Prioritization of CWR based on potential use value
Given limited resources, a national conservation strategy for crop wild relatives (CWR) requires the prioritization of species based on their potential use value to crop breeding. This focuses the priorities of the strategy on those relatives of major crops with active breeding programs.
In order to prioritize the importance of crops on the global level to food security, agricultural production, and income generation, major statistical resources and publications were collated, including:
- FAOSTAT production data- listing the most important crops in the world by quantity (tonnes) and by area (hectare), utilizing 2007 data1. Data includes food, fiber, some forage, and some industrial crops.
- FAOSTAT consumption data- listing all plant commodities recorded for food availability within Food Balance Sheets, utilizing 2007 data1.
- Crops listed in Annex 1 of the International Treaty on Plant Genetic Resources for Food and Agriculture (ITPGRFA)2. These crops are covered under the Multilateral System of Access and Benefit-sharing due to their international contribution to food security and because of interdependence among countries with regard to their genetic resources. Data includes food and forage crops.
- Crops listed in Appendix 2 (“Important Food Crops”) of the World Atlas of Biodiversity3. Data includes food crops of major global significance as well as secondary, or local importance.
- All plant commodities listed in Prescott-Allen and Prescott-Allen (1990)4, a classic publication on the top plant species that feed the world. Data within this study derives from FAO Food Balance Sheets 1979-1981.
In compiling these sources, crops were divided into two categories: first tier for major crops [including all plant commodities listed in FAOSTAT resources, all crops in Annex 1 of the ITPGRFA with the exception noted below, and all crops listed in Groombridge and Jenkins (2002) and in Prescott-Allen and Prescott-Allen (1990)]. The second tier received crops contained within general commodity listings in the FAOSTAT resources [e.g. ‘Cereals NES’ general commodity contains canagua or coaihua (Chenopodium pallidicaule); quihuicha or Inca wheat (Amaranthus caudatus); adlay or Job’s tears (Coix lacryma-jobi); and wild rice (Zizania aquatica)]. Also included in the second tier were the forage crops, and the “Brassica complex” crops (aside from the crops within genus Brassica itself), which generally represent minor mustard crops, listed in Annex 1 of the ITPGRFA.
Crops within the compiled World’s Top Crops list were then analyzed with regard to the quantity of sources listing the crops as important. First tier crops listed in more than one source were placed in a Priority 1 category. Any crops listed as both first and second tier (from different sources) defaulted to Priority 1. First tier crops from only one source were designated as Priority 2, as were all second tier crops.
Crops on the World’s Top Crops list were then listed by the genera within which the crops belong, and any additional genera known to be included within the genepools of the crops were added or moved to appropriate prioritization levels. Additions included: Ensete for banana, Vavilovia for pea, Tripsacum for maize, Tornabenea for carrot, Patellifolia for beet, Diplotaxis for Brassica crops, Poncirus and Fortunella for citrus crops, and Aegilops, Agropyron, Amblyopyrum, Dasypyrum, Elymus, Leymus, Psathyrostachys Pseudoroegneria, Secale, and Thinopyrum for wheat.
The resulting list of the World’s Top Crops includes 242 crops/268 genera (101 crops/119 genera in Priority 1, and 141 crops/149 genera in Priority 2). This list includes all the most important agricultural crops around the world by a number of measures, and covers all major crops listed in FAOSTAT for U.S. production and food supply1.