Manejo integrado de plagas en legumbres almacenadas mediante el uso de atmósferas modificadas y de control biológico
- Autores: Rey David Iturralde García
- Directores de la Tesis: Jordi Riudavets (dir. tes.), Cristina Castañé (codir. tes.)
- Lectura: En la Universitat Politècnica de Catalunya (UPC) ( España ) en 2020
- Idioma: español
- Materias:
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- Resumen
Spain is one of the main producing countries of chickpeas and beans in Europe and is also the main importer. Nowadays, pest control is mainly based on the application of phosphine. However, the risks on human health and on the environment of phosphine, demands to implement alternatives for pest control. The present thesis was carried out to improve the application of modified atmospheres (MA) and biological control (BC) as alternatives for the control of Callosobruchus chinensis, Rhyzopertha dominica, Acanthoscelides obtectus and Zabrotes subfasciatus in stored chickpeas and beans.
MA are used in gas-tight packages, and sorption by the commodity produces a vacuum effect in the package. The first two chapters of this thesis are devoted to evaluate CO2 sorption by chickpeas packed with MA, and the effect of CO2 on the mortality of R. dominica in packaged infested chickpeas with three MA at different exposure times. Trials to determine the CO2 sorption by chickpeas were conducted in rigid plastic containers with three filling ratios. While, two extreme cases of filling ratios were compared to evaluate sorption effect on the mortality of R. dominica. The maximum sorption was obtained with the lower filling ratio and sorption decreased with the decline in the CO2 concentration. The time to reach the equilibrium sorption depended on the CO2 concentration and the filling ratio. The vacuum effect produced by sorption resulted in a negative pressure that increased with the increase in the filling ratio and the CO2 concentration. The exposure time to reach 50% mortality of R. dominica (LT50) was estimated at a low filling ratio. The mortality of eggs and adult of R. dominica decrease at high filling ratio, while for the larvae and pupae the susceptibility remained at the exposure time estimated of LT50.
To implement BC in legumes, the third and fourth chapter of this thesis was focused on the evaluation of various species of predatory mites and parasitoid wasps on the control of C. chinensis in chickpeas and of A. obtectus and Z. subfasciatus in beans. In chickpeas the results obtained indicate that while Amblyseius swirskii preyed on the weevil eggs Blattisocius tarsalis did not. However, Anisopteromalus calandrae and Lariophagus distinguendus were very effective against C. chinensis larval population, and were able to parasitize the host at depths until 150 cm. A. calandrae was effective at reducing the bruchid population at different parasitoid-to-host ratios tested. Moreover, A. calandrae efficiently reduced C. chinensis populations when released in 25-kg commercial bags of chickpeas in simulated warehouse conditions. In beans, B. tarsalis and A. swirskii were able to prey on A. obtectus eggs, reducing the bruchid population. Anisopteromalus calandrae and L. distinguendus were effective at suppressing bruchid populations, but when A. calandrae was combined with B. tarsalis the control efficacy was substantially improved.
