Bushland Weeds Manual - Environmental Weeds Action Network

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26 Chapter 3 Grass <strong>Weeds</strong> Case Studies Figure 2. One of the 2 m x 2 m plots set up to monitor the Perennial Veldgrass control program at Blue Gum Lake In 1998 the spray contractors were not available to treat the grass until early September – well past the peak growth period and after the plants had begun to flower. The kill rate was disappointing and not surprising given that Fusilade ® should be applied pre-boot stage. This was discussed with the contractors who agreed to address the matter. In 1999 the contractors sprayed in June, which is too early! It was not until 2000 that the plants were sprayed at the correct time – just before flowering, in mid July. Research at Kings Park, Perth, has shown how crucial timing is for the control of Perennial Veldgrass (Dixon 1998a). It is important to wait until the majority of the new season’s adventitious buds are actively growing to allow sufficient herbicide to be taken into the plant, but not leave it so long that flowering has begun. The results from monitoring plots provided the evidence to both contractors and local council about the importance of timing (Figure 3(a)). Results from counts of seedlings showed the expected high numbers following the wildfire in the year previous to the trials (Figure 3(b)). Fire is known to enhance germination of Perennial Veldgrass seed (Milberg and Lamont 1995, Myut 2001). The much lower numbers in the control plots in subsequent years suggests that Veldgrass recruitment may be density dependent, competition from the resprouting adults limiting seedling establishment. Mean number of mature Veldgrass plants 60 50 40 30 20 10 0 control treatment 1998 1999 2000 2001 Year a Less obvious were the changes in species composition. In terms of presence or absence there were no apparent differences between control and treatment plots. Ursinia (Ursinia anthemoides) increased in cover in the last year (2001), but observations from other bushland sites in the Perth area suggest this was a good year for the weed. Flatweed (Hypochaeris glabra) cover Figure 3. Mean number of mature Perennial Veldgrass clumps (a) and Perennial Veldgrass seedlings (b) in control and treatment plots at Blue Gum Lake from 1998 to 2001. Mean number of Veldgrass seedlings 60 50 40 30 20 10 0 1998 1999 2000 2001 Year b control treatment
fluctuated throughout the period and all other weeds reduced in cover or remained similar. There was no influx of weeds following the Veldgrass removal which was encouraging – but nor was there an increase in native germination. Chapter 3 Grass <strong>Weeds</strong> Case Studies Table 1. Native species occurring in the monitoring plots unaffected by the Fusilade ® treatment. Annual herbs Crassula colorata Homalosciadium homalocarpum Lobelia tenuior Perennial herbs Conostylis aculeata Desmocladus fasciculatus Desmocladus flexuosa Dianella revoluta Isotropis cuneifolia Lepidosperma angustatum Lepidosperma spp Lomandra caespitosa Lomandra hermaphrodita Lomandra preissii Lomandra sp. Lyginia barbata Opercularia vaginata Patersonia occidentalis Phlebocarya ciliata Schoenus curvifolius Tricoryne elatior Perennial herbs-geophytes Burchardia congesta Caesia micrantha Drosera menziesii ssp menziesii Microtis media Pyrorchis nigricans Sowerbaea laxiflora Thysanotus manglesianus The impacts of grass-specific herbicides on native plant communities are thought to be minimal. The sedges, rushes and many geophytes (orchids, native lilies, etc.) which are monocots like grasses, may however be particularly susceptible. From monitoring of plots at Blue Gum Lake it appears that Fusilade ® applied between June and September, has little impact on a range of native species (Table 1). Perennial grasses Austrodanthonia caespitosa Austrostipa compressa Shrubs Acacia stenoptera Bossiaea eriocarpa Dampiera linearis Dasypogon bromeliifolius Eriostemon spicatus Eucalyptus calophylla Gompholobium aristatum Gompholobium tomentosum Hardenbergia comptoniana Hibbertia hypericoides Hibbertia racemosa Hovea pungens Hovea trisperma Hypocalymma robustum Jacksonia furcellata Kennedia prostrata Lechenaultia floribunda Leptomeria empetriformis Macarthuria australis Petrophile linearis Pimelea rosea 27
Page 1 and 2: Bushland Weeds A practical guide to
Page 3: Acknowledgments This manual is the
Page 6 and 7: iv Introduction The Banksia, Tuart
Page 8 and 9: 2 Chapter 1 The Project Blue Gum La
Page 10 and 11: 4 Chapter 1 The Project Both Arum L
Page 12 and 13: 6 Chapter 2 Managing Weeds in Bushl
Page 14 and 15: 8 Chapter 2 Managing Weeds in Bushl
Page 16 and 17: 10 Chapter 3 Grass Weeds Many grass
Page 18 and 19: 12 Chapter 3 Grass Weeds Box 3.3 Gr
Page 20 and 21: 14 Chapter 3 Grass Weeds • Transi
Page 22 and 23: 16 Chapter 3 Grass Weeds Control te
Page 24 and 25: 18 Chapter 3 Grass Weeds Rhizomatou
Page 26 and 27: 20 Chapter 3 Grass Weeds Case Studi
Page 34 and 35: Chapter 3 Grass Weeds Management Ta
Page 36 and 37: Chapter 3 Grass Weeds Management Ta
Page 38 and 39: 32 Chapter 4 Corms, Bulbs and Tuber
Page 58 and 59: Chapter 4 Corms, Bulbs and Tubers W
Page 60 and 61: Iridaceae Moraea miniata Two Leaf C
Page 62 and 63: Chapter 5 Broadleaf Herbs, Sedges a
Page 64 and 65: 58 Chapter 5 Broadleaf Herbs, Sedge
Page 72 and 73: Chapter 5 Annual Broadleaf Herbs, S
Page 74 and 75: Chapter 5 Annual Broadleaf Herbs, S
Page 76 and 77: Chapter 5 Perennial Broadleaf Herbs
Page 78 and 79: Chapter 5 Perennial Broadleaf Herbs
Page 80 and 81: 74 Chapter 6 Trees, Shrubs and Clim
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76 Chapter 6 Trees, Shrubs and Clim
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Chapter 6 Trees, Shrubs and Climber
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Chapter 6 Trees, Shrubs and Climber
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90 Chapter 7 Weed Mapping in Remnan
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92 Chapter 7 Weed Mapping in Remnan
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94 Chapter 8 Herbicide Use in Bushl
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100 Final Note In the end, environm
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102 References 1 Aarssen, L.W., Hal
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104 References 101 Dixon, B. (2002)
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106 References 204 Mann, R. (1998)
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108 307 The Nature Conservancy (200
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