Eclipta prostrata (L.) L. as a new weed of rice fields in Sardinia (Italy)

The spread off, prostrata in Sardinia can be dated to very recent times and it is related to the expansion of rice cultivation. The weed finds refuge in the raised banks of artificial channels and in the wet areas surrounding the rice fields. Its establishment is enhanced by inadequate and/or inefficient cleaning of the channels. The weed produces a great amount of seeds and, thus, control techniques should not be limited only to cultivation areas. The spread of E. prostrata in Sardinia has been encouraged by neglect. Since the first records, in 1985, the plant has actually invaded almost all Sardinian rice fields. The colonisation process starts from the raised banks of channels. It invades the rice field during the dry phase of cultivation, shortly before harvesting, especially when other weeds have been eliminated by herbicides. Apart from competing directly with the rice plants, the alien is very harmful because its sprouts clog the operating mechanisms of the harvesting machines.