Slow Decline of Black Pepper (Piper nigrum L.) and Role of Plant Parasitic Nematodes and Phytophthora Capsici in the Disease Complex

Abstract

A field trial on management of slow decline of black pepper (Piper nigrum L.) in arecanut black pepper mixed cropping system was taken up with soil application of phorate, neem cake and bavistin. Application of nematicide and neem cake was highly effective in reducing the populations of Meloidogyne incognita and Radopholus similis. However , treatments did not show clear evidence of remission of slow decline symptoms. Moreover , during the course of three years of trial the vine death ranged from 16.6 to 58.3 per cent in different treatments. Phytophthora capsici was isolated from feeder roots of disease affected vines. This suggests that P. capsici also may be playing a role in the slow decline complex. High percentage of mortality in bavistin treated vines is another indirect supporting evidence for phytophthora involvement in root rot since this fungus is insensitive to bavistin. There appears to be a lack of spatial segregation of plant parasitic nematodes and phytophthora under field conditions. The studies strongly indicate the need for integrated disease management of check both plant parasitic nematodes and phytophthora and to boost the vigour and productivity of the pepper vines.