Effect of plant growth promoting substances from rhizo- and cyano -bacteria on sugar beet growth, yield and yield quality in saline soil

The production of plant growth promotors [indole acetic acid, gibberellic acid and abscissic acid] by rhizobacteria and cyanobacteria has been taken as a main criterion in the selection of the microbial strains used in this study. A field experiment was conducted at Sahl El Hussinia Station, El Sharkia Governorate, during the winter season of 2008/2009 to investigate the effect of rhizobacteria and cyanobacteria either individually or in combination on growth, yield and yield quality of sugar beet under salinity stress. Soil biological activity in terms of dehydrogenase activity was significantly affected by the biological treatments. The dehydrogenase recorded its highest value when the combined inoculum of rhizobacteria and cyanobacteria was applied. Inoculation with rhizobacteria and/or cyanobacteria in saline soil alleviated the salinity effects on the sugar beet and enhanced photosynthesis [leaves chlorophyll content], proline and phenoic accumulation in roots, along with, increasing the concentrations of N, P and K and decreasing Na[+] concentrations in roots. This physiological positive response of the plant growth promoting rhizobacteria and/or cyanobacteria resulted in significant increases in sugar beet root yield and yield quality [TSS, sucrose and purity%]. Best results were obtained by the combined mixture of bacteria and cyanobacteria followed by the individual treatments of either. This investigation pointed out that plant growth promoting substances secreted by rhizobacteria [PGPR] and cyanobacteria could be used as a good tool to alleviate salinity stress and promote sugar beet productivity and yield quality as it provides an ceo-friendly biological approach under saline soil conditions

Potentiality of rhizobacteria to support wheat productivity in saline environments

Pots experiment was conducted at the experimental greenhouse of Microbiology Department, Soils; Water and Environment Research Institute [ARC], Giza, Egypt and field experiment was carried out at the experimental saline sodic soil at Sahi El Tina in winter season of 2008-2009 to evaluate the response of wheat plant cultivar Sakha 93 to inoculation with Bacillus sp. and Pseudomnonas sp. isolates, which were isolated from salt affected soil of SahI Eltina Valley. Results revealed that plant height, fresh and dry weight [g/plant] and chlorophyll content of wheat through the pots experiment significantly increased as a result of inoculation with single or dual isolates. Regarding a field experiment, data indicated that inoculation with Bacillus sp. and Pseudomonas sp. isolates reduced the negative effect of salinity on wheat plant, where it significantly increased plant height [72cm] and dry weight [14.1g/plant] through the growth period. Also, spike weight [3.21 ton fed[-1]] and grain yield [1.85 ton fed[-1]] significantly increased. Inoculation with both isolates significantly enhanced the activity of dehydrogenase enzyme in the rhizosphere and crude protein of wheat grain. Concentrations of N, P, K of wheat grain significantly increased [57.6%, 53.6%, 35.4%] by inoculation, where the isolates mixture led to the highest values of N and P while inoculation with Pseudomonas isolate caused the maximum records of K and Na

Impact of biofertilizer and elemental sulphur on growth and yield of wheat [triticum aestivum var.] grown in saline sodic soil

Two field experiments were carried out at Sahl El-Hossainya Research Station, El-Sharkia Governorate during winter seasons [2007-2008] and [2008-2009] to study the effect of salt tolerant N[2] fixers, Azospirillum Azospferum, Azotobacter chroococcum, Bacillus polymyxa and Klebsiella penumoniae as well as plant growth promoting rhizobacteria [Pseudomonas fluorescens and Bacillus subtilis], on soil biological and chemical properties as well as growth and yield of wheat cv. Sakha 93, grown in saline sodic soil amended with elemental sulphur [0.5 ton/fed] and two levels of inorganic N-fertilizer [75 and 100% of the recommended dose]. Results indicated that inoculation with a mixture of N[2] fixers+PGPRs in presence of 0.5 ton/fed elemental sulphur and 75% of the recommended dose of N-fertilizer, resulted in superior improvement of enzymes activities [nitrogenase and dehydrogenase], CO[2] evolution, growth parameters [plant height, plant dry weight and No. of tillers] and chlorophyll content in leaves at 80[th] day of wheat sowing. At harvesting, the same treatment recorded the optimum NPK, total amino acid and crude protein contents in grains, and the highest grain yield, straw yield and weight of 1000 grains comparing to uninoculated and control treatments. Also, the same treatment recorded improvement in some soil chemical properties [pH, EC and available NPK]. So, our study supports the use of biofertilizers and chemical amendment [sulphur] as beneficial source for sustainable agriculture specially in saline sodic soil under reclamation