The other, ignored HIV — highly invasive vegetation
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- Gressel, J. & Valverde, B.E. Food Sec. (2009) 1: 463. doi:10.1007/s12571-009-0038-7
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.