rikkimaara

Rikkimaara is a term used in Finnish agronomy and weed management to describe a threshold level of weed infestation that justifies taking control actions in a crop stand. The word combines rikk(i) meaning weed and maara meaning amount or threshold, and in practice it is linked to decisions about when to apply control measures such as mechanical weeding or herbicides. The concept appears in Finnish agricultural literature and extension materials as part of decision-support for integrated weed management.

Definition and scope vary by source and agricultural context. In general, rikkimaara refers to a density or biomass level of weeds within a crop row or field at a given growth stage that would, if exceeded, trigger management intervention. Measurements may be expressed as weed density per unit area, percent ground cover, or weed biomass per area. Methods for estimating rikkimaara range from visual scoring and sampling with quadrats to more formal biomass harvests, with the chosen method influenced by crop type, weed species, and resource constraints.

Applications and implications also differ regionally. The concept aims to optimize control efforts, reduce unnecessary herbicide use, and protect yields by acting only when economic or agronomic thresholds are reached. Because thresholds depend on crop value, weed species, and local practices, rikkimaara is not standardized across countries or farming systems but serves as a practical guideline within Finnish crop management.

See also: economic threshold, weed management, integrated pest management.