PRELIMINARY OBSERVATIONS ON THE EFFECTS OF ADDING ETHIOFENCARB TO THE RECIRCULATING NUTRIENT SOLUTION OF NON-SOIL GROWN ROSE

Preliminary trials were carried out to evaluate the effect on aphids of a systemic insecticide, ethiofencarb, authorized in Italy for use on rose. An experimental rose cultivation technique with recovery and re-utilization of drainage water was adopted, and ethiofencarb was added to the recirculating nutrient solution. Application of ethiofencarb during spring and summer at 138 ppm concentration of active ingredients achieved good containment of aphids, resulting in colony mortality ranging from 77.3 % to 100 %. In contrast, autumn application showed marked reduction in effectiveness, with mortality ranging only from 11.9 to 18.3 %, despite administration of higher concentrations (230 ppm and 368 ppm).

These preliminary observations, together with the chemical characteristics of ethiofencarb (low vapor pressure, acceptable toxicologic profile, good systemia) indicate that it should prove possible to use the product successfully on ornamental plants in recirculating cultivation systems. In a broader perspective, results obtained suggest that chemical plant protection substances applied at root level in non-soil cultivation may not be completely effective against certain sucking pests, on account of numerous factors such as climatic zone, season, type of insects.