A plant disease is a disruption or modification of a plant's normal state that disrupts or affects its important functions. Plants of all kinds, wild and cultivated, are susceptible to illness. Although each species is prone to specific diseases, there are only a few of them in each situation. Plant diseases vary in occurrence and prevalence from season to season, depending on the pathogen present, environmental circumstances, and the crops and kinds produced. Some plant kinds are more susceptible to disease outbreaks, while others are more resistant. Plant diseases have been known since before the beginning of known records. Plant disease losses can lead to famine and starvation, especially in less-developed nations where disease-control technologies are restricted and yearly losses of 30 to 50 percent for important crops are not uncommon.