Effect of Seed Depth on Population Frequency and Viability of Wild Oat (Avena spp.) in Wheat Monoculture Cropping Systems

Document Type : Research Paper

Abstract

Considering the effect of tillage on seed density and distribution, predicting wild oat germination in various soil depths, as affected by plowing system, is necessary. An experiment was designed to count number of wild oat seeds in soil samples taken from four depts in two occasions: first-pre spring plowing (soil surface, 0-5cm, 5-10 cm, 10-15 cm), and 15-20 cm).  and second post spring plowing ( 0-5 cm, 5-10cm, 10-15). The experiment was run as randomized complete blocks design with 4 treatments (soil depths), 4 blocks (farms), and 5 replications (observations). Results indicated that pri-plowing, surface seeds had the lowest germination rate of 35%. Number of seeds reduced of depth 0-5 cm. viable seeds in pre-plowing were 81% which was significantly lower than the post-plowing 96%. It was also shown that number of seeds increased by 28% in post-plowing samples, but germination was low due to dormancy.

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Aghaalikhany, M. and Rahimian Mashhadi, H. 2007. Population dynamics of weeds. University of Tehran Press (in Persian). 149 Pp.
Baskin, J.M. and Baskin, C.C. 2004. A classification system for seed dormancy.Seed Sci. Re. 14: 1-16.
Cardina, j., Herms, C.P. and Doohan, D.J. 2002. Crop rotation and tillage system effects on weed seed banks. Weed Sci. 50: 448–460.
Chauhan, B., Gill, G. and Preston, C. 2006. Influence of tillage system on vertical distribution, seedling recruitment and persistence of rigid ryegrass (Lolium rigidum) seed bank. Weed Sci. 54:669-676.
Conn, J.S., Beattie, K.L. and Blanchard, A. 2006. Seed viability and dormancy of 17 weed species after 19.7 years of burial in Alaska. Weed Sci. 54: 464–470.
Gallant, E.R., Fuerst, E.P. and Kennedy, A.C. 2004. Effect of tillage, fungicide seed treatment, and soil fumigation on seed bank dynamics of wild oat (Avena fatua). Weed Sci. 52:597-604.
Hanan, E.D. 2007. Influence of salicylic acid on stress tolerance during seed germination of Triticum aestivum and Hordeum vulgare. Biological Res. 1: 40-48.
Mazhari, M., Tadayon, M.R. and Tadayon, A. 2012. Breaking dormancy of some monocotyledon weed seeds Avena fatua, Aegilops cylindrical, Bromus dantoniae and Setaria viridis under different burial depths and burial times. Proceedings of the 4th Iranian Weed Sci Con. 6-8 February, Ahvaz, Iran.
Menalled, F. 2008. Weed seedbank dynamics and integrated management of agricultural weeds. Montana State University-Bozeman. 4 Pp.
Nakamoto,T., Yamagishi, J. and Miura, F. 2006. Effect of reduced tillage on weeds and soil organisms in winter wheat and summer maize cropping on humic Andosols in central Japan. Soil & Tillage Re 85: 94–106.
Peralta Caroca, R., Silva Candia, P. and Acevedo Hinojosa, E. 2010. Characterization of the weed seed bank in zero and conventional tillage in central chile. Chilean J. of Agr. Re. 71: 140-147.
Souhani, M. 1998. Seed technology. Guilan University Publication. 166 Pp. (In Persian).
Tkasy, S., Rashed Mohassel, M.H. and Banayan, M. 2012. Allelopathic potential of aqueous extract of the aerial parts of alfalfa on seed germination and seedling growth of four weed species. Iran. J. Field Crops Res. 9: 60-69..