STUDY OF WEED FLORA OF MAIZE CROPS IN THE NISAVA DISTRICT

The damage from the present weeds in maize crop is shown by the reduction of yield in almost every year and their suppression is completely economically justified. The right selection of herbicides mostly depends on the presence of dominant weed species and the time of application. The paper presents the distribution and existence of economically harmful, invasive and quarantine weed species (Abutilon theophrasti, Agropyrum repens, Amaranthus retroflexus, Ambrosia artemisiifolia, Capsela bursa-pastoris, Chenopodium album, Chenopodium hybridum, Cirsium arvense, Convolvulus arvensis, Datura stramonium, Avena fatua, Calystegia sepium …) on ten locations of maize crops in the Nisava district. Estimation of the species presence was done in two shootings (May and August) on scale 1-4 (1 - species appears individually and occupy up to 5% of the surface, 2 - appears and occupies 5-25% of the surface, 3 - appears often and occupies 25-50% of the surface, 4 - the species prevails over the cultivated plant and occupies over 50% of the surface).