Harrisia
This Weed Risk Management Assessment uses a series of questions to arrive at scores for weed risk and feasibility of coordinated control for this weed, and displays the necessary management actions derived from these scores.
This information is then used to make decisions about the introduction, prioritisation and declaration of this weed in New South Wales.
| Weed (Scientific name) | Harrisia martinii and H. tortuosa | ||
| Weed (Common name) | Harrisia cactus | ||
| Region | All of NSW | ||
| Management area | Mostly rangeland in western NSW | ||
| Landuse | 2.1 Grazing natural vegetation | ||
| Assumptions | Harrisia cactus, Cactaceae Standard weed management is limited. Varied stocking rates most common. Fire used in some instances. Very little use of broad-scale herbicide applications and cultivation. Density in land use - medium. | ||
| Weed Risk | |||
|---|---|---|---|
| Invasiveness | Score Total | Answers | Source and comments |
| Q1. What is the ability of the weed to establish amongst existing plants? | ? | Do not know | Do not know' - possibly requires major disturbance - see Parsons and Cuthbertson (2001), pg 357-358. |
| Q2. What is the weed's tolerance to average weed management practices in the land use? | 3.0 | 95% + weeds survive common management | Tanner (2009) |
| Q3. What is the reproductive ability of the weed in the land use? | 2.0 |
a. Parsons and Cuthbertson (2001), pg. 357. This is from seed and shorter times may occur from transplanted segments. b. Parsons and Cuthbertson (2001), pg. 356 i.e. (400-1000 seeds). c. Parsons and Cuthbertson (2001), pg. 357. | |
| (a) Time to seeding | 0.0 | >3 yrs/never | |
| (b) Annual seed production | 1.0 | Low | |
| (c) Vegetative reproduction | 2.0 | Frequent | |
| Q4. How likely is long-distance dispersal (>100m) by natural means? | 2.0 |
Parsons and Cuthbertson (2001), pg. 357, Biosecurity Qld (2007), pg. 3, Tanner (2009). Water and wind not mentioned. | |
| (a) Flying animals | 2.0 | Common | |
| (b) Other wild animals | 2.0 | Common | |
| (c) Water | 0.0 | Unlikely | |
| (d) Wind | 0.0 | Unlikely | |
| Q5. How likely is long-distance dispersal (>100 m) by human means? | 2.0 |
Parsons and Cuthbertson (2001), pg. 357, Biosecurity Qld (2007), pg. 3, Tanner (2009). Deliberate spread not mentioned and is now probably occasional to rare. | |
| (a) Deliberate spread by people | 1.0 | Occasional | |
| (b) Accidentally by people and vehicles | 1.0 | Occasional | |
| (c) Contaminated produce | 0.0 | Unlikely | |
| (d) Domestic/farm animals | 2.0 | Common | |
| Total | 7.0 | ||
| Impacts | Score Total | ||
| Q1. Does the weed reduce the establishment of desired plants? | ? | Do not know | Do not know' |
| Q2. Does the weed reduce the yield or amount of desired vegetation? | 1.0 | < 10% reduction | Biosecurity Qld, pg. 3 but really this is quite non-specific |
| Q3. Does the weed reduce the quality of products, diversity or services available from the land use? | 1.0 | Low | Degrades appearance of areas where it infests |
| Q4. What is the weed's potential to restrict the physical movement of people, animals, vehicles, machinery and/or water? | 3.0 | High | Parsons and Cuthbertson (2001), pg. 357, Biosecurity Qld (2007), pg. 3 - medium to high |
| Q5. What is the weed's potential to negatively affect the health of animals and/or people? | 2.0 | Medium | Parsons and Cuthbertson (2001), pg. 357, Biosecurity Qld (2007), pg. 3. |
| Q6. Does the weed have major positive or negative effects on environmental health? | 0.0 | References do not mention any major environmental health effect. | |
| (a) food/shelter | 0.0 | Minor or no effect | |
| (b) fire regime | 0.0 | Minor or no effect | |
| (c) altered nutrient levels | 0.0 | Minor or no effect | |
| (d) soil salinity | 0.0 | Minor or no effect | |
| (e) soil stability | 0.0 | Minor or no effect | |
| (f) soil water table | 0.0 | Minor or no effect | |
| Total | 4.5 | ||
| Potential distribution | Total | ||
| Q1. Within the geographic area being considered, what is the percentage area of land use that is suitable for the weed? | 2.0 | 10-20% of land use | Estimate (based on Weeds Australia (2010) potential distribution. Most common on brigalow soils, but increasingly in box and pine country in Qld (Biosecurity Qld (2007), pg 3. |
| Comparative weed risk score | 63 | ||
| Weed risk category | Medium | ||
| Feasibility of coordinated control | |||
| Control costs | Score Total | ||
| Q1. How detectable is the weed? | 2 |
a. and d. Personal observations. b. Parsons and Cuthbertson (2001), pg. 356 c. Parsons and Cuthbertson (2001), pg. 356 - generally less than 0.5 m high | |
| (a) Distinguishing features | 1 | sometimes distinct | |
| (b) Period of year shoot growth visible | 0 | > 8 months | |
| (c) Height at maturity | 2 | <0.5 m | |
| (d) Pre-reproductive height in relation to other vegetation | 2 | below canopy | |
| Q2. What is the general accessibility of known infestations at the optimum time of treatment? | 0 | high | Personal observations. |
| Q3. How expensive is management of the weed in the first year of targeted control? | 3 |
a. Spot spraying using a range of chemicals b. Estimate based on spot spraying and digging out. c. In most situations it would be low - even the physical moving of stems infested with biocontrol agent. Cultivation also fits in here (if pursued). | |
| (a) Chemical costs/ha | 1 | low (< $100/ha) | |
| (b) Labour costs/ha | 4 | very high (>$500/ha) | |
| (c) Equipment costs | 1 | low | |
| Q4. What is the likely level of participation from landholders/volunteers within the land use at risk? | 1.0 | medium | Personal observations. |
| Total | 5.0 | ||
| Persistence | Score Total | ||
| Q1. How effective are targeted management treatments applied to infestations of the weed? | ? | do not know | Do not know' - it is unclear from the references used. Follow up treatment is certainly recommend in many cases. |
| Q2. What is the minimum time period for reproduction of sexual or vegetative propagules? | 0 | >2 years | Parsons and Cuthbertson (2001), pg. 357. This is from seed and shorter times may occur from transplanted segments. |
| Q3. What is the maximum longevity of sexual or vegetative propagules? | ? | do not know | Do not know' - it is not mentioned in the references. |
| Q4. How likely are new propagules to continue to arrive at control sites, or to start new infestations? | 2.0 | Parsons and Cuthbertson (2001), pg. 357, Biosecurity Qld (2007), pg. 3, Tanner (2009). | |
| (a) Long-distance (>100m) dispersal by natural means | 2 | frequent | |
| (b) Long-distance (>100m) dispersal by human means | 0 | rare | |
| Total | 4.1 | ||
| Current distribution | Total | ||
| Q1. What percentage area of the land use in the geographical area is currently infested by the weed? | 0.1 | <1% of land use | Relatively few areas with problems - Botanic Gardens Trust (2010) and Tanner (2009). |
| Q2. What is the number of infestations, and weed distribution within the geographic area being considered? | 1.0 | scattered | Between restricted and scattered. Main infestation (H. martinii) between Boggabilla and Keetah area (Tanner 2009). |
| Total | 0.9 | ||
| Comparative feasibility of coordinated control score | 19 | ||
| Feasibility of coordinated control category | High | ||
| Management priority category | Protect priority sites | ||
| Calculation of overall uncertainty score | 11% | ||
| Positive impacts | Originally introduced into Australia as an ornamental but not used as such now. | ||
| References/Other comments | |||
|
Weeds Australia (2010). Harrisia cactus. http://www.weeds.org.au/cgi-bin/weedident.cgi?tpl=plant.tpl&state=&s=&ibra=all&card=S14 (Accessed 29 April 2010). Biosecurity Queensland (2007). Harrisia cactus. Fact sheet PP22. Biosecuirty Queensland, Brisbane. 4. pp. Botanic Gardens Trust (2010). PlantNET - The Plant Information Network System of Botanic Gardens Trust, Sydney, Australia http://plantnet.rbgsyd.nsw.gov.au (Accessed 29 April 2010). Parsons, W. T. and Cuthbertson, E. G. (2001). Noxious Weeds of Australia, 2nd edition. CSIRO publishing, Collingwood. pg. 355-359. Tanner, L. (2009). Harrisia cactus. http://www.northwestweeds.nsw.gov.au/harrisia.htm (Accessed 29 April 2010). The species Harrisia martinii and H. tortuosa are uncommon weeds in NSW (Botanic Gardens Trust 2010). Synonyms for these two species include Eriocereus martinii and Eriocereus tortuosa respectively (Botanic Gardens Trust 2010). Assessment by Dr Stephen Johnson, Weed ecologist, I&I NSW, 29 April 2010. Biocontrol agent - the mealy bug Hypogeococcus festerianus appears to be more effective in Queensland than NSW (Biosecurity Qld c.f. Tanner (2009) - probably due to cooler temperatures. Parsons and Cuthbertson (2001) mention that once populations of less than 200 shoots of Harrisia per hectare are reached then mealy bug populations die out. There appear to be a number of knowledge gaps for species in this genera. Declaration to continue to support biological control efforts. | |||
