Plant Science & Physiology

Biography

Biography: Nagaraju N

Abstract

Synthetic chemical based pesticides are extensively being used in agriculture to manage plant diseases particularly plant viruses transmitting through insect vectors. Since non availability of viricides as such. However the vector management through pesticides is the only means of chemical control.  However, continuous use of pesticides for the management of vectors of plant viruses cause severe and long term environmental pollution and are even carcinogenic to humans and animals. Furthermore, insect vectors become resistant to many of these chemicals resulted in resurgence of pests. Management of viral pathogens by using organic products viz., plant extracts, seaweed extracts etc., has gained importance. Antiviral effect of seaweed extracts viz., Euchema spinosum J. Agardh, Kappaphycus alvarezii doty-1, Kappaphycus alvarezii doty-2 and Halymenia durvillae Bory saint-vincent at 10ml L^-1, 4ml L^-1, 6ml L^-1 and 10ml L^-1 respectively including commercial products viz., Vacciplant and Jingo were tested for their optimum dose under field condition against Cucumber Mosaic Virus (CMV) was determined based on ELISA values of CMV infected gherkin samples during kharif and rabi 2016. Seaweed extracts Kappaphycus alvarezii-1 (4ml L^-1) sprayed gherkin plants recorded less mean PDI of 16.65 and 16.06 with an increased mean yield (13.33 t ha^-1) followed by Halymenia durvillae (10ml L^-1) with mean PDI (18.34 and 18.98) and mean yield (12.17 t ha^-1) compared to control with mean PDI (31.77 and 31.96) and mean yield (8.74 t ha^-1) respectively. The active principle present in these two seaweed extracts are mainly polysaccharides viz., kappa-carrageenan and sulphated galactan respectively. Hypothetically, polysaccharides might have helped in triggering defense by inducing plant hormones/signaling molecules viz., salicylic acid, Jasmonic acid or ethylene by inducing ISR.