The phenology of plant-nematode interaction and yield loss

Plant-parasitic nematodes, often referred to as ′hidden enemies′, are among the most widespread and important pathogens causing crop loss. They are major pathogens in their own right and through their interaction with other disease-causing agents (Sidhu and Webster, 1977, Sidhu and Webster, 1981b). However, the accurate assessment of crop loss data and the nature of its cause are difficult to determine and are best described by the following quote: Our present estimates and determinations of crop loss from any given factor leave much to be desired. Experiments to measure crop loss are difficult to design because of the many overlapping interactions involved. Nonetheless, it is necessary to do the best job we can in making such estimates and determinations. Dowler and Van Gundy(1984)