Kristiansen, P.; Sindel, B.M.; Jessop, R. and Cerrai, D. (2005) Brassica cover crops for weed control in organic vegetable production. Paper at: Shaping Sustainable Systems. Proceedings of the 15th IFOAM Organic World Congress, Adelaide Australia, 20-23 September 2005.
Cover crops (or green manures) are commonly used by organic vegetable growers for soil fertility building and other benefits including weed control. Brassica crops have been reported to control weeds in subsequent crops, usually attributed to the allelopathic effects of glucosinolates (GSL) in the brassica residues, although the effects are inconsistent. New brassica varieties with high GSL levels (Brassica juncea cv. Fumus and Raphanus sativus cv. Weedcheck) were tested in combination with mechanical weed control and another locally grown forage crop (Lolium multiflorum cv. Conquest) for their effects on weed growth during the pre-crop phase and subsequent weed and lettuce growth during the in-crop phase. The cover crops and bare fallow controlled weeds effectively during the pre-crop phase, but did not affect weed and lettuce growth in the following in-crop phase. The cover crops provided better on-going weed control than the bare fallow. Reducing the delay between the pre- and in-crop phases from four weeks to one day did not affect weed and lettuce growth. Weed control was closely related to the amount of light reduction by the cover crops, while competition for nutrients and water appeared to be less important in weed suppression by the cover crops. The use of cover crops requires careful selection of appropriate varieties, attention to good cover crop husbandry (particularly establishment) and an awareness of prevailing weed seed bank levels.
|EPrint Type:||Conference paper, poster, etc.|
|Type of presentation:||Paper|
|Keywords:||organic; brassica; cover crop; green manure; vegetables; lettuce; weed|
|Subjects:|| Crop husbandry > Crop combinations and interactions|
Crop husbandry > Weed management
|Research affiliation:||Australia > University of New England|
|Deposited By:||Kristiansen, Dr Paul Erik|
|Deposited On:||28 Aug 2008|
|Last Modified:||12 Apr 2010 07:37|
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