Yield losses by Phytonematodes: challenges and opportunities with special reference to Egypt

Plant-parasitic nematodes (PPN) constitute a major constraint to agriculture.Estimates of their crop-loss are important for establishing research, extension, andbudget priority. Regulatory policy action, pesticide impact assessment, resourceallocation, and program prioritization are usually contingent upon such crop lossdata. Recent questionnaire results of important PPN genera and estimates of croplosses in Egypt due to PPN are presented herein. Crop losses due to thenematodes on 80 crops, 15 of which are ‘life sustaining’, were estimated at L.E.15.85 (= $2.30) billion annually based on 2011-2012 Egyptian production figuresand prices. Crop loss estimates of vegetables, fruits, and field crops demonstratedstaggering figures and therefore nematode problems warrant considerably moreeffort and support than they are currently receiving. Current challenging nematodeissues include reduced number of effective nematicides available and limitation intheir use due to environmental issues, increased adoption of intensive agriculture,climate change, occurrence of resistance-breaking PPN pathotypes oneconomically important crops, and potential introduction of quarantine-nematodes.Therefore, basic and applied nematological research should be more oriented toprovide better management of plant-parasitic nematodes in an economically andenvironmentally beneficial manner.