2013 ASHS Annual Conference

Spike wheel liquid injection systems were developed in the late 1980’s as a method for applying fertilizer post emergence with minimal root damage and soil disturbance.  The system can also be used to apply soil applied pesticides to mature plants since it can be used without damaging plant roots or causing crop injury.  Recently, the authors conducted a one year study to determine if the useful life of the insecticide Coragen could be extended by making a second, split application 26 days after seeding (DAS).  At 35 DAS, the results showed that as compared to the conventional treatment where the full rate of the insecticide was applied at sowing, use of the system increased insecticide concentration levels in lettuce plants from 10 part per million (ppm) to over 600 ppm.  Additional study is needed to validate these results.  The objectives of this research are to repeat the previous study to obtain additional data to 1) confirm that the useful life of the insecticide Coragen can be extended by making a second, post emergence application with the spike wheel system 25 DAS and 2) obtain a better understanding of the fate of the insecticide in the plant tissue over time.  Appropriate field trials will be conducted to achieve the stated objectives.  If this research shows that use of spike wheel injection systems increases the useful life of highly immobile, systemic insecticides, it will significantly increase the options growers have for managing yield limiting pests.