Annual seed production of diffuse (Centurea diffusa) and spotted knapweed (Centurea maculosa) is reduced in dry years by a reduction in the number of viable seeds per seed head and increases when above-normal precipitation occurs by increase in the number of heads/flower stem. Seed production was approximately 1,000-fold that needed to maintain observed levels of infestation. Seedlings emerging in April had a high rate of survival with most plants flowering the following season, while those emerging after May 15 had a very low survival rate and almost no flower stem production the following season. This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries. The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact lbry-journals@email.arizona.edu for further information. Migrated from OJS platform August 2020
Scholarly peer-reviewed articles published by the Society for Range Management. Access articles on a rolling-window basis from vol. 1, 1948 up to 5 years from the current year. Formerly Journal of Range Management (JRM). More recent content is available by subscription from SRM.