Agriculture & Food, Volume 10, 2022

Abstract: Potato (Solanum tuberosum L.) is considered to be one of the most competed crop by weeds. They may cause great losses, reducing the yield by 20-35%, consume large amounts of water and nutrients, decrease the effectiveness of treatments against diseases and pests and mechanized harvesting becomes difficult or impossible. The observations and assessments carried out aimed at deciding the problem weeds in the potato crop against which prevention and control measures must be effectively applied. The research targeted the monitoring and mapping of weeds in potato crops in Dâmbovița, Prahova and Călărași counties, in Romania. 30 determinations per hectare were conducted during 2020-2021, using the metric frame and the observations focused on density (number of plants/m2), participation (% in which each species is involved in the whole weed infestation), frequency (% in which each species was found in the observation points), class (pteridophytes, monocotyledonous, dicotyledonous) and the life span of each species (ephemeral, annual, biennial, weeds that can overwinter, perennials). The results obtained marked that the problem weeds in potato crops are usually perennial species difficult to control. Thus, among the dicotyledonous weeds, the species of Cirsium arvense, Sonchus arvensis and Convolvulus arvensis were identified as problem weeds, and among the monocotyledonous weeds, Sorghum halepense and Agropyron repens. Also in Lungulețu, due to the monoculture, the species Equisetum arvense, Ambrosia artemisiifolia and Symphitum officinalis created special problems for control, in Călărași county at Dâlga Cannabis ruderalis and in Prahova, Polygonum convolvulus and the Xanthium species. Even annual species, when they find favorable conditions for growth and development, are causing troubles: Chenopodium album, Polygonum aviculare, Echinochloa crus-galli. It has also been noted the increasing presence of invasive species: Ambrosia, Erigeron, Veronica, Xanthium.