Composition, structure, and level of weed diversity in oil palm plantation in Pagar Merbau Village, Tanjung Morawa, Indonesia

Weed vegetation growth affects the and production of oil palm plants. To control weeds in plantation land, especially by using herbicides or bioherbicides, weed analysis is needed. This research was conducted to determine composition, structure, level diversity plantations owned community Pagar Merbau village, Tanjung Morawa District. The method used a descriptive with sampling technique done porposive sampling. results showed that found were 7 families, 10 species, 3153 individuals. species were: Clidemia hirta, Borreria alata, Mimosa invisa, Setaria barbata, Ageratum conyzoides, Paspalum conjugatum, Ottochloa nodosa, Cyclosorus aridus, Calopogonium mucudoines, Ophioglossum reticulatum. nodosa type has highest importance value index 66.52% (1323 individuals) barbata lowest important 1.00% (4 individuals). this moderate category (H '= 1.3741). system be carried out must consider dosage types bioherbicides so it does not have potential reduce grass broadleaf weeds.