Plant Pathology Science

During recent years, the newly emerging disease, citrus sudden decline (CSD) has destroyed many of citrus trees grafted onto bael rootstock in the south of Kerman Province. The disease is caused by Candidatus Liberibacter asiaticus and its simultaneous infection to soil born pathogens or Ca. Phytoplasma aurantifolia, or heat and drought stresses can increase the disease severity and appearance of the decline symptoms. Using the healthy and certified rootstock, using the Sour Orange or Volkamer Lemon as rootstock, control of the sucking insects at the time of flushing, optimum irrigation with appropriate distribution especially during the summer season, control of soil born fungi and nematodes, avoiding stress to plant and appropriate pruning are recommended for prevention and management of CSD disease in the south of Kerman Province.

Plant diseases play a critical and limiting role in crop production and their control by using pesticides cause serious problems regarding food safety and environmental health and increase the need for other sustainable disease management techniques. Some of plant pathogens may infect the aerial parts of plants, but spent part of their life cycle in the soil and maintained their survival. In such cases, part of the life cycle of the plant pathogen in soil may be very important, even if that microorganism does not infect the roots. Mono culturing and cultivation of crops belonging to the same family increase the potential of disease incidence. Using and applying the suitable and correct cultural practices that limit damage of root diseases is necessary for sustainable management of soil-borne pathogens. Cultural operations, including the use of cover green crops, crop rotation, organic composts, certified seeds and propagative materials, amended organic material to soil, proper tillage systems, soil solarization, resistant cultivars, mycorrhizal fungi, all are reported and confirmed as management options for long time saving soil quality and good sustainable management of soil borne diseases.