Superior Plant Growth Research Articles

Biologicals and New Generation Fungicides in the Management of Blast Disease in Rice

Background: Blast is a devastating disease in rice production. The current research tested the efficacy of biologicals and fungicides against blast. Aqueous extracts of Azadirachta indica, Ocimum basalicum, Cymbopogan flexousus, Thymus vulgaris, Aloe vera, Tagetes patula, Cordia curassavica, Aegle marmelos, Allium fistulosum, Syzygium aromaticum, and Calotropis gigantea were tested in vitro at 5, 10, and 15% concentrations against Magnaporthe oryzae. Also, two isolates, Bacillus cereus OG2L and B. subtilis OG2A, and one isolate, Azotobacter SAG19, and, similarly, five new generation fungicides were evaluated at three different doses against blast pathogen M. oryzae in vitro. The treatments that exhibited the best performance in vitro were further evaluated against blast disease under field conditions.Results: Extracts of T. patula (5%), C. gigantea (5%), C. curassavica (10%), A. fistulosum (10%), and A. marmelos (15%) showed greater than 81% inhibition to M. oryzae in vitro. Likewise, all three biocontrol agents, viz. B. cereus OG2L, B. subtilis OG2A, and Azotobacter SAG19, demonstrated more than 50% inhibition of mycelial growth of pathogen in vitro, and the commercial formulations of fungicides Propineb, Trifloxystrobin+Tebuconazole, Tebuconazol+Triadimenol, Bacillus subtilis Strain QST 713, and Cinnamon Oil 8%+Clove Oil 2% also significantly inhibited M. oryzae. Under field conditions, C. curassavica (10%), A. marmelos (15%), C. gigantea (5%); B.cereus OG2L; B.subtilis OG2A; Proineb and Trifloxystrobin+Tebuconazole were effective in reducing disease in addition to yield enhancement.Conclusion: Overall, the plant extracts (C. curassavica at 10%, A. marmelos at 15%, C. gigantea at 5%); bio-agents (B. cereus OG2L, B. subtilis OG2A both at 2g/l), and new generation fungicides Antracol 70WP (Proineb) at 2.5 g/l and Nativo 75 WG (Trifloxystrobin+Tebuconazole) at 0.5 g/l provided effective control against blast disease and superior plant growth and yield compared with other treatments and untreated control.

Nutrient expert system optimizes fertilizer management to improve potato productivity and tuber quality.

Improving potato productivity and quality plays an important role in enhancing global food security and human health. However, inappropriate fertilizer management negatively affects potato growth and tuber development, especially in developing countries where there are large numbers of smallholders without modern soil testing equipment. Nutrient Expert (NE), a new and convenient fertilization decision system, was evaluated in the present study by conducting four site-years field experiments in Northeast China, aiming to determine its effectiveness and applicability for potato production relative to local farmers' practice (FP) and fertilizer recommendation based on soil testing (ST). The excessive fertilization at planting promoted seedling growth for potato plants in FP. Nevertheless, superior plant growth and tuber development were observed in NE at the middle and later growing stages, by optimizing fertilizer input and implementing split fertilization. Overall, compared to FP, the NE system increased total and marketable tuber yields by 12-15% and 16-26%, respectively, at the same time as obtaining 19-31% higher net returns and enhanced fertilizer use efficiencies. Moreover, NE improved tuber quality by increasing the contents of starch, soluble protein and vitamin C and decreasing reducing sugar content relative to FP, as well as increasing starch yields by 23-52%. The ST method also showed comprehensive improvements in potato performances compared to FP, although it did not show any advantages compared to NE system. The NE system improved potato productivity and tuber quality by optimizing fertilization management, which is an effective and promising alternative to the ST method for potato production in China and other developing countries. © 2021 Society of Chemical Industry.

Growth and Yield of Sweetcorn as Influenced by Zinc Fertilization

In order to investigate the effect of zinc nutrition on growth, yield, and quality parameters of sweetcorn, a field experiment comprising of nine treatments with three replications was carried out in Randomised Block Design during Kharif, season 2020 on sandy clay soils of Agricultural College Farm, Bapatla. The analysis of variance showed a significant effect of zinc application on growth and yield parameters. The detailed results of the study showed that among the various zinc fortification treatments, RDF + Zn EDTA @ 10 kg ha-1 (Soil) + Nano ZnO @ 250 ppm at 20 & 40 DAS (Foliar spray) registered superior plant growth characters like plant height at harvest (214.4 cm) leaf area index at harvest (2.94) and dry matter accumulation at harvest (9903 kg ha-1). The yield parameters like no. of seed rows per cob (16.84), no. of seeds per row (32.57), green cob yield (12,638 kg ha-1), and green fodder yield (19,674 kg ha-1) were maximum with RDF + Zn EDTA @ 10 kg ha-1 (Soil) + Nano ZnO @ 250 ppm at 20 & 40 DAS (Foliar spray) which was significantly superior over rest of the treatments whereas lower growth and yield was noticed with RDF alone.

Influence of shade and organic nutrition on growth, yield and quality of memory enhancing herb, Brahmi (Bacopa monnieri L.)

Memory enhancing herb - Brahmi (Bacopa monnieri L.) has growing national and international demand owing to its various medicinal properties. In order to study the influence of shade and nutrient levels, an experiment was laid out in strip plot design with shade levels as the main plots (35% shade, 50% shade and 100% sunlight) and nutrients requirement as sub plots [50, 75 and 100% N equivalent through FYM, 50, 75 and 100% N equivalent through vermicompost, RDF (100:60:60 kg NPK/ha), RDF (100:60:60 kg NPK/ha) + FYM (10 t/ha)]. The results revealed that among different shade levels tried, superior plant growth, fresh and dry herbage yield and cumulative dry herbage yield of seven harvests were obtained in 35% shaded condition compared to 50% shade and open conditions. Among different nutrient levels tried, conjunctive use of recommended dose of fertilizers (100:60:60 kg NPK/ha) + FYM (10 t /ha) gave the highest dry herbage yield (16.35 t/ ha), which was on par with organic treatment consisting of 100% N equivalent through FYM + Arka microbial consortium @ 12.5 kg/ha/year (16 t/ha). However, highest content of bacopasaponin C and bacoside A were observed in 100% sunlight condition (1.88 and 2.93%, respectively) and in integrated nutrient management treatment. The results were very promising for acceptance of Brahmi for commercial cultivation especially in organic production scenario to ensure steady supply of quality raw material to cater the increasing national and international demand.

Aquatic Macrophytes in Morphological and Physiological Responses to the Nanobubble Technology Application for Water Restoration

Nanobubble technology, as an emerging and sustainable approach, has been used for remediation of eutrophication. However, the influence of nanobubbles on the restoration of aquatic vegetation and the mechanisms are unclear. In this study, the effect of nanobubbles at different concentrations on the growth of Iris pseudacorus (Iris) and Echinodorus amazonicus (Echinodorus) was investigated. The results demonstrated that nanobubbles can enhance the delivery of oxygen to plants, while appropriate nanobubble levels will promote plant growth, excess nanobubbles could inhibit plant growth and photosynthesis. The nanobubble concentration thresholds for this switch from growth promotion to growth inhibition were 3.45 × 107 and 1.23 × 107 particles/mL for Iris and Echinodorus, respectively. Below the threshold, an increase in nanobubble concentration enhanced plant aerobic respiration and ROS generations in plants, resulting in superior plant growth. However, above the threshold, high nanobubble concentrations induced hyperoxia stress, particularly in submergent plants, which result in collapse of the antioxidant system and the inhibition of plant physiological activity. The expression of genes involved in modulating redox potential and the oxidative stress response, as well as the generation of relevant hormones, were also altered. Overall, this study provides an evidence-based strategy to guide the future application of nanobubble technology for sustainable management of natural waters.

Evaluation of plant probiotic performance of Pseudomonas sp. encapsulated in alginate supplemented with salicylic acid and zinc oxide nanoparticles

Plant growth promoting rhizobacteria (PGPR) are efficient candidates for the application in agricultural field to enhance the crop yield and to suppress the plant diseases. As the changes in agro-climatic conditions negatively affect the soil fertility and functioning of soil microbial community, there are significant demand for the innovative delivery methods for the PGPR to ensure its optimal performance. In the present study, Pseudomonas sp. DN18 has been entrapped in the alginate beads along with the supplemented salicylic acid (SA) and zinc oxide nanoparticles (ZnONPs). This modified formulation was further demonstrated for the IAA production and also antifungal activity against the Sclerotium rolfsii. In addition, superior plant growth promoting and biocontrol properties of the encapsulated Pseudomonas sp. DN18 supplemented with SA and ZnONPs have also been demonstrated on Oryza sativa seedlings by comparing with the free living Pseudomonas sp. DN18. This revealed the agricultural promises of Pseudomonas sp. DN18 encapsulated in a modified delivery system due to its functional superiority and stability over the free living bacteria based formulation.

Toxicity of seed-applied pesticides to Azospirillum spp.: an approach based on bacterial count in the maize rhizosphere

The objective of this work was to investigate the impact of pesticides on the survival of the plant growth- promoting bacteria Azospirillum in the surface of coated seeds as well as in the maize rhizosphere. Our results showed that the greater the time that the bacteria are in contact with the seed surface, the higher the cell mortality. In uncoated maize seeds, inoculation increased bacterial concentration in root tissues and ensured superior plant growth up to 12 hours of Azospirillum contact with the seed surface, while for the coated seeds, a similar performance was observed only up to six hours of exposure.

Effect of Integrated Farmyard Manure and NP Fertilizers Use on Hybrid Maize Yield and Soil Properties in Western Ethiopia

A study was carried out to assess the effect of integrated Farmyard Manure (FYM) and inorganic NP fertilizers use on yield and soil properties in Bako-Tibe district of Oromia, western Ethiopia. Five treatments (i.e., 110 kg N ha-1 + 46 kg P2O5 ha-1 (T1), 12 ton FYM ha-1 (T2) , 55 kg N ha-1 + 23 kg P2O5 ha-1 + 6 ton FYM ha-1(T3), 27.5kg N ha-1 + 11.5 kg P2O5 ha-1 + 6 ton FYM ha-1(T4) and the control (T5)) were used in a Randomized Complete Block Design (RCBD) with five replications using five farmers’ fields. Yield and yield related parameters were analyzed using SAS statistical software version 9.0. Economic analysis was performed to compare treatments advantages. The treatment with half the recommended NP (55 kg N ha-1 + 23 kg P2O5 ha-1 + 6 ton FYM ha-1) showed superior plant growth performance as compared to other treatments. Pure use of inorganic NP resulted in high Na, K, Ca and P composition of grain while pure FYM use resulted in high content of Mg and Ca composition. The level of P in grain decreased with the increasing of FYM. Soil fertility parameters considered showed no significance difference (P: 0.05) among the treatments. The mean difference values indicated that use of pure inorganic fertilizer increased soil PH, exchangeable Na, and available S. Use of pure farmyard manure resulted in an increase in the soil exchangeable Na, K, Mg, total Nitrogen, and available K and S. The use of half of the recommended inorganic fertilizer and FYM can enhance soil fertility in addition to yield improvement.

Technosol as an integrated management tool for turning urban and coal mining waste into a resource

The present study aims to evaluate plant growth and chemical characteristics of technosols produced from fine coal waste and an organic compost from urban waste. This could be an alternative method for current disposal practices and a way to promote vegetation cover of mined lands. The experiment was conducted in 2 L containers filled with different substrates conditions: (I) exclusively coal waste, (II) coal waste + 2.5% organic matter, (III) coal waste + 5.0% organic matter, and (iv) agricultural soil as control. All substrates were performed in triplicate, with and without Alfalfa (Medicago sativa) planting. Plant growth was monitored for biomass production and plant tissue composition. Soils were evaluated in terms of fertility, acid generation potential, and sulfur speciation. The substrate composed exclusively of coal waste had almost no plant growth. However, the addition of compost allowed equivalent (with 2.5% organic matter) or even superior (with 5.0% organic matter) plant growth in terms of dry matter compared to the agricultural soil. At both levels of organic matter, soil fertility parameters were appropriate for Alfalfa growth. Regarding the plant tissue, the elemental composition of the shoots was considered adequate for cattle nutrition. Also, there was a reduction of both pyrite content and acid generation potential of the substrates after plant growth. In relation to urban waste, it is estimated that each hectare of technosol (condition III) could utilize around 550 t of organic compost. Thereby, this study addresses the possibility of improving waste management in both mining and urban contexts consistent with circular economy concepts.

Functional characterization of endophytic bacilli from pearl millet (Pennisetum glaucum) and their possible role in multiple stress tolerance

Endophytic bacteria are common residents of living host tissue and occupy vital role in sustaining crop growth and health under adverse environmental situations. At present, scanty information is available about the salt-tolerant plant growth promoting (PGP) endophytic bacilli from pearl millet (Pennisetum glaucum). In the study, 102 endophytic Bacillus strains from root, leaf and stem region of pear millet host plant were isolated and limited to 28 strains depending on the salt (≥10%) tolerance ability. Phenotypic and biochemical features, together with 16S rDNA gene sequence similarity comparison with type strains identified endophytes as Bacillus albus, B. amyloliquefaciens, B. aryabhattai, B. halotolerans, B. haynesii, B. pacific, B. paramycoides, B. proteolyticus, B. pumilus, B. subtilis, B. siamensis, B. tequilensis, B. wiedmannii and B. zhangzhouensis. The rigorous in vitro screening for PGP traits, nutrient solubilization, heavy metal, polyethelene glycol, extracellular enzyme production and antagonistic potential identified B. amyloliquefaciens EPP90 as a potent multi-stress tolerant crop growth promoter. Under greenhouse experiments, plants treated with this strain reflected significantly superior plant growth relative to untreated pearl millet seed grown under saline (200 mM NaCl) environment. The research findings clearly displayed the prospective function of endophytic B. amyloliquefaciens EPP90 as an excellent multi-stress reliever and crop growth promoter.

Comparation of Hydroponic System Design for Rural Communities in Indonesia

The interest of the younger generation in Indonesian rural areas to become farmer generally decreases. The problem they face is the reduced agricultural land also due to lack of farming ability. Since the introduction of hydroponic system for rural region, many young farmers are motivated to become independent farmer. This study is intended to find a hydroponic system that is suitable for rural situations and conditions in Indonesia. This research examines various existing hydroponic systems with comparative and experimental methods to find the most suitable model. The results obtained show a variety of promising qualities. One hydroponic design with a perforated bulkhead system that produces nutritional water waves, shows superior plant growth results. This hydroponic design with the application of hydrotropism shows a positive correlation between the movement of water and the growth of roots and leaves. Hydroponic products with hydrotropism components as the findings of this study can be recommended to be developed in rural areas in Indonesia

Zat Pengatur Tumbuh dalam Nutrisi Hidroponik pada Pertumbuhan dan Hasil Tanaman Pakchoy (Brassica rapa).

This research were conducted using the plant growth regulator treatment plan consists of three threatments (without ZPT, ZPT superior plant growth (hantu), and ZPT gibgrow). Environmental design used was a complete randomized design with six replications. Data were analyzed using analysis of variance and multiple range test DMRT level of 5%. The results obtained are given ZPT hydroponic growing media to improve the growth and yield pakcoy, and ZPT hantu is best to plant growth substances.

Selecting elite groundnut (Arachis hypogaea L) genotypes for symbiotic N nutrition, water-use efficiency and pod yield at three field sites, using 15N and 13C natural abundance

About 70% of the groundnut (Arachis hypogaea L.) produced in Ghana is from the Guinea savanna. However, low soil nutrients, especially N, together with erratic rainfall distribution have often resulted in poor grain yield. The aim of this study was to evaluate plant growth, N2-fixing efficiency, N contribution, water-use efficiency and pod yield of 21 elite groundnut genotypes in the Guinea savanna of Ghana, using the 15N natural abundance technique. The data revealed significant variations in plant growth, symbiotic N contribution, and pod yield among the 21 genotypes tested at each field site. Average N contribution by groundnut genotypes ranged from 48 to 108 kg N ha−1. Also, mean pod yield ranged from 0.58 to 2.1 t ha−1. Genotypes ICGV-IS 08837, ICG 6222, ICGV 03315 and NKATIESARI demonstrated superior plant growth, symbiotic N contribution and greater pod yield. In fact, ICGV-IS 08837 yielded almost 2.5 fold more than CHINESE which is the most widely cultivated variety in the region. Genotypes ICGV-IS 08837, ICG 6222, ICGV 03315 and ICGV 99247 are therefore recommended for development into varieties for the Guinea savanna of Ghana. Genotypes ICG (FDRS) 4, ICGV00362 and ICGV99247 exhibited increased water-use efficiency, but were low in N2 fixation and N contribution, and would therefore be good parental material in breeding programs aimed at enhancing water-use efficiency in high N2-fixing genotypes.

Standardization of rapid multiplication protocol in petaloid male sterile lines of African marigold (Tagetes erecta) through in vitro culture

Marigold (Tagetes erecta L.) is one of the farmer’s first choice for commercial cultivation. It is commonly propagated through seeds, but some ornamentally high valued petaloid and gynomonoecious lines can only be maintained through vegetative propagation. Therefore, the objective of the present investigation was to develop efficient in vitro protocol for mass multiplication of commercially high valued petaloid male sterile cultivars. Nodal segments were chosen as explant from two thermotolerant marigold cultivars, viz. Siracole Orange and Siracole Yellow. Explants were pre-treated with carbendazim (0.2%) + metalaxyl (0.2%) + 8-hydroxy quinoline citrate (200 mg/l) for 60 minfollowed by surface sterilization with 0.1% HgCl2 for 4 min to eliminate the microbial contamination. Highest culture establishment (82.2%) and earliest bud emergence (3.88 days) was recorded in Murashige and Skoog (MS) medium supplemented with BAP (0.5 mg/l) and NAA (0.05 mg/l). Maximum (6, 28, 122 and 404 shoots/explant) proliferation with healthy shoots and free from callus was obtained on MS medium supplemented with 0.5 mg/l BAP + 0.1 mg/l NAA + 2.5 mg/l AgNO3 in 30, 60, 90 and 120 days after culture respectively. Maximum elongation (2.10 cm) wasobserved on MS media devoid of growth regulators (control). Highest rooting percentage (96.50%), maximum number of roots (23.37), rapid root induction (5.25 days) and high ex vitro survival (91.25%) was noted in ½ MS medium supplemented with 0.5 mg/l IBA. Highest plant survival (98.10%) and superior plant growth was observed when rooted plants were shifted to low-cost polypropylene glasses instead of traditional glass bottle system. This protocol is highly useful for mass multiplication of true-to-type, disease free planting material as well as helpful in long termmaintenance of germplasm lines.

Wheat colonization by an Azospirillum brasilense ammonium-excreting strain reveals upregulation of nitrogenase and superior plant growth promotion

Aims In this work, an ammonium-excreting strain (HM053) of A. brasilense was further characterized genetically and biochemically, and its abilities to colonize and promote wheat growth were determined.

Phylloplane associated plant bacteria of commercially superior wheat varieties exhibit superior plant growth promoting abilities

ABSTRACTPhylloplane of a plant constitutes an important habitat for a variety of microbes many of which play important roles in plant growth. The objective of this study was to compare plant growth promoting (PGP) phylloplane bacteria of three commercially popular wheat varieties, namely Sehar, Faisalabad and Lasani, in order to assess whether better wheat variety harbours better PGP bacteria that play part in its superior yield. Phylloplane bacteria were isolated from the three wheat varieties thrice during the plant growth. The bacterial load increased with the growing season and Sehar variety carried maximum bacterial load (CFUg−1 1.1 × 109). Succession of bacterial community was also observed during the plant growth. Isolates belonging to Sehar phylloplane produced auxin in highest amounts (52.95 µg ml−1) during second sampling when plant was showing rapid growth. Many isolates from all three varieties fixed nitrogen, solubilized phosphates and some isolates also produced hydrogen cyanide. The results clearly indicated that the beneficial bacteria associated with phylloplane of better yielding variety were showing better PGP abilities when compared to their counterparts on low yielding varieties. Isolates exhibiting best PGP profiles were identified as Bacillus, Microbacterium, Acinetobacter, Proteus, Psychrobacter, Pseudomonas, Streptomyces and Kineococcus species through 16S rRNA gene sequencing.

Factors influencing in vitro shoot regeneration from leaf segments of Chrysanthemum

The objective of this research was to develop an efficient protocol for shoot regeneration from leaf segments of the Chrysanthemum cv. Vivid Scarlet by examining the effects of plant growth regulators, dark incubation period, gelling agents, and silver nitrate. The highest number of shoots per explant (12.3) was regenerated from leaf explants cultured on Murashige and Skoog (MS) medium supplemented with a combination of 1mgL−1 of 6-benzyladenine (BA) and 2mgL−1 of α-naphthaleneacetic acid (NAA) under light conditions without any initial dark period. Gelrite was the most effective gelling agent for shoot regeneration among those tested, whereas the presence of silver nitrate distinctly inhibited shoot regeneration. Superior plant growth and rooting was observed on a hormone-free MS medium solidified with Gelrite. Flow cytometry analysis revealed no ploidy variation between the regenerated plants and the mother plant grown under greenhouse conditions. The established protocol was applicable to shoot regeneration for four out of six cultivars tested. This research will facilitate the genetic transformation and micropropagation of Chrysanthemum cultivars.

Cassava Starch Based Superabsorbent Polymer as Soil Conditioner: Impact on Soil Physico‐Chemical and Biological Properties and Plant Growth

ABSTRACTSuperabsorbent polymers (SAPs) are macromolecules with the ability to absorb water and release it slowly to the surroundings. SAP hydrogels can be used as soil moisture conditioners which act as water reservoirs and release water depending upon the need of plant roots. In the present study, a cassava starch based superabsorbent hydrogel was evaluated as a soil conditioner and its effect on physical, chemical, and biological properties of the soil as well as on plant growth parameters was studied. Amendment of the soil with the starch based SAP hydrogel significantly altered the physical and chemical properties of the soil. Bulk density of the soil was decreased, whereas water holding capacity and porosity were increased on SAP treatment. There was an improvement in the soil status of major, secondary and micronutrients and organic carbon in the SAP amended soil. An increase in bacteria (16%) and fungi counts (18%) as well as superior plant growth were observed for the treatment with SAP and irrigated at an interval of 3 days, compared to those of control without SAP. Soil amendment with starch based SAP hydrogel was found to be beneficial for maintaining the physicochemical and biological soil properties as well as plant growth.

Overexpression of the mitochondrial PPR40 gene improves salt tolerance in Arabidopsis

Mitochondrial respiration is sensitive to environmental conditions and can be influenced by abiotic stress. Previously we described the Arabidopsis mitochondrial pentatricopeptide repeat domain protein PPR40, and showed that the stress hypersensitive ppr40-1 mutant is compromised in mitochondrial electron transport (Zsigmond et al., 2008) [20]. Overexpression of the PPR40 gene in Arabidopsis resulted in enhanced germination and superior plant growth in saline conditions. Respiration increased in PPR40 overexpressing plants during salt stress. Reduced amount of hydrogen peroxide, diminished lipid peroxidation, lower ascorbate peroxidase and superoxide dismutase activity accompanied salt tolerance. Proline accumulation was enhanced in the ppr40-1 mutant, but unaltered in the PPR40 overexpressing plants. Our data suggest that PPR40 can diminish the generation of reactive oxygen species by stabilizing the mitochondrial electron transport and protecting plants via reducing oxidative damage during stress.

Improving Casuarina growth and symbiosis with Frankia under different soil and environmental conditions—review

Casuarinas are very important plants for their various uses and survival in adverse sites or harsh environments. As nitrogen fixation, in symbiosis with Frankia, is an important factor for the survival of these plants under various conditions, the basis for selecting both effective and tolerant Frankia strains and Casuarina spp., are provided. Enhancement of the symbiotic relationship between Frankia and Casuarina, by mycorrhizal infection and other biofertilizing microorganisms such as Bacillus and Azospirillum, is reflected by superior plant growth. Casuarina leaf litter is also a great source for both inorganic and organic nutrients. Therefore, careful management of the top soil layer under Casuarina trees is very important. Litter decomposition ratio is affected by many physical chemical and biological factors including temperature, moisture conditions, lignin, and C-to-N and N-to-P ratios in addition to soil biota. In general, here the above relations are discussed and an alleviation model is presented for important disturbances of natural and human origin made in soil and environment, especially in the dry regions. In conclusion, we suggest how to optimize the nitrogen fixation and plant growth under the prevalent conditions.