Prospects for plant defence activators and biocontrol in IPM - Concepts and lessons learnt so far

Abstract
There is an urgent need to develop new interventions to manage pests and diseases as the availability of conventional pesticides is increasingly restricted by evolution of pesticide resistance and changes in legislation. We investigated â-aminobutyric acid (BABA), Jasmonic acid (JA) and fructose as possible plant defence activators against grey mould disease, Botrytis cinerea, and the root knot nematode, Meloidogyne incognita. We also tested Trichogramma achaeae parasitoid wasps and an antifeedant plant extract for biocontrol of the invasive tomato leafminer, Tuta absoluta. BABA and JA were found to enhance resistance to B. cinerea but neither treatment provided complete protection and the efficacy of treatment varied over time with BABA being more durable than JA. Efficacy was partly dependent on tomato cultivar, with some cultivars responding better to BABA treatment than others. Furthermore, treatment of tomato with BABA, JA and fructose led to partial suppression of M. incognita egg laying. Biocontrol agent, T. achaeae, performance against T. absoluta could be enhanced by adjusting the rearing conditions. Both attack rate and longevity were improved by rearing the parasitoids on T. achaeae rather than on other insects. Finally, Ajuga chamaepitys extract was shown to have significant antifeedant activity against T. absoluta. Taken together, our findings suggest that there are potential new solutions for protection of crops but they are more complicated to deploy, more variable and require more biological knowledge than conventional pesticides. They may also not provide the same level of protection as pesticides and therefore may need to be used in combination with other tactics in IPM strategies.
Year
2017
Category
Refereed journal
Output Tags
WP6.4 - Prevention and control of important diseases of plants