Technical Yearbook 2023

The Australian grapevine moth can cause serious late season defoliation but is attacked by a range of beneficials such as parasitic wasps; this individual has several wasp eggs on the ‘neck’ area from where it is unable to groom them off.

The familiar garden ornamental plant, alyssum, appears well suited as an under-vine cover crop where it competes with weeds, forms a dense but prostrate groundcover that provides good air flow beneath the vine canopy. It also reduced damage by light brown apple moth and late season botrytis bunch rot. a challenge. At the relatively small scale of research plots in this study it was possible to use small, motorised machinery and hand tools, but this would not be economical at a commercial scale. Tractor-mounted machinery can be used to prepare a seed bed for mid-row cover crops; indeed, this is not uncommon, but establishing under-vine cover crops requires specialised machinery to work around vines, posts and irrigation lines. Currently, such equipment is not common and relatively expensive. Potentially, however, there is no need to use tillage to establish a fine seed bed if herbicides are used to reduce weed competition and allow cover crop plant seeds to be surface-sown (suitable for species such as alyssum) or if using small ‘tube stock’ native plants. The costs of planting material are also a consideration. Some cover crops – such as buckwheat, alyssum and several commercial blends – are inexpensive, widely available and grow vigorously enough to give a good ‘strike’. Alyssum offers the advantage of self seeding to provide a perennial strip and has an extremely long flowering period which is important in order to give season long nectar availability to beneficials. Buckwheat tends to bloom very rapidly but sowing time is important because it is very susceptible to frost so cannot be sown early in cooler districts. Whilst buckwheat has a short blooming period it is possible to extend nectar availability by slashing part of the width of mid-row strips to encourage a new flush of growth. Native species are the costliest of the treatments we evaluated because small-potted plants were used since seed availability was poor for most species. Whilst the natives are perennial

The low-growing native shrub, Myoporum parvifolium , grew vigorously beneath vines producing large numbers of white flowers that laboratory tests showed were effective in boosting the performance of Trichogramma wasps.

anticipate that the benefits of these native plants in year two will be even stronger as they cover more area and provide more nectar resources to beneficial insects. From a practical perspective, establishing cover crops remains

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TECHNICAL YEARBOOK 2023