In Romania, maize crop is the main cereal occupying 4 millions hectares from 10 millions arable lands. From those about 500000 to 700000 ha are infested with Sorghum halepense L., a weed which produce high damages in maize agro ecosystems (85-90%). The herbology papers pointed long time ago the presence of this weed in our country [Anghel, Ionescu-Şişeşti, Şarpe etc.] especially in the southern parts of Romania. The infested area extended permanently in the same time with the increasing number of weeds per square meter. This invasive weed is, without doubt, the most damaging species in the south-west part of the country. in order to achieve a better approach of weed infestation level of maize agroecosystems with Sorghum halepense from Timis county, we used the quantitative and numerical determination method.  The observations were made in experimental years 2006-2009, in 16 locations. This method relies on counting the number of plants present in 1 square meter, methodology used in mapping works in Romania [Chirilă, 1989]. The assessments allow us to put together in a master table the obtained results and the location along with the maximal constant level. Further than that, the mapping allows us to realize maps wit the locations in where the Sorgum halepense was present and its density in maize crop. For showing down the mean of the infestation level we used the colours code presented in the work “the weeds from agricultural crop mapping” [Chirilă, 1989]. We concluded after four observation years that the Sorgum halepense species develop themselves very good on chernozem and aluvisoils causing a significant yield loses even total loses.

Johnson grass; mapping; corn

Presentation: oral