Physical weed control on hard surfaces in urban areas: first results obtained in Central Italy

In order to promote the reduction or the complete elimination of herbicides in Italian urban weed management, some experimental tests on physical weed control on hard surfaces were carried out in 2004 by CIRAA “E. Avanzi” of the University of Pisa in the town of Livorno (Tuscany – Central Italy). Two weed management systems (physical and chemical) were compared on three types of hard surface (packed earth surface, gravel surface, and porphyry blocks). The physical treatments were carried out using a knapsack flaming machine, while for the chemical treatments the herbicide adopted was a commercial formulation containing 31% of glyphosate. Thermal treatment was relevantly faster in the manifestation of its effect, reducing the weed canopy of about 50% ten days after treatment (DAT). No weed canopy was found in glyphosatetreated plots 45 DAT, and these areas were also subsequently characterized by a higher level of weed re-colonization. Flaming, on the contrary, allowed a more constant weed control during the experimental season and resulted in a very low final surface weed cover. After this experiment, in the three years period 2006-2008 other two experiments on urban weed control were planned and are actually carried out in the cities of Livorno and Pisa, in order to compare flaming with chemical and mechanical (mowing) systems. Preliminary results show that areas following chemical and mechanical treatments were characterized by a multispecific weed canopy, while flame-treated areas showed less weed cover and a lower species richness. In these experiments, a prototype of self-propelled flaming machine, projected and built at the University of Pisa, has been also used since October 2006 onwards.