NSW Department of Primary Industries organic horticulturist, Karen O’Malley, said mustard was being used to manage weeds and fumigate the soil before planting Tempranillo and Sauvignon Blanc vines.

A mustard crop is laying the foundation for the first organic vineyard trial at the Centre for Organic Farming in Bathurst.

"The mustard cover crop will be used as green manure and because it produces natural pest suppressants, mainly glucosinolates, mustard also helps reduce weeds, diseases, insects and nematodes in the vineyard," Ms O’Malley said.

"As a green manure with a high plant biomass, the mustard will be slashed prior to seed-set to increase soil organic matter and reduce subsoil compaction.

"Mustard’s deep taproot system helps reduce soil crusting and improves moisture infiltration."

According to Ms O’Malley, these soil improvements will contribute to future disease management and vineyard health.

"Research shows that mustard green manure crops can suppress root-knot nematodes and diseases such as verticillium, aphanomyces and sclerotina," she said.

"Mustards can be used as catch crops to retain nitrogen already in the soil but growers need to be aware that their residues break down more rapidly than most grasses and the nitrogen may be freed more rapidly.

"Timing of mulching is important for the release of nitrogen into the soil."

Sown this April, the mustard green manure crop will be grown for about 100 days until early flowering and mulched before setting seed to prevent competition with the new vines and volunteer mustard plants.

"And we hope to see an abundance of bees, ladybirds and other beneficial insects attracted to the mustard."

The mustard crop is just one part of the weed management strategy for the organic vineyard.

Mulching around the young vines, inter-row sowing of beneficial plants, slashing and an organic herbicide made from pine oil are all in the plan.

Contact Karen O’Malley, Bathurst, (02) 6330 1212.