most protective oils, followed by Myristica and Mentha. Spraying gunnysacks with 1% conc., of the aforementioned natural oils separately elicited high reduction in PTM progeny; while their combinations did not elicit any significant synergistic effect. According to their tuber damage indices, it was found that Cymbopogon oil alone or mixed with Myristica oil showed the best protective effect, followed by Myristica oil alone and Mentha oil mixed with Cymbopogon oil. Assessment of the persistence index of various tested materials during storage indicated that: Vapors of Cymbopogon and Myristica (nutmag) gave the best protection from PTM infestation during storage (for 20 days). Dusting potato tubers with plant oil of Cymbopogon (mixed with talcum powder) gave the best protection during storage (for 15 days). Spraying gunnysacks with natural plant oils of Cymbopogon and Myristica, separately or mixed elicited the best protection from infestation by PTM during storage up to 20 days.

Palabras clave: Potato tuber moth Phthorimaea operculella natural oiles terpenes different application treatments.

2018-10-24   |   103 visitas   |   Evalua este artículo 0 valoraciones

Vol. 6 Núm.1. Enero 2014 Pags. 45-59 Ecologia Balkanica 2014; 6(1)