Plant nematode pests as a sole and co-factor(s) in guava malady ? A global perspective

Plant nematodes one of the major components of crop patho system is responsible for effecting significant crop damage. Their role in impacting the economic crops damage in many life sustaining crops especially the short duration once is established. By and large they affect the crop on debilitating scale rather than the annihilating one. Since the conspicuous specific symptoms, barring a few notable exceptions, are lacking their importance in the realm of crop pathosystem gets unduly diminished. However, they play a vital role in exacerbation of many a diseases primarily caused by other soil microbes. Symptoms in guava being a perennial crop are hardly expressed at initial stages of nematode infestation. By and large soil factors have been implicated for the malady observed in the field. Consequently, the symptoms observed are assigned to other soil factors. Of late, role of plant nematode as a vital co-factor in guava wilt and guava decline has also come to fore. A proper understanding of soil factor dynamics would be helpful in devising the ways and means based on management principles of exclusion, immunization, chemotherapy and soil microbes /antagonistic flora exploitation in developing the sustainable management system.