KAUSHAL, RAJESHGUPTA, SHWETA2017-01-042017-01-04201147725http://krishikosh.egranth.ac.in/handle/1/94378ABSTRACT Plant growth promoting rhizobacteria (PGPR) refers to rhizosphere bacteria that colonize plant roots in the competitive environment and enhance the crop growth as well as productivity by exerting beneficial effects through direct and indirect mechanisms. Capsicum is a renumerative crop to the farmers and is grown in both open fields and protective structures. The nutrient requirements and its sensitivity to extremes of environment coupled with higher incidence of diseases such as Damping off (Pythium spp.), Phytophthora blight (Phytophthora spp.), fruit rot (Colletotrichum spp.) and pests infestation resulted in sizeable yields loss in mid hills of Himachal Pradesh. The use of PGPR to supplement chemical fertilizers and pesticides is a potential alternative but no commercial formulation is available for use. So, the present investigations entitled “Studies on selected plant growth promoting rhizobacteria on growth and yields of Capsicum (Capsicum annuum L.)” was carried out during 2009-2011. Rhizosphere and root samples of capsicum were collected from four locations i.e. Taradevi, Theog, Nauni and Lanachetah in Shimla and Sirmour districts of H.P. A total of 56 isolates were isolated by using modified replica plate method. On the basis of colony morphological similarities 10 isolates were selected for screening of possession of multifarious plant growth promoting traits. Out of 10 isolates, only 6 isolates were selected for net house studies. Among which RS7 isolate possesses maximum plant growth promoting attributes like P-solubilization (80.0%) on PVK solid medium, (201.67 μg/ml) in broth, growth on Jensen medium, siderophore production (83.3%), auxin production (28.33 μg/ml), HCN production and antagonism against Pythium spp. (41.7%), Phytophthora spp. (42.5%) and Colletotrichum spp (40.1%). On the basis of morphological (Gram +ve rods), physiological (optimum growth at 35 ° C and 7 pH) and biochemical characteristics (Glucose fermentation, production of gelatinase and catalase enzymes) RS7 isolate tentaviley identified as Bacillus spp. Seed bacterization with RS7 isolate not only showed maximum increase in plant parameters such as shoot length (50.7% 41.6% and 8.0%), shoot biomass (48.5%, 39.8% and 10.1%), root length (49.0%, 39.7% and 3.6%), root biomass (45.1%, 37.9% and 10.2%) and yields (51.4%, 51.3% and 5.7%) over C1 (uninoculated absolute control), C2 (uninoculated fungicide control) and C3 (reference strain; PM9) treatments, respectively but also increased available N, P and K by 23.8%, 21.1% and 15.1%, respectively over innitial contents. On the basis of efficacy i.e. rhizocompetence and plant growth promoting efficiency under net house studies the bacterial isolate RS7 has good potential to be used as biofertilizer and biocontrol agent for Capsicum.enThesis