Nodulation Status Research Articles

Facultative nitrogen fixation by legumes in the central Congo basin is downregulated during late successional stages

AbstractThe contribution of the legume community to the nitrogen cycle during natural forest regeneration remains poorly understood. We systematically assessed the changes in abundance and nodulation status of all legumes, across taxa and plant types, in a forest succession gradient in the Equateur Province of the Democratic Republic of the Congo. Our results clearly show that symbiotic N2 fixation is downregulated during late successional stages.

Influence of chemical and biological properties of field grown pea and lentil rhizospheres on nodulation status and resident rhizobial population in acidic soils of Assam, India

The influence of rhizospheric properties on nodulation status and resident rhizobial population of pea and lentil grown at twenty three sites of Assam were assessed. Besides the plant infectivity of rhizobia isolated from pea and lentil nodules were tested for symbiotic effectiveness. The survey established significant variation of nodule number ((35.-223.plant)), nodule dry weight (6.6 to 271. mgplant) and most probable number count ( to 147g soil) across the twenty three diverse sites. Rhizospheric properties <italic>viz</italic> pH, organic carbon, available P<sub>2</sub>O<sub>5</sub> and K<sub>2</sub>O could establish significant correlation with nodule number (r=0.892*, 0.771*, 0.753* and 0.669*) and most probable number(r=0.784*, 0.580*, 0.615* and 0.649*) counts, correspondingly. Microbial biomass carbon showed significant correlation with nodule number(r=0.672*). Dehydrogenase and phosphomonoesterase activities too showed significant correlation with nodule number(r=0.695* and 0.634*) and most probable number (r=.575* and 0.534*) count, respectively. The symbiotic effectiveness of isolated rhizobia demonstrated significant variation of nodule score (1.33-3.67). Only 6 isolates could attain nodule score of ≥3.0, irrespective of resident rhizobial population.

Effect of Household Solid Waste on Initial Growth Performance of Acacia auriculiformis and Cedrela toona in Mycorrhiza Inoculated Soil

Solid waste disposal and management became one of the major environmental concerns in Bangladesh. Realising the problem, the present study has been undertaken with a view to find a sound and effective way of bio-degradable solid waste management. The study was carried out in the nursery of Institute of Forestry and Environmental Sciences at University of Chittagong to determine the effects of solid waste and waste inoculated with mycorrhizal soil on initial growth performance of Acacia auriculiformis and Cedrela toona. Before planting the seedlings, decomposable waste and mycorrhiza inoculated decomposable waste were placed on the planting holes. Physical growth parameters of seedlings (shoot and root length, leaf and branch number, fresh and dry weight of shoot and root and nodulation status) and the macro nutrients (N, P and K) were recorded after six months of planting. The highest performance of physical parameters was recorded in the soil treated by mycorrhiza inoculated waste. Cedrela toona was represented by maximum nutrients uptake (N-2.60%, P-0.21% and K-2.34% respectively) in the soil treated with mycorrhiza. In case of Acacia auriculiformis, N uptake was maximum (3.02%) in control while K uptake was highest (1.27%) in soil with waste and P (0.18%) uptake was highest in the soil treated with mycorrhiza inoculated waste. Highest initial growth performance was revealed by seedlings treated with mycorrhiza inoculated waste. This study suggested to use mycorrhiza and waste for plantation purposes for hygienic disposal of solid waste and to reduce cost of cultivation.

Improvement of Growth and Yield of Pea Plants Using Integrated Fertilization Management

Two field experiments were carried out during two successive winter seasons at 2013 and 2014, in a private farm at Abuo-Hammad area, Sharkia Governorate, Egypt, to evaluate the integrated fertilization management i.e. chemical fertilization (NPK), biofertilization (Rhizobium leguminosarum. bv. vicieae, Glomas bagyarajii, Bacillus circulans) with or without foliar applications of yeast extract (Saccharomyces cereviseae) and micronutrients on enzymes activity, nodulation status, growth characteristics, chemical constituents, mycorrhizal infection (%) and yield of pea (Pisum sativum L.) cv. Master B grown under loamy sandy soil conditions. All estimated parameters were affected by biofertilizers application, especially in combination with foliar applied with yeast extract. The highest values of the most studied parameters were recorded in combination between biofertilizers with foliar application of micronutrients and yeast extract.

Effects of Inoculation of Rhizobium on Nodulation and Nitrogen Accumulation in Cowpea Subjected to Water Availabilities

With high protein content, the cowpea is one of the most widely consumed legumes in northeastern Brazil. This study was aimed to evaluate the rhizobia inoculation effect on nitrogen accumulation and nodulation in cowpea subjected to water availability. The experiment was conducted in a greenhouse, in a completely randomized design, with six water availabilities (40%, 60%, 80%, 100%, 120% and 140% of maximum soil water retention capacity), with four replications. Soil moisture maintenance was performed by gravimetric method. The BR3267 strain (Bradyrhizobium japonicum) recommended for cowpea grown in Brazil was used. At thirty-five days after treatments implementation, the nitrogen nutritional status was assessed through SPAD reading, shoot nitrogen concentration and total accumulation. Nodulation was assessed by nodules number and dry matter. The increased water availability provided negative effect on SPAD reading and shoots nitrogen concentration. Shoot nitrogen accumulation was favored to up to 78.8% water availability, with subsequent decline. Nodulation was favored when soil water availability was between 85% and 87%. Water availability affects nodulation and cowpea nutritional status, although negative effects are more pronounced when there is soil water excess.

Impact of nitrogen fixing and plant growth-promoting bacteria on a phloem-feeding soybean herbivore

In soybean (Glycine max L.) production systems, growers often inoculate seeds with the symbiotic N-fixing species Bradyrhizobium japonicum along with other bacterial species or chemicals intended to enhance plant growth and yield. However, microbes associated with plant roots can also impact the biology of above-ground insect herbivores through influencing various aspects of plant physiology, with effects dependent on the bacterial species. Because rhizobial seed inoculants can potentially affect densities of soybean herbivores, we investigated the performance of phloem-feeding soybean aphids (Aphis glycines Matsumura) on: (1) soybeans receiving one of four commercially available rhizobial seed inoculants, (2) non-inoculated soybeans associated with existing soil bacteria, or (3) non-inoculated soybeans receiving high levels of fertilizer to suppress N-fixation while still providing adequate N as nitrate. We quantified effects of inoculants and aphid presence on parameters associated with plant growth, N-fixation, and foliar N levels, and explored relationships between aphid densities and these plant parameters. Regardless of inoculation treatment, aphid presence negatively affected plant biomass, pod density, and total N concentration in aerial plant tissues, although, effects on the concentration of ureide N (primary products of N-fixation) were not significant. Inoculant identity significantly impacted aphid populations in both short- (1 week) and longer-term experiments (2 months), with pest densities negatively related to the number of root nodules per plant. This research indicates that nodulation status of soybeans can influence above-ground herbivores.

Improving Acacia auriculiformis seedlings using microbial inoculant (Beneficial Microorganisms)

A microbial inoculant, known as effective microorganisms (EM), was applied to determine its efficacy on seed germination and seedling growth in the nursery of Acacia auriculiformis A Cunn. ex Benth. The seedlings were grown in a mixture of sandy soil and cow dung (3:1) and kept in polybags; EM was poured at different concentrations (0.1%, 0.5%, 1%, 2%, 5% and 10%). Seed germination rate and growth parameters of seedlings — shoot and root lengths, fresh and dry weights of shoots and roots, vigor, volume, and quality indices and sturdiness — were measured. The nodulation status influenced by EM was also observed, along with the measurement of pigment contents in leaves. The highest germination rate (72%) was observed in 2% EM solution while the lowest (55%) was found in control treatment. The highest shoot and root lengths (30.6 cm and 31.2 cm respectively) were recorded in 2% EM and were significantly (p <0.05) different from control. Both fresh and dry weights of shoots were maximum (8.66 g and 2.99 g respectively) in 2% EM, whereas both fresh and dry weights of root were maximum (2.56 g and 1.23 g respectively) in 5% EM solution. Although the highest vigor index, volume index, and sturdiness (4450, 628 and 67.5 respectively) were found in 2% EM, the highest quality index (0.455) was found in 5% EM solution. The nodule number was higher at a very low (0.5%) concentration of EM but it normally decreased with the increase of concentration. The contents of chlorophyll a, chlorophyll b, and carotenoid were maximum (43.26 mg·L−1, 13.56 mg·L−1and 17.99 mg·L−1 respectively) in 2% EM. Therefore, low concentration of EM (up to 2%) can be recommended for getting maximum seed germination and seedling development of A. auriculiformis in the nursery.

Two-way transfer of nitrogen between Dalbergia odorifera and its hemiparasite Santalum album is enhanced when the host is effectively nodulated and fixing nitrogen

Nutrient translocation from a host plant is vital to the growth and survival of its root parasitic plant, but few studies have investigated whether a parasitic plant is also able to transfer nutrients to its host. The role of N2-fixation in nitrogen (N) transfer between 7-month-old Dalbergia odorifera T. Chen nodulated with Bradyrhizobium elkanii DG and its hemiparasite Santalum album Linn. was examined by external (15)N labeling in a pot study. Four paired treatments were used, with (15)N given to either host or hemiparasite and the host either nodulated or grown on combined N. N2-fixation supplied 41-44% of total N in D. odorifera. Biomass, N and (15)N contents were significantly greater in both nodulated D. odorifera and S. album grown with paired nodulated D. odorifera. Significantly higher total plant (15)N recovery was in N donor D. odorifera (68-72%) than in N donor S. album (42-44%), regardless of the nodulation status in D. odorifera. Nitrogen transfer to S. album was significantly greater (27.8-67.8 mg plant(-1)) than to D. odorifera (2.0-8.9 mg plant(-1)) and 2.4-4.5 times greater in the nodulated pair than in the non-nodulated pair. Irrespective of the nodulation status, S. album was always the N-sink plant. The amount of two-way N transfer was increased by the presence of effective nodules, resulting in a greater net N transfer (22.6 mg plant(-1)) from host D. odorifera to hemiparasite S. album. Our results may provide N management strategies for D. odorifera/S. album mixed plantations in the field.

Effect of plant growth promoting rhizobacteria (PGPR) on the healthy and productivity of soy bean plant

A pot and field experiment were conducted to evaluation some rhizobacteria namely Pseudomonas fluorescens, and Bacillus subtilis. The pot experiment was executed to evaluate probable suppressive effect of rhizobacteria as bioagents against Macrophomina phaseolina, Fusarium solani and Sclerotium rolfsii under artifically infested soil. Results showed that co-inoculation of soy bean with rhizobacteria led to a significant decrease in pre- and post-emergence damping-off caused by all pathogens under investigation. In addition to enhance the nodulation status, growth, N-content and pod yield plant under uninfested or infested soil. Field experiment were carried out in El-Sharqia governorate to evaluate the promotive and suppressive disease effects of rhizobacteria on nodulation, plant growth and yield of soy bean. Results showed that the inoculation with rhizobacteria led to a significant increase in the nodulation status, shoot dry matter and N-content after 15, 45, 75 days of planting. Moreover, the co-inoculation of Bacillus subtillis with Rhizobium sp. Salient superiority in suppressive disease.

Peanut plant growth and yield as influenced by co-inoculation with Bradyrhizobium and some rhizo-microorganisms under sandy loam soil conditions

The ability of tested rhizomicrobial isolates (Serratiamarcescens and Trichoderma harzianum) along with a strain of root nodule bacteria (Bradyrhizobium spp.) to exhibit some PGP-properties was evaluated in vitro conditions. The main PGP-properties, namely the ability to solubilize-P and production of IAA, as well as production of siderophores and HCN were examined. Additionally, field trials were conducted on sandy loam soil at El-Tahrir Province during two successive summer seasons to study the effect of co-inoculation with Bradyrhizobium either individually or together with S.marcescens and/or T. harzianum on nodulation, some plant growth characters, peanut yield and its yield components. The in vitro experiment revealed that all of the tested microorganisms were apparently able to trigger PGP-properties. Phosphate solubilization was the common feature of the employed microorganisms. However, T. harzianum appeared to be superior to other microorganisms, and Bradyrhizobium displayed the lowest capacity. The ability of the microorganisms to produce indole compounds showed that S.marcescens was more effective in IAA production and followed by Bradyrhizobium. Capacity of S.marcescens and T. harzianum to excrete ferric-specific ligands (siderophores) and HCN was detected, while Bradyrhizobium failed to produce such compounds. Results of field trials showed that the uninoculated peanut had the least nodulation status, N2-ase activity and all vegetative growth characters in both studied seasons. Bacterization of peanut seeds with bradyrhizobia exerted considerable improvement in number and mass of root nodules, increased the rate of acetylene reduction and all growth characters in comparison to the uninoculated control. The synergy inoculation between bradyrhizobia and any of the tested microorganisms led to further increases of all mentioned characters and strengthened the stimulating effect of the bacterial inoculation. However, the promotive action on peanut nodulation, N2-fixation performance and vegetative characters was obvious with the dual inoculation with Bradyrhizobium plus S.marcescens. The other tested treatments, Bradyrhizobium conjugated with Trichoderma or with a mixture of the examined microorganisms, occupied the second rank. Additionally, peanut yield (pods and straw) and it’s components (seed and straw protein contents, hundred seed weight, as well as pod and seed weight/plant and shelling%) along the two consecutive seasons followed a similar pattern to that of the vegetative growth stage.

Nursery practice on seed germination and seedling growth of Dalbergia sissoo using beneficial microbial inoculants

Nursery practice using microbial inoculants was performed to find out the efficacy of the inoculants on seed germination and seedling growth of sissoo (Dalbergia sissoo Roxb.). Microbial inoculants or effective microorganisms (EM) are a mixture of many different beneficial microorganisms in a solution. The seedlings were grown in a mixture of sandy soil and cowdung (3:1) kept in polybags with pouring EM solution at different concentrations (0.1%, 0.5%, 1%, 2%, 5% and 10%) before and after a week of sowing the seeds. Seed germination rate and growth parameters of seedlings were measured, such as, shoot and root length, vigor index, fresh and dry weight of shoot and root and total biomass increment. The nodulation status influenced by EM was also observed along with the measurement of pigment contents in leaves. The highest germination rate (69%) was observed in 2% EM treatment, followed by 67% and 65% in 1% and 5% EM. The highest shoot length (33.2 cm) was in 2% EM, whereas highest root length (26.3 cm) was in 1% EM. Both fresh and dry weights from shoot and root, were maximum (4.16 g and 1.57 g; 2.12 g and 0.83 g respectively) in 2% EM and were significantly (p ≤ 0.05) different from control. Vigor index was highest (4071) in 2% EM, which was significantly (p ≤ 0.05) different from control. Total dry weight increment was highest in 2% EM treatment, followed by 1% and 5% concentrations of EM. Nodulation number was higher at very low (0.1%) concentration of EM solution but it normally decreased with the increase of EM concentrations. The contents of chlorophyll a, chlorophyll b and carotenoid were highest (60.11, 17.05 and 42.48 mg·L−1 respectively) in 2% EM treatment and lowest (39.35, 13.55 and 27.29 mg·L−1 respectively) in control treatment. Therefore, low concentration of EM (up to 2%) can be used for getting maximum seed germination rate and seedling development of Dalbergia sissoo Roxb.

Transcription profiling of the isoflavone phenylpropanoid pathway in soybean in response to Bradyrhizobium japonicum inoculation

Isoflavones are legume-specific secondary metabolites that function as defence compounds, signal molecules and regulators of gene expression during both pathogen attack and beneficial plant-microbe interactions. They are synthesised by a branch of the core phenylpropanoid pathway, using several isoenzymes within each enzymatic step. Gene-specific quantitative real-time reverse transcriptase PCR (qRT-PCR) was used to quantify expression of isoflavone synthesis genes in soybean (Glycine max L). Genes encoding chalcone synthase 7 (CHS7), chalcone synthase 8 (CHS8) and isoflavone synthase 1 (IFS1) displayed high basal expression levels in roots compared with hypocotyls, suggesting they could be the gene family members encoding the isoenzyme that contributes the most to the principal substrate flux towards specific isoflavone synthesis in roots. The genes encoding phenylalanine ammonia lyase 1 (PAL1) and IFS1 showed induction in root tissue after inoculation with Bradyrhizobium japonicum (Kirchner) Jordan, suggesting a control point. The absence of a functional nodulation regulator, GmNARK (G. max nodulation autoregulation receptor kinase), in the soybean mutant nts1007 resulted in significantly increased basal expression of PAL1 compared with levels induced by B. japonicum, suggesting that GmNARK is a negative regulator for isoflavone phenylpropanoid pathway genes during nodulation and that distinct genes, as opposed to the complete pathway, are coordinately regulated by the nodulation status of the mutant.

Evaluating the nodulation status of leguminous species from the Amazonian forest of Brazil

Numerous leguminous species are used or have potential uses for timber production, pharmacological products, or land reclamation. Through N(2)-fixation, many leguminous trees contribute to the N-balance of tropical wetlands and rainforests. Therefore, studies of the N(2)-fixation ability of leguminous species appear to be crucial for the better use and conservation of these resources. The global nodulation inventory in the Leguminosae family is constantly being enriched with new records, suggesting the existence of undiscovered nodulated species, especially in tropical natural ecosystems and other hot spots of biodiversity. In this respect, the nodulation of leguminous species from the Amazonian forest of Porto Trombetas (Brazil) was surveyed. Overall, 199 leguminous species from flooded and non-flooded areas, were examined for their nodulation status by combining field observations, seedling inoculations, and screening of N(2)-fixing bacterial strains from the collected nodules. The results revealed a tendency for a higher relative frequency of nodulation in the species from the flooded areas (74%) compared with those from the non-flooded areas (67%). Nodulation was observed in the Caesalpinioideae, Mimosoideae, and Papilionoideae, with 25, 88, and 84% of the examined species in each subfamily, respectively. Of the 137 nodulated leguminous species, 32 including three Caesalpinoideae, 19 Mimosoideae, and 10 Papilionoideae are new records. One new nodulated genus (Cymbosema) was found in the Papilionoideae. Twelve non-nodulating leguminous species were also observed for the first time. The results are discussed based on the systematics of the Leguminosae family and the influence of available nutrients to the legume-bacteria symbiosis.

The Effect of Indigenous Root-Nodulating Bacteria on Nodulation and Growth of Faba Bean (Vicia Faba) in the Low-Input Agricultural Systems of Tigray Highlands, Northern Ethiopia

This study was initiated to isolate and characterize indigenous rhizobia nodulating faba bean, and evaluate symbiotic characteristics between the crop and the rhizobia in major faba bean producing areas in Tigray highlands. Field crops were also surveyed for nodulation in selected sites of seven (7) faba bean growing districts. A total of 44 rhizobial strains were isolated and their symbiotic properties (nodule number, fresh weight, color and plant growth) were recorded. A total of 12 strains with good symbiotic properties were characterized for their morphological and physiological traits on Yeast Extract Manitol Agar (YMA) medium. The result of the study showed the presence of diversity in morphological, physiological and symbiotic properties among the rhizobial strains. There was statistically significant difference in nodule number, fresh weight and shoot height (p< 0.05) and great variation in nodule color within and among the districts. Nodulation status of the field crops was poor except Ofla, D/Temben and Alaje districts. Though the presence of diversity among the strains revealed the possibility of getting potentially effective adaptable rhizobial strains that enhance faba bean productivity, the weak symbiotic properties observed during isolation and nodulation status survey might partly be responsible for yield variation and reduction in low input cropping systems of Tigray. Hence, studies on a need for inoculation and factors responsible for poor nodulation need to be undertaken to realize the role of biological nitrogen fixation in Tigray cropping systems. Key words: Biological nitrogen fixation, Faba bean, Nodulation, Rhizobia, Symbiotic Effectiveness, Tigray.

In Situ Phylogenetic Structure and Diversity of Wild Bradyrhizobium Communities

Bacteria often infect their hosts from environmental sources, but little is known about how environmental and host-infecting populations are related. Here, phylogenetic clustering and diversity were investigated in a natural community of rhizobial bacteria from the genus Bradyrhizobium. These bacteria live in the soil and also form beneficial root nodule symbioses with legumes, including those in the genus Lotus. Two hundred eighty pure cultures of Bradyrhizobium bacteria were isolated and genotyped from wild hosts, including Lotus angustissimus, Lotus heermannii, Lotus micranthus, and Lotus strigosus. Bacteria were cultured directly from symbiotic nodules and from two microenvironments on the soil-root interface: root tips and mature (old) root surfaces. Bayesian phylogenies of Bradyrhizobium isolates were reconstructed using the internal transcribed spacer (ITS), and the structure of phylogenetic relatedness among bacteria was examined by host species and microenvironment. Inoculation assays were performed to confirm the nodulation status of a subset of isolates. Most recovered rhizobial genotypes were unique and found only in root surface communities, where little bacterial population genetic structure was detected among hosts. Conversely, most nodule isolates could be classified into several related, hyper-abundant genotypes that were phylogenetically clustered within host species. This pattern suggests that host infection provides ample rewards to symbiotic bacteria but that host specificity can strongly structure only a small subset of the rhizobial community.

ENHANCEMENT OF NITROGEN FIXATION, GROWTH, AND PRODUCTIVITY OF BRADYRHIZOBIUM-LUPIN SYMBIOSIS VIA CO-INOCULATION WITH RHIZOBACTERIA IN DIFFERENT SOIL TYPES

The current investigation was conducted in two different soil types (sandy and clay loam) at Ismailia and Sids Research stations, Agricultural Research Center, Egypt. The target of this study was to evaluate the promotive effect of various rhizobacterial co-inoculants for enhancing the nodulation, growth and productivity of lupin plants grown in the two different soil types. At preliminary, some plant growth promoting properties could be exerted by the tested rhizobacteria were examined under in vitro conditions. Afterwards, field trails were conducted at Ismailia and Sids sites during the two consecutive seasons of 2005/2006 and 2006/2007. Results of in vitro examination revealed that all tested rhizobacteria had a positive impression for exhibiting the PGP-properties, with clear superiority of Pseudomonas and Serratiafor producing IAA. In other side, Bradyrhizobium and Bacillus megatherium failed to excrete cyanid or siderophores. Results of field trials exerted that sole inoculation of lupin seeds with bradyrhizobia resulted in significant increases in nodulation status, dry matter and total N content of the plants either grown in sandy or clay loam soils after 75 days of planting during the two studied seasons. However, these parameters were significantly enhanced when the lupin plants co-inoculated with bradyrhizobia and any of the tested rhizobacteria in both investigated soils at the two studied seasons. Additionally, lupin yield and it's attributes gave the same tendency as a result of enhancement of nodulation, plant vigour and nitrogen fixation performance. For instance, the highest values of percentage increase attained in seed yield of lupin plants grown in sandy soil were 47.46% due sole inoculation with bradyrhizobia, then these values raised to range from 75.36 to 99.33% as function of co-inoculation with various rhizobacteria, during season of 2005/2006. The corresponding values attained for clay loam soil were 39.35% and 59.69 to 73.13%, respectively. Moreover, results exhibited that nodulation status and productivity of lupin plants grown in sandy soil (Ismailia site) exerted high responses to sole or/and co-inoculation approaches rather than these grown in the clay loam one (Sids site).

Effects of phosphorus and potassium addition on growth and nodulation of Dalbergia sissoo in the nursery

A study was conducted to test the influence of different inorganic fertilizers (phosphorous and potassium) on the nodulation and growth of Dalbergia sissoo grown in the nursery. Before seeds sowing, different combinations of P, K fertilizers were incorporated with the nutrient-deficient natural forest soils, and then amended with cowdung (soil: cowdung = 3:1). Nodulation status (nodule number, shape, fresh weight, dry weight and color) in the roots and the plant growth parameters (length of shoot and root, collar diameter, fresh and dry weight of shoot and root) were recorded 60 days after seeds sowing. Nodulation status and growth of the plants varied significantly (P<0.05) in the soils amended with fertilizers in comparison to the control. The highest nodule number (62), fresh (0.50 g) and dry (0.07 g) weights were recorded with the dose of PK at the rate of 160 kg/hm2. Nodule shape and color also varied widely in different treatments. In case of plant growth parameters, shoot and root length, collar diameter, fresh and dry weight of the plants took on a significant difference (P<0.05) among various combination of fertilizers. From the study, it is revealed that PK at the rate of 160 kg/hm2 fertilizer with soil and cowdung mixture (soil: cowdung = 3:1) is recommended for optimum growth and nodule formation of D. sissoo in degraded soils at a nursery level.

Effects of sludge on germination and initial growth performance of Leucaena leucocephala seedlings in the nursery

A study was carried out to determine the influence of different types of sludges (municipal, industrial and residential) on field germination, growth and nodulation of L. leucocephala seedlings in the nursery. Before sowing of seeds, different combinations of sludges were incorporated with the nutrient deficient natural forest soils. Field germination, nodulation status and physical growth parameters of seedlings (shoot and root length, vigor index, collar diameter, leaf number, fresh and dry weight of shoot and root and total dry biomass increment) were recorded after three and six months of seed sowing. Field germination, nodulation status and growth parameters were varied significantly in the soil amended with sludges in comparison to control. The highest number of nodule was recorded from soil amended with residential sludge (1:1) and highest fresh and dry nodule weight was also found from the same combination in both three and six month old seedlings. In case of growth parameters, the highest growth was recorded from soil and residential sludge (1:1) combination compared to control. From the study, it can be recommended that soil amended with residential sludge (1:1) provide better field germination, growth and nodule formation of L. leucocephala in degraded soil.

GROWTH, YIELD AND YIELD COMPONENT OF INOCULATED CHICKPEA AND FABA BEAN PLANTS AS AFFECTED BY USING METHYLOTROPHIC BACTERIA

Two pot experiments were performed in Giza research station, AgriculturalResearch Center (ARC) using 2 isolates of Pink-Pigmented FacultativelyMethylotrophic bacteria (PPFMs) originated from chickpea and Faba bean. Foliarapplication with PPFM isolates were conjugated with specific rhizobial inoculumand N-fertilization (15 Kg N Fed-1). Nodulation status, nitrogen fixation and growthyield and yield component were recorded. Results clearly indicated that Chickpeawas superior in its response to foliar application with PPFM.C. As it gave higherrecords of number and dry weight of nodules, dry matter and N-content of plants ascompared to Faba bean. A field experiment was also conducted in sandy loam soil atSouth EL-Tahreer province to investigate the effect of foliar application withPPFM.C strain + specific Rhizobia and N-fertilization on nodulation, growth andyield of chickpea legume plants. Results indicated that foliar application withPPFM.C in the presence of specific rhizobial inoculation scored significant increasesin economic turnover of chickpea in the range of 21-32% as compared to Nfertilizationat rate 50 Kg N Fed-1. Foliar application with 5 L Fed-1 in the presenceof 15 Kg N Fed-1 and specific rhizobial inoculation led to an increase of 518 kg fed -1productivity of seed yield , with economic turnover of 2491 L.E.

Effect of microbial inoculants on Albizia saman germination and seedling growth

Microbial Inoculants as Effective Microorganisms (EM) were applied to find out their effects on germination and seedling growth of Albizia saman in the nursery. The seedlings were grown in a mixture of sandy soils and cow dung (3:1) kept in polybags. The EM solution at different concentrations (0.1%, 0.5%, 1%, 2%, 5% and 10%) was incorporated before and after a week of sowing seeds. Germination and physical growth parameters, including shoot and root length, vigor index, collar diameter, leaf number, fresh and dry weight of shoot and root and total biomass increment over the control were measured. The nodulation status influenced by EM was also observed along with the estimation of chemical parameters like chlorophyll a, chlorophyll b and carotenoid. Both germination and the measured physical growth parameters were found significantly (P<0.05) higher in seedlings treated with different concentrations of EM solution in comparison to the control. Maximum growth was found at 2% followed by 1% EM solution. Nodulation was higher at 0.1% concentration but it normally decreased with the increase of concentrations. Although there were a higher amount of pigments in leaves of the treated seedlings than of the control, the variations recorded with respect to chlorophyll a, b and carotenoid were not significantly higher in most of the treatments. Treated seedlings showed variable results along with the increment of EM applications and most of the parameters showed best results at the medium range of concentrations. The study indicates that the Microbial Inoculant (EM) technology might be useful to improve the growth of seedlings in the nursery. This also indicates that the associated beneficial organisms along with the polybag soils might be of value in improving the degraded soil or poor field soil for better nutrient and water uptake during the initial growth of transplanted seedlings.