Effect of sowing date and insecticide application against European corn borer (Lepidoptera: Crambidae) on fumonisin contamination in maize kernels

Management of fumonisin contamination in maize kernels through the timing of insecticide application against the European corn borerOstrinia nubilalisHübner

“…At present, pyrethroid treatment applied after the first generation ECB flight peak is normal practice for farmers in Northern Italy, since they usually spray when adult catches decline, after the peak has been reached. In our experiments, the efficacy in reducing fumonisin contamination observed with pyrethroid application at approximately 7 days after the ECB flight peak was between 26 and 54%, confirming values observed in previous studies (Alma et al 2005;Saladini et al 2008;Blandino et al 2008a). Considering the greater efficacy in reducing fumonisin content observed in this study with earlier applications, it can be stated that the timing of chemical treatment needs to be reconsidered.…”

“…Several studies have established that the control of ECB clearly affects fumonisin levels in maize kernel at harvest. This has been demonstrated through the use of methods such as insecticide treatment (Blandino et al 2008a;Folcher et al 2009), biological control with parasitoids (Dowd 2000) and genetic control involving genetically modified Bacillus thuringiensis (GM Bt) technology Papst et al 2005). Aerial applications of spray formulations of Bt appear less interesting since Bt toxins show a low persistence and are susceptible to rapid degradation in sunlight (Tamez Guerra et al 1996).…”

“…Despite the vast literature database on the biology and biological control of O. nubilalis, the use of chemical insecticides is still the main method for ECB management, where Bt maize cultivation is not permitted (Saladini et al 2008). Insecticide treatment against second generation larvae of ECB plays an increasing role in maize crop practices, and several insecticides, mainly synthetic pyrethroids, are currently labelled for ECB control in maize and generally applied after the first generation flight peak of adults (Blandino et al 2008a). On the other hand, insecticide treatments can not always guarantee maize production with contamination levels of fumonisins below the thresholds (Saladini et al 2008).…”

“…A scale of 1 to 7 was used in which each numerical value corresponds to a percentage interval of surfaces exhibiting visible symptoms of the disease according to the following (Blandino et al 2008a). ECB damage severity and ear rot severity scores were converted to percentage of ears exhibiting symptoms and each score was replaced with the midpoint of the interval.…”

“…ECB damage severity was calculated as the percentage of kernels per ear with injuries due to larval activity. A scale of 1 to 7 was used, in which each numerical value corresponds to a percentage interval of surfaces exhibiting visible kernel damage due to larval activity according to the following schedule: 1 ¼ no injuries, 2 ¼ 1-5%, 3 ¼ 6-10%; 4 ¼ 11-20%, 5 ¼ 21-35%, 6 ¼ 35-60%, 7460% (Blandino et al 2008a).…”