Pre sowing dressing with plant growth substances for management of bakanae in aromatic rice (Oryza sativa L.) varieties

In this study, we evaluated the potential of seed priming with plant growth substances on morpho-physiological and yield attributes of bakanae infected seedlings of aromatic rice varieties Pusa Basmati 1121 and Pusa Basmati 1509. The study involved laboratory and field examination of seed priming for 6 h in SA at 5 mg L−1 &10 mg L−1 concentration, MeSA at 50 mg L−1 and 100 mg L−1 concentration, Prohexadione-Ca at 100 mg L−1 and 200 mg L−1 concentration, BABA at 5 mg L−1 and 10 mg L−1 concentration, followed by inoculation with the fourteen-day-old pure culture of Fusarium fujikuroi. The positive (inoculated hydroprimed seeds) and negative controls (un-inoculated untreated seeds) were maintained for both varieties simultaneously and the growth and physiological observations were made at 7, 14 and 21 DAG. The seed priming treatments recorded enhancement in germination, fresh and dry weight, vigour index, total chlorophyll and carotenoid content over the positive control. The optimum dose of each plant growth substance from laboratory evaluation was selected for the field studies. The procedure for priming and inoculation was same for field trial and observations were recorded at tillering, booting and anthesis stage. The seed priming treatments resulted in reduction in percent disease incidence and visible symptomology of bakanae concomitant with an enhancement in field emergence, biochemical attributes under field conditions. The study can be further used to decipher the biochemical and molecular mechanism underlying cross talk of plant growth substances during bakanae infestation in rice in order to design a disease management strategy.