KAUSHAL, RAJESHSOOD, GAURAV2017-03-242017-03-242016http://krishikosh.egranth.ac.in/handle/1/5810005875ABSTRACT Wheat (Triticum aestivum L.) and Maize (Zea mays L.) are members of Poaceae family, ranked among the top three cereal crops of the world. Cereals constitute the staple food of Indians and about 61% of the protein requirement is met through these crops. Wheat and Maize requires large amount of nitrogen and phosphorus in comparison to other essential nutrient elements. The deterioration of soil health coupled with decreasing nutrient use efficiency is a matter of great concern which compelled the scientists to explore renewable low cost non bulky inputs to bridge the gap of crop production which can improve the crop productivity and also sustain soil health. So, the present investigations were carried out to study the effect of plant growth promoting rhizobacteria and chemical fertilizers on crop productivity and soil properties in wheat- maize cropping system under rain fed conditions. A total of 127 isolates were isolated from all the four agro-climatic zones of Himachal Pradesh, out of which 67 bacterial isolates (36 from rhizosphere and 31 from roots) were morphologically and physiologically characterized and tested for multifarious PGP traits viz. phosphate solubilization (390.20- 408.68 µg/ml), HCN production, Growth on nitrogen free medium (3-6 mm colony diameter), auxin production (27.23- 32.77 µg/ml) and siderophore production (17.18- 29.38 % siderophore unit) as well as antagonism against Alternaria triticina, Claviceps purpurea and Fusarium graminearum. Three isolates (B2, SIR1 and BIS2) exhibited maximum multifarious PGP traits. On the basis of morphological, biochemical and molecular (16S rRNA gene sequencing) characteristics possessed by the selected isolates, they were identified Serratia sp. (B2) and Bacillus subtilis (SIR1). Three isolates (B2, SIR1 and BIS2) for wheat and (B1N1, DHK and J2) for maize possesses maximum PGP attributes were screened at different doses of N & P fertilizer (80, 60 and 40% of recommended doses of NP) levels under net house conditions and finally two isolates (B2 and SIR1) for wheat and (B1N1 and DHK) for maize along with optimum dose i.e. 80% of NP were selected for field experimentation. The application of selected isolates (B2 and SIR1) for wheat and (B1N1 and DHK) for maize at 80% recommended dose of N and P fertilizers level not only registered significant increase in yields for two consecutive years over uninoculated control (100% recommended doses of NPK fertilizers) besides a saving of 20% N and 20% P fertilizers. Similarly, the application of indigenous plant growth promoting isolates (B2 and SIR1) in wheat and (B1N1 and DHK) in maize can induce drought tolerance by increasing the antioxidant enzymes (SOD, CAT and POD) activities in addition to their ability to act as PGPR. The application of indigenous PGPR isolate (B2) reduced the disease incidence against Alternaria leaf blight by 20.00% as compared to chemical control. The B2 isolate for wheat and B1N1 for maize can be used as biofertilizers, biostimulants and bioprotectant and the conjoint application of B2 and B1N1 isolate for wheat and maize at 80 per cent can be recommended for multi locational trials in different agro-climatic zones of H.P.ennullThesis