Mitra, N.G.Uikey, Motilal2016-07-302016-07-302014http://krishikosh.egranth.ac.in/handle/1/70278The present investigation had been designed with the objectives to find out the effects of bio-priming with BCA and PGPR and its best compatibility (combination) with the other priming methods. The field experiment was performed during Rabi, 2011-12 in the premises plots and the laboratory experiments at Biofertilizer Production Centre (BPC), Department of Soil Science & Agril. Chemistry, JNKVV, Jabalpur. The biocontrol agent (BCA) T. viride and plant growth promoting rhizobacterium (PGPR) P. fluorescens were obtained from the production unit of BPC. The healthy seeds of okra (cv. VRO-6, short duration of 85 – 90 days, yield potential of 250–350 q/ha, and resistant to yellow vein mosaic virus) were obtained from the Department of Horticulture, JNKVV, Jabalpur. The experiment comprising a total 16 treatment combinations (including one untreated control) was laid out in RBD design with 3 replications. Primarily, the seed (500 g) treatments were: Hydro-priming (HP) with moisture imbibitions for 16 hr; Osmo-priming (OP) with PEG-6000 253 g/lit water at osmotic potential -1.2 MPa for 12 hr; Matrix priming (MP) with carbonized bagasse- 250 g sugarcane pressmud charred at 121oC mixed with sand soil (4:1) for 24 hr; and bio-priming for seed coating with BCA (log10 4 cfu/seed) and PGPR (log10 7 cfu/seed). The seeds were then conditioned to dry at room temperature for 72 hrs till original seed moisture content (SMC) comes down to 7-10%. The combination of seed treatments were performed first with individual priming either HP/OP/MP and conditioned, then bio-primed with either BCA/PGPR alone and dual inoculated with BCA+PGPR. Observations were made on germination attributes of the primed seeds for mean germination time (MGT), germination index (GI), time to germinate 50% seeds (T50%), and seed vigour index (SVI); physico-chemical properties of initial composite soil sample; chemical analysis of soil (plot wise) for total and available N and P at crop harvest; and chemical analysis of plants (whole) for contents of N and P at crop harvest. Microbiological analysis was accomplished for population dynamics of T. viride and P. fluorescens on surface of seeds at 0, 1 and 2 months of storage; and population dynamics in rhizospheric soils at seedling, flowering and harvest of the crop. Laboratory visual test of plants for incidence of soil borne fungal diseases (using Disease rating scale) was performed at seedling, flowering and harvest of the crop. Fruit yield of okra was also recorded at harvest. The data on microbial population were processed for semi-logarithmic transformation prior to undergoing statistical test of significance. The recorded data for each parameter individually were computed statistically for test of significance of the treatments applied. The treatments of HP+BCA+PGPR, HP+BCA, and BCA+PGPR performed the best for decreasing MGT by -29.23%, -28.30%, and -28.16% (untreated control 6.00 days); decreasing T50% by -30.40%, -24.87%, and -24.07% (control 6.193 days); increasing GI by 10.88, 10.85, and 10.52 (control 72.12); and increasing SVI by 42.13%, 39.18%, and 39.09% (control 697.73). The overall population dynamics of T. viride on surface of the seeds changed hyperbolically as 5.19x105 cfu/seed (log cfu 5.71518), 3.88x105 cfu/seed (log cfu 5.58813) and 2.51x105 cfu/seed (log cfu 5.39998) and that of P. fluorescens as 4.50x107 cfu/seed (log cfu 7.68115), 1.83x107 cfu/seed (log cfu 7.26240) and 7.25x106 cfu/seed (log cfu 6.86051). But, the change in population dynamics of T. viride in rhizospheric soil was parabolic 5.92x105 cfu/g soil (log cfu 5.8026), 1.62x106 cfu/g soil (log cfu 6.20972) and 6.82x105 cfu/g soil (log cfu 5.83372) and that of P. fluorescens as 6.64x104 cfu/g soil (log cfu 4.82227), 2.77x105 cfu/g soil (log cfu 5.44258) and 1.43x105 cfu/g soil (log cfu 5.15561). The overall mean of the disease incidence at the three respective growth stages of the crop exhibited a hyperbolic change as 4.21, 3.10, and 3.16 percent. For soil total nitrogen, the treatments HP+BCA+PGPR, BCA+PGPR, HP+PGPR, and PGPR alone increased but non-significantly by 0.59%, 0.50%, 0.49%, and 0.38%, respectively (998.53 kgN/ha); for soil available nitrogen increased significantly by 25.49%, 24.71%, and 22.27%, respectively (control 262.35 kgN/ha); and for soil total phosphorus increased but non-significantly with HP+BCA+PGPR, HP+PGPR, BCA+PGPR, and PGPR alone by 2.30%, 1.71%, 1.54%, and 1.52%, respectively (control 350.38 kgP2O5/ha); for soil available phosphorus increased significantly by 41.71%, 39.16%, 39.85%, and 38.84%, respectively over untreated control (22.77 kgP2O5/ha). The response for plant nitrogen content with HP+BCA+PGPR, BCA+PGPR, HP+PGPR, and PGPR alone by 37.77%, 37.65%, 31.98%, and 31.57%, respectively (control 2.75% N); for plant phosphorus content by 26.66%, 26.66%, 26.66%, and 20.00%, respectively (control 0.15% P). Similarly, the okra pod yield was 22.70%, 20.39%, and 19.97%, respectively (control 22.78 q/ha) with the treatments of HP+BCA+PGPR, HP+PGPR, and PGPR alone, respectively. Further, it was concluded that the basic priming methods were responded in the order of HP>OP>MP, might be due to respective better imbibitions and environment for improved seed germination and uniformly healthy stand of plants. Further, bio-priming in addition to the basic priming was essential in view to support microbial activities on seed and in rhizosphere.enThesis