Cape tulip (Homeria)

Introduction:

Named after Homer, the epic Greek poet, Homeria is a South African native produced from corms. Although there are about 32 known species (now part of Moraea), many are not commercially cultivated and are still found growing in the wild. The slender, grass-like foliage and unusual-shaped, bicolored flowers range from yellow and orange to salmon-pink. Homeria plants prefer sunny locations in well-drained, sandy soil. Plant Homeria corms in the spring or fall approximately 1-2 inches deep. Since Homerias have very small corms, do not plant the corms too deeply or too far apart. In fact, a good way to plant them is by massing them in small groups. The corms that are planted in the spring will bloom later in the summer, while corms planted in the fall will flower in the spring. Although the individual flowers do not last long, the plant produces so many of them that the flowering displays can be enjoyed for a long period of time. Mature plants reach about 2 feet tall; use them as mass plantings in beds and borders for greatest effect, where their unusual color can be appreciated. The Homeria’s unusual shapes and colors also make it particularly useful as a container-grown plant. During winter in colder regions, it is better to lift the corms and store them in a dry, frost-free environment. In other regions, they can remain undisturbed in the soil with an adequate layer of mulch for winter protection.

Background:

Both one-leaf Cape tulip (Moraea flaccida) and two leaf Cape tulip (Moraea miniata) have become major weeds in Australia since being introduced from South Africa. Both have attractive orange or salmon pink flowers and were introduced into Australia in the mid-nineteenth century as ornamental plants. These species were previously known as Homeria flaccida and H. miniata. By the early 1900s, both species were established weeds of pastures in New South Wales, Victoria, South Australia and Western Australia, with the most extensive infestations being in parts of Victoria, South Australia and Western Australia. Cape tulips are unpalatable to livestock. Cape tulip has also recently increased its invasion of native habitats and has the potential to be a weed of conservation importance.Control options for Cape tulips include herbicides and cultivation with weed control occurring in the subsequent crop. However these control options are often not justified for economic reasons and access to waterlogged areas, where Cape tulips often occur, can be difficult.

Biological control therefore seemed a possible option, in particular for control of Cape tulip in Western Australia.

Distribution Map:

Biological control:

CSIRO Entomology looked at the possibility of using biological control for Cape tulips by trying to identify potential biological control agents in the weeds region of origin,

the Western Cape Province of South Africa. They also assessed the risk associated with the introduction of any potential agents into Australia. In 1999-2001, survey work in South Africa for potential agents identified weevils feeding on corms and Urodon weevils feeding on seeds. The most promising potential agent was the rust fungus, Puccinia moraeae, which affects the leaves. It appeared to cause significant damage to plants in its native habitat and has not been recorded outside the genus Moraea. Little is known of the biology of this rust. Cape tulips are considered suitable targets for biological control because there are few close relatives among Australian native species and no related crops.

Current research

Supported by the Department of Agriculture and Food Western Australia, a one year trial is currently underway to look at the feasibility of using the rust as a biological control agent. This involves testing various rust isolates in the microbiological area of the CSIRO Black Mountain Containment Facility in Canberra to see how effective they are on Australian Cape tulips. The isolates will also be tested on a few key closely related, non-target plant species, an important first step in deciding if the rust should undergo future comprehensive host-specificity testing.

Sourced From:padil.gov.au/seeds/Pest/Main/141824