Pr otection Ouartedy Vol 1(4) 1986 163

The ecology and control of fireweed ( madagascariensis Poir.)

B. M. Sindel Department of Agronomy a nd Horticu ltural Science. Faculty of Ag ricultu re. Un ive rsity of Sydney. N.S.w. 2006

Summary are 'golden button' (bolon de oro) and cause poisoning in liveslock, varies This review includes a full descriplion 'the yellow flower of Mar del Plata' widely bel ween Senecio spec ies of Ihe soulhern African planl Sellecio (flor ama rill a de Mar del Plata) (Lag­ (Walker and Kirkland 198 1). However, madagascariensis, now widespread in uinge 1959, cited by Verona el al. because of the variabililY Ihal occurs coaslal New Soulh Wales, a key 1982). within the S. lalllus complex and Ihe differenlialing il from closely relaled The great abundance of fireweed in possibility of hybridization and gene forms of Ihe Auslralian nalive many parts of coasta l New South excha nge bel ween its different forms S. laullis. an accounl of ils life cycle Wa les after the breaking of the (Ali 1966; OrndufT 1964), differentia­ and dislribulion. and a general Ireal­ drought in 1983, its continued spread lio n from S. madagascariensis can be men I of faclors relaled 10 its loxicily inlo new areas, particularly along the difficult . and mel hods of conlrol involving south coast, and recent reports o n its Ali (I 964a,b) was able 10 show Ihal herbicides, pasture management and toxicity to cattle have stimulated a in A ustralia five main ecological cultivalion. The polenlial of biologi­ study of the existing literature which groups, called genoecodemes, may be cal conlrol is discussed. is reviewed here. A typical severe recognized in the S. lautus complex, infestation of fireweed is shown in namely: coastal, moist gull y, mallee, Figure I. montane and deserl. A fl er considera­ Introduction tion of the geneti c syslem wilhin the complex (Ali 1966), he laler gave Ihese Fireweed (Senecio madagascariensis Description and identification taxa subspecies status, with the excep­ Pair.) belo ngs 10 Ihe family A Sleraceae Because fireweed (S. madagascarien­ ti on of the desert group (A li 1969). (Compositae) a nd 10 th e tribe Sene­ sis) fit s, in general terms, the descrip­ T hey a re respectively ss pp. maritimus, cioneae. For many year.s in Ih is yel low-flo wering weed (somelimes tions of Ihe similar nalive S. laulus lanceolaills, dissecli/olills and alpin us. complex given in Australian floras, it Because the desert group is morpho­ referred 10 as 'variable groundsel') was Ihoughl 10 be a form of Ihe very vari­ is important to differentiate bel ween logicall y similar 10 members of Ihe the 111'0 species. This is especiall y rele­ ma llee and coastal genoecodemes, Ali able native species, Senecio laulus Forsl.f. ex Willd. (A li 1969; Walker vant since members of Ihe S. lalilus described such a POpu lalion as 'aff. complex are essent ia ll y no n-weedy and Kirkland 1981). However. speci­ ssp. dissecli/olius a nd ssp. marilimus'. mens sent 10 Dr O. M. Hilliard, (Michael, personal communication) Leaf shape was used predominanlly and Ihe content of alkaloids, which for distingui shing these subspecies, but Universil Y of Nalal, Soulh Africa, in 1980 connrmed suspicion Ih at the species originates in south-eastern Africa a nd (Michael t98 1) and has been introduced 10 Australia. S. madagascariensis was first desc ribed by Poi rei in 1817, Ihe Iype specimen having been coll ecled by Commerson in Madagascar. II has a lso been clas­ sified in some instances under the names S. ruderalis, S. junodianus, S. illCOgllillls, S. burchellii (Hilliard 1977) and S. laulus afT. ssp. lanceD la­ Ius (Ali 1969). Possible expla nalions for il s com­ mon name include it s ability to 'spread like wi ld fire', it s bright yell ow colo ur. its apparent potential to cause spon­ taneo us combustion in lucerne hay. and it s appearance soon a fter bush­ fires. It should not be confused, how­ ever. with Dlher sometimes also referred to as fircweed, e.g. cotton fire­ weed (S. qlladridel/tallls) , fireweed groundsel (S. lil/eari/olius) and hill fireweed (S. hispidullls). In Argenlina. where S. madagascariellsis a lso occurs, two o f the co mmo n na mes given to it Figure 1 Cattle grazing tYPical fireweed·infested pasture in lale winter near Gloucester. New South Wales. 164 Plant Protection Ouarterly Vol 1(4) 1986 characters such as height, leaf length, number of involucral bracts, number of disc florets, and the length of the coroll a of both the ray and disc florets, were also measured. While Ali did not recognize S. mad­ agascariensis as such, it is known from a st udy of herbarium specimens (Nel­ son 1980) that he included it among his group of plants known as S. laurus aff. ssp. lanceolatus (Ali 1969). Despite Ali's differentiation of the various members of the S. laulus co m­ plex, it was not possible prior to the taxonomic work of both Nelson (1980) and Daniel (1984), to differentiate bet wee n S. laurus a nd S. madagascari­ ensis. Nelson (1980) concluded that the number of involucra I bracts or phyl­ laries (20- 21) is of major importance as a distinguishing characteristi c of , S. madagascariensis. Only the desert . '\ : . ~. genoecodeme of S. laU/us has a simi­ '.:;.. .. > lar number of involucral bracts (19) • per capitulum (Ali 1964b), but owin g Figure 2 Flreweed seedlings at the one-leaf stage (above). and lhe seven·leaf stage (below) to it s geographic isolation, confusion between them in the field is unlikely. One known difference is that of achene or 'seed' size. The achenes of the desert genoecodeme (Ali 1968) are much lar­ ger than those of S. madagascariensis. In Argelllina, th e number of involucra I bracts wa s also found to be critical in the co rrec t identification of S. madagascariensis (V crona et al. 1982). The sha pe of the ph yll aries, achene mo rpho logy, ca lyc ular bract morphology a nd leaf shape are also important for idemifica tion . Beca use th e number of ray florets (commonl y called 'petal ') varies, and is similar (usua ll y 13) in some members of S. {allllls, it is of lillie li se in distin­ gui shing S. madagascariellsis from the S. !au/lis co mplex. A detai led descripti o n of fire weed (5. madagascariellsis) and a key, wh ich allows for th e differentiation between th ese two spec ies, can now be given.

(aj Habit A glabrous or very sparsely hairy bush tic-Ianceolate, apex aC llte, margins corymbose panicles, terminal or axil­ or herb up to c. 60 em tall (Daniel denticulate to coarsely a nd irregularly lary, the small decurrent bracts si milar 1984). Rarely decumbent (Nelson toothed, tapering to a narrow petiole­ to the calycu lar bracts of the capitulum 1980), most commonly found as an like half clasping base, sometimes (see Figure 4a). In volu cre campanu­ erect plant, stem often simple (Hilliard minutely ea red. Upper occasionall y late, 3- 5 mm diam. , principal bracts or 1977) a nd weakly li gnified at th e base, pinnately lobed, reduced petiolate, phyllaries c. 20-21 (N elson 1980), often much branched above. Seedlings subsessi le or sess ile. Poss es ses herbaceous wit h membranous edges, at two different growth stages are predominantly ,,2-type leaves (Daniel 4-5(-6) mm long about equalling or a shown in Fi gure 2. 1984) according to the classifi cation of little shorter than the disc (Hilli ard leaf forms of the S. laurus complex 1977), width 0.8-1.3.mm , keeled, (bj Leaves give n by Ali (I 964b) (see Figure 3). nerves 1- 3, resinous, attenuated to an Bright green, alternate, ve ry va riable. acute apex. Calycular bracts c' 8-12, up to 12 x 2.5 em (Hilliard 1977) but (cj Flowers 'h to Vi length of upper bracts, often often mu ch smaller. Cauline leaves Heads heterogamous, radiate, rew to purple-tipped (Nelson 1980). Disc mostl y linea r- Ia nceolate to ellip- many on bracreare peduncles in open. florel s many, rays c. 13 , ray corolla Plant Protection Quanerly Vol 1( 4) 1986 165 length 8-14 mm (Nelson 1980). often z 3 4 5 • revolute with 4 resinous lines, partic­ ularly obvious on upper surface. Ray and disc florets canary yell ow.

(d) Fruits Achenes (see Figure 4b) 1.5-2.5 mm long. 0.30-0.45 mm wide. cylindrical. shallo'-'Iy ribbed. with short hairs or a bristles c. 0.025 mm long in c. 9-10 longitudinal lines or bands. each band 0.03-0.05 mm wide (Daniel 1984). Achenes dark brown. light brown or green with light brown being most abundant (Verona el al. 1982). Pappus 3.5-65 mm long.

(e) Rools Shallow. branched. annual or peren­ nating taproot with numerous fibrous roots. growing from 10 to 20 em deep (Watson el al. 1984) . The following key allows for simple differentiation between S. madagas­ cariensis and the more common representatives of the S. laulus complex.

Agricultural significance Fireweed is significant principally y , because of its invasiveness and (oxicity. , t Figure 3 Leaf IOfms of the SenecIO lau/us complek Forms cr , {3 and Y are the three main types recognized, Invasiveness while numbers 1 6 refer to subtypes (All 1964b) Fireweed (S. madagascariensis) is an opportunistic weed with the ability to invade and colonize a great variety of habitats in a short period of time (Fer­ Key to the species nandez and Verona 1984). It is. how­ A. Prostrate herb with -y- type leaf pattern (see Figure 3). ever. found predominantly 'in poorly s. lau/us ss p. lI/pill/lS (Mont ane) . Alpine and subalpine regions in New South Wales. Victoria grassed. neglected or heavily grazed and Ta smania . pastures and on cultivated land during the autumn to spring period (Green A .'" Erect or dec umbent herbs or small shrubs with a- or !3-lypc leaf pattern (see 1953; Whittet 1958; Martin and Col· Figure 3). man 1977; Walker and Kirkland 1981). In most areas colonized. it has the B. Leaf pallern IJ-type; in vo lu cral bracts 13 -20 (mean 15). 3.5-6.0 mm lo ng; competitive advantage of active winter achenes 1.9- 2.7 mm long. mostl y hairy. growth when pasture production is S. l(mlllS ssp. (/iSS('('lijolills (Malice). Widel y distributed in all Slates. low. The extent to which pasture B. ' Leaf pattern a-type. growth is suppressed depends on the level of infestation. C. In vo lueral bract s c. 13. Fireweed is important because of its ability to invade pastures growing on D. Leaves noti ceably succ ulent; biggest cauline leaf not lobed. less highly fertile soil (Verona el al. 1982). than 5.5 cm lo ng x 1.2 em wide. In vo lucral bracts 4- 12 ,nm Watson el al. (1984) also observed that long; aehenes prominently ribbed. 1.9-4.5 mm lo ng. fireweed will quickly invade pastures S. IUllfIIS ssp. lIIorilimlls (syn. S. spolllII/OfllS A. Rich .) (CoastaL) Usuall y on after drought. They suggested that fire­ sand dunes or exposed to the sea in southe rn Queensland and all other t3tes. weed competes strongly with existing pasture plants for light. moisture and D.· Leaves not succ ulent; biggest caul inc leaf not lobed, grea ter soil nutrients (notably phosphorus and than 5.5 cm long x 1.2 cm wid e. In vo lu cral bracts 4.5-6.5 nitrogen). and that this competition mm long; ac hcncs 1.8-2.0 min long. can lead to the deterioration of S. 1(1111/15 ssp. It/l/ceol(llliS (Moi st gull y). Queensland. New SOllt h Wal es. Vic­ pastures. toria and Western Austra lia. Previously. Martin and Colman c.' In vo lu cral bracts 20- 21. 4- 6 mm long; achenes 1.5-2.5 mm long (1977) considered that fireweed prob­ with shorl hairs in longi tudinal lines, ribs very shall ow. ably had scant influence on pasture s. l1/at/lIgllsmrieflsis (Firewccd) . Sout h-e ,, <: tern Queen <; land and coastal New Sout h production. at least in warm climate Wales. 166 Plant Protection Quarterly Vol . 1(4) 1986

jacobaea (ragwort) is responsible for in the Hunter Valley, significant mor­ more deaths of livestock than all other tality and poor growth of stock can a_ poisonous plants together (Robins occur from it s ingestion_ 1977). In Australia, several Senecio species Symploms and treatment have also been incriminated in the The disease pyrrolizidine alkaloidosis poisoning of grazing animals (Bull el or se neciosis, produced by the con­ 01. 1968), S. lou Ius (Bennells 1935) and sumption of Senecio plants, is charac­ S. madagascariensis (then known as teristically chronic in nature with most S. lou IUS) (Green 1953; Whillet 1958) being among them. pyrrolizidine alkaloids being cumula­ tive poisons (Swan 1967) . These induce Mortalities and poor growth of a form of liver (hepatic) damage cattle in the Hunter Valley of New characterized by megalocytosis and South Wales were shown by Walker inhibition of cell division (Bull el 01. and Kirkland (1981) to be also caused 1968). The disease is progressive, by fireweed toxicity. Fireweed, experi­ sy mptoms and deaths of animals com­ b. mentally fed to three calves, caused the monly occurring weeks or months after death of two within 77 days and dep­ consumption of the plant has ceased ressed growth rate in the thi rd. These (Swan 1967; Anon. 1930; Bull 1955). findings were augmented by a study of The pathological sym ptoms charac­ a substantial field mortality of cattle in teristi c of the disease (Bull el 01. 1968 ; the Bulahdelah district on the central Hooper 1978) have all been reported coast of New South Wales (Kirkland in animals which have grazed or been el 01. 1982). On the basis of the fed fireweed (Walker and Kirkland 1mm autopsy findings, hi stopathology and 1981; Kirkland el 01. 1982). consumption of fireweed, it was con­ The clinical signs that have been cluded that fireweed toxicity was the Figure 4 (al Involucre 01 the capitulum, and (b) observed in callie suffering from fire­ achene 01 Itreweed. principal cause of these mortalities. weed poisoning are diverse, but weak­ It is known that as well as causing ness, marked loss of condition, and poor growth and death of stock, other grass pastures, and that competition emaciatio n with rec umbency and death Senecio species have been responsible with pasture species was small. Their were most prominent (Walker and for a drop in milk production in dairy conclusion was based on th e fact that Kirkland 1981). Nervous signs such as cattle (Watson el 01. 1984). at the highest density in their st udy aimless wandering, slight or incom­ Fireweed is poisonous owing to th e (4 _79 plants m-') total flreweed yie ld plete paralysis, loss of muscular co­ presence of a pyrrolizidine alkaloid (106 kg ha-I) was not a significant ordination, insen sibility and apparent believed to be se necionine (Culvenor part of the total herbage on offer. blindness have been seen infrequently. unpubL data, ci ted by Bull el 01. 1968; However, as Green (1953) and Whit­ In older slock, photosen siti zation, McBarron 1976) . The structures of tet (1958) noted, fireweed is much jaundice and abdominal straining were senecionine and the general form of branched and generally avoided by observed in sporadic cases. Other signs pyrrolizidine alkaloids are given in stock, along with the pasture growin g may include duliness, chroni c scouring Figure 5. beneath it. Consequently, the effective and loss of appetite and condition grazing area is reduced considerably. (Watson el 01. 1984). Densities much hi gher than five plants The most comm on effect attributed m-' are also likely to occur. to fireweed in callie is ill -thrift and While fireweed can grow in all types poor growth in young stock. A condi­ of pasture (Green 1953; Whittet 1958), tion in callie on th e Central Coast of the amount appears to be influenced by New South Wales known as coastal ill­ the quantity of ground cove r and com­ thrift, is believed to be partly due to petition provided by the pasture at fireweed toxicity. Varying deg rees of particular stages of growth of the chronic but not fatal damage are seen weed. It is not generaliy a problem in in these animals (Watson el 01. 1984). a. b. irrigated pastures or crops, possibly There is no effeclive treatment for due to the bell er overall growth and Figure 5 Siructures 01 (a) lhe general lorm of pyrroh­ this disease (Reynolds 1936; Craig el Zld,ne alkaloids (R .. H. OH or a-acyl , the more intensive management of R, - alkyl) . and (b) senec,onme, the 01. 1930; Watson el 01. 1984) . Move­ these sit uati ons (Watson el 01. 1984) . pyrrol lz,dtne alkalOid present In ment of stock to areas free of fireweed T he potential of fireweed for further flreweed may prevent furt her deve lopment of coloni zati on once established, due to the disease but because this form of liver damage is irreversible (Bull el high seed producti on, is another of its The alkaloid content of Senecio 01. important invasive characteristics (Nel­ species is very variable (White 1969) 1968), the sy ndrome of ill-thrift and son 1980). and especially among members of th e poor growth will continue. In order to prevent the access of li vestock to fire­ S. laulus complex (Walker and Kirk­ ToxicilY land 1981). Mature fireweed weed and the possibility of poisoning, control of the weed is most desirable. Sellecio was one of the first plant (S. madagascariensis) has been repor­ genera to excite attention as being ted as having a total alkaloid content harmful to domestic li vestock (Bull el ofO.03"!• . Although this is only a rela­ Faclors affecting poisoning 01. 1968). In many countries, ingestion tively moderate level, Walk er and Poisoning may be affected by several of the widespread species Senecio Kirkland (198 1) conclude that, at least factors. These include the palatability Plant Protection Quarterly VOl . 1(4) 1986 167 of fireweed, age of the plant, availa­ incriminated in stock losses under these for 6 months. In cases of poisoning bility of alternative feed, variation in conditions (Kater 1965). Poor seasonal with other Senecio species, increased animal tolerance and weather conditions or droughts and heavy mortality has also occurred following conditions. stocking rates present potentially dan­ environmental changes (Donald and The risk to livestock grazing infes­ gerous situations. Shanks 1956). ted pastures is contested because fire­ In prepared feeds containing fire­ weed is generally unpalatable to cattle weed, selection is difficult for the and horses (Watson el al. 1984). Many animals and poisoning is more likely life cycle other Senecio species are also regarded to occur. Hay containing other Sene­ Fireweed (S. madagascariensis) is a as unpalatable to livestock. Feed rejec­ cio species has caused livestock poison­ short-lived perennial plant (Green tion problems have been encountered ing (Craig el al. 1930; Leyshon 1926), 1953; Whittet 1958; Cabrera and Re with both S. laulus (Bennetts 1935) while silage is also reported as danger­ 1965; Martin and Colman 1977; Ver­ and fireweed (S. madagascariensis) ous (Donald and Shanks 1956; Fergu­ ona el al. 1982) which behaves most (Walker and Kirkland 1981) in experi­ son 1940). This suggests that the commonly as an annual (Hilliard 1977; ments with sheep and cattle pyrrolizidine alkaloids are not des­ Walker and Kirkland 1981). respectively. troyed in either the hay-making or the The majority of plants die off at the Some evidence suggests that when ensiLing processes. Therefore the con­ end of their first year of growth, but the Senecio pyrrolizidine alkaloids are trol of fireweed (S. madagascariensis) especially in agricultural soils, it is in their N-oxide form they may be in areas to be used for hay or silage is common to find plants which continue more palatable and therefore more critical. to grow and reproduce actively during likely to cause poisoning (Schoental While seneciosis has been reported their second year (Verona el al. 1982). 1955). This was observed in young in all the major classes of livestock, This is true even without some exter­ growing plants (Schoen tal 1957). susceptibility varies. Though sheep and nal stimulus, such as mechanical Preference for young Senecio plants, goats readily eat fireweed, they are damage which could promote the however, has not been confirmed much less susceptible to poisoning than regeneration of its stem. For example, (Cockburn el al. 1955). cattle and horses (Bull 1955; Smith plants which are slashed are not killed The palatability of some toxic Sene­ 1983; Watson el al. 1984). They may but may regrow and become two-year cio species, including fireweed, may be even show preferem:e to it over other plants. This persistence through sum­ improved by spraying (Matt hews 1971) pasture plants. Sheep have often been mer is confirmed by observations made or slashing, possibly because wilted or used to graze down pasture land badly by Nelson and Michael (1982). In some dried material is more readily con­ infested by ragwort (S. jacobaea) plants, regrowth from roots can occur sumed (Murnane 1933). Because fire­ (Hexter 1950; Parsons 1973) with following the death of the top growth weed remains poisonous when dry apparently no ill effects (Reynolds over summer (Watson el al. 1984). (Walker and Kirkland 1981), there is 1936). However, other evidence sug­ Since rooting along the woody stems a danger that poisoning may occur fol­ gests that sheep are affected by pyrroli­ of decumbent fireweed plants has also lowing such operations. zidine alkaloids but progression of the been observed (Nelson 1980), it is pos­ Since the evidence concerning the disease is much slower (Bull el al. 1956; sible that shoots associated with these effect of age on the toxicity of Senecio Bull el al. 1968). Detoxification of the adventitious roots remain alive, while plants is contradictory, and the relative alkaloids by specific bacterial enzymes those of the parent roots die off. Ver­ toxicity of immature fireweed has not in the rumen of sheep (Bull el al. 1968), ona el al. (1982) had reservations in been reponed, potential toxicity or the high activity of a hepatic considering it a strict perennial. throughout the life (and death) of the microsomal enzyme (Swick el al. however. because with rare exceptions, plant should be assumed (Nelson 1983), could account for their relative the few plants that survive the second 1980). resi stance. year are decrepit and ready to senesee. Providing sufficient alternative feed It is likely that the age of livestock It is likely for this reason that Hum­ is available, callie and horses will con­ also affects tolerance. Thus Walker bert (1963) reports S. madagascarien­ sume only small quantities of fireweed. and Kirkland (1981) found group sis as a biennial. Where its ingestion cannot be avoided, mortalities most often in calves. In It is not uncommon therefore to find poisoning is more likely to occur. Such contrast, mortalities in older animals variations in the life cycle of this plant. circumstances may include pastures occurred sporadically and the syn­ Similar variations are known to occur heavily infested with young fireweed drome of poor growth was more prom­ in S. jacobaea (Forbes 1977, cited by plants and poor quality pastures where inent. This may reflect a greater toler­ Verona el al. 1982), a biennial plant there is a shortage of alternative feed ance due to larger body size and prior which may also behave as a perennial (Watson el al. 1984). It is in the laller exposure to the plant. under certain conditions. In this con­ sit uation, where a pasture has a low Evidence suggests that changes in text , S. madagascariensis represents a grazing capacity, that fireweed is often weather conditions may also influence species with high plasticity or capacity most prevalent (Green 1953; Whillet fireweed poisoning. During January to vary its life cycle. This undoubtedly 1958; Martin and Colman 1977). In the and February 1980, 75 callie died from is associated with the duration and Hunter Valley, like other areas along a herd of 800 in the Bulahdelah district stability of the habitat which supports the New South Wales coast, there is on the Central Coast of New South it (Southwood 1977, cited by Verona often a seasonal shortage of pasture Wales. Kirkland el al. (1982) conclu­ el al. 1982). from late winter to mid or late sum­ ded that fireweed toxicity was the prin­ Fireweed is capable of growing and mer (Walker and Kirkland 1981). It is cipal cause. They also observed that reproducing during a large part of the at these times that fireweed is most the peak of these mortalities occurred year, although most seed germinates abundant and a scarcity of alternative after major changes in the weather, from March to July with the plants feed forces callie to consume the plant e.g. after rain and an improvement in dying off from September to Novem­ despite its unpalatability. COllon fire­ nutrition. At the time of the mortali­ ber. At the moment of dispersion a weed (S. quadridenlalus) has also been ties, drought conditions had prevailed high proportion of seed is viable and 168 Planl Protecti on Quarterly Vol. 1(4) 1986 ready to germinate (Alonso el al. 1982; 10 weeks after emergence. Time to Wales, distribution does extend into Nelson and Michael 1982). Nelson and flowering decreases with increasing the northern and southern Tablelands Michael showed this to be 900/0 three temperature (Nelson 1980). Growth (Nelson and Michael 1982) and an iso­ days after collection at 20°e. It is sug­ rates (dry matter and leaf area) are lated occurrence exists further inland gested that because of this more than positively correlated with mean air at Dubbo (Watson el al. 1984). The one generation may occur throughout temperature (Nelson 1980; Fernimdez potential distribution of fireweed in the winter period (Nelson 1980). While and Verona 1983). Dry matter all oca­ Australia is not known, but in view of ex treme temperatures induce dor­ tion to leaves prevails during the early its rapid spread in recent years it can mancy of the seeds (Alonso el al. developmental stages with an increas­ be expected to occupy areas much lar­ 1982), innate dormancy is negligible ing proportion of assimilates going ger than at present. under normal conditions. High spring into the stems over the life of the plant. In so uthern Africa it is known to and summer temperatures may help to All ocation to roots decreases rapidly occur up to 1500 m above sea level and explain the lack of new seedlings with plant age (Fernandez and Verona is widely distributed from Madagascar appearing in that period. 1983). and the Mascarene is lands through Nelson and Michael (1982) showed S. madagascariensis is a precocious coastal Mozambique to Natal, the that most rapid ge rmination occurred species with flower intensity greatest at Transkei and eastern and southern between 20°C and 25 °C. Highest ger­ the beginning of spring. A flu sh in Cape as far west as the Uniondale dis­ mination after 14 days occurred bet­ flowering also occurs in the middle of trict. Though not common, it is also ween 15 °C and 27°C with greatly autumn (Verona el al. 1982). An indi­ found in the Transvaal (Hill iard 1977). reduced germination at lower and vidual plant has the ability to produce In , though originall y clas­ higher temperatures. This helps to large quantities of seed during its li fe sified as S. incognillls (Cabrera 1941) explain why fireweed can germinate cycle. In a seed production study (Nel­ and subsequently as S. burchellii over much of the year. Nelson and son, personal communication) the (Cabrera 1963; Cabrera and Re 1965), Michael also found, and this has been average plant produced approximately S. madagascariensis was first known in confirmed by the author, that there is 230 flowers with 80 seeds per flower the early 1940s surrounding the port of no germination at 35 °C but seed expo­ (total of 18 000 seeds). At a nominal Bahia Blanca. Sin ce th en it has spread sed to this temperature was viable germination rate of 500/0, it was esti­ greatly and is now a signifi cant weed when germinated at 20 °e. The opti­ mated that the average plant produced of agri cultural in the south­ mum temperatures observed for germi­ 9000 viable seeds. Because the seeds eastern part of Buenos Aires province nation and the ability of the seeds to are small and li ght (135 I'g) and each (Verona el al. 1982). withstand high summer temperatures is attached to a relatively persistent The present distribution of S. mada­ are those expected of a winter-growing pappus of white hairs (Daniel 1984), gascariensis in so uthern Africa, Aus­ species in parts of coastal New South they are easily spread by wind. It is the tralia and Argentina is shown in Wales (Nelson 1980). dispersal of large amounts of seed in Figure 6. Although li gh t (Nelson and Michael this way that is considered to be the On a local scale the pattern of dis­ 1982; Alonso el al. 1982) and nitrates major factor responsible for the rapid tribution may vary considerably on (Alonso el al. 1982) are not essential, spread of the weed over large areas and account of differences in soil and previ­ they generall y stimulate ge rmination. long distances (Watson el al. 1984). ous cultural systems. Fireweed is Responsiveness to light has also been The seeds can also be spread in hay drought tolerant and able to grow on reported in S. vulgaris (Po pay and and grain products, on clothing and a wide range of soil s of varying fertil­ Roberts 1970) and may be of direct vehicles, and by li vestock, birds and ity (Verona el al. 1982) . Although it consequence to the establishment and other animals. There have also been prefers soils which are we ll drained, survival of seed, by determining the suggestions that seed has blown into not compacted, and of high fertility, maximum depth of so il from which piles of superphosphate and then been it can also grow in sa nd and heavily germination may take place (Koll er spread to new areas when the ferti li z­ li med soil. Low fertilit y soils are less 1964). The depth of S. madagascarien­ er was applied aeriall y. li kely to support vigorous pastures sis seed in the soil does affect germi­ and, lacking 'competition, fireweed grows freely (Watson el al. 1984) . nation with seed ling emergence not Distribution occurring below 2 em (Alonso el al. Although these authors also state that 1982). The earli est record of fireweed in New it will not persist in poorly drained or Osmotic potentials ranging between South Wales - and probably in Aus­ waterlogged situations, Verona el al. o and - 3 bars did not differ in their tralia - is a specimen collected at Ray­ (1982) concluded the opposit e to be effects on germination (Alonso el al. mond Terrace in 191 8 (Nelson 1980). true. The results of a trial conducted 1982). Although the percentage It fir st became prominent in pastures by Daniel (I 984) also suggest that fire­ decreased at potentials below this level, in the Hunter Valley and from there weed may show adapt ion to different some seeds were still able to germinate spread throughout many partS of drainage regimes and indicate that it at - 10 bars. The three types of coastal New South Wales, being intro­ has a large potential for physiological achenes (dark brown, light brown and duced to the North Coast in about va ri ati on. green) (Verona el al. 1982) had differ­ 1940 in crop seed (Martin and Colman ent germination behaviour and mor­ 1977). It is now especially abundant in the Ri chmo nd , Manning and Hunter phological characteristics. Control It has been es timated that, under Valleys, in the County of Cumberland laboratory storage, all seeds lose their and bet ween Wollongong and Berry on Although fireweed was declared a nox­ viabi lity after 4 to 5 years (Alonso el the Sout h Coast. The weed is also ious weed in ce rt ai n shires of New al. 1982). Nothing is known concern­ known to occur as far south as Bega South Wales from 1946 to 1971 (Mar­ ing the longevity of seed in the field. and in south-eastern Queensland. tin and Colman 1977), it is now gener­ Fireweed seedlings develop rapidly While the weed primarily infests the all y consid ered that eradication and with the plants producing flowers 6 to coastal river va ll eys of New South prevention of spread are not feasible. Planl Protection Quarterly Vol. 1(4) 1986 169

ously been recognized by Green (1953) and Whittet (1958). Any factors which open up pastures such as overgrazing, drought, uncompetitive pasture species and areas bared by trampling, e.g. around watering or feeding places, appear to favour the development of . ~~~ ...... ~ .. 1~.05 fireweed . A dense, vigorous and competitive ...... ' ...... ~ .. ?rt5 pasture during early autumn to wi nter is likely to provide the best form of control. It is possible that this could be ,,~~ ...... , ...... rJ ....<1 .5°5 achieved by the growing of early winter pasture species, by allowing standover of summer pasture feed, or by combi­ Figure 6 World distribution of Senecio madagascaflensis nations of winter-summer pastures (Watson el al. 1984). This is particu­ larly relevant since fireweed is of greatest abundance in natura li zed The characteristics of fireweed wnich Further trials assessed the use of summer-growing pastures such as often make it s control difficult include: ropewick applicators on fireweed pas palum (Paspalum dilata­ I. resistance to drought; (Launders I 984a,b). These enable non­ tum)/ carpet grass (Axonopus affinis) 2. prolifi c seed production; selective herbicides such as glyphosate dominant pastures of the Centra l to 3. ease of seed distributio n; to be selectively applied to species. North Coast regions of New South 4. annual/perennial habit; Both bromoxynil at 200 g a.i. per litre, W ales (Martin a nd Colman 1977; 5. adaptability and vari a bility in the a nd glyphosate at 100 g a.i . per litre Launders 1979). The low productivity field ; proved effective against young plants, a nd high relative stocking rates in the 6. establishment when summer pasture but glyphosate was needed to ensure a winter months predisposes them to growth is declining but before most good ki ll after flowering (Launders invasion. winter past ure growth has beg un; 1984a). In the second trial, two passes Due to the need for continuity of 7. germination, growth and fl owering of the applicator using glyphosate gave feed, partic ularly on dairy farms, new during much of the year; and a 94% ki ll o f fl owering plants com­ pasture species may need to be drilled 8. a long fl owering period. pared to 69% with only one pass directly into the existi ng pasture rather Despite the importance o f the weed, (Launders I 984b). When glyphosate is th an using conve ntional cultiva ti on very little work has been done on it s applied via a ropewick applicator the before sowi ng. Possible winter species cont rol, and that has been mostly target weeds sho uld be at least 15 em include phalaris. ryegrass, fescue, confined to work with herbicides. An taller than the pasture. To help achieve white clover, subterranea n clover and integrated approach is surely desirable. this situati on the area should be grazed oats, while summer species such as To this end, a range of possible con­ prior to treatment. kikuyu, paspalum, setaria a nd Rhodes trol met hods is discussed here. Tests to determine whether these grass have potential. Kikuyu domi­ two herbicides have a ny effect on the nance, even under heavy grazing, is germination of fireweed seeds when the said to markedl y reduce fir eweed den­ Herbicides plants have been sprayed in the la te sit y (Martin and Colman 1977). possi­ The most desirable time for herbicide fl owering stage, indicate that both bly because kikuyu has a longer period application is during the small seedling reduce germination, with. glyphosate of active growth in autumn than either to earl y flowering stages (normally being the more effective of the two. carpet grass or paspalum (Colma n autumn to winter) (Watson et al. As previously mentioned, fireweed 1970). It therefore com petes more 1984). While a number of herbicides plants treated with herbicides may, strongly with regenerating seedlings of have been compared for efficiency in however, become more attracti ve and fireweed. kill ing fir eweed, glyphosate (as Round­ palatable to stock. This could increase Careful fertilizer management is also up) and bromoxynil (as Brominil) have the ri sk of fireweed poisoning even likely to be a critical tool in fi reweed proved to be the most effective (Laun­ tho ugh stock may be withheld from control (Nelson 1980). T he applicati on ders 1979). the treated areas until the plants are o f fertilize r during the active growth An excellent kill of young fireweed completely dead. period of the grasses could increase was achi eved with a n application of Because pastures that initially their yield a nd therefore decrease the bromoxynil at 280 g a. i. ha· l . proved suitable for invasion by fire­ density of fireweed. However, the However, when applied to adva nced weed arc li kely to suffer the same fate opposit e may be true if application plant s, the percentage kil l dropped to again, herbic ide control must be con­ occurs when co nditions are unfavour­ less than 55'70 (Launders, personal sidered a temporary measure a nd be a ble for response by the pasture, for communi cation). It was concluded that ca rried out in conjunct ion with pasture example, in autumn when the summer­ after bud formation, between 500 and improvement. growing species have ceased active 560 g a.i. ha·1 were needed. Bromox­ growth. yn il is a selecti ve herbicide. While Pasture management through con­ grasses are un affected it will cause Pasture management trolled grazing, appropriate fertilizer some scorching of the upper leaves of The essentia l principle in any fireweed applications and the sowing of new clover. This effect, however, is tem­ control progra m according to Smith species. as a met hod of fireweed con­ porary a nd the clover gene rall y reco­ (1983) must be provision of a vigorous, trol, has potential and warrants further ve rs quickl y. competitive pasture. This had previ- investigation . 170 Plant Protection Quarterly Vol t{4) 1986

Mowing soil (Daniel 19 84). At present , pseudococcid has a lso been observed Very lillie has been reporled concern­ howeve r, nothing is known of the sur­ in the root s. In greenhou se-g rown ing the effectiveness of mowing or vival of fireweed seed in a so il sys tem . plallls an aphid (MyzlIs persicae) has slashing as a means or controlling fire­ Because cu lti vation will mix weed seeds been ro und to feed on the leaves, while weed. The results of mowing through­ between co nditions enforcing dor­ in gardens the yo ung plant s are ealen out the au tumn to spring period have mancy and co nditi ons whi ch favour by a snail (Helix aspera) . been variable (Watson el 01. 1984). In germination (RobertS 1964), Ihe longe­ In Australia, insec ts such as the lar­ trials near Taree close mowing did not vi lY or the seeds or firewecd in culti­ vae o f a pyralid mOlh (H omoesoma kill th e plants but only slowed their vated ground is expected to be much sp.), the cin eraria leaf min er growth and delayed ~owerin g. Because less than in undisturbed ground. (Phytomyza sYllgenesiae), th e senecio mowing may promote regrowth (Ver­ mOlh (Nyclemera all/ica), Ihe metallic ona el 01. 1982), il will cause some fire­ Crazing flea beet le (Hallica sp.) and va rious weed plant s to survive through summer While low stocking rates are recom­ pasture slu gs are known to feed on the and co ntinue to grow and Bower in the mended to a ll ow paslUre to compele pl a nt (Watson el 01. 1984). A Lygaei­ seco nd year. more vigorously wi th fireweed, it is bel­ dae bug (Nysius sp.) is a lso commonly Nevertheless, regular mowing can ieved (hat graz ing with sheep or goa ts found on th e infloresce nce. ass ist in co ntrol over small areas. It is may be of some use in fireweed co n­ A rela lively widespread autoecious likely to be more successrul ir carried trol (Walson el al. 1984). They have rust, Puccinia lagell opliorae, infests out at late nowering rather th an earl­ bee n used in Australi a and overseas for fire wecd in the field and ca n cause co n­ ier in the life cycle o f the planl. Mow­ Ih e contro l of olher weedy Senecio siderable growth retard ation on heavil y ing when co nditions are unfavo urable species in past ures. For example, in the infecled pla l1l s. Lik e olher pla nl d is­ for pasture growth, or in yo ung and Gippsland area of Vi ctori a, many eases, the severit y and spread of Ihis unlhrifl Y pastures, should be avoided dairy farmers ca rry some sheep, rll st on I1reweed is depe nden t on sin ce th e weed may recove r more usuall y crossbred wet hers, for the sale prevailing. favourable wea th er condi­ quick ly than the paslure and therefore purpose o r c ontrolling ragwort ti ons. In Brit ai n, S. vulgaris and become dominant. (S. jacobaea) (Parsons 1973). S. squalidus are readily allacked by il. Becau e wilt ed or dried fireweed Although Ihe efl'eci or deroliation on The ru st, lhought to be nati ve to Aus­ plalll s rela in Iheir 10xicilY and may fi reweed has nO! been documented, tra li a a nd New Zeala nd, was di sco­ become mo re palalable to stock, the experience shows that sheep and goa ts vered here as early as 1884 (Wilson el risk of poisoning may also be do provide a level of control wort hy of 01. 1965). II has bOlh lelia and accia increased. serious co nsideration . bUI no pycni a. The teli a a nd aecia, This method , however, is not when fou nd on the leaves and stems of plant s are dark brown to bla ck and Cultivatioll wi th out diffi culti es. Running sheep under coastal conditions would lead to pale yellow to orange respecli vely. The Foll owing the finding or Nelson (1980), an increased incid ence of parasites and ru st attacks a ra nge of plant s in the that germination of fireweed in the di seases. Improved or additi onal family ASleraceae and it is beca use of dark was only 8"'0, it appears tha i fences and yards may be required a nd it s relm ive ly wid e hos t ra nge th at its burial of the seed could a id in reduc­ fl ock composition would need to be use in inundat ive bi ological co ntrol is ing plant populalions. An ex periment , a ltered regul arly in order to avoid unlikely. II is capa ble or infecting designed among other things, to tes t eve ntual poisoning of the animals. many garden pl ant s including ca len­ Ihis as a method o f control (Daniel Siocking rates would a lso have to be dula, or Engli sh marigold (Calendula 1984) showed, howeve r, Iha l even managed carefull y so Ih at lhe fir eweed officinalis), English daisy (Bellis perel/­ wh ere the so il was inve rted by mould­ was suppressed but th e pasture was not /lis) and garden cin eraria (Senecio board ploughing, fireweed increa sed overgrazed. Lastl y, many fa rmers cruellflls) (Wilson ef al. 1965). Watson ral her than decreased in densil Y. C ul ­ wo uld fee l it impracti cal 10 introduce el 01. (1984) report I hal a grey mould ti va tion of natural carpet grass sheep il1lo predominanlly dairying ru ngus (Bolrylis cil/erea) also infecls pastures, in ord er to es tablish impro­ areas . flrc weed. ved species, has also been observed to A s S. madagascariensis is nOI a in crease th e densit y of f1reweed (Laun­ nati ve of Australia, it is po ss ible th at ders 1979). Biological some pathogen or natural enemy of th e M ore often than not , soil culti vation Allhough a number of insects bOlh in plant may be found in SOUl hem Arri­ stimulates ma ssive germination of fir e­ Australia and Argentina are known to ca or Madagascar which would enable weed seed and providcs a suil a ble bed feed on S. madagascariensis and a rus t co nlrol. However, du e to stri ct legis­ for seed s blown in from ot her areas. infest it , their impact is still relatively lation and Ihe need for ex tensive Therefore to be eO'ecl ive a nd kill unknown. ex peri mentation such co ntrol is, of emerg in g seedlin gs, cultivation must be In Argentina, during it s vegeta ti ve necess ity, a long-term goa l. Ihorough, repealed and fo ll owed up stages of growth . S. madagascariensis with the es tab li shment of ei ther a suit­ is a frequenl host o r a lli S, principall y able pe renni al pasture or, alternatively, Acromirmex lundii (Verona el 01. a wi nt er crop fo ll owed by a perennial 1982). These cat the leaves and vegela­ Acknowledgments paslure (Watson el 01. 1984). Where tiv e shoo ts an d in th e more advanced co ntinuit y of feed is important, com­ plallls feed on the beginnings o r Ihe I gralefull y acknowledge Ihe support plele culti va tion s of this nature are inflorescences. Another in sec t. still not of Ihe W. C. Turla nd, Universily or likely 10 be uneconomical. idenlified, feeds on the ovaries, reduc­ Sydney po Igraduale scholarship, for Any considerali on of Ih e long-Ierm in s th eir growth and th e reprod uctive resea rch int o the ecology an d co ntrol implica ti ons of weed co ntrol mu st tak e capacily o f the weed. In young of fireweed. Thanks are also give n to into account the populati on of dor­ branches, Il y larvae (Lamproxynella Dr P. W . Michael for hi s assistance mant, viable weed seed s present in the sp.) cause Ihe formation of galls. A and comment s on th e manusc ript. Plant ProtectIOn Quarterly Vol 1(4) 1986 171

References provincia de Bu enos Aires. Revisla Kater, J . C. ( 1965). Cott on fireweed de 10 Fawltad de Agronomia. La (Senecio quadridentata) poisoning in Ali, S. I. (I 964a). Senecio laUluscom­ Plata. 41 ,43-50. cattle. Veterinary Inspector 29, plex in Australia. I. Taxonomic con­ Cockburn, R. S., Eaton, G. , Hudson, 45-7. sid erati ons and di scussion of some J. R., Morgan, K. G., W ood, Kirkland, P. D. , Moore, R. E., of the rela ted taxa from New E. C., and Wo rden, A. N. (1955). Walker, K. H., Seaman, J. T ., a nd Zealand. A uSlralian Journal oj Acute poisoning of cattle by com­ Dunn, S. E. (1982). Deaths in cattle Botany 12, 282-91 . mon rag wort (Senecio jacobaea L.). associated wi th Senecio lautus co n­ Ali , S. I . (1964b). Senecio laUlus com­ Veterinary Record 61, 640. sumption. A lIstralian Veterinary plex in Australia. II . C ultural Colman, R. L. (1970). Future use of Journal 59, 64. studies o f popula ti ons. Australian nitrogen fert ilizers on pastures and Koller, D. ( 1964). The survival value Journal oj Botany 12, 292-316. crops in sub-tropical New South o f germination-regulating mecha n­ Ali, S. I. (1966). Senecio laullls com­ Wales. Journal oj the A IIstralian isms in the field . Herbage Abstracts plex in Australia. III. The genetic In stitllte oj Agricultural Science 36, 34, 1- 7. system. Australian Journal oj Bot­ 224-32. Laguinge, E. G. (1959). Nombres vul­ any 14, 317-27. C raig, J . F., Kearney, W., and gares de malezas . Ali , S. I. (1968). Senecio laUlus com­ Timo ney, J . F. (1930). Ragwort Memoria de la reunion de lu cha plex in Australia. IV. The biology of poisoning in cattle and ci rrhosis of cont ra la maleza. Revista Argelllina the complex. Phy tan (Hom , A us­ th e li ver in horses. Veterinary de Agronomia Suplemenlo No.3. tria) 13, 53- 62 . Record 10, 159-14. Bs.As. Ali, S. I. (1969). Senecio laUlus com­ Da ni el, R. P. (1984). The biology and Launders, T. (1979). Can fir eweed plex in Australia. V. Taxonomic control o f fireweed (Senecio (Senecio lautus) be extingui shed? interpretations. Australian Journal madagascariensis). B.Sc.Agr. Australian Weeds Research Newslet­ oj Botany 17, 16 1-76. Thesis, Uni versi ty of Sydney. ter 21, 26-7. Alonso, S. I., Fermindez, O. N., Lan­ Donald, L. G., a nd Shanks, P. L. Launders, T . (I 984a) . Use of ropewick gero, S. I. , and Verona, C. A . (1956). Ragwort poisoning from applicato rs on fireweed (Senecio (1982). Characteristics of seed si lage. British Veterinary Journal madagascariensis). A us t ralian germinat ion o f Senecio madagas­ 112,307-11. Weeds Research Newsleller 32, 21. cariensis Poiret (Compositae) (In Ferguson, H. N. (1940). Suspected La unders, T. (1984b). Use of ropew ick Spani sh) . Ecologia Argelllina 7, ragwort poisoning in cattle. Veteri­ applicators on fireweed (Senecio 95- 11 6. nary Record 52 , 758-9. madagascariensis), 1983 trial. A us­ Anon. (1930). Ragwort poisoning a nd Fernandez, O. N., and Verona, C. A . tralian Weeds Research Newsleller cirrhosis of th e li ver. Vererinary (1 983). Growth and dry ma tter par­ 32, 22. Record 10, 175. lition in Senecio madagascariensis Leyshon, W. J. (1926). Ragwon Bennetts, H. W. ( 1935). An investiga­ Poiret (Compositae) (In Spani sh). poisoning. Veterinary Record 6, ti on of plants poisono us to stock in Revista Facultad de A gronomia 4, 687-8. Western Australia. Journal oj the 213-25. McBarron, E. J . (1976). 'Medical and Departmelll oj Agriculllire, Western Fernandez, O. N., and Vero na, C. A. Veterinary Aspects of Plant Poisons A llstralia 12, 431-41. (1984). Reproducti ve characteristi cs in New South Wales.' p.83. (Studio Bull, L. B. (1955). The histological evi­ of Senecio madagascariensis Poi ret Press: Sydney .) dence of liver damage from pyrroli­ (Compositae) (In Spanish). Revista Martin, R. J ., and Colm a n, R. L. zi dine alk aloias: megalocytosis of Facultad de Agronomia 5, 125-37. ( 1971). The effects of fertilizers, her­ the liver cells and inclusion globules. Forbes, J . C. (1971). Popul ation flu x bicides a nd grazi ng in tensity on the Australian Veterinary Jo urnal 31, a nd mortalit y in ragwort (Senecio incidence of fireweed (Senecio 33-40. jacobaea L.) infestation. Weed 10111 us) in sub-t ropical pastures. Bull, L. B. , C ul ve nor, C. C. J ., a nd Research 11 ,387-91. Australian Journal oj Experimental Di ck, A. T . ( 1968). 'The Pyrroli zi­ Green, K. R. (195 3). Fireweed. The Agriculture and A nimal Husbandry dine Alkaloids - Their Chemistry, Agricultural Gazelle oj New South 11, 296-300. Pathogenicity and other Bi ological Wales 64, 521. Matthews, L. J . (1971). Ragwort. New Properties. ' (North Ho ll a nd Pub. Hexter, G. W. (1950). Ragwort. Con­ Zealand Journal oj Agricultllre 123, Co.: Amsterdam.) Irol by pasture improvement. Jour­ 95-7. Bull, L. B. , Di ck, A . T., Keast , J . c., nal oj the Department oj A gricul­ Mi chael, P. W . (198 1). Alien pl ant s. and Edgar, G. ( 1956). An experi­ ture, Victoria 48, 217- 18. In 'Austral ian Vegelation'. ed. R. H . mental invest igation of the hepato­ Hilliard, O. M. ( 1977). 'Composit ae in Groves, p. 44. (Cambridge Univer­ toxic a nd ot her efrects on sheep of Natal.' p. 404. (University of Natal si ty Press: Cambridge.) cons umption of HeliolropiwlI eu ro­ Press: Pietermarilzburg.) Murnane, D. (1933). Ragwort poison­ paellm L. Heli otrope poisoning of Hooper. P. T. (1978). Pyrroli zidine ing in cattle in Victoria. Journal oj sheep. A IIs tralian Journal oj alkaloid poisoning - Pathology the CouncilJor Scientijicand Indus­ Agricultural Research 7, 281 - 332. wit h particular reference to differ­ trial Research 6, 108- 10 . Cabrera, A. L. (1941). Compuestas ences in an imal and plant species. In Nelson, N. R. (1980). The ge rmination bonaerenses . Revista del Museo de 'Tile EO'ects of Poisonous Plants on and growth characteristics of fire­ La Plata 4, 1- 450. Li vestock', eds R. F. Keeler, K. R. weed (Senecio madacascariensis) . Cabrera, A. L. (1963). Compositae. In Van Kampen and L. F. J ames, B.Sc.Agr. Thesis, University of 'Flora de la Provi ncia de Buenos p. 161. (Academic Press: New Sydney. Aires.' Torno IV , 6 (Colecci6n cien­ York.) Nelson, N. R., a nd Mi chael, P. W . tilka del INTA. Bs.As.) Hum bert , H . ( 1963). ' Flore de (1982). Germination a nd growt h of Cabrera, A. L., a nd Re, R. R. (1965). Madagascar.' p. 734. (Museum Na­ Senecio madagascariensis Poir. (fire­ Sabre un Senecio adventicia en la tional d'Histoire Nat urell e: Pa ri s. ) weed). a toxic plant of pastures in ,

172 Plant Protection Quarterly Vol. 1(4) 1986

coastal New South Wales. Proceed­ J. B. Harborne and B. L. T urner, Verona, C. A., Fe rn andez, O. N., ings o f the 2nd Austra lian Agro­ p. 83 1. (Academic Press: London.) Montes, L. , and Alonso, S. I. nomy Conference, p. 173. (Griffin Schoental, R. ( 1955). Palatability of (1 982). Agroecological a nd biologi­ P ress: Netley, South Austra lia.) N-oxides of pyrroli zidine alkaloids cal aspects of Senecio madagas­ Ornduff, R. (1 964). Evolutionary path­ as a fac tor in Senecio po isoning. cariensis Poiret (Composit ae) (I n ways of the Senecio lautus a ll iance Nature 175 , 595. Spani sh). Ecologia Argentina 7, in New Zealand and Australia. Evo­ Schoenlal, R. ( 1957). Hepatotoxic 17-30. IlIIion 18, 349-60. action of pyrrolizidi ne (Senecio) Walker, K. H., and Ki rk land, P. D. Parsons, W. T . ( 1973). 'Noxious alkaloids in rela ti on to their struc­ (198 1). Senecio lalllus toxicity in Weeds of Victori a', p. 11 0. (Inkata ture. Nature 179, 361- 3. callie. A ustralian Veterinary Jour­ Press: Melbourne.) Smith, L. W. (1983). Fireweed. Weed­ na157, 1-7. Popay, A. I. , and Roberts, E. H. ers Digest News Leller. Noxious Wa tson, R., Launders, T ., and Maca­ (1970). Factors in volved in the dor­ Plants Advisory Commillee, New dam, J. ( 1984). Fireweed. Agfact mancy and germination of Capsel/a South W a les Depa rtment o f P7.6.26, New South Wales Depart­ bursa-pastoris (L.) Medi k. and Agricul ture 6, 3-4. ment of Agriculture. Senecio vulgaris L. Journal oj Ecol­ Southwood, T. R. E. (1 977). Ha bi tat, White, E. P. (2969). AlkaJoids of some ogy 58, 103-22. the templet for ecological strategies? herbaceous Senecio species in New Reynolds, A. J . S. (1 936). Ragwort Journal oj A nimal Ecology 46 , Zealand. New Zealand Journal oj poisoning in Pembrokeshire. Veteri­ 337-65. Science 12 , 165- 70. nary Record 48, 1407 . Swan, G. A. (1967). 'An Introduct io n Whillet, J. N. (1 958). 'Weeds', p. 25 1. Roberts, H. A. (1964) . Emergence and to the Alkaloids', p. 15 1. (Blackwell (New South Wales Government lo ngevit y in culti vated soil of seeds Scientifi c Publicati ons: Oxford.) Printer: Sydney .) o f some annual weeds. Weed Swick, R. A ., Mi ra nda, C. L. , Wilson, I. M., Walshaw, D. F., and Research 4, 296-307. Cheeke, P. R., and Buhler, D. R. Walker, J. ( 1965). T he new ground­ Robins, D. J. ( 1977) . Senecioneae­ (1 983). Effect of phenobarbitaJ o n sel rust in Britain and its relationshi p Chemical review. In 'The Biology tox icity of pyrrolizidine (Senecio) to certain Australas ian rusts. Trans­ and Chemistry of the Composit ae.' alkaloids in sheep. Journal oj actions oj the British Mycological Vo lume II , cds V. H. Heywood, A nimal Science 56, 887-94. Society 48, 501- 11.

Plant Protection Quarterty Volume 2 1987 ISSN 0815-2195

Subscription

If you wish to subscribe to Plant Protection Quarterly please complete the order form below. Subscriptions will be for four quarterly issues. Enquiries, order forms and payments should be directed to the Publisher: Inkata Press Pty Ltd, 4 Longbourne Avenue, North Clayton, Victoria 3168, Australia.

Subscriptions Wlthtn Ind ividuals AS30.00 Over.... Individuals ASSO.OO Overse.. Individuals AS70.00 Austrana Companies & (.urface Companies & (at,mall) Companies & Volume 2 1987 (poot patd) Institutions ASSO .OO moU) Institu tions A$60.00 Institutions ASBO.OO

Order Form Plant Protection Quarterly To Inkata Press Ply Ltd , 4 Lon9bourne Avenue, North Clayton, Victoria 3168 , Australia Please find enclosed chequelmoney order no ...... for $ ...... being a subscription for 1 year (4 issues) of Plant Protection Quarterly. Overseas subscriptions must be paid in Australian currency. Name ...... Position ...... Address ...... Plant Prolecllon Quarterly Vol 2(1) 1987 37

gence obtained in the 0.00320/0 a.c. References Wismer, C, A. ( 1961). Pineapple dis­ prochloraz treatment at 86 days is not Hughes, C. G ., and C hristie, G . A. ease. In 'Sugar Cane Diseases o f the known . In the field trial at Bundaberg World,' Vol. I , eds J . p , Martin, (1949). The treatment o f cane sett s in 1984 (Ta ble 2), prochloraz a t E. V. Abbott, and C. G. Hughes with mercurial so lutions. Cane 0.0126% was as effective in sett treat­ Growers' Quarterly Bulletin 13 , (Elsevier Publishing Company: Am­ ment as th e recommended organomer­ 43- 52. sterdam .) pp. 222-45. curi al fungicide treatment in eith er the billet- or trash-planting systems. Ri caud, C. (1972). Benla te for con­ From the studies reported in this trolling pinea pple disease. Sugar paper, prochIoraz at 0.0126% a.c. is Pathologists' Newsleller, 8, 19 . recommended as a commercial cane­ Rya n, C. c., Taylor, p , W. J ., Hall , seU trealment as this co ncentration P., a nd Campbell , C. B. (1983 ). provides a sati sfactory sa fety margin . BayIeton fungicide as a sugar-cane The unexpected result from very low sett treatment for the control o f rates of prochIoraz indicates tha t pineapple disease (Ceratorystis similar studies arc req uired with Olher paradoxa). 4t h In ternational Con­ recommended sell treatment s. gress of Plant Pathology, Mel­ bourne, August 17-24, Abstract No. 314. Acknowledgments Taylor, p, W. J" and Rya n, C. C. We wish to thank Mr R. Magarey, J . ( 1984). Propiconazole fungicide as Lopez, B. Pearce and N. McG ill of a sell treatm ent for the co ntrol of BSES and Mr D. Biffin ofSchering Pt y pineapple disease. Sugar Calle 5, Ltd for th eir assistan ce. 5- 8.

Erratum

On page 166 of Plant Protection a. Quarterly Volu me I (4), sca le lines b. were accid en tally o mitted from Figure 4 of the paper 'The eco logy an d co ntrol of fireweed (Senecio madagascariensis Pair.)' by B. M. t Sindel. The correct diagram is shown here.

lmm (a) Involucle 01 the capitulum (0) achene of IIleweed