Rugose leaf curl

Rugose leaf curl is a significant plant disease caused by a phytoplasma. This pathogen specifically colonizes the phloem tissue of the host plant, disrupting the movement of photosynthates and leading to severe systemic physiological degradation of the crop.

The disease primarily affects peanut (Arachis hypogaea) crops. It is recognized as a major constraint in specific peanut-growing regions where the ecological conditions support the survival and proliferation of both the pathogen and its insect vectors throughout the year.

Key symptoms include the characteristic rugose (wrinkled) appearance of leaves, severe stunting, and shortened internodes. Affected plants often exhibit leaf rolling, yellowing of margins, and a proliferation of auxiliary shoots, which gives the plant a bushy or stunted appearance.

The transmission of the pathogen is mediated by insect vectors, most notably leafhoppers. These insects acquire the phytoplasma while feeding on infected weed hosts or diseased peanut plants and subsequently transmit the infection to healthy plants during the sap-feeding process.

Effective management strategies include the strategic use of insecticides to suppress leafhopper populations and the elimination of weed reservoirs surrounding the production fields. Additionally, the use of resistant or tolerant peanut varieties is highly recommended to mitigate potential yield losses in high-risk areas.