EPIPHYTOTIOLOGY OF PHYTOHELMINTHIASIS IN THE 21st CENTURY

Abstract

Plant parasitic nematodes are recognized as one of the biggest threats to crop production. Annual crop loss from phytohelminths range from 78 to 128 billion US Dollars. The initial position of the epiphytotic process (EP) theory in phytohelminthiasis is to recognize the infestation as a form of parasitism, and therefore, for the phytohelminth species to be preserved, they need a mandatory and constant change by their pathogen of individual host plants, which is externally perceived as an infection. Such process, i.e. a continuous chain of systematic incidence, occurs involving infected plants (a source of an infectious agent), the mechanism of preserving and transmitting the phytohelminthiasis pathogen, and a susceptible plant(s), which is the biological basis for the epiphytotic process. Based on the analysis of the literature and original data, the primary factors (a source of invasion, a mechanism of preserving and transmitting the pathogen, and a susceptible host plant) and secondary factors (abiotic, biotic, anthropogenic, and social factors) of the epiphytotic process are considered for various phytohelminthiases. From the point of view of epiphytotiology, the list of host plants for the phytohelminthiasis pathogen should include those species of susceptible plants that are naturally included in the epiphytotic process and that provide the indefinitely long existence of the phytohelminth in populations of susceptible plants. The epiphytotic process provides the existence, reproduction and spread of phytohelminths in the nature and agricultural ecosystems.