Seedling emergence characteristics of carthamus oxyacantha and vaccaria pyramidata in the soil profile: Winter annual species

Abstract

Carthamus oxyacantha and Vaccaria pyramidata are winter annual weed species frequently found in rainfed crops e.g. wheat and barley. Seedling emergence patterns of C. oxyacantha and V. pyramidata were studied with seeds buried at soil depths of 0, 2, 4, 6, 8, and 10 cm in outdoor pots during two years. The seedling emergence of C. oxyacantha mainly took place during February to March after which it was negligible and sporadic. The seedling emergence slightly delayed with increasing of soil depth. Start of seedling emergence was coincided with a daily mean soil temperature of 5°C at all soil depths. The main flush of seedling emerged when the minimum and maximum soil temperatures were between 4°C to 20°C, respectively. In the first year of the experiment, total seedling emergence was 45.5 % for seeds placed at soil surface, it increased in seeds buried at 2 cm depth (88 %) followed by a decrease at the rest of the depths. However, total seedling emergence did not show a consistent pattern in the second year. The seedling emergence of V. pyramidata was also took place from February to March with fewer and sporadic emergences after this time. A minimum daily soil temperature of ca 4°C was found necessary for start of seedling emergence. Most of the seedlings emerged when the minimum and maximum soil temperature were between ca 3 and 14°C, respectively. Total seedling emergence was low for seeds placed at the soil surface in both years (22% in 2010 and 18.5% in 2011); and it was increased at the depth of 2 cm (% 59.5 in 2010 and 51.3% in 2011) followed by a decrease at rest of the depths in 2010. Although large numbers of seedlings of both species may emerge over a short period of time as a main seedling flushes, the sporadic seedling emergences over a relatively extended period enable them to escape weed control operation and maintain problematic in the cultivation © 2013 Nova Science Publishers, Inc.

Published in

Title: Weeds and their Ecological Functions
Publisher: Nova Science Publishers, Inc.

SLU Authors

• Anbari, Saghi

  • Department of Crop Production Ecology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Agricultural Science

Publication identifier

• ISBN: 9781628083323

Permanent link to this page (URI)

https://res.slu.se/id/publ/132153