Perpetuation of Phoma naikii in the crop debris of pigeonpea

Abstract

Infected debris such as leaves, stem, petiole and twig could be an important source of survival for the pathogens and source of inoculum for the subsequent spreads from one season to the next and from one area to another area. This study was conducted to determine the length of survival of Phoma naikii in the infected pigeonpea debris under different storage conditions viz., room, refrigerator, pot and field conditions. Under pot conditions, the samples were buried under 5 and 7.5 cm and one set were placed on surface of the soil. These samples were subjected for isolation at 15 days interval incubated at 25 ±2 ^oC. The observations were recorded for growth and development of pathogen in the tissues after a week. The results revealed that frequency of recovery of pathogen decreased over time and the fungus was capable of overwintering for 23 weeks (% reduction was 86.66-6.66) in infected debris buried in sterilized soil regardless of burial depth. It has survived for 27 weeks (% reduction was 93.33-13.33) in field conditions, 30 weeks (% reduction was 100.0-20.0) on surface of soil, 34 weeks (% reduction was 100.0-20.0) in room conditions and 36 weeks (% reduction was 100.00-26.66) in the refrigerated conditions. Hence, the present study indicates the variation in the viability of the pathogen in the infected debris stored ate six different conditions.