Induction of systemic resistance through antiviral agents of plant origin against papaya ring spot disease (Carica papaya L.).

The antiviral agents namely Boerhaavia diffusa root extract and Clerodendron aculeatum leaf extract were found to be significantly effective in inducing systematic resistance against papaya ring spot virus in papaya. However, B. diffusa root extract showed more efficient properties as compared to C. aculeatum leaf extract. Maximum reduction in disease incidence (72.25% and 74.00%), maximum plant height (119.05 and 126.61 cm), number of fruit (20.04 and 24.05 plant-1) and fruit yield (22.86 and 25.93 kg plant-1) were observed with the application of B. diffusa root extract as seed treatment + nursery treatment + field treatment during 2005-2006 and 2006-2007 respectively. However, maximum disease incidence (78.79% and 70.56%) minimum plant height (87.46 and 92.40 cm), number of fruit (11.36 and 13.50 plant-1) and fruit yield (9.85 and 11.03 kg plant-1) were recorded with the application of B. diffusa root extract as seed treatment + nursery treatment + field treatment during both the years. [ABSTRACT FROM AUTHOR]