The current study is focused and designed to formulate a suitable carrier for PGPR bioformulations based on the strategy theme i.e., a product of land for the land with minimum environmental disturbance. On the basis of physiochemical properties, nutrient composition and cost-effectiveness, two agro-industry by-products i.e., wheat bran and rice husk were selected to be tested as a potential biocarrier for PGPR bioformulation preparations. For bioformulations preparation, 100g of sterilized materials were separately inoculated with 15ml (106 cfu/ml) of four PGPR isolates i.e., Achromobacter sp. (P1), Bacillus sp. (P2), Enterobacter sp. (P3) and Pseudomonas sp. (P4) to prepare wheat bran based bioformulations (WB1, WB2, WB3 and WB4) and rice husk based bioformulations (RH1, RH2, RH3 and RH4) separately. A plant-microbe interaction assay was conducted with Zea mays as test crop under three different treatments i.e, T1, T2 and T3 to observe the efficiency of these PGPR bioformulations based upon the survivability of bio-inoculants. Significant increments upto 150% in shoot length, number of leaves, fresh weight, protein content and total chlorophyll content and root architectural modifications of treated plants especially with treatment T2 illustrated wheat bran and rice husk as potential cost-effective and viable biocarriers for eco-friendly PGPR bioformulations. These agricultural by-products can be efficiently utilized as environment friendly and low-cost organic carriers for bioformulation preparations which enables the applications of PGPR biofertilizers a success.

Index Terms- Achromobacter sp., Bacillus sp., Bioformulations, Enterobacter sp., Pseudomonas sp., PGPR, Rice husk, Wheat bran