WILT DISEASES OF BLACK PEPPER

Abstract

Among the major diseases affecting black pepper , foot rot(quick wilt) and pepper yellows (slow wilt) are important, inflicting heavy losses in plantation. Foot rot is caused by Phytophthora palmivora and is characterized by rotting of collar and/or root and leaf, die back of twigs and spike shedding. The disease incidence is generally high when relative humidity is high (91-99%) and temperature is low (19-23oC). The nature of spread supports the view that it is mainly through soil and water. Heavy rainfall and wind contribute to aerial spread leading to foliar infections. The pathogen has got a wide host range. Its mode of perennation, population build up during different seasons and primary infections are areas requiring investigations. Existence of difference in virulence in the pathogen cannot be ruled out. Piper colubrinum, P.obliquum, and P.guineense are reported to be resistant to the pathogen. No effective curative control measures have so far been evolved against the disease. The importance of evolving resistant lines and adoption of management practices in conjunction with chemical treatment is indicated in developing control schedules.