EFFECT OF SOIL SOLARIZATION AND SIP 5561 ON HETERODERA CAROTAE AND DITYLENCHUS DIPSACI AND ON YIELD OF CARROT AND ONION

Abstract

The effectiveness of 4-8 week periods of solarization and of 10 kg a.i./ha of SIP 5561 as single or spilt application, far the control of Heterodera carotae on carrot and Ditylenchus dipsaci on onion, was investigated in Italy. These treatments were compared with 300 l/ha of DD and single and split applications of 10 kg a.i./ha of aldicarb. SIP 5561 was more effective than aldicarb in controlling H. carotae, resulting in greater yield increase. There was no difference between singIe applications in the control of D. dipsaci but aldicarb had better performance than SIP 5561 as a split application. The efficacy of soil solarization increased with the length of the mulching period far both nematode species. Only 17.5% of H. carotae eggs survived in the eight week solarized plots, resulting in suppression of carrot feeder root invasion by the nematode and greater yield increase than with aldicarb and SIP 5561. Highest mortality of H. carotae (100%) and carrot yield were achieved with DD, and this fumigant was equally effective as the other treatments against D. dipsaci.