Seed Health Management for Better Productivity - Govind Ballabh ...

(Seed Health Management for Better Productivity)infection on all leaf sheaths and leaves below the ear placement partial infection on cobs, 5.0 =very little or no grain formation, grain become chuffy or cob may be rotten.Chemical ControlThe experiment was planned using 18 fungicides in three replications following randomizedblock design. The plot size was kept 5 x 3 m 2 with 4 rows at 75 cm apart. All the plants wereartificially inoculated at 40 th and 50 th day of planting followed by foliar sprays of fungicides after 3days of inoculation. The observation on disease severity, 1000-grain weight, grain yield per haand cobs/plant were recorded and analyzed statistically. Only thiobendazole was found mosteffective followed by Duter & Vitavax in reducing the disease severity and resulting in higher grainyield while in following year only 10 fungicides were included based on the performance inprevious year testing. Of these vitavax (carboxin), TPTH (Triphenyl tin hydroxide) andthiobendazole were found to be most effective.During last few years, some newer chemicals which are claimed to be effective againstsheath blight disease were also tested under different sets of experiments. The chemicals viz.,Propaconazole, 0.1% (Tilt) & carbendazin, 0.05% (Savistin or Bavistin) were tried followingdifferent methodology.Both the chemicals were applied as foliar sprays at 30, 40 and 50 th day ofplanting alone or in combinations of application. The experiments were planted in threereplications following Randomized Block Design. The plot size was 7.5 m 2 with 2 rows of 75 cmapart. Artificial inoculations were carried out after 40 th day of planting and repeated after 2 days offirst one. The chemicals were applied as per treatment and the data on disease severity and yieldparameters were recorded and analyzed statistically. The result indicated that the effectiveness ofPropaconazole was markedly observed when the chemical was applied at initial stages at 30 th or40 th day of planting and the second spray at 10 days after first. Foliar sprays of Carbendazimshowed the ineffectiveness against BLSB as well as on the yield parameters.Visualizing the efforts on chemical control which were not so effective from practicalapplication point of view, the other approaches for disease management were also included in thestudies.Biological ControlBio-control agents Trichoderma harzianum, Gliocladium virens, Pseudomonas sp. weretried alone or in combination with propaconazole and carbendazim along with a cultural controltreatment with common check. All the methodology was the same as discussed in previousexperiments.None of the treatment effectively reduced the disease but foliar sprays of T. harzianum +Tilt followed by T. harzianum sprays, Saivistin + Tilt + T. harzianum, Savistin + Tilt and Savistinalone could exhibit some reduction in disease levels. Cultural practice, removal of lower leavesalone was not be so effective and would not be practicable to the farmers. While evaluating thebiocontrol bacteria against R. solani, the fluorescent Pseudomonas could not reduce the BLSB.- 131 -