ABSTRACT
Citrus is susceptible to a large number of diseases caused by different types of pathogens, namely fungi, bacteria, viruses, viroids, phytoplasmas, spiroplasmas, nematodes, etc. There are also a few diseases for which the causal organisms are still not properly known. Most of these diseases are systemic in nature while the infection caused by others is restricted to certain parts of the plant. Systemic diseases threatening to citrus cultivation are mostly graft transmissible but also transmitted by vectors. Most of the nonsystemic diseases, where pathogens are soil-or air-borne, affect the productivity and quality of production.
