Current status and distribution of common heliotrope (Heliotropium europaeum L.) in New South Wales

J. J . Dellow J . T. Seaman New Soulh Wales Departmenl of Agr icullure. Agricullural Research and Velerinary Cenlre. Foresl Road. Orange. New Soulh Wales 2800

Summary

A survey of local government areas in spring- summer of 1983- 84 revealed that Heliotrop;um europaeum was widespread throughout New South Wales. Heaviest infestations were confined to the southern half of the Slate, in particular the drai nage systems of the Lachlan, Murrum bidgee a nd Murray Rivers.

Introduction

H elio lropillm europaeum L. (Boraginaceae) is the mOSI important of the fi ve Heliolropium spp. having economic significan ce in Austra lia. The ot her four species arc blue hel iotrope, H . amplexicQule Vahl 1= H.anchusljolium Poir]; rough heliotrope, H. asperrimufII R.Br.; smooth helio trope. H . curassovicum L. ; a nd pros­tratc helio trope, H . supinum L. (Delfosse and Cullen 1980) .

early summer rains (Bull el 01. 1968) and if these do not occur it may be relat ively inconspicuous in graz ing a reas (Whittet 1968). Once established, H. europaeum will grow a nd thri ve under conditions dry enough to stunt or kill most ot her plants (Walker 1966).

A ccording to M oore (1956). Cunning­ham er al. (1981) and Everest (198 1), H. europaeul1l becomes common in a reas dominated by winter·growing annuals such as Hordeum leporinu11I (barley grass), Vulpia spp. (s il ver grass) and Trifolium sublerralleum (sub. clover) or in d istu rbed areas such as fallows and stubbles, a nd in degraded wi nter annual pastures. It is nOl commo n in undisturbed areas where na ti ve perennial grasses do minate. Pasture com­position and conditions are more important than the soil type in the occurrence of the pla n!.

The problem

The problem aspects o f H. europaeum are primarily as ociated with toxici ty to graz­ing li vestock. H. europaeum contains a t least fi ve pyrro lizidine a lkaloids which a re potentia lly toxic 10 li vestock (Culvenor el al. 1954). H eliotrope poisoning of sheep has been documented by Bull el 01. (1956). C ul veno r (l978) considered it to be the major cause of pyrrolizidine al kaloid rela­ted di seases of livestock in Australia. It has been estimated that throughout south­eastern Australia 20 million sheep are at ri sk to helio t rope poisoning with a tota l

PlanT Protection Quanerly Vol. 2(4) 1987 165

overall loss from mortalities and reduced productive life spans of $tO x J()6 annually (Culvenor 1985). A pro po rtion of thi s loss would be due to Echium plantagilleum (Paterson's curse) since the two pla nts occupy approximately the same geographi· cal regions, pa rticularly in sou thern New South Wa les, a nd the effect of their pyrro­li zid ine a lka loids is additive (C ulveno r 1985). Culvenor (1985) est imated [hat o f this total annual loss from pyrrolizidine a lka loidos is in sheep in south·eastem Aust· ra li a, $7.5 x 1()6 could be due to H. euro­poeum and $2.5 x 10 6 due to E. plantagilleum.

H . europoeum is also responsible fo r pyrrolizidine alkaloid poisoning in cattle. a lthough est ima tes of the overa ll economic importance are not avai lable. The plant has been reported as poison ing ca ttle in Vic· [oria(Buli el 01. 1961 ; Kinnairdelal. 1968). South Aust ra lia (McLennan a nd Dodson 1972) and New South Wales (Bull er 01. 196 1; Wihjer and Walker 1974; Seaman a nd Walker 1985). P yrro li zidine alkaloid poiso ning in calves has a lso been reported due to the contamination of st raw bedding by H. europaeum (H arper el al. 1985).

H. europaeu11l is a lso a serio us competi· to r of summer pastu res, particularly in dis­IU rbed a reas. Delfosse a nd C ullen (1980) s ta te that mOsl farm ers cope with H . euro­paeu11l by a combina tion of cultural con· trol and li vestock ma nagement. Seedlings less tha n 7 cm high can be controlled with non-selec ti ve herbicides; however. large plants are quit e resis ta nt to herbicides (Anon. 1975). Repeated appl ica tion of her­bicide is necessary to control later ge rmi · nations (Fromm 1985; Delfosse a nd Cullen 1980): these herbicides can have a det rimen­tal effect o n pasture compositio n.

Combinations of herbicide and cult iva· lio n can be useful, but due to success ive germinations successful contro l is limit ed (Anon. 1975). Noble (1970, personal com· munica tion) demonst rated in the western Ri verina area that H. eUfOpaeU11I could be completely contro ll ed over three seasons with dense stands of dryland lucerne (2 1-77 plant s n1'2). Lucerne sta nds wi th popula·

H . europoeum , a summer·growing a nnual of Mediterranean areas is wide· sp read in south-eastern Australia infest ing over 10 million ha (Culvenor 1985). II is likely H . europaeum was introduced into Australia prior to 1800 from either south· ern France or Ita ly. The first recorded col· iectio n occurred in 1802 at Spencer's G ulf, South Australia (Delfosse a nd C ullen 1980) . The earli est reco rd ing of H. euro· poewlI by the National Herba rium of New South Wales (Sydney) was from Parkes (Cenlral West) in March 1899 (R . Lewis, peTS. comm. 1986). Prior to [he 1920s, 14 specimens had been lodged with the Nat · ional Herbarium o f New South W ales. All these specimens were collected in the central a nd southern areas of the S ta te, ranging from Forbes and Maryvale in the Central West. Bro ken Hill (2 specimens) in the Far West, 10 Corowa in the south on the Mur· ray Ri ver (R . lewis, pers. comm. 1986).

Table I Density of infestation of H. europaeum in New South Wales on a sta tisti ca l regio n basis

H. eUfopaeum occurs in the Australian Capital Territory, New South Wales, South Australia. Victoria and W estern Australia (Delfosse and Cullen 1980) and southern Queensland (Everest 1981). Moore (1 956) fo und tha t H. europaeum occurs in New South Wales a nd Victoria in the area west a nd north of the Greal Dividing Range respectively a nd largely within the 300 to 500 mm per annum winter·dominanl rain· fall zone.

Germination of H. europaeum occurs during lale spring (late November to ea rl y December) with summer fallow conditions being ideal for growth (Moore 1956). H owever, esta blishment is dependent on

Statistical regions

I . Sydney 2. Hunter 3. JII awarra 4. Richmond- Tweed S. Mid North Coast 6. 7. 8. 9.

to . [\. [2 .

Total

Northern North Western Central West South Eastern Murrumbidgee Murray Far West

4

3 3

II

Category (no. of shirts)

2

6 6 2

6 8

29

3

2

[

6 3 5 5 2

24

4

7 10 5 7

[[

[J

I 5

[2

3 2

76

166 Plant Protection Quarterly Vol . 2(4) 1987

lions < 12 plants m·2 proved inadequate in controlling the plant. Other perennial pasture species such as Sirocco phalaris, which is more summer dormant, were also ineffective in controlling H. europaeum.

H. europoeum has been nominated as a candidate for biological control. The CSIRO Division of Entomology is cur­rently investigating biological control and Delfosse and Cullen (1980) consider bio­logical control offers the only practical long-term solu tion to the management of H. europaeum.

139

H. europaeum is not a proclaimed noxious plant under the Local Government Act, 1919 (Anon. 1919). However, the perennial species H. amplexicaule is proclaimed noxious in 12 local government areas in New South Wales (Anon. 1919) .

Method

A questionnaire survey was conducted by the New South Wales Department of Agriculture's Noxious Plant Advisory

Officers in ear ly 1984. In formation was sought on the distribution of H. europaeum and E. planlagineum (Dellow and Seaman 1985) from weed control bodies in 140 local government a reas in New South Wales (including ACI). The Sydney metropolitan area was not surveyed.

The area of the individual local govern­ment areas surveyed varied in size from Gou lburn City, which was the smallest o f the non-metropolitan municipalities (54 km2), to the largest shire, Central Darling (52 000 km' ).

• heavy

f!iil medium

o light

o nil

Figure 1 Distribution of He/ie/rapiurn europaeum in New South Wales on a local government area basis. (Map: Local. Ref : Government. No Area.)

Calegory I (Heavy): 71 Dubbo,79 Bland,84 Forbes,85 Lachlan,89 Parkes, 109 Carrot hool, 11 7 Lockhart, 118 Murrumbidgee, 124 Balranald, 136 Wakool, 138 Wentworth .

Calegory 2 (Medium): 15 Murrurundi,49 Gunnedah,52 Manilla,55 Nundle,56 Parry, 57 Quirindi,59 Tamworth Ci ty, 64 Bogan, 70 Coon amble, 72 Gilgandra, 74 Narromine, 76 Warren, 77 Wellington, 82 Cowra, 91 Weddin, 110 Coolamon, 113 Gundagai, 114 Hay, 119 Narrandera, 120 Temora, 122 Wagga Wagga, 125 Berrigan, 126 Conargo, 127 Corowa, 128 Cuicai rn , 129 Deniliquin, 132 Jerilderie, 133 Murray, 135 Urana.

Category 3 (Light): 14 Merriwa,20 Scone,54 Narrabri,65 Bourke,67 Cobar,68 Coolah, 69 Coonabarabran,73 Mudgee,75 Walgell, 81 Cabonne,83 Evans, 90 RylSlone,95 Boorowa, 101 Harden,105 Tallaganda, 107 Yass, 108 Young, III Cootamundra, 11 2 Griffith , 11 5 Junee, 11 6 Leeton, 121 Tumul, 13 1 Hume, 137 Windouran.

Statistical Regions: 1 Sydney, 2 Hunter, 3 Dlawaml, 4 R1chmond-Tweed, S Mid North Coast, 6 Northern ,1 North Western, 8 Central West,9 South Eastern, 10 Murrumbidgee, 11 Murray, 12 Far West.

By re lying o n the four Noxious Plant Advisory Officers 10 contact the weed con­t rol officers in their reg io ns, an efficient method was used 10 ensure a 100010 response.

Respondellls to the survey were required to indicate the degree of infestation o f H . eliropaeUI11 on private property specifying o ne of four categori es, namely: I . heavy (numerous dense infestations); 2. medi um (numerous iso la ted plants o r

occasional dense infestations); 3. li ght (scatlered isolated plan ts. i.e. a

recording that it occurs in the shire); and 4 . nil (no plant s present).

Results

The distribution and density of infestion of H. eurOpa(!U111 throughout the 140 local govern ment areas surveyed is given in Figure I. Table I provides a summary of the plant's distribution based on stati stical regions.

H. europaelll11 was presen t in 46070 o f the loca l government areas surveyed in early 1984. Of a ll H. europaeU111 infestat ions 64% were located in centra l and southern New Sou th Wales. As stated by Walker (1966), H . europaelll11 is most widespread and dense in the ri ver drainage systems of the Central West. Murrumbidgee and Mur­ray regions of the State. Of the heavy in festations (category I) 91 010 were found in the three regions of central and sout hern New South Wales (Table I) . T hese three regions accoun t for 56% of a ll in festations of 1-1. europueum in New South Wales (Table I) .

Discussion

1-1. europaeum is now more wide ly di s­tributed th roughout New SOllth Wales than previous ly recorded (F ig. I) . In addi tion 10 all areas identified by Jacobs a nd Pick a rd (1981) , 1-1. europaeum is now also present in the Cen tra l Tablelands. The heavy (cale­gory I) infestations of H . europaeum in 1984 were mainly confined to the sou thern ha lf of western New South Wales.

The result s provide an estima te o f the di stribution and abundance o f H. euro­paeWll in New South Wales in 1984 . Pre­violls surveys and censes are hi stori cal records showing where H. europaeul11 specimens had been collected over a usually long period. They do no t indicate the den­sity of plant population as the records are based on plant specimens lodged with va r­ious herbaria and institutions.

Being an an nual , population densities of H. (!uropaeum great ly fluctuate from yea r to yea r depending o n climatic conditions and farm management. The rate of spread of the plan t throughout New Sou th Wales has nOI been defined. Keast (1949) stated that the plant appeared to make consider­able spread in many areas of the State

during the 10 to 15-yea r period preceeding 1949. The adopt ion of new farming tech­niques such as 'conservat ion ti ll age', which relics o n minimal so il disturbance, reten­tion of st ubbles and sometimes the substi­tuting of herbicides for cultivations may have an impact o n the spread and density of H . europaeum. In areas where the plant is most dense (category I) the lo ng fa llows necessary for successful winter-cereal crops also allow for the establishment of 1-1. euro­paewn. The change in farming techniques coupled with the prevailing weather con­ditions and the ground cover will determine the continued spread of H. europaeum.

Acknowledgments

Information provided by Noxious P lant Advisory Offkers, namely Mess rs D. Brown (Tamworth). P . Gorham (C owra), P. Gray (Dubbo) and H. Milvain (Yanco) of the New South Wales Department of Agriculture, is grat e full y acknowledged.

References

Anon. (19 19). Local Government Act, 1919 - Proc lamation. Government Gazelle No. 52, 81h March 1985 .

Anon. (1975). Weed Conlrol NOles. Soul h Australian Department of Agriculture Bullet in .

Bull , L. B., Dick, A . T. , KeaSl, 1. c.. and Edgar, G. (1956). An experimental invest igation of the hepatotoxic and ot her effects on sheep of Heliotropium europaeum L.: Heliotrope poisoning of sheep. Australian Journal 0/ Agricul­tural Research 7,287-97 .

Bull, L. B. , Rogers. E. 5., KeaSl. J. c., and Dick. A. T. (196 1). H eliolropiu l11 pois­oni ng in cattle. Australian Veterinary JOllrnal 37. 37-43.

Bull, L. B. Cu lveno r, C . C. J . . and Dick, A. T. (1968). 'The Pyrrolizid ine Alka­loids' , p. 14. (Nort h Ho lland : Amster­dam.)

Culvenor, C. C . J . • Drummond. L. J . , and Price, J . K. (1954). The a lkaloids of Heliotropiul11 europaeul11 L. I. Helio­trine a nd lasiocarpine. Australian Jour­nal oj Chemistry 7, 287-97 .

C ul veno r, C. C. J . (1978). Prevention of pyrrolizidine a lka lo id poisoning - an i­ma l adaptation or plant control? 111 'Effect of Poi sono u s Plants o n Livestock', eds R. F. Keeler, K. R. van Kamp.en and L. F. James. pp. I 89-200. (A cademic Press: New York.)

Cu lvenor, C. C. J . (1985) . Economic loss due to poisonoll s plant s in Austra lia . In 'Plant Toxicology', Proceedings 0/ {he A ustralian- U. S .A. Poisonous Plams Symposium, Brisbane 1984. pp.3- 13. Eds A. A. Seawrighl, M. P . Hegafly, L. F. J ames and R. F. Keeler (Queensland Poisonous Plants Comm itt ee: Yerrong­pilly.)

Plant Proiectlon Quanerty Vot 2(4) 1987 167

C unningham , G. M. , Mulham, W. E., Mihhorpe, P. L., and Leigh, J . H . (1981). ' Plallls of WeSlern New Soul h Wales'. (N.S. W. Government Printing office: Syd ney.)

Delfosse, E. 5 ., and Cullen, J . M. (1980). New activities in biological control of weeds in Australia . 1. Common helio­trope, Heliotropium europaeum. Proceedings 0/ the Fi/th International Symposium 0/ Biological Control 0/ Weeds, Brisbane, Austra lia, pp.545-61.

Dellow, J. 1., and Seaman, J . T . (1985) . Distribution of Echillm plaflfagineum L. and its associa tio n with pyrrolizidine a lkaloid poisoning in horses in New South Wales. Plafll Protection Quarterly 2. 79-83.

Everest, S. L. (1981). 'Poisonous P lants of AUSlra lia' , pp. 11 9-120. (Angus and Rob­ertso n: Sydney.)

Fromm. G. M. (1985). Common heliotrope (Heliotropill111 europaeum L.) con trol in past ure. Australian Weeds Research Newslelfer No. 33, 27-29.

Harper, P . A. W., Walker. K. H. t Krahen­buh l. R. E., and C hriSlie, B. M. (1985). P yrrolizidine a lka loid poiso ning in calves due to co ntamination of straw by Heliotropium europaeum. Australian Veterinary Journal 62, 382-3.

Jacobs, S. W. L., and Pickard, J . (1981) . 'P lants of New SOllth Wales: A Census of Cycads, Conifers and Angiosperms' . (National Herbarium of New South Wales: Royal Botanic Gardens. Sydney.)

Keast. J . C. ( 1949). Helio trope poiso ning in sheep. The Agricultural GauHe 0/ N.S. w. 60. 439-40.

Kinnaird , P . J., Chan, P . , and Leaver. D. D. (1968). Heliotrope poison ing in cal ­t Ie. A IIstralian Veterinary Journal 44. 39 .

McLennan, M. W .. and Dodso n, M. E. (1972). Heliotropium poisoning in cat ­tle . Australian Veterinary Journal 48. 480.

Moore. C. W. E. (1956) . Observat ion s on the autecology of f1eliotropium europae­um L. in New Sou th Wales and Victor­ia . CS IRO Technica l Paper No.7. 13.

Seaman, J . T . , and Walker. K. H . (1985) . P yrro li zidine a lka loid poisoning of cat ­tle and horses in New South Wales . , ,, 'Plant Toxicology', Proceedings 0/ the Australian- U.S.A . Poisonous Plants Symposium, Brisbane 1984. pp.235-46. Eds A. A. Scawrighl M. P . Hegafly. L. F. Jamesand R. F. Keeler (Queensland Poiso nous Plants Commillee: Yeerong­pi ll y.)

Walker. D. J . (1966) . Hel iolrope poison­ing in sheep and ca llie. The Agricultur­al Gazette oj N.S. W. 77, 11 -14 .

\Vhillel, J. N. (1%8) . 'Weeds', p.269. New South Wales Department of Agriculture.

Willjer, J . c., and Walker. C. E. J . (1974) . Rectal prolapse in cattle associated with pyrrolizidine alkaloid poisoning. Aust­ralian Veterinary Journal 50. 579-80.