Net House Research Articles

Essential oil-grafted copper nanoparticles as a potential next-generation fungicide for holistic disease management in maize.

Sustainable food production is necessary to meet the demand of the incessantly growing human population. Phytopathogens pose a major constraint in food production, and the use of conventional fungicides to manage them is under the purview of criticism due to their numerous setbacks. In the present study, essential oil-grafted copper nanoparticles (EGC) were generated, characterized, and evaluated against the maize fungal pathogens, viz., Bipolaris maydis, Rhizoctonia solani f. sp. sasakii, Macrophomina phaseolina, Fusarium verticillioides, and Sclerotium rolfsii. The ED50 for the fungi under study ranged from 43 to 56 μg ml-1, and a significant inhibition was observed at a low dose of 20 μg ml-1 under in vitro conditions. Under net house conditions, seed treatment + foliar spray at 250 and 500 mg L-1 of EGC performed remarkably against maydis leaf blight (MLB), with reduced percent disease index (PDI) by 27.116 and 25.292%, respectively, in two Kharif seasons (May-Sep, 2021, 2022). The activity of enzymatic antioxidants, viz., β-1, 3-glucanase, PAL, POX, and PPO, and a non-enzymatic antioxidant (total phenolics) was increased in treated maize plants, indicating host defense was triggered. The optimum concentrations of EGC (250 mg L-1 and 500 mg L-1) exhibited improved physiological characteristics such as photosynthetic activity, shoot biomass, plant height, germination percentage, vigor index, and root system traits. However, higher concentrations of 1,000 mg L-1 rendered phytotoxicity, reducing growth, biomass, and copper bioaccumulation to high toxic levels, mainly in the foliar-sprayed maize leaves. In addition, EGC and copper nanoparticles (CuNPs) at 1,000 mg L-1 reduced the absorption and concentration of manganese and zinc indicating a negative correlation between Cu and Mn/Zn. Our study proposes that the CuNPs combined with EO (Clove oil) exhibit astounding synergistic efficacy against maize fungal pathogens and optimized concentrations can be used as an alternative to commercial fungicides without any serious impact on environmental health.

Achieving near-zero carbon dioxide emissions from energy use: The case of Sri Lanka

Signatories to the Paris Agreement are to achieve net zero Green House Gas (GHG) emissions during the half-century to pursue the efforts limiting global average temperature increase by 2 °C compared to pre-industrial levels. This study models ambitious to challenging scenarios involving energy demand and supply side actions for energy system transition toward net-zero for Sri Lanka. To analyze these scenarios a least cost optimization-based bottom-up type energy system model was developed from 2015 to 2050. A Business-as-usual (BAU) scenario and four countermeasure (CM) scenarios termed Plausible, Ambitious, Challenging, and Stringent were developed. Four different carbon tax rates were used to fathom the level of carbon tax needed to achieve net-zero emissions. The CM scenarios were formulated considering different technology options and policy measures such as the diffusion of efficient technologies, availability of renewable energy sources, use of cleaner fuels, the introduction of nuclear and carbon capture and storage technologies, and green hydrogen for power generation. The result of this study reveals that the stringent scenario which includes aggressive policy measures in both the energy supply and demand sectors, such as nuclear, and renewable energy for power generation, diffusion of efficient Enduse devices, fuel switching, including the introduction of electric cars, and increased share for public transport achieves the near carbon-neutral scenario at a carbon tax trajectory of 32 US$/tCO2 in 2020 and 562US$/tCO2 in 2050. The Net Energy Import Dependency (NEID) of the country decreases to 13 % in 2050 compared to that of the BAU scenario (65 %) under the near carbon neutral scenario, which is a positive sign from the energy security perspective.

Impact of Different Shed Houses and Growing Media on Growth, Yield and Quality of Strawberry

Partial controls of the microclimatic conditions have a major influence on plant growth and productivity. Moreover, plant growth is largely dependent on the physicochemical properties of the growing media. The purpose of this study was to see how different growing media and shade houses affected strawberry plant growth, yield, and quality attributes. The experimental treatments include net house, UV poly shade house, and open field (control) conditions; and three different growing media i.e., 50% soil + 50% cowdung, 50% soil + 50% vermicompost, and 50% soil + 50% cocopeat were studied. According to the findings, strawberries grown in a net house with cocopeat substrate had the highest chlorophyll content (SPAD value) (46.1), fruit yield (289.16 g plant-1), total soluble solid (8.0%), reducing sugar (8.75 mg g-1) and total anthocyanin (30.80 mg 100 g-1). In contrast, fruits grown under UV poly shed with cocopeat substrate exhibited increased plant height (20.33 cm) and ascorbic acid (46.94 mg 100 g-1). Vermicompost based growing media showed no satisfactory improvement in the reproductive growth characteristics of strawberry plants. Therefore, cocopeat based growing media and net house shade may be recommended to obtain better strawberry yield and quality.

Study on Growth Pattern of Capsicum in Greenhouse

Abstract: Polyhouse is a specialized structure that provides a controlled climate condition for the growth of different plants and other crops. It is a major innovation supported by state governments by providing subsidies for establishing the structure. Polyhouse farming requires less water, fertilizer, and pesticides, and provides a higher yield compared to traditional farming methods. The use of polyhouses is not limited to growing flowers, vegetables, and fruits, but also for developing new techniques for agriculture. The material which is used in this construction is bamboo which is very cheaper comparing to other construction material and easily available, and the strength of bamboo is excellent, it also provides a protected environment for crops from adverse climatic conditions like heavy rainfall. For this protective structure government is also providing subsidy up to 50% for the construction of Greenhouse & Shade net House. Apart from this, 20% additional subsidy is given to small, marginal, scheduled caste & scheduled tribe farmers i.e., 80% subsidy is payable to them. For small and marginal farmers this is a best option for growing different fruits and vegetables is different season.

Economic analysis of horticulture nursery enterprises in Koppal district of Karnataka

Nursery is a place where plants are grown, nurtured and sold out. In current scenario nursery raising is the mostbenefited sector, because it needs small area and short time to generate more income. The Koppal district was purposelyselected as it occupies prime place in the nursery raising of horticultural crop in the region. The primary data was collectedfrom 30 nursery owners in the study area. The present study aims to analyze the costs and returns of nursery enterprisesin Koppal district of Karnataka state. The findings of the study revealed that, the costs involved in the production ofseedlings was `2,64,840.43 and `6,20,071.01 in small and large sized shade net house, respectively. Of which, variablecost and fixed costs constituted `2,42,111.04 and `22,729.39 in small sized and `5,69,347 and `50,724.01 in large sizedshade net house, respectively. The financial feasibility analysis indicated net present worth of `1,73,128 and `2,87,789with a discounted benefit cost ratio of 2.29 and 2.40 and payback period was estimated to be 1.05 and 1.07 years and theIRR generated in the nursery enterprise was found to be 28 and 30 percent for small and large nurserieswhich is higher thanthe prevailing interest rate. According to the study, the ratio of variable costs has a higher share compared to that of fixed costsand also this business has vast potentials of generating employment and income of the owners in rural areas of Koppal district

Productivity of strawberry as influenced by mulch materials and gibberellin under net house condition

Plant growth regulators in combination with mulch materials have been shown to regulate physiological processes related to plant growth and development. The experiment was conducted to investigate the responses of different mulch materials and GA3 on plant morphological, physiological and yield attributes of strawberries during the period from November 2020 to March 2021. The experimental treatments included three different mulch materials: black polythene, white polythene, saw dust, and control (no mulch); and GA3 (0 and 200 ppm) were studied. According to the findings, strawberries grown with sawdust and GA3 had the highest chlorophyll content (SPAD value) (48.23), relative water content (76.45%), leaf area (48.23 cm2), maximum number of fruits (19.66) and fruit yield (321 g/plant). In contrast, individual fruit weight (18g) was the highest for plants grown in sawdust without GA3. Black polythene mulch showed no satisfactory improvement in the growth and yield characteristics of strawberry plants. Therefore, sawdust based mulching and GA3 may be recommended to obtain better strawberry growth and yield.

Foliar sprays of salicylic acid induce diosgenin synthesis in the leaves of hellenia speciosa (J. Koenig) s.r. dutta

hellenia speciosa (J. Koenig) s.r. dutta, commonly known as spiral ginger, is a potent medicinal plant in the family Costaceae. it has a wide range of applications in traditional and modern medicine with many active ingredients. diosgenin is a steroidal sapogenin obtained from h. speciosa. it is commercially used as an important raw material for the synthesis of steroidal drugs. Foliar sprays of salicylic acid (sa) were used to study the induction of diosgenin synthesis in the leaves of h. speciosa. three different concentrations, 1mM, 5mM, and 9mM, were applied on plants grown in shade net houses. after 60 days of weekly sa application, plants were harvested along with rhizome, dried, and extracted in methanol using the soxhlet apparatus. acid hydrolysis was performed to obtain diosgenin in the extract. the high- Pressure thin layer Chromatography (hPtlC) technique was used to detect the presence of diosgenin in the methanolic extract of leaves. elicitation of diosgenin synthesis was evident in all three extracts obtained from salicylic acid-treated plants. diosgenin was obtained at an rf maximum of 0.58-0.59. the amount of diosgenin was quantified with chromatographic techniques. the maximum quantity of diosgenin was present in the extract treated with 9mM sa. this experiment highlights the effect of stress signals on selected secondary metabolites.

Effect of Different Levels of Chromium With and Without Organic Sources on the Availability of Primary Nutrients and Yield of Wheat

A pot experiment (2020-21) was conducted with different levels of -1 chromium (0, 10,20,30,40,50 mg kg ) with and without FYM or vermicompost (25g/10 kg soil) in completely factorial redomised block design in net house of the Department of Soil Science & Agricultural Chemistry, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi. The experiment was conducted in factorial completely randomized design (FCRD). Maximum plant height was recorded in Cr0+VC (21.6 cm) followed by Cr0+FYM (19.8 cm)at 30 DAS. The increasing chromium concentration decrease the chlorophyll content in all the treatments Highest grain and straw yields of wheat were associated with Cr0+VC treatment, highest available N, P, K was recorded with Cr20+VC, Cr30+VC and Cr10+VC respectively.

Variations in Root Morphology and Yield among Rice Varieties in Response to Potassium under Subtropical Conditions

The relationship between rice root morphology and Potassium (K) is a major concern for its growth and development, and it has a substantial impact on yield as well. In light of this, the current pot research was run in the net house of the Department of Agronomy at the Bangladesh Agricultural University, Mymensingh, Bangladesh, throughout the boro (dry season irrigated) season of 2020–2021. Binadhan-10, Hira-2 and BRRI dhan29 were grown with five K fertilizers: 0 kg K ha−1 (K0), 32 kg K ha−1 (K32), 65 kg K ha−1 (K65), 98 kg K ha−1 (K98) and 130 kg K ha−1 (K130). Three replications of the investigation were conducted using a completely randomized design (CRD). The root number (RN), root length (RL), root volume (RV), root porosity (RP) along with leaf area index (LAI), total dry matter (TDM) and yield were assessed. Binadhan-10 with the K65 treatment significantly increased the RN, RL, RV, LAI, TDM and yield. With the further increase in the dosage of K that was under K98 and K130, the value of the root traits and yield did not increase. A positive connection was documented between the grain yield (GY) and all the root traits, excluding the RP. Binadhan-10 can be grown with 65 kg K ha−1 at field level for a satisfactory yield.

Foliar Application of Salicylic Acid and Zinc Sulphate Levels on Growth and Yield of Squash under Net House Condition

A field experiment was conducted at Horticulture Farm of Sher-e-Bangla Agricultural University, Dhaka during November, 2020 to February, 2021. The experiment was laid out in a Randomized Complete Block Design with three replications. The experiment had two factors (Different levels of salicylic acid, S0= No salicylic acid (control), S1= 60 ppm of salicylic acid, S2= 90 ppm of salicylic acid and different levels of zinc, Z0= No zinc sulphate (control), Z1= 25 ppm of zinc sulphate, Z2= 50 ppm of zinc sulphate. Different levels of salicylic, zinc sulphate and also their combinations showed significant influence on different growth, yield contributing parameters and yield of squash. The treatment, S2 showed highest results in fruit yield per plant (2422.7 g), fruit yield per plot (9.68 kg) and fruit yield per ha (37.83 t) compared to control. In case of zinc treatments, the highest results in fruit yield per plant (2597.1 g), highest fruit yield per plot (10.38 kg) and highest fruit yield per ha (31.74 t) were found from Z1 compared to control. Likewise, the treatment combination of S2Z1 (90 ppm of salicylic acid and 25 ppm of zinc sulphate) gave the highest fruit yield per plant (3045.4 g) fruit yield per plot (12.18 kg) and highest yield per ha (47.57 t) where the lowest results were found from the treatment combination of S0Z0 (control). The highest gross return (BDT 1189425), net return (BDT 881669) and BCR (3.86) were obtained from the treatment combination of S2Z1 where the lowest was obtained from S0Z0. It can be concluded that from economic point of view, S2Z1 (90 ppm of salicylic acid and 25 ppm of zinc sulphate) treatment combination is suitable for squash cultivation than other treatment combinations.

Effect of Mulch Materials and Foliar Application of Micronutrients on the Growth and Yield of Sweet Pepper under Net House

The study was carried out to evaluate the effect of different mulch materials and foliar application of micronutrients on growth and yield of sweet pepper under net house. The experiment consisted of two factors. Factor A: Three mulch materials viz., M0-No mulch (control), M2-Black polyethylene mulch and M2-Rice straw mulch and Factor B: Three foliar application of micronutrients viz., N0-control (No micronutrients), N1-Zn @0.6% as ZnSO4 and N2-B @0.6% as H3BO3. The experiment was laid out in a Randomized Complete Block Design (RCBD) with three replications. Data were recorded on growth, yield components, yield and quality of sweet pepper and significant variation was observed for most of the studied characters. Analysis revealed that the M2N2 treatment combination appeared to be best for achieving the higher growth, fruit yield and economic benefit of sweet pepper.

Propagation of Antidesma alexiteria and Syzygium caryophyllatum, two underexploited fruit plants in Sri Lanka: Effect of cutting types, potting media and auxin application

Antidesma alexiteria and Syzygium caryophyllatum are two fruit species found in Sri Lanka of which the commercial development potential has not been fully identified. To bring these fruit species back into cultivation, establishment of suitable propagation systems for mass propagation is important. Therefore, this research was designed to identify suitable potting media, stem cutting types and requirement of auxin for successful vegetative propagation of the two fruit species. Softwood, semi-hardwood and hardwood cuttings of the fruit trees were planted in three potting media (M1 – topsoil, sand 1:1, M2 – topsoil, sand, compost 1:1:1 and M3 – topsoil, sand, coir dust 1:1:1) under two treatments; T1 – with plant growth reg­ulator indole-3-acetic acid (IAA) and T0 – controls without IAA. Each treatment was conducted with 15 replicates. The cuttings were planted in individual propagators and were kept in a net house of 50% shading under room temperature. Growth performance of the cuttings was monitored in regular intervals (every 28 days) for a period of six months. According to sprouting, survival, and growth performance, both softwood and semi-hardwood cuttings are suitable for vegetative propagation of A. alexiteria. The M3 medium showed 100% sprouting and survival but with respect to overall growth performance, the M1 medium was the most suitable for softwoods of A. alexiteria without auxin. Sprouting and survival of semi-hardwood cuttings were 100% with high values of growth parameters in M3 under T1 treatment. The M1 medium without auxin can be recommended for better performance of softwoods while M3with auxin is for semi-hardwoods of A. alexiteria. Softwoods, semi-hardwoods and hardwoods can be recommended for vegetative propagation S. caryophyllatum in M1 medium. Both softwood and semi-hardwood cuttings under T1 treatment expressed higher sprouting and survival percentages while semi-hardwood cuttings under T1 treatment have shown the highest sprouting and growth performance. Hence, semi-hardwood cuttings with auxin can be con­sidered as the best planting material for vegetative propagation of S. caryophyllatumwhile M1 is the best medium. The vegetative propagation of S. caryophyllatum and A. alexiteria through stem cuttings can be recommended as suitable mass propagation method for the purpose of commercialization.

Effect of Nano Nitrogen and Zinc Application on Dry Matter at Different Stages and Grain, Straw Yield of Paddy

A Pot culture experiment was carried out at Agriculture Research Institute, Rajendranagar, To study the impact of Nano Nitrogen in combination with zinc (soil application or foliar spray) on yield, in paddy crop. The soils employed in net house experiment were selected based on low, medium and high zinc availability classes obtained from the zinc analysis data of surveyed samples. They are low (0.4 mg kg-1), medium (0.71 mg kg-1) and high (1.30 mg kg-1). The results revealed that the highest dry matter at Panicle initiation, Grain and Straw yield were observed in the treatment applied with hundred percent recommended dose of nitrogen through NCU granules along with RDPK and soil application of 25 kg zinc sulphate ha-1 resulted in an increase in grain and straw yields by 23 & 24 % over basal application of 1/3rd of 100 % RDN through NCU granules along with RDPK coupled with Nano nitrogen sprays (each at MT & PI stages in rice) and soil application of 25 kg zinc sulphate ha-1

Bacterial synthesized silver nanoparticle inhibits Rhizoctonia solani Kuhn, the causal organism for sheath blight disease of rice

Rhizoctonia solani Kuhn (AG 1-IA) is one of the most devastating pathogens of rice causing sheath blight disease and being a prime reason for the unsatisfactory productivity of rice in India. The goal of the present study was to investigate the efficacy of silver nanoparticles (AgNPs) synthesized using an agriculturally important bacterium, Pseudomonas fluorescens OKC, in managing the sheath blight disease of rice. Successful biosynthesis of AgNPs was monitored by UV-visible spectroscopy, showing a peak at 432 nm. The AgNPs were further characterized using a Transmission Electron Microscope (TEM), Dynamic Light Scattering (DLS) and Fourier Transform Infrared spectroscopy (FT-IR). The TEM result confirmed that the size of the synthesized nanoparticles was less than 100nm. DLS results revealed that the average particle size of the AgNPs was 74 nm and the zeta potential was -23.6 mV, indicating that the synthesized nanoparticles were of good stability at room temperature. The antifungal potential of AgNPs was tested against the test fungus in vitro and maximum growth inhibition was recorded in AgNPs treatment (69.09%) as compared to the control. Moreover, this result was further authenticated under net house conditions, where AgNPs successfully reduced the incidence of R.solani Kuhn. The findings showed that the biosynthesized AgNPs inhibited the growth of R. solani Kuhn and could be useful in the management of sheath blight disease in rice.

Biocontrol of Foot and Root Rot Disease of Groundnut (Arachis hypogaea) by Dual Inoculation with Rhizobium and Arbuscular Mycorrhiza

The present study was carried out to investigate the potential of AM (Arbuscular mycorrhiza) fungi alone and in combination with bioinoculants i.e., Rhizobium to find out the best combination on dry biomass, nodulation, colonization, and yield, along with their biocontrol against groundnut foot and root rot caused by Sclerotium rolfsii. The study was carried out under pot culture conditions in the net house of the Soil Science Division, Bangladesh Agricultural Research Institute, Joydebpur, Gazipur in 2020 and 2021. The experiment was designed in RCBD with eight treatments and four replications. Peat-based rhizobial inoculum (BARI RAh-801) was used @ 1.5 kg ha-1 in this experiment. Soil-based AM inoculum containing approximately 252 spores and infected root pieces of the host plant was used in pot-1. The treatments were Arbuscular mycorrhiza (AM), Rhizobium, AM+Rhizobium, Sclerotium rolfsii, Sclerotium rolfsii+AM, Sclerotium rolfsii+Rhizobium, Sclerotium rolfsii+AM+Rhizobium and Control. Dual inoculation (AM+Rhizobium) significantly increased dry biomass, nodulation, colonization, yield, and yield attributes of groundnut compared to single inoculation or other treatments. The result showed that dual inoculation (AMF+Rhizobium) increased nut yield (59.61% in 2020 and 26.32% in 2021) and stover yield (23.21% in 2020 and 33.74% in 2021) compared to control. On the contrary, Sclerotium rolfsii+AMF+Rhizobium increased nut yield (65.50% in 2020 and 52.94% in 2021) and stover yield (36.45% in 2020 and 99.35% in 2021) compared to only Sclerotium rolfsii treatment. The plant dry biomass, nodulation, colonization, nutrient concentration and uptake were increased by dual inoculation under pathogenic and non-pathogenic conditions leading to an improved yield of groundnut. Therefore, AMF species and its combination with rhizobial inoculum were significant in the formation and effectiveness of AM fungi symbiosis. They also increased yield and reduced the incidence of foot and root rot disease in groundnut plants.

Insight into the physiological and biochemical mechanisms of biostimulating effect of Ascophyllum nodosum and Moringa oleifera extracts to minimize cadmium-induced oxidative stress in rice.

Cadmium (Cd) is a serious threat for environmental sustainability as it can be taken up quickly by plants and transported to the food chain of living organisms. It alters plants' metabolic and physiological activities and causes yield loss, thereby, enhancing plant tolerance to Cd stress is of utmost essential. Therefore, an experiment was executed to investigate the potential role of Ascophyllum nodosum extract (ANE) and moringa (Moringa oleifera) leaf extract (MLE) to confer Cd tolerance in rice (Oryza sativa cv. BRRI dhan89). Thirty-five-day-old seedling was subjected to Cd stress (50mgkg-1 CdCl2) alone and in a combination of ANE (0.25%) or MLE (0.5%) in a semi-controlled net house. Exposure to Cd resulted in accelerated production of reactive oxygen species, enhanced lipid peroxidation, and disrupted antioxidant defense and glyoxalase system, thus retarded plant growth, biomass production, and yield attributes of rice. On the contrary, the supplementation of ANE or MLE enhanced the contents of ascorbate and glutathione, and the activities of antioxidant enzymes such as ascorbate peroxidase, dehydroascorbate reductase, monodehydroascorbate reductase, glutathione reductase, glutathione peroxidase, and catalase. Moreover, supplementation of ANE and MLE enhanced the activities of glyoxalase I and glyoxalase II which prevented the overgeneration of methylglyoxal in Cd stressed rice plants. Thus, because of ANE and MLE addition Cd-induced rice plants showed a noticeable declination in membrane lipid peroxidation, hydrogen peroxide generation, and electrolyte leakage, whereas improved water balance. Furthermore, the growth and yield attributes of Cd-affected rice plants were improved with the supplementation of ANE and MLE. All the studied parameters indicates the potential role of ANE and MLE in mitigating Cd stress in rice plants through improving the physiological attributes, modulating antioxidant defense and glyoxalase system.

Management of Seed Associated Fungi and Alternaria Leaf Spot Disease of Black Mustard (Brassica Nigra L.) Using Botanicals

The efficacy of five native botanicals viz., neem, castor, akondo, basok and ata against the seed associated fungi and in controlling the leaf spot disease of black mustard was evaluated. In blotter method, maximum reduction (85.91%) of seed associated fungi was observed in the seeds treated with ata (1:1) while neem (1:1), ata (1:2) and castor (1:1) gave 83.52, 82.59 and 82.39%, respectively reduction of fungi over control. Maximum seed germination (93%) was observed in seeds treated with akondo (1:1), where neem (1:1), castor (1:1) and akondo (1:2) supported 92, 92 and 90% seed germination, respectively. Maximum reduction of percent disease incidence (29.22%) and percent diseases severity (24.67%) were recorded with the application of neem (1:1) at 28 days after sowing with highest shoot length (16.09cm), root length (4.69cm), vigor index (1842.56%) and seed yield (33.70%) comparison to control in the net house. The findings neem (1:1) was found as an effective botanical for the ecofriendly management of seed associated fungi and Alternaria leaf spot diseases of black mustard.
 Bangladesh J. Agril. Res. 46(4): 407-416, December 2021

Effect of Substrates on Growth, Yield and Quality Of Anthurium in Soilless Culture

An experiment was conducted at the Floriculture Shade Net House under Horticulture Research Centre of Bangladesh Agricultural Research Institute, Gazipur during 2020-21 to evaluate the effect of different substrates on growth, flowering, yield and quality of anthurium. Six treatments were used viz,. T1: Soil (control), T2: Cocodust, T3: Perlite, T4: Sawdust, T5: Cocodust + Perlite (1:1), and T6: Cocodust + Sawdust (1:1). The experiment was laid out in Completely Randomized Design with five replications. The result showed that Cocodust + perlite (1:1) followed by Cocodust singly performed the best in respect of growth, flower number and quality characteristics of anthurium. Poor performance of all characteristics of anthurium was exhibited in control treatment. Gross return and BCR was the highest in T5 treatment. The result suggested that Perlite + Cocodust (1:1 ratio) followed by Cocodust (100%) could be used for flower yield maximization and quality improvement of anthurium in pot cultivation.
 Bangladesh J. Agril. Res. 46(4): 435-443, December 2021

Novel synergism of Cedecea lapagei KU14 and Bacillus subtilis KU21 for sustainable productivity of Rosmarinus officinalis in Northwest Himalayas

The current study aimed to assess the scope of native potential endophytic bacteria Bacillus subtilis KU21, Pseudomonas aeruginosa SI12 and Cedecea lapagei KU14 for synergistic effect to develop as consortium biofertilizer of rosemary. All the three strains were assessed for multiple plant growth promoting (PGP) traits viz., P solubilization, siderophore and Indole-3-acetic acid production (IAA). Consortia of strains (KU21, SI12 and KU14) showed significantly high production of IAA, siderophore production and P-solubilization over the single inoculants. All the isolates i.e., KU21, SI12 and KU14 individually and their consortia were assessed for in vivo growth studies of rosemary under net house conditions. Combined application of these strains significantly increased growth parameters of rosemary over single inoculation and untreated control. Based on the results, two consortia i.e., B. subtilis KU21+ C. lapagei KU14 and B. subtilis KU21+ C. lapagei KU14+ P. aeruginosa SI12 were further evaluated under field conditions. The combined application of B. subtilis KU21+ C. lapagei KU14 significantly improved rosemary growth parameters (at vegetative and flowering stage), nutrient acquisition, and soil quality parameters over uninoculated control. This is the first field report that describes the efficacy of novel endophytic strains i.e., B. subtilis KU21+ C. lapagei KU14 for improving rosemary production and soil health simultaneously, hence may be recommended for sustainable production of R. officinalis in Northwest Himalayan region.

Accumulation of nitrogen, phosphorus, potassium and sulfur in capsicum (Capsicum annuum L.) as influenced by vermicompost and NPK fertilizers

Soil fertility is one of the most promising factors that directly impact sustainable crop production. Therefore, a pot experiment was conducted in net house on capsicum (Capsicum annuum L.) in the agricultural soil to study the effects of vermicompost (VC) and inorganic fertilizers (NPK) on growth, yield and nutrient content in capsicum plants. The growth parameters and nutritional values were observed during the experiment under eleven treatments. The treatments variables are T1 (control, -VC & -NPK), T2 (VC 5 ton/ha), T3 (VC 10 ton/ha), T4 (VC 15 ton/ha), T5 (N60P35K60 kg/ha), T6 (VC 5 ton/ha +N48P28K48 kg/ha), T7 (VC 10 ton/ha + N48P28K48 kg/ha), T8 (VC 15 ton/ha + N48P28K48 kg/ha), T9 (VC 5 ton/ha + N36P21K36 kg/ ha), T10 (VC 10 ton/ha + N36P21K36 kg/ha), T11 (VC 15 ton/ha + N36P21K36 kg/ha) which were arranged in a completely randomized design (CRD) with three replications. There were statistically significant differences in each treatment for growth and yield parameters. The highest plant height (45 cm), the highest number of leaves (44 no/plant), and the highest leaf area index (90 cm2) were found in the treatments T6, T5 and T9 respectively. The lowest values for all of the above parameters were found in the treatment T1 (control). Then the highest yield parameters fruit no/ plant (3), total fresh weight (39.60 g/plant), and total dry weight (2.38 g/plant) were observed under the treatment T11. The results of the growth and yield parameters varied significantly (p<0.05). The concentrations of total N, P, K and S in different parts were measured and varied significantly (p<0.05) in leaf, stem, root and seeds. Analysis of post-harvest soil also revealed that every physico-chemical property and nutritional value were changed significantly due to different treatments. Dhaka Univ. J. Biol. Sci. 32(1): 73-81, 2023 (January)