Results of national weed surveys in arable land during the past 50 years in Hungary

The change of political regime in Hungary in 1990 has caused significant mo difications in the conditions of agricultural production and businesses. At present family (small) farming systems are account for some 25-30% of the cropping area while 2-3% of the total area is uncultivated. This situation has influenced the weed population of cultivated land; both cover and the d istribution of some weed species have considerably increased. These results were demonstrated in an earlier publication (Toth el al., 1997) which cons idered the results of four surveys conducted between 1950 and 1997 in winte r wheat and maize in which 202 locations were surveyed. The primary aim of our work has been to help Hungarian farmers develop regional weed managemen t programmes suited to local weed populations. In order to produce manageme nt programmes that will take account of local conditions we have begun to e xamine the national weed survey data in detail, paying particular attention to variations in soil type. Results are presented for three different agri cultural regions that inculde 17 soil types or sub-types.