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Purpose: The current study aimed to figure out the types and dosages of biocomposts supplied with cellulose-degrading Trichoderma strains for ameliorating soil properties, and the growth and yield of pineapple. Method: The experiment with two factors followed a completely randomized block design, including 20 treatments (4 replications). The first factor (A) was the types of biocomposts inoculated with different Trichoderma spp., which were (i) the biocompost supplied with the commercial Trichoderma (the Trichoderma of Can Tho University) as the positive control treatment, and the biocompost supplied with Trichoderma strains of (ii) TC1 (TC1 biocompost), (iii) TC2 (TC2 biocompost), (iv) TC3 (TC3 biocompost), and (v) TC1, TC2, and TC3 (TC123 biocompost). The second factor (B) was rates of bio-compost used (t ha-1) as follows: (i) 1, (ii) 2, (iii) 3, and (iv) 4. Results: The application of TC123 bio-compost at 4 t ha-1 contributed to the greatest available N, soluble P, concentrations, and N, P, and K uptake values. The treatments with the TC123 biocompost correspondingly increased plant height, leaf number, D-leaf length, peduncle height, fruit length, and fruit width by 1.9, 31.8, 16.7, 5.4, 7.8, and 12.1%, in comparison with the treatments with the positive control. The TC123 biocompost fertilization increased fruit size, resulting in enhanced pineapple yield by 9.80% in comparison with the commercial biocompost fertilization. Conclusion: The TC123 biocompost surpassed the commercial one in enhancing the characteristics of pineapples (Ananas comosus (L.) Merr). At 4 t.ha-1, this biocompost performed the greatest.

The aim of the current study was to assess the potency of the exopolymeric substances (EPS)-secreting purple non-sulfur bacteria (PNSB) on rice plants on acidic salt-affected soil under greenhouse conditions. A two-factor experiment was conducted following a completely randomized block design. The first factor was the salinity of the irrigation, and the other factor was the application of the EPS producing PNSB (Luteovulum sphaeroides EPS18, EPS37, and EPS54), with four replicates. The result illustrated that irrigation of salt water at 3–4‰ resulted in an increase in the Na+ accumulation in soil, resulting in a lower rice grain yield by 12.9–22.2% in comparison with the 0‰ salinity case. Supplying the mixture of L. sphaeroides EPS18, EPS37, and EPS54 increased pH by 0.13, NH4+ by 2.30 mg NH4+ kg−1, and available P by 8.80 mg P kg−1, and decreased Na+ by 0.348 meq Na+ 100 g−1, resulting in improvements in N, P, and K uptake and reductions in Na uptake, in comparison with the treatment without bacteria. Thus, the treatments supplied with the mixture of L. sphaeroides EPS18, EPS37, and EPS54 resulted in greater yield by 27.7% than the control treatment.

Stem-end rot disease has been causing damage to the production of pomelos in Vietnam. The cur-rent study aimed to (i) isolate fungal pathogens causing pomelo stem-end rot disease (PSERD) and (ii) discover Trichoderma spp. that had an antagonistic ability against pathogens under in vitro conditions. Fungi causing PSERD were isolated from pomelo fruits with symptoms of stem-end rot disease and collected from pomelo farms in Ben Tre province, Vietnam. Moreover, 50 fungal strains of Trichoderma spp. also originated from soils of these pomelo farms in Ben Tre province and were dual-tested with the fungal pathogen on the PDA medium. The results demonstrated that 11 pathogenic fungi causing PSERD were isolated from the fruit and showed mycelial growth of roughly 5.33–8.77 cm diameter at 72 h after inoculation. The two fungi that exhibited the fast-est growth, namely, S-P06 and S-P07, were selected. ITS sequencing of the S-P06 and S-P07 fungi resulted in Lasiodiplodia theobromae. All the 50 Trichoderma spp. strains were allowed to antago-nize against the S-P06 and S-P07 strains under in vitro conditions. The greatest antagonistic effi-ciency was found in Trichoderma spp. T-SP19 at 85.4–86.2% and T-SP32 at 84.7–85.4%. The two antagonists were identified as Trichoderma asperellum T-SP19 and T-SP32. The selected strains of Trichoderma asperellum were potent as a biological control for fruit plants.

Saline soils negatively affect and cause serious problems for rice cultivation. This study aimed to evaluate the efficacy of the purple nonsulfur bacteria (PNSB) capable of secreting 5-aminolevulinic acid (ALA) to reduce soil salinity, improve soil fertility, and enhance rice growth and yield. A two-factorial experiment was conducted in a randomized complete block design with four replications. Factor one was the salinity of the irrigated water, and factor two was the supplementation of the ALA-producing PNSB. The results indicated that watering with saline water above 3‰ led to decreases in plant growth and rice yield compared to the treatments watered with tap water. Application of either an individual strain or the mixture of W01, W14, and W22 ameliorated soil properties and increased total NPK uptake, whereas treatments supplied with the mixed strains reduced total Na uptake (9.50 mg Na pot−1). Supplying the W01, W14, and W22 strains individually or in a mixture enhanced the plant height by 3.51–5.45% and rice grain yield by 14.7–26.2%, compared with those of the control treatment. From the study, the combination of the L. sphaeroides W01, W14, and W22 strains is promising for application in saline or salt-contaminated regions to aid the damages caused by salinity on cultivars there, especially rice. Furthermore, this is a biological approach to ease an environmental problem and improve crop performance, which is supposed to be a trend in the sustainable agriculture.

The aim of the current research was to evaluate the effects of members of purple nonsulfur bacteria (PNSB), Rhodopseudomonas palustris strains of VNW02, TLS06, VNW64, and VNS89, mixed with spent rice straw (SRS) from mushroom cultivation as a carrier on promoting sesame growth and yield, and ameliorating the alluvial soil (AS) fertility in dykes. A 4 × 3 factorial experiment consisting of different levels of the solid PNSB biofertilizer mixture at 0, 3, 4, and 5 t·ha−1 (0, 1.81 × 108, 2.24 × 108, and 2.68 × 108 cells pot−1, respectively), and nitrogen (N) and phosphorus (P) inorganic fertilizer rates (100, 75, and 50 kg·N·ha−1; 60, 45, and 30 kg P2O5·ha−1, respectively) was performed in pots with the sesame variety of ADB1 in the dyked AS. The solid PNSB biofertilizer mixture at at least 3 t·ha−1 significantly enhanced the sesame seed yield by providing higher macronutrients for plants by increasing available N and soluble P concentrations in the soil. The solid PNSB biofertilizer mixture in addition to 75% of the recommended N and P fertilizers produced an equivalent yield in comparison to the utilized 100% of N and P inorganic fertilizers. The solid PNSB biofertilizer mixture in the SRS from the mushroom production reduced at least 25% of N and P chemical fertilizers for gaining the maximal seed yield and enriched soil characteristics for the sustainable black sesame cultivation in the dyked AS.

The present study aimed to identify the abilities of the δ-aminolevulinic acid (ALA) producing purple non-sulfur bacteria (PNSB), Luteovulum sphaeroides W22 and W47, to reduce the Na+ concentration, and to ameliorate the soil fertility, nutrients uptake, growth and yield of rice on the salt-contaminated soil. A two-factor experiment was conducted following a completely randomized block design. The factors were the frequency of applying saline irrigation (zero, one, two, three and four times) and the ALA-producing PNSB supplementation (applying only W22, only W47 and mixed W22 + W47). The results revealed that supplying the PNSB mixture not only reduced the proline content but also increased the plant height, number of panicles per pot, percentage of filled seeds, contents of NH4+, PO43−, total N, P uptake and grain yield. The mixed PNSB application also reduced the Na content and the total Na uptake in plants. L. sphaeroides W22 and W47 decreased the proline content by 31.3% and increased the grain yield by 27.2% in the condition of applying 5‰ saline irrigation four times.

The aim of this study was to determine the proper combination of nitrogen (N) fertilizer level and nitrogen fixing endophytic bacteria (NFEB) supplementation for the maximum grain yield of sesame cultivated in alluvial soil in dykes. The experiment followed a completely randomized block design with two factors. The first one was the levels of N fertilizer used, including 0, 50, 75, and 100% N of recommended fertilizer formula (RFF), and the other consisted of no bacteria applied, an individual strain of Enterobacter cloacae ASD-48 or E. cloacae ASD-21 applied, and their mixture, with 5 replicates. The results revealed that fertilizing with 100% N of RFF led to an enhancement of the plant height (16.8 cm), the chlorophyll a and b and their total content (6.45, 1.86, and 8.30 μg mL−1), the number of capsules per plant (7.22 capsules plant−1), the total N uptake (126.5 mg N pot−1), and the grain yield (9.08 g pot−1), in comparison to no N fertilizer applied. Supplementation of two NFRB strains enhanced the soilconcentrations of NH4+ and NO3−, the total N uptake, and the grain yield. The treatment fertilized with 75% N of RFF plus an individual NFEB strain or their bacterial mixture had equivalent total N uptake to that the treatment fertilized with 100% N of RFF had, 120.8–125.5 mg N pot−1 compared to 124.4 mg N pot−1. Regarding the sesame yield, with a reduction by 25–50% N of RFF plus ASD-48 and ASD-21, either individually or in mixture, it increased by 2.39–8.56%, compared to that in the treatment fertilized with 100% N of RFF.

The present study was aimed to evaluate the effects of nitrogen (N) fixing Rhodopseudomonas palustris strains, VNW64, VNS89, TLS06 and VNS02 on soil fertility, growth and yield of hybrid maize cultivated on in-dyke alluvial soil (IDAS). The pot experiment followed a completely randomized block design with 10 treatments, 4 replicates for each treatment. The treatments comprised of (i) fertilization with 100% N following recommended fertilizer formula (RFF), (ii) fertilization with 85% N, (iii) fertilization with 70% N, (iv) fertilization with 55% N, (v) treatment i plus a mixture of four purple nonsulfur bacteria (MFPNSB), (vi) treatment ii plus MFPNSB, (vii) treatment iii plus MFPNSB, (viii) treatment iv plus MFPNSB, (ix) no chemical fertilization, and (x) Treatment ix plus MFPNSB. The result indicated that treatments supplied with MFPNSB enhanced soil properties, including soil pHWater, NH4+ content and total N uptake, in comparison with no supplemented bacteria, 6.11–6.15, 16.4–17.7 mg NH4+ kg-1 and 1.43–5.02 mg N pot-1 in comparison with 5.74–5.99, 11.3–12.7 mg NH4+ kg-1 and 0.82–3.11 mg N pot-1, respectively, for hybrid maize cultivated on IDAS. Inoculation of MFPNSB on maize seeds contributed to reduce 45% N of RFF, but still caused no decline in the grain yield of maize. At 100% N of RFF, the treatment supplemented MFPNSB possessed a grain yield of 20.2% higher than the treatment without supplemented MFPNSB. Additionally, the treatment fertilized with 85% N of RFF plus MFPNSB, the maize grain yield was increased by 12.5% compared to the treatment fertilized with 100% N of RFF. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the effects of purple non-sulfur bacteria (PNSB) biofertilizers on soil properties, nitrogen (N) and phosphorus (P) uptakes, growth, and grain yield of sesame cultivated on salt-affected soil. N2-fixing and P-solubilizing bacteria used as biofertilizers were PNSB Rhodopseudomonas palustris VNW64, VNS89, TLS06 and VNS02, and endophytic bacteria (EB) Enterobacter cloacae X4 and Burkholderia acidipaludis X5. The experiment was conducted in a completely randomized block design, with 9 treatments (i) 100% N and 100% P of recommended fertilizer formula (RFF), (ii) 75% N and 50% P, (iii) 50% N and 50% P, (iv) treatment ii plus PNSB biofertilizers, (v) treatment iii plus PNSB biofertilizers, (vi) treatment ii plus EB biofertilizers, (vii) treatment iii plus EB biofertilizers, (viii) PNSB biofertilizers only, and (ix) carriers only, a rice straw and hush ash mixture. Results revealed that application of PNSB biofertilizers significantly improved soil fertility, nutrient uptakes, and yield as compared to treatments that used chemical fertilizers with or without EB biofertilizers at the same amount of N and P fertilizers applied. The use of 75% N and 50% P of RFF plus PNSB biofertilizers enhanced soil pHH2O, NH4+, soluble P, and N, P uptakes in sesame as compared to 100% N and 100% P of RFF. PNSB biofertilizers not only reduced 50% N and 50% P of RFF, but also maintained yield as compared to the treatment using 100% N, P of RFF (6.06 and 6.09 g pot−1, respectively) and limited Na uptake in sesame and Na+ concentration in the soil. [ABSTRACT FROM AUTHOR]

This study aimed to (i) select endophytic bacteria in maize root for its phosphorus solubilization ability and (ii) evaluate the efficacy of selected indigenous bacterial strains on soil fertility, phosphorus (P) uptake, growth, and maize yield. A total of 31 maize root samples were collected from An Phu District, An Giang Province, to isolate the bacteria. In addition, the pot experiment was conducted with nine treatments of (i) 100% P of the recommended fertilizer formula (RFF), (ii) 75% P of the RFF, (iii) 50% P of the RFF, (iv) 25% P of the RFF, (v) 75% P of the RFF plus a mixture of the 3 selected strains, (vi) 50% P of the RFF plus a mixture of the 3 selected strains, (vii) 25% P of the RFF plus a mixture of the 3 selected strains, (viii) 0% P of the RFF plus a mixture of the 3 selected strains, and (ix) 0% P of the RFF plus none of the 3 selected strains. The results identified 72 isolates from LGI medium. All isolates were screened in a broth medium at pH 5.0, but only 16 isolates obtained OD660 > 0.5. All 16 isolates were able to solubilize various insoluble P fractions. Of those, strain ASD-21 had the highest P solubilization ability for the insoluble Al-P compound. Strains ASD-08 and ASD-21 had the highest Fe-P concentration at 39.8-41.5 mg P L-1. Strains ASD-08 and ASD-21 had the highest Ca-P concentration (46.6-51.3 mg P L-1) for 48 h of incubation. They were identified as Enterobacter spp. Results also showed the application of a mixture of strains ASD-08, ASD-10, and ASD-21 increased soil fertility by increasing phosphorus content by 13.7 mg P kg-1 and replacing 25% of P fertilizer, but this mixture did not change maize yield. [ABSTRACT FROM AUTHOR]

Acid sulfate soils are limiting the productivity of pineapples (Ananas comosus (L.) Merr. var. comosus) by lacking available P content. This study aims to evaluate the potency of P-solubilizing bacterial endophytes, Burkholderia silvatlantica L-VT09 and N-VT06, on acid sulfate soil properties and features of pineapples grown in that soil. The two-factor experiment was arranged according to a completely randomized block design. One factor was P fertilizer levels: 25% P, 50% P, 75% P, and 100% P; the other was supplementations of P-solubilizing bacterial endophytes: No supplementations, individual supplementation of L-VT09, individual supplementation of N-VT06, and mixed supplementation of both L-VT09 and NVT06. The result revealed that supplying the mixture of B. silvatlantica L-VT09 and N-VT06 did improve the soil fertility as increasing available P content and bacterial density (12.6 mg P kg-1 and 3.82 most probable number g-1 dry soil weight, respectively), P uptake (19.2 kg ha-1), growth as boosting plant height (8.30 cm), leaves number per plant (6.60 leaves plant-1), D-leaf length and width (2.80 and 0.32 cm, correspondingly), stem size (3.40 cm in length and 0.44 cm in diameter), yield components as enhancing fruit length and fruit diameter (3.50 and 1.46 cm, sequentially), yield (11.5 t ha-1), and pineapple fruit quality as ameliorating sugar content (1.71 °Brix) and water content (166.4 mL), in comparison with the no bacteria supplied case. Supplying the mixture of B. silvatlantica L-VT09 and N-VT06 altered 75% P but still maintained pineapple yield. [ABSTRACT FROM AUTHOR]