Field-scale estimates of grass weed populations in arable land
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Field-scale estimates of grass weed populations in arable land

Estimates of numbers of weed grass inflorescences in a single wheat field were made using 0·25 m2 quadrat counts. Precise estimates of mean field density could be achieved only at high sampling intensity, at least 18 locations (m2) ha-1.

The standard error expressed as a percentage of the mean was less than 20% for more abundant species and over 30% for rarer species at that sampling intensity. However, the data were highly skewed and followed a negative binomial frequency distribution for each species. This implies it may be usual for arable weeds that plants are clumped, with clumps occurring at random. A computer mapping program that interpolates arithmetically between sample points did not reflect accurately plant distributions and was affected by sampling intensity. The implications for decision making for weed control using densities are discussed.

Author: Marshall E.J.P.

More information on this article on the Website  of Wiley Online Library HERE

Date de modification : 25 avril 2023 | Date de création : 16 septembre 2013 | Rédaction : IPM network, contributor: Mathieu BONNEAU.