Puccinia melampodii Diet. and Holow. as a Biological Control Agent of Parthenium hysterophorus

Parthenium hysterophorus is an annual, extremely prolific weed of Asteraceae that causes severe economic losses, health problems and habitat destruction in many tropical and sub tropical countries. In Sri Lanka, it was first observed in Vavuniya district in 1999 and subsequently it has spread to many areas of the country.The fungus Puccinia melampodii, introduced from Australia, was evaluated for its efficacy as bio control agent against P. hysterophorus under local conditions to use as a component of integrated pest management programme. Life cycle studies revealed that P. melampodii completes its life cycle within 8-11 days at 25°C night and 28°C day temperature. Continuous fungal infection resulted complete destruction of Parthenium plants within 30 days. In vitro studies to determine the effect of temperature on teliospore germination of P. melampodii indicated that it occurs over a wide range of temperatures from 5 to 30°C. The optimum temperature was 25°C and the fungus did not survive at 35°C after an inoculation period of 24 h and 48 h.Host specific studies of P. melampodii showed that, of 30 different plant taxa in 14 plant families tested, only P. hysterophorus were susceptible to the infection. Fungal infection at different growth stages of the Parthenium; rosette, preflowering and flowering stages, suppressed the plant growth, especially the leaf and flower production. Results revealed that the fungus P. melampodii can be effectively used as a potential bio-control agent against the Parthenium weed.

Key words: Parthenium weed; Puccinia melampodii; teliospore germination; mycelium

DOI: 10.4038/jfa.v1i1.1835

Journal of Food and Agriculture Vol.1(1) 2008 pp.13-19