The paper is based on data collected in 112 winter wheat parcels and 97 corn parcels, in 2006 and 2007, according to the Göttingen method. The sampled parcels are mostly situated in plain area of the Timiş County. We divided weed species in significant and non-significant ones, the last ones with a minor contribution to the weeding degree. We consider as diversity parameters the species number per parcel (significant, non-significant, minimal, maximal, average values for each year) and the Shannon-Wiener index. In winter wheat fields we found an average number of weed species per parcels of 26.5 (in 2006) and 23.1 (in 2007), while in corn fields the values were of 22.2 (2006) and 17.5 (2007). The average number of non-significant weed species per parcel per year ranks from 5.5 (corn, 2007) to 7.7 (corn, 2006). The Shannon-Wiener index values ranks from 2.53 (corn, 2007) to 3.27 (winter wheat, 2007). We didn’t find strong correlations between the total weed species number per parcel and the corresponding Shannon-Wiener index values. We explain this by the variety of conditions and cultural techniques.

weeds; specific diversity; Shannon-Wiener index; winter wheat; corn; Timiş county

Presentation: oral