Title: Cover crops and weed suppression in vineyards
Abstract: The mid-row area accounts for about 70% of the vineyard floor, and weed management is the principal reason for activities on this area. Many growers have now changed their thinking about plants growing of their own volition in the mid-row, from being weeds requiring control to plants providing low-cost soil cover. Cover cropping is also widely practiced, utilising a wide range of native or exotic species to provide particular benefits such as weed or nematode suppression, biological nitrogen, high or low water use, and beneficial insect habitat. The capacity for cover crops to compete with weeds varies considerably between species. Cereals, especially barley, and to lesser degrees wheat, triticale, rye and oats, are strong competitors. Fodder turnip also displays strong early growth to compete with weeds. Dense stands of medics and sub-clovers generate large amounts of spring biomass, and will compete strongly, particularly in nitrogen deficient soil. Perennial ryegrass and medics/sub-clover are also a very compatible mix for weed control. Once established, native species such as perennial prostrate saltbush (Atriplex semibaccata) and wallaby grass (Austrodanthonia richardsonii) are also very strong competitors. Saltbush is very suitable for use as a mid-row planting in the dry inland regions where it provides habitat for beneficial insects and suppresses the growth of caltrop (Tribulus terristris). Wallaby grass is well suited to the 300-500mm rainfall zone and effectively suppressed the growth of caltrop and wireweed (Polygonum spp.). [Chris Penfold & Cassandra Collins (2012). Cover crops and weed suppression. Fact Sheet June 2012: University of Adelaide][Caption: Soursob growing undervine during winter suppresses the growth of other plants. (Photo courtesy Joch Bosworth)]
