Rotboellia cochinchinensis (itchgrass)

Transcription

1 Australia/New Zealand Weed Risk Assessment adapted for Florida. Data used for analysis published in: Gordon, D.R., D.A. Onderdonk, A.M. Fox, R.K. Stocker, and C. Gantz. 28. Predicting Invasive Plants in Florida using the Australian Weed Risk Assessment. Invasive Plant Science and Management : Rotboellia cochinchinensis (itchgrass) Question number Question Answer Score. Is the species highly domesticated? n.2 Has the species become naturalised where grown?.3 Does the species have weedy races? 2. Species suited to Florida's USDA climate zones (-low; -intermediate; 2-high) Quality of climate match data (-low; -intermediate; 2-high) Broad climate suitability (environmental versatility) 2.4 Native or naturalized in habitats with periodic inundation y 2.5 Does the species have a history of repeated introductions outside its natural y range? 3. Naturalized beyond native range y 3.2 Garden/amenity/disturbance weed y 3.3 Weed of agriculture y 3.4 Environmental weed n 3.5 Congeneric weed n 4. Produces spines, thorns or burrs y 4.2 Allelopathic y 4.3 Parasitic n 4.4 Unpalatable to grazing animals? 4.5 Toxic to animals n 4.6 Host for recognised pests and pathogens y 4.7 Causes allergies or is otherwise toxic to humans n 4.8 Creates a fire hazard in natural ecosystems n 4.9 Is a shade tolerant plant at some stage of its life cycle y 4. Grows on infertile soils (oligotrophic, limerock, or excessively draining soils) n? 4. Climbing or smothering growth habit n 4.2 Forms dense thickets y 5. Aquatic n

2 5.2 Grass y 5.3 Nitrogen fixing woody plant n 5.4 Geophyte n 6. Evidence of substantial reproductive failure in native habitat 6.2 Produces viable seed y 6.3 Hybridizes naturally 6.4 Self-compatible or apomictic y 6.5 Requires specialist pollinators n 6.6 Reproduction by vegetative fragmentation n 6.7 Minimum generative time (years) 7. Propagules likely to be dispersed unintentionally (plants growing in heavily y trafficked areas) 7.2 Propagules dispersed intentionally by people y 7.3 Propagules likely to disperse as a produce contaminant y 7.4 Propagules adapted to wind dispersal n 7.5 Propagules water dispersed y 7.6 Propagules bird dispersed y 7.7 Propagules dispersed by other animals (externally) n 7.8 Propagules dispersed by other animals (internally) y 8. Prolific seed production y 8.2 Evidence that a persistent propagule bank is formed (> yr) y 8.3 Well controlled by herbicides y 8.4 Tolerates, or benefits from, mutilation or cultivation Effective natural enemies present in Florida, or east of the continental divide Total Score 22 Outcome Reject* *Used secondary screen from: Daehler, C. C., J.L. Denslow, S. Ansari, and H. Kuo. 24. A risk assessment system for screening out harmful invasive pest plants from Hawaii s and other Pacific islands. Conserv. Biol. 8:

3 section # questions answered satisfy minimum? A 7 yes B yes C 2 yes total 38 yes Data collected Question number Reference Source data. no evidence of selection for reduced weediness North American Plant Protection Organization (23) Pest fact sheet: Rottboellia cochinchinensis (Lour.) Clayton ( Holm, Plucknett, Pancho, and Herberger (977) The 2.5 Valverde (23) Progress on Rottboellia Management for Developing Countries, Addendum. FAO Plant Production and Protection Paper 2 le=/docrep/6/y53e/y53e7.htm). 3. Valverde (23) Progress on Rottboellia Management for Developing Countries, Addendum. FAO Plant Production and Protection Paper 2 le=/docrep/6/y53e/y53e7.htm). 3.2 Waterhouse (997) The major invertebrate pests and weeds of agriculture and plantation forestry in the southern and western Pacific. ACIAR Monograph No. 44, 99p Holm, Plucknett, Pancho, and Herberger (977) The 2. Waterhouse (997) The major invertebrate pests and weeds of agriculture and plantation forestry in the southern and western Pacific. ACIAR Monograph No. 44, 99p. "preferring tropical and subtropical climates" "In South Africa it frequents wet places and, in Madras, may even grow in shallow water." Native to the Old World (Afro- Asian) but common throughout the New World. Native to the Old World - very weedy in the New World tropics. Considered a weed of gardens and roadsides in the Pacific.. "It is a weed of 8 crops in 28 countries." "its importance as a weed of several cultivated world crops is increasing" 2. Considered a major weed of agriculture in the Pacific - affects sugarcane and other crops. 3

4 3.4 no evidence 3.5 no evidence 4. Holm, Plucknett, Pancho, and Herberger (977) The 4.2 Valverde (23) Progress on Rottboellia Management for Developing Countries, Addendum. FAO Plant Production and Protection Paper 2 le= /DOCREP/6/Y53E/y53e7.htm). 4.3 Holm, Plucknett, Pancho, and Herberger (977) The 4.4 Holm, Plucknett, Pancho, and Herberger (977) The 4.5 Holm, Plucknett, Pancho, and Herberger (977) The "it has fiberglass-like needles on the sheath which penetrate the flesh, break off, and result in painful infections" "it has been suggested to be allelopathic to crops, including to maize (Bridgemohan et al. 992, Bridgemohan and McDavid, 993) and rice, (Casini et al. 998)" no description of this "Although attempts have been made to use it for pasture in many areas, there have been conflicting reports of its desirability Although it is used for hay in Africa, it is also suitable for green fodder and silage. Cattle and horses appear to relish it at times...in Ceylon it is considered to be dangerous for stock because the stiff hairs may lacerate the animals' mouths and intestines." used for hay, green fodder, and silage [and no evidence of toxicity] 4.6 Holm, Plucknett, Pancho, and Herberger (977) The "R. exaltata [synonym] is an alternate host of rice leaf gall virus and corn leaf gall virus" 4.7 no evidence 4.8 no evidence 4.9 "In some regions it requires sunny Holm, Plucknett, Pancho, and Herberger (977) The or moderately shaded places, whereas in others it is found in thickets or teak forests." 4. Holm, Plucknett, Pancho, and Herberger (977) The 4. USDA, NRCS. 25. The PLANTS Database, Version 3.5 ( Data compiled from various sources by Mark W. Skinner. National Plant Data Center, Baton Rouge, LA USA. 4.2 Holm, Plucknett, Pancho, and Herberger (977) The 5. terrestrial 5.2 USDA, NRCS. 25. The PLANTS Database, Version 3.5 ( Data compiled from Poaceae In Rhodesia [now Zimbabwe], "the weed was recorded only on heavier soils - clay to sandy clay loams It is not a serious problem on lighter soils in Rhodesia." growth habit: graminoid forms dense stands in Rhodesia [now Zimbabwe]; up to 4 m tall 4

5 various sources by Mark W. Skinner. National Plant Data Center, Baton Rouge, LA USA. 5.3 USDA, NRCS. 25. The PLANTS Database, Version 3.5 ( Data compiled from various sources by Mark W. Skinner. National Plant Data Center, Baton Rouge, LA USA. 5.4 Holm, Plucknett, Pancho, and Herberger (977) The Holm, Plucknett, Pancho, and Herberger (977) The herbaceous Poaceae roots appear fibrous in illustration "Reproduction is by seeds." Valverde (23) Progress on Rottboellia Management for Developing Countries, Addendum. FAO Plant Production and Protection Paper 2 le=/docrep/6/y53e/y53e7.htm). predominantly inbreeding 6.5 most grasses wind-pollinated 6.6 Valverde (23) Progress on Rottboellia Management for Developing Countries, Addendum. FAO Plant Production and Protection Paper 2 le=/docrep/6/y53e/y53e7.htm) Holm, Plucknett, Pancho, and Herberger (977) The 2. North American Plant Protection Organization (23) Pest fact sheet: Rottboellia cochinchinensis (Lour.) Clayton ( 7. Holm, Plucknett, Pancho, and Herberger (977) The 7.2 Holm, Plucknett, Pancho, and Herberger (977) The 7.3 Holm, Plucknett, Pancho, and Herberger (977) The 7.4 North American Plant Protection Organization (23) Pest fact sheet: Rottboellia cochinchinensis (Lour.) Clayton ( Holm, Plucknett, Pancho, and Herberger (977) The 2. Smith, Valverde, Merayo, and Fonseca (2) Integrated management of itchgrass in a corn cropping system: "Itchgrass reproduces solely by seeds". plants took between 47 and 54 days to flower 2. "Seed production begins 6-7 weeks after emergence" seeds are spread by harvesting machines "It was introduced into the Caribbean for grazing." seeds are spread in poorly cleaned crop seeds fruit is an awnless spikelet [no evidence of adaptations for wind dispersal]. seeds are spread by water 2. "Itchgrass seed floats easily, and irrigation or floodwater is known to be a source of contamination for other fields" 5

6 modeling the effect of control tactics. Weed Science 49: Smith, Valverde, Merayo, and Fonseca (2) Integrated management of itchgrass in a corn cropping system: modeling the effect of control tactics. Weed Science 49: Valverde (23) Progress on Rottboellia cochinchinensis management. In Labrada (ed.) Weed Management for Developing Countries, Addendum. FAO Plant Production and Protection Paper 2 le= /DOCREP/6/Y53E/y53e7.htm). 7.7 North American Plant Protection Organization (23) Pest fact sheet: Rottboellia cochinchinensis (Lour.) Clayton ( 7.8 Smith, Valverde, Merayo, and Fonseca (2) Integrated management of itchgrass in a corn cropping system: modeling the effect of control tactics. Weed Science 49: Smith, Valverde, Merayo, and Fonseca (2) Integrated management of itchgrass in a corn cropping system: modeling the effect of control tactics. Weed Science 49: Holm, Plucknett, Pancho, and Herberger (977) The World's Worst Weeds: Distribution and Biology. The University Press of Hawaii, Honolulu Holm, Plucknett, Pancho, and Herberger (977) The 2. North American Plant Protection Organization (23) Pest fact sheet: Rottboellia cochinchinensis (Lour.) Clayton ( 8.3 Valverde (23) Progress on Rottboellia Management for Developing Countries, Addendum. FAO Plant Production and Protection Paper 2 le=/docrep/6/y53e/y53e7.htm) "Thomas (97a) found that guinea fowl, mongoose, and cattle but not smaller birds and mammals could disperse itchgrass seed in Zimbabwe." But in another study, only a small percentage of seeds survived passage through the gut of birds. 2. seeds disseminated by birds fruit is an awnless spikelet [no evidence of any means of attachment] "Thomas (97a) found that guinea fowl, mongoose, and cattle but not smaller birds and mammals could disperse itchgrass seed in Zimbabwe.". "Curves fitted to itchgrass seed production (Table ; Figure 3) indicate that under very severe uncontrolled infestations of itchgrass, seed production of >, seeds m -2 is possible." 2. Individual plants can produce between 2,2 and 6,5 seeds.. "The dormancy of the seeds and the germination habit vary a great deal across the world In other areas the seeds are said to have a deep dormancy, sometimes lasting for years" 2. "The seed remains viable in the soil for up to 4 years" "Typically, selective itchgrass chemical control has been achieved with some triazines (e.g. dimetamethrin), dinitroanilines (e.g. pendimethalin) and acid amides (e. g. diphenamid)." 6