Crop Protection and Global Food Security
Dr. Gary BrewerNovember 2011 With the global population expected to increase by 3 billion by 2030 and the amount of arable land available for production remaining unchanged, agriculture is facing challenges at least equivalent to those defining the Green Revolution. Besides needing to feed more people, agriculture will be challenged by increasingly scarce and costly inputs (Neff et al. 2011), pest exacerbation due to climate change, a reduction in cropland available per capita, stricter regulations, and growing numbers of resistant pest species. With more people demanding higher quality diets a second green revolution (Serageldin and Persley 2000) is needed. In part, the success of the first green revolution was dependent on intensive pest management practices (Fresco 2009). To succeed, the second green revolution will need biologically based products to replace conventional chemical pesticides and other scarce or expensive inputs. And it will need sustainable management systems where the environment is a priority, where genetics and biotechnology are used to improve productivity, and where crop resistance to biotic and abiotic stressors is an emphasis. To protect our crop genetics and plant protection products, we need implementation strategies to reduce the likelihood of pests becoming virulent to these management approaches. The United Nations Environmental Program has listed pesticide resistance as the third most serious threat to global agriculture behind soil erosion and water pollution. In the United States, crop losses due to pesticide resistance are estimated to be $1.4 billion annually (Hart and Pimentel 2002). In Nebraska alone, the occurrence of pesticide resistance in the western corn rootworm increased control costs, reduced yields, and was estimated to cost producers at least $4,000,000 annually from 1995-1998. Today, corn rootworms are showing signs of developing resistance to GMO corn in Nebraska and other midwestern states. Current approaches to crop protection are inadequate for meeting future food production needs. Despite a 7-fold increase in the use of crop protection products over the last 40 years, losses to all categories of crop pests have remained essentially level. Currently, insects alone consume or damage sufficient food to feed 1 billion people (Oerke et al. 2004, Oerke 2006). Climate change is likely to further increase insect pressure on crop production (Gregory et al. 2009, Newton et al. 2011). To address these challenges, an emphasis shift from reactive crop protection to a preventative genetic and ecological systems approach is essential. Plant resistance to arthropods and other pests, whether developed through conventional breeding or genetic engineering approaches, must be a fundamental objective of future crop development and protection. Resistant crops limit the build-up of pest populations and minimize crop losses. They are compatible with other management techniques and are effective in conditions that can impede other pest management practices. Another critical component to insuring food security is ecological engineering of our agroecosystems to promote diverse and robust populations of natural enemies, pollinators, and other beneficial organisms as a necessity of sustainability. Ecological engineering, especially when applied on an area-wide basis, will enhance cropping system heterogeneity and build environmental resistance to pests. Based on a thorough understanding of pest and crop ecology, designed agroecosystems will protect yield, reduce the need for pesticides, promote sustainability, and reduce selection pressure on pests. The final element of improved crop protection involves ways to protect crops when conditions greatly favor pest outbreaks or before effective plant resistance or ecological engineering technologies are available. Included are techniques such as inundative biological control, semiochemicals (pheromones, repellents, and attractants) that disrupt pest behavior, and judicious use selective pesticides to provide local management. A crop protection toolbox based on genetic and ecological systems complemented with specific and low-impact technologies will protect agroecosystem health and sustainability. A shift away from pesticides to genetic and ecological systems will reduce grower costs, protect crop quality and quantity, and better position agriculture to meet growing food security needs. References
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