Food Security

, 1:463

The other, ignored HIV — highly invasive vegetation



The greatest cost to the farmer in time and variable costs is control of weeds (Highly Invasive Vegetation = HIV). Despite farmer efforts, weeds still result in the greatest crop losses of all biotic constraints. The costs due to this HIV are greatest in the parts of the developing world where manual labor (more typically “femanual”) is used, and the populations are becoming more aged (due to youth abandoning agriculture), or more feeble due to debilitating diseases such as malaria and HIV-AIDS. Two case studies are presented: the previously intractable problems with Striga (witchweed) species in Africa; and rice cultivation and the emerging problems with the labor-saving shift to direct seeding, which has resulted in outbreaks of a weedy/feral form of rice, as well as herbicide-resistant Echinochloa spp. Biotechnology has much to offer as part of the solution to these major HIV problems, whether as transgenic herbicide resistant crops, or as weed resistant crops or through transgenically enhanced weed-specific biocontrol agents. Where necessary, transgenic tricks will also be needed in many cases to prevent transgene flow from crop to related weedy relatives, and possible technologies are described. Ever since the advent of agriculture, solutions to crop protection problems have been effective but ephemeral, and new solutions will be needed in the future. Using mixed solutions leads to solutions lasting synergistically longer, so efforts should be made to use mixed technologies to extend the lifetime of the next generation of sorely needed solutions to the problems of HIV.


Weeds Striga Witchweed Rice Weedy rice Feral rice Echinochloa Maize Sorghum 


  1. Abayo GO, English T, Eplee RE, Kanampiu FK, Ransom JK, Gressel J (1998) Control of parasitic witchweeds (Striga spp.) on corn (Zea mays) resistant to acetolactate synthase inhibitors. Weed Sci 46:459–466Google Scholar
  2. Akobundu IO (1991) Weeds in human affairs is sub-Saharan Africa. Weed Tech 5:680–690Google Scholar
  3. Al-Ahmad H, Gressel J (2006) Mitigation using a tandem construct containing a selectively unfit gene precludes establishment of Brassica napus transgenes in hybrids and backcrosses with weedy Brassica rapa. Plant Biotech J 4:23–33CrossRefGoogle Scholar
  4. Al-Ahmad H, Galili S, Gressel J (2005) Poor competitive fitness of transgenically mitigated tobacco in competition with the wild type in a replacement series. Planta 222:372–385CrossRefPubMedGoogle Scholar
  5. Al-Ahmad H, Dwyer J, Moloney M, Gressel J (2006) Mitigation of establishment of Brassica napus transgenes in volunteers using a tandem construct containing a selectively unfit gene. Plant Biotech J 4:7–21CrossRefGoogle Scholar
  6. Alokit C (2009) Unlocking the cereal production potential in east Africa by eliminating the Striga threat—the Kilimo trust project. Haustorium 55:10–12Google Scholar
  7. Amusan IO, Rich PJ, Menkir A, Housley T, Ejeta G (2008) Resistance to Striga hermonthica in a maize inbred line derived from Zea diploperennis. New Phytol 178:157–166CrossRefPubMedGoogle Scholar
  8. Anderson DM, Cox ML (1997) Smicronyx species (Coleoptera: Curculionidae), economically important seed predators of witchweeds (Striga spp.) (Scrophulariaceae) in sub-Saharan Africa. Bull Entomol Res 87:3–17CrossRefGoogle Scholar
  9. Broster JC, Pratley JE (2006) A decade of monitoring herbicide resistance in Lolium rigidum in Australia. Australian J Exp Agric 46:1151–1160CrossRefGoogle Scholar
  10. Carey VF, Hoagland RE, Talbert RE (1997) Resistance mechanism of propanil-resistant barnyardgrass.2. In-vivo metabolism of the propanil molecule. Pesticide Sci 49:333–338CrossRefGoogle Scholar
  11. Ciotola M, Watson AK, Hallett SG (1995) Discovery of an isolate of Fusarium oxysporum with potential to control Striga hermonthica in Africa. Weed Res 35:303–309Google Scholar
  12. de Framond A, Rich PJ, McMillan J, Ejeta G (2007) Effects on Striga parasitism of transgenic maize armed with RNAi constructs targeting essential S. asiatica genes. In: Ejeta G, Gressel J (eds) Integrating new technologies for Striga control—towards ending the witch hunt. Singapore, World Scientific, pp 185–196Google Scholar
  13. De Groote H, Wangare L, Kanampiu FK, Odendo M, Diallo A, Karaya H, Friesen D (2008) The potential of a herbicide resistant maize technology for Striga control in Africa. Agric Syst 97:83–94CrossRefGoogle Scholar
  14. Doggett H (1988) Sorghum. Longman, Harlow, p 512Google Scholar
  15. Ejeta G (2007) The Striga scourge in Africa: a growing pandemic. In: Ejeta G, Gressel J (eds) Integrating new technologies for Striga control—towards ending the witch hunt. World Scientific, Singapore, pp 3–16Google Scholar
  16. Ejeta G, Gressel J (eds) (2007) Integrating new technologies for Striga control—towards ending the witch hunt. World Scientific, SingaporeGoogle Scholar
  17. Ejeta G, Rich PJ, Mohamed A (2007) Dissecting a complex trait to simpler components for effective breeding of sorghum with a high level of Striga resistance. In: Ejeta G, Gressel J (eds) Integrating new technologies for Striga control—towards ending the witch hunt. World Scientific, Singapore, pp 87–98Google Scholar
  18. Elzein A, Kroschel J (2004) Fusarium oxysporum Foxy 2 shows potential to control both Striga hermonthica and S. asiatica. Weed Res 44:433–438CrossRefGoogle Scholar
  19. Fischer AJ (2009) Scaling out Alternative Rice Establishment Practices to Control Herbicide Resistant Weeds. Annual Report 2008. Comprehensive Rice Research, California, 25 p. Available
  20. Fischer AJ, Ateh CM, Bayer DE, Hill JE (2000) Herbicide-resistant Echinochloa oryzoides and E. phyllopogon in California Oryza sativa fields. Weed Sci 48:225–230CrossRefGoogle Scholar
  21. Foy CL, Jain R, Jacobsohn R (1989) Recent approaches for chemical control of broomrape (Orobanche spp.). Rev Weed Sci 4:123–152Google Scholar
  22. Garcia-Prechac F, Ernst O, Siri-Prieto G, Terra JA (2004) Integrating no-till into crop-pasture rotations in Uruguay. Soil Tillage Res 77:1–13CrossRefGoogle Scholar
  23. Gealy DR (2005) Gene movement between rice (Oryza sativa) and weedy rice (Oryza sativa)—a US temperate rice perspective. In: Gressel J (ed) Crop ferality and volunteerism. CRC, Boca Raton, pp 323–354Google Scholar
  24. Grenier C, Ibrahim Y, Haussmann BIG, Kiambi D, Ejeta G (2007) Marker-assisted selection for Striga resistance in sorghum. In: Ejeta G, Gressel J (eds) Integrating new technologies for Striga control—towards ending the witch hunt. World Scientific, Singapore, pp 159–171Google Scholar
  25. Gressel J (1988) Multiple resistances to wheat selective herbicides: new challenges to molecular biology. Oxf Surv Plant Mol Cell Biol 5:195–203Google Scholar
  26. Gressel J (1999) Tandem constructs: preventing the rise of superweeds. Trends Biotechnol 17:361–366CrossRefPubMedGoogle Scholar
  27. Gressel J (2002) Molecular Biology of Weed Control. Taylor & Francis, London, p 520Google Scholar
  28. Gressel J (2005) Problems in qualifying and quantifying assumptions in plant protection models: resultant simulations can be mistaken by a factor of million. Crop Protect 24:1007–1015CrossRefGoogle Scholar
  29. Gressel J (2008) Genetic glass ceilings: transgenics for crop biodiversity. Johns Hopkins University, BaltimoreGoogle Scholar
  30. Gressel J (2009) Crops with target site herbicide resistance for Orobanche and Striga control. Pest Mgmt Sci 65:560–565CrossRefGoogle Scholar
  31. Gressel J, Joel DM (1997) Use of glyphosate salts in seed dressing herbicidal compositions. US Patent: 6(096):686Google Scholar
  32. Gressel J, Valverde BE (2009) A strategy to provide long-term control of weedy rice while mitigating herbicide resistance transgene flow, and its potential use for other crops with related weeds. Pest Mgmt Sci 65:723–731CrossRefGoogle Scholar
  33. Gressel J, Segel LE, Ransom JK (1996) Managing the delay of evolution of herbicide resistance in parasitic weed. Intl J Pest Mgmt 42:113–129CrossRefGoogle Scholar
  34. Hearne SJ (2009) Control—the Striga conundrum. Pest Mgmt Sci 65:603–614CrossRefGoogle Scholar
  35. Holm LG, Plucknett JD, Pancho LV, Herberger JP (1977) The World’s Worst Weeds, Distribution and Biology. University Press of Hawaii, Honolulu 609 ppGoogle Scholar
  36. Huang B-q, Gressel J (1997) Barnyardgrass (Echinochloa crus-galli) resistance to both butachlor and thiobencarb in China. Resistant Pest Mgmt 9:5–7 summerGoogle Scholar
  37. Huang GZ, Allen R, Davis EL, Baum TJ, Hussey RS (2006) Engineering broad root-knot resistance in transgenic plants by RNAi silencing of a conserved and essential root-knot nematode parasitism gene. Proc Natl Acad Sci USA 103:14302–14306CrossRefPubMedGoogle Scholar
  38. Joel DM, Kleifeld Y, Losner-Goshen D, Herzlinger G, Gressel J (1995) Transgenic crops against parasites. Nature 374:220–221CrossRefGoogle Scholar
  39. Kanampiu FK, Ransom JK, Gressel J (2001) Imazapyr seed dressings for Striga control on acetolactate synthase target-site resistant maize. Crop Protect 20:885–895CrossRefGoogle Scholar
  40. Kanampiu FK, Kabambe V, Massawe C, Jasi L, Friesen D, Ransom JK, Gressel J (2003) Multi-site, multi-season field tests demonstrate that herbicide seed-coating herbicide-resistance maize controls Striga spp. and increases yields in several African countries. Crop Protect 22:679–706CrossRefGoogle Scholar
  41. Kanampiu FK, Diallo A, Burnet M, Karaya H, Gressel J (2007) Success with the low-biotech of seed-coated imidazolinone resistant maize. In: Ejeta G, Gressel J (eds) Integrating new technologies for Striga control—towards ending the witch hunt. World Scientific, Singapore, pp 145–158Google Scholar
  42. Kanampiu F, Karaya H, Burnet M, Gressel J (2009) Needs for and effectiveness of slow release herbicide seed treatment Striga control formulations for protection against early season crop phytotoxicity. Crop Protect 28:845–853CrossRefGoogle Scholar
  43. Khan ZR, Midega CAO, Hassanali A, Pickett JA (2007) Field developments on Striga control by Desmodium intercrops in a “push-pull” strategy. In: Ejeta G, Gressel J (eds) Integrating new technologies for Striga control—towards ending the witch hunt. World Scientific, Singapore, pp 241–252Google Scholar
  44. Leah JM, Caseley JC, Riches CR, Valverde B (1994) Association between elevated activity of aryl acylamidase and propanil resistance in jungle-rice, Echinochloa colona. Pesticide Sci 42:281–289CrossRefGoogle Scholar
  45. Li J, Lis KE, Timko MP (2009) Molecular genetics of race-specific resistance of cowpea to Striga gesnerioides. Pest Mgmt Sci 65:520–527CrossRefGoogle Scholar
  46. Lin C, Fang J, Xu X, Zhao T, Cheng J, Tu J, Ye G, Shen Z (2008) A built-in strategy for containment of transgenic plants: creation of selectively terminable transgenic rice. PLoS ONE 3:e1818CrossRefPubMedGoogle Scholar
  47. Madsen KH, Valverde BE, Jensen JE (2002) Risk assessment of herbicide-resistant crops: A Latin American perspective using rice (Oryza sativa) as a model. Weed Tech 16:215–223CrossRefGoogle Scholar
  48. Meir S, Amsellem Z, Al-Ahmad H, Safran E, Gressel J (2009) Transforming a Nep1 toxin gene into two Fusarium spp. to enhance mycoherbicide activity on Orobanche—failure and success. Pest Mgmt Sci 65:588–595CrossRefGoogle Scholar
  49. Messeguer J, Fogher C, Guiderdoni E, Marfa V, Catala MM, Baldi G, Mele E (2001) Field assessments of gene flow from transgenic to cultivated rice (Oryza sativa L.) using a herbicide resistance gene as tracer marker. Theor Appl Genet 103:1151–1159CrossRefGoogle Scholar
  50. Moss SR, Perryman SAM, Tatnell LV (2007) Managing herbicide-resistant blackgrass (Alopecurus myosuroides): theory and practice. Weed Tech 21:300–309CrossRefGoogle Scholar
  51. Mundy PJ (2000) Red-billed queleas in Zimbabwe. In: Cheke RA, Rosenberg LJ, Kieser ME (eds) Workshop on research priorities for migrant pests of agriculture in southern Africa. Natural Resources Institute, ChathamGoogle Scholar
  52. Naqvi S, Zhu CF, Farre G, Ramessar K, Bassie L, Breitenbach J, Conesa DP, Ros G, Sandmann G, Capell T, Christou P (2009) Transgenic multivitamin corn through biofortification of endosperm with three vitamins representing three distinct metabolic pathways. Proc Natl Acad Sci USA 106:7762–7767CrossRefPubMedGoogle Scholar
  53. Olofsdotter M, Valverde BE, Madsen KH (2000) Herbicide resistant rice (Oryza sativa L.): global implications for weedy rice and weed management. Ann Appl Biol 137:279–295CrossRefGoogle Scholar
  54. Oswald A (2005) Striga control—technologies and their dissemination. Crop Protect 24:333–342CrossRefGoogle Scholar
  55. Paine JA, Shipton CA, Chaggar S, Howells RM, Kennedy MJ, Vernon G, Wright SY, Hinchliffe E, Adams JL, Silverstone AL, Drake R (2005) Improving the nutritional value of Golden Rice through increased pro-vitamin A content. Nature Biotech 23:482–487CrossRefGoogle Scholar
  56. Parker C (2009) Observations on the current status of Orobanche and Striga problems worldwide. Pest Mgmt Sci 65:453–459CrossRefGoogle Scholar
  57. Powles SB, Shaner DL (eds) (2001) Herbicide Resistance and World Grains. CRC, Boca-RatonGoogle Scholar
  58. Preston C, Boutsalis P, Malone J, Dolman F, Storrie A (2008) Resistance to glyphosate in Echinochloa colona in Australia. V International Weed Science Congress, Vancouver, pp 226–227Google Scholar
  59. Ransom JK, Babiker AG, Odhiambo GD (2007) Integrating crop management practices for Striga control. In: Ejeta G, Gressel J (eds) Integrating new technologies for Striga control—towards ending the witch hunt. World Scientific, Singapore, pp 213–228Google Scholar
  60. Rao AN, Johnson DE, Sivaprasad B, Ladha JK, Mortimer AM (2007) Weed management in direct-seeded rice. Adv Agron 93:153–255CrossRefGoogle Scholar
  61. Rector BG (2009) A sterile-female technique proposed for Striga hermonthica and other intractable weeds: advantages, shortcomings and risk management. Pest Mgmt Sci 65:596–602CrossRefGoogle Scholar
  62. Rich PJ, Ejeta G (2008) Towards effective resistance to Striga in African maize. Plant Signal Behav. 3:618–621PubMedGoogle Scholar
  63. Riches CR, Knights JS, Chaves L, Caseley JC, Valverde BE (1997) The role of pendimethalin in the integrated management of propanil-resistant Echinochloa colona in Central America. Pesticide Sci 51:341–346CrossRefGoogle Scholar
  64. Smith MC, Holt JS, Webb M (1993) Population model of the parasitic weed Striga hermonthica (Scrophulariaceae) to investigate the potential of Smicronyx umbrinus (Coleoptera: Curculionidae) for biological control in Mali. Crop Protect 12:473–476Google Scholar
  65. Still CC, Kuzirian O (1967) Enzyme detoxication of 3′, 4′-dichloropropionanilide in rice and barnyard grass a factor in herbicide selectivity. Nature 216:799–800CrossRefPubMedGoogle Scholar
  66. Swarbick PJ, Scholes JD, Press MC, Slate J (2009) A major QTL for resistance of rice to the parasitic plant Striga hermonthica is not dependent on genetic background. Pest Mgmt Sci 65:528–532CrossRefGoogle Scholar
  67. Talbert RE, Burgos NR (2007) History and management of herbicide-resistant barnyardgrass (Echinochloa crus-galli) in Arkansas rice. Weed Tech 21:324–331CrossRefGoogle Scholar
  68. Timko MP, Li J (2009) Gene-for-gene resistance in Striga-cowpea associations. Science 325:1094 + supplementary information onlineCrossRefPubMedGoogle Scholar
  69. Traoré D, Vincent C, Stewart RK (1995) Life history of Smicronyx guineanus and Sm. umbrinus (Col.: Curculionidae) on Striga hermonthica (Scrophulariaceae). Biocontrol Sci Tech 40:211–221Google Scholar
  70. Tuinstra M, Al-Khatib K (2008) Acetolactate synthase herbicide resistant sorghum. US Patent Application 20080216187.Google Scholar
  71. Tuinstra MR, Soumana S, Al-Khatib K, Kapran I, Toure A, van Ast A, Bastiaans L, Ochanda NW, Salami I, Kayentao M, Dembele S (2009) Efficacy of herbicide seed treatments for controlling Striga infestation of sorghum. Crop Sci 49:923–929CrossRefGoogle Scholar
  72. Valverde BE (2005) The damage by weedy rice—can feral rice remain undetected? In: Gressel J (ed) Crop Ferality and Volunteerism. CRC, Boca Raton, pp 279–294Google Scholar
  73. Valverde BE (2007) Status and management of grass-weed herbicide resistance in Latin America. Weed Tech 21:310–323CrossRefGoogle Scholar
  74. Valverde BE, Gressel J (2005) Implications and containment of gene flow from herbicide-resistant rice (Oryza sativa). Proc. Asian Pacific Weed Science Society, Agricultural Publishing House, Ho-Chi Minh City, pp 63–84.Google Scholar
  75. Valverde BE, Itoh K (2001) Herbicide resistance and its management in world rice ecosystems. In: Powles SB, Shaner DL (eds) Herbicide Resistance and World Grains. CRC, Boca Raton, pp 195–249Google Scholar
  76. Valverde BE, Riches CR, Caseley JC (2000) Prevention and Management of Herbicide Resistant Weeds in Rice. Cámara de Insumos Agropecuarios, San José, pp 1–123. available online at:
  77. Valverde BE, Chaves L, Garita I, Ramirez F, Vargas E, Carmiol J, Riches CR, Caseley JC (2001) Modified herbicide regimes for propanil-resistant junglerice control in rain-fed rice. Weed Sci 49:395–405CrossRefGoogle Scholar
  78. Venne J, Beed F, Avocanh A, Watson A (2009) Integrating Fusarium oxysorum f. sp. strigae into cereal cropping systems in Africa. Pest Mgmt Sci 65:572–580CrossRefGoogle Scholar
  79. Vidotto F, Ferrero A (2005) Modeling population dynamics to overcome feral rice in rice. In: Gressel J (ed) Crop Ferality and Volunteerism. CRC, Boca Raton, pp 355–370Google Scholar
  80. Walsh MJ, Powles SB (2007) Management strategies for herbicide-resistant weed populations in Australian dryland crop production systems. Weed Tech 21:332–338CrossRefGoogle Scholar
  81. Westwood JH, Roney JK, Khatibi PA, Stromberg VK (2009) RNA translocation between parasitic plants and their hosts. Pest Mgmt Sci 65:533–539CrossRefGoogle Scholar
  82. Yang YK, Kim SO, Chung HS, Lee YH (2000) Use of Colletotrichum graminicola KA001 to control barnyard grass. Plant Dis 84:55–59CrossRefGoogle Scholar
  83. Yasuor H, Osuna MD, Ortiz A, Saldain NE, Eckert JW, Fischer AJ (2009) Mechanism of Resistance to Penoxsulam in Late Watergrass [Echinochloa phyllopogon (Stapf) Koss.]. J Agric Food Chem 57:3653–3660CrossRefPubMedGoogle Scholar
  84. Yih RY, McRae DH, Wilson HF (1968) Mechanism of selective action of 3', 4'-dichloropropionanilide. Plant Physiol 43:1291–1296CrossRefPubMedGoogle Scholar
  85. Yoder JI, Gunathilake P, Wu B, Tomilova N, Tomilo AA (2009) Engineering host resistance against parasitic weeds with RNA interference. Pest Mgmt Sci 65:460–466CrossRefGoogle Scholar
  86. Yoshida S, Shirasu K (2009) Multiple layers of incompatibility to the parasitic witchweed, Striga hermonthica. New Phytol 183:180–189CrossRefPubMedGoogle Scholar
  87. Yun MS, Yogo Y, Miura R, Yamasue Y, Fischer AJ (2005) Cytochrome P-450 monooxygenase activity in herbicide-resistant and -susceptible late watergrass (Echinochloa phyllopogon). Pestic Biochem Physiol 83:107–114CrossRefGoogle Scholar
  88. Zhang WM, Watson AK (1997a) Efficacy of Exserohilum monoceras for the control of Echinochloa species in rice (Oryza sativa). Weed Sci 45:144–150Google Scholar
  89. Zhang WM, Watson AK (1997b) Host range of Exserohilum monoceras, a potential bioherbicide for the control of Echinochloa species. Can J Bot 75:685–692CrossRefGoogle Scholar
  90. Zhang L, Lu Q, Chen HG, Pan G, Xiao SS, Dai Y, Li Q, Zhang JW, Wu XZ, Wu JS, Tu JM, Liu KD (2007) Identification of a cytochrome P450 hydroxylase, CYP81A6, as the candidate for the bentazon and sulfonylurea herbicide resistance gene, Bel, in rice. Molec Breeding 19:59–68CrossRefGoogle Scholar

Copyright information

© Springer Science + Business Media B.V. & International Society for Plant Pathology 2009

Authors and Affiliations

  1. 1.Plant SciencesWeizmann Institute of ScienceRehovotIsrael
  2. 2.Investigación y Desarrollo en Agricultura Tropical (IDEA Tropical)AlajuelaCosta Rica
  3. 3.The University of CopenhagenTaastrupDenmark

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