1. 1 Seedling emergence of Amaranthus blitoides affected by soil depth Alireza Taab, Mehrangiz Akbari and Saghi Anbari JOINT WORKSHOP OF THE EWRS WORKING GROUPS: Weed management in arid and semi-arid climate and Weed management systems in vegetables 4-8 September 2011 Huesca, Spain In The Name of God Dept. of Agronomy and plant breeding, Faculty of Agriculture, Ilam University, 69315-516, Ilam, Iran Email: a.taab@mail.ilam.ac.ir ILAM UNIVERSITY IRAN

2. 2 Introduction Problem ? Weed in soybean, beans, vegetables etc. Crop yeild loss Background Number of emerged seedling to deacrease with soil depth Weed Management - Time of weed emergence - Number of weed emergence - Depth Weed Emergence! When? And How Many? Weed Control Options! Crop

3. 3 Experiments  Pot experiment outdoor Soil: CLAY; Organic C: 1.16% 1 Species x 4 Blocks x 6 Soil Depths x100 Seeds Depths: 0, 2, 4, 6, 8, 10cm Seed collection: 5 January 2010 Sowing date: 12 January 2010 Materials and Methodes: Records: - soil temperature at 6 depths - numbers of emerged seedlings

4. 4 Results

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9. 9 Conclusion Seedling emergence: -When mean daily soil temperature increased above ca 10ºC with ca 5 to 25ºC fluctuation -The seedling emergence was stopped when the daily soil temperature raised above 20ºC, possibly due to induction of dormancy -Maximum seedling emergence was observed for seeds at soil surface and decreased with depth! -Seedling emerged over an extended period which make the species difficult to control -Weed control measures over an extended period with focus on larger seedling flushes

10. 10 Thanks For Your Attention