Implementation of iceplant production under semi-controlled conditions

Mesembryanthemum crystallinum is considered a drought and saline stress-tolerant plant with many biological activities that has been revalued as cool flavouring plant. The objective of this work was to assess optimum mode of cultivation of M. crystallinum to produce edible parts under greenhouse conditions. Therefore, three soilless media were evaluated: peat, vermiculite and hydroponic culture. Pot culture in peat did not result to be a good substrate for iceplant, with little biomass production. However, vermiculite and hydroponics allowed optimum growth of M. crystallinum, with a significantly greater yield in plants grown in vermiculite irrigated with nutrient solution. In fact, plants cultivated in vermiculite enhanced leaf area and leaf fresh weight, together with high foliar concentrations of N, Mg, Mn, Fe, Na, clorophylls and carotenoids. Furthermore, increased succulence and Na concentration of edible parts of glacier lettuce grown in vermiculite can offer more interesting taste, consistence and nutrient content for consumers. Higlights Hydroponic and vermiculite cultures led to optimum crystallinum growth. Peat pot culture did not seem to be an adequate substrate to cultivate crystallinum. Ice plants grown in vermiculite presented highest leaf fresh yield and high foliar N, Mg, Mn, Fe, Na, chlorophyll and carotenoid concentrations.

Endophytic Fungi as Potential Bio-Control Agents against Root Knot Nematode, Meloidogyne incognita in Banana

A Survey was conducted in 12 districts of Assam to collect 92 healthy banana root samples. A total of 55 fungal isolates were successfully isolated from commercial banana cultivars. The culture filtrates were extracted from 55 endophytic fungal isolates and screened against root knot nematode, Meloidogyne incognita in vitro and pot culture studies. Among them, five fungal isolates viz., EF4, BF7, BF27, BF28 and BF35 showed 100% inhibition of egg hatching and 96.33 to 81.33% juvenile mortality of M. incognita with an exposure period of 72h when compared to other isolates and control. On paddy seed treatment with endophytic fungi of five promising isolates, two isolates viz., BF7 and BF28 significantly enhanced germination percentage (82.67%, 73.33%) and vigour index (62.91, 47.24%), respectively. The selected five endophytic fungal isolates were evaluated for their efficacy against M. incognita in banana under pot culture conditions. The study revealed that culture filtrates of BF7 and BF28 significantly reduced the soil and root nematode population, number of adult females, egg masses and root gall index of M.incognita compared to untreated control. The isolates BF7 and BF28 also significantly increased the growth parameters viz., pseudostem height, root length and pseudostem girth. These promising endophytic fungal isolates viz., BF7 and BF28 were identified as non-pathogenic Fusarium oxysporum strains (Accession no. MN567668) and (Accession no. MN567710), respectively by PCR -18S rRNA of ITS region of gene sequence and phylogenetic tree construction.

Compost-Based Growing Media Improved Yield of Leafy Lettuce in Pot Culture

Compost-based media were examined for effects on plant growth of leafy lettuce (Lactuca sativa L.) in pot culture. Four types of locally sourced composts were created using different proportions of wood chips from untreated pallets and mixed tropical tree debris, food waste from restaurants, and chicken manure. Compost-based media were prepared by mixing each compost with a commercial peatmoss to create 25, 50, and 100% compost-peatmoss mixtures (by volume). In Trial One, cv. Starfighter had the greatest shoot (leaves/stems) biomass when grown in 100% compost containing wood chips, food waste, and chicken manure. In Trial Two, cvs. Starfighter and New Red Fire were examined. Growing media affected all plant growth parameters including fresh and dry shoots and roots, shoot and root length, and number of leaves. Cultivar affected all except fresh root weight. Interaction effects of growing medium and cultivar type were found for fresh shoot weight, dry root weight, shoot, and root length. Regression analyses indicated increases in amount of compost in growing media increased dry shoot and root weights. Composts containing recyclable organic materials can be an alternative to commercial media in pot culture.

Efficacy of Trichoderma Fortified Organic Amendments on Fusarium Wilt Suppression, Growth and Yield of Eggplant

Trichoderma harzianum is commonly used as effective biological control agent against phytopathogens especially the soil-borne fungi while some isolates are able to ameliorate plant growth. In the present study, Trichoderma fortified with different organic amendments were evaluated to reduce the pre-emergence and post-emergence seedling mortality, diseases of stem and root of eggplant caused by Fusarium oxysporum f. sp. melongenae, a soil-borne fungal pathogen. Two experiments were set up, one at pot culture and second in the field under natural epiphytotic conditions. Among the nine Trichoderm harzianum fortified amendments tested, neem seed cake recorded significant and superior effect as pre-sowing soil application against Fusarium wilt with respect to seed germination (92.33%), pre-emergence seed rot (7.66%) and post-emergence seedling mortality (15.33%) in pot culture. However, cotton cake recorded least efficacy in all respect. Similar trend observed in wilt incidence under field experiments during autumn 2018 (17.47%) and 2019 (18.60%) with T. harzianum fortified neem cake soil application against Fusarium wilt with mean inhibition of disease incidence (58.43%) and also observed excellent enhancement of mean yield (54.63%). It is observed that organic amendment at higher concentrations further increase the microbial populations and stimulate the microbial activity in soil against Fusarium oxysporum resulted to decrease the pathogen populations. Moreover, yield and yield related attributes increased remarkably due to fortified amendments providing adequate nutrient reservoir to the bioagents thereby enhancing its survival in a hostile environment.

Garden post-transplant effects of pre-transplant plug cell volume and growing medium quality (as abiotic stresses) in Impatiens walleriana

Although much is known about the production of bedding plants, including Impatiens walleriana, little has been documented on their post-production performance. Thus, the aim of this work was to understand how pre-transplant crop management related to root restrictions imposed by plug cell volume and substrate quality affects the post-production performance related to biomass accumulation. To this end, we tested four plug cell volumes, as well as four growing media with significantly different physical and chemical properties, during nursery and pot culture. We also evaluated the difference between use and nonuse of synthetic cytokinin spray (benzyl aminopurine, BAP), a proven stress alleviator. Our novelty data validated the previous hypothesis and showed that plant quality and garden performance are dependent on these potential stress sources. The physiological mechanisms involved included differences in leaf area expansion (estimated mainly by relative leaf area expansion rate) and differences in CO2 fixation capacity (estimated by net assimilation rate). The sum of these responses determined significant differences in total fresh and dry weight during pot culture, which were amplified when plants were transplanted to a field bed. Spraying plants with synthetic cytokinin early during nursery allowed overriding of most root restriction abiotic stresses related to plug cell volume and growing media; therefore, synthetic cytokinin constitutes a tool to improve the yield of bedding plants (at the grower's level) and garden performance.

Different soil potassium fractions and their contribution towards its uptake under long-term rice-rice cropping system in an Inceptisol of subtropical eastern India

A pot culture experiment was conducted by taking soils from a long term fertilizer experimental field to evaluate the contribution of different K fractions towards rice biomass yield and potassium uptake in different long term fertilizer management practices. Twelve different soils were taken for pot culture and graded dose of potassium @ 0, 20, 40, 60, 80 and 100 kg K2O ha-1 was applied. Rice variety Lalat was grown as test crop. The forms of potassium were determined in the surface soil of 0-15 cm after maturity of crop. The result shows that water soluble form of K is the major contributor to biomass yield in soils taken from100% PK, 100% NPKZn, 100% NPKZnB,100% NPKZnS,100% NPK lime and control treated plots of the main field where as exchangeable K is dominant form of K in 100% NPK and 150% NPK. Ammonium acetate K contributes to yield in NPKFYM lime treatment. The nitric acid extractable K is a major contributor to yield in 100% NPKFYM,100% N or100% NP treatment. The water soluble form of K is the major source towards uptake in 150% NPK, NPKFYM lime ,100% NPKZnB, or control. Ammonium acetate K becomes the main source by applying 100% PK,100% NPK,100% NPKZn,100% NPKZnSor 100% NPKlime whereas exchangeable K becomes major contributor by100%N,or 100% NP application and 1 N HNO3 extractable K is the main source of K uptake in NPKFYM treatment. Therefore due importance of different form of potassium should be given in soil test value for better fertilizer management.

Effects Of Seed Priming On Root- Shoot Behaviour And Stress Tolerance Of Pea (Pisum Sativum L.)

A pot culture experiment was carried out under controlled conditions for the detailed study of morphophysiological and advanced stress response adaptive mechanisms along with yield performance of pea varieties under the influence of seed priming substances. The performances of selected seed priming substances in different pea varieties were tested with water stress. Growth and physiological parameters documented at the stress period. From the experiment, it can be inferred that seed priming substances like KH2PO4 (1.5 and 3%), H2O2 (10 mM) and PEG (5%) were significantly outperformed in inducing higher growth with positive physiological changes. Bangladesh J. Bot. 50(2): 199-208, 2021 (June)

Bioefficacy of fungicides and bioagents against Macrophomina phaseolina causing charcoal rot in maize

In recent years Macrophomina phaseolina causing charcoal rot of maize is more problematic in maize growing parts of Maharashtra. Present investigation was taken on evaluation of fungicides and bio-agents against M. phaseolina under laboratory condition and pot culture. Under laboratory condition, nine fungicides and six bio- agents were evaluated against M. phaseolina by poison food technique and dual culture method, respectively. Among fungicides Carbendazim 63 % + Mancozeb 12% and Carbendazim alone recorded maximum inhibition of (100 %) mycelial growth. Among the bio-agents tested Trichoderma harzianum was found more effective as compared to other bio-control agents and inhibited maximum fungal growth (63.33 %) of M. phaseolina. Under pot culture study, as soil application and seed treatment, among the fungicides, carbendazim + Mancozeb was found most effective. However, among bioagents Trichoderma harzianum was remarkably manage the charcoal rot.

Genome-Wide Association Study on Root Traits Under Different Growing Environments in Wheat (Triticum aestivum L.)

Plant roots are critical for water and nutrient acquisition, environmental adaptation, and yield formation. Herein, 196 wheat accessions from the Huang-Huai Wheat Region of China were collected to investigate six root traits at seedling stage under three growing environments [indoor hydroponic culture (IHC), outdoor hydroponic culture (OHC), and outdoor pot culture (OPC)] and the root dry weight (RDW) under OPC at four growth stages and four yield traits in four environments. Additionally, a genome-wide association study was performed with a Wheat 660K SNP Array. The results showed that the root traits varied most under OPC, followed by those under both OHC and IHC, and root elongation under hydroponic culture was faster than that under pot culture. Root traits under OHC might help predict those under OPC. Moreover, root traits were significantly negatively correlated with grain yield (GY) and grains per spike (GPS), positively correlated with thousand-kernel weight (TKW), and weakly correlated with number of spikes per area (SPA). Twelve stable chromosomal regions associated with the root traits were detected on chromosomes 1D, 2A, 4A, 4B, 5B, 6D, and unmapped markers. Among them, a stable chromosomal interval from 737.85 to 742.00 Mb on chromosome 4A, which regulated total root length (TRL), was identified under three growing environments. Linkage disequilibrium (LD) blocks were used to identify 27 genes related to root development. Three genes TraesCS4A02G484200, TraesCS4A02G484800, TraesCS4A02G493800, and TraesCS4A02G493900, are involved in cell elongation and differentiation and expressed at high levels in root tissues. Another vital co-localization interval on chromosome 5B (397.72–410.88 Mb) was associated with not only RDW under OHC and OPC but also TKW.

Chromium (VI) Induced Physiological and Metabolic Responses in Vigna Mungo L. cv. BVN-3

The present study investigates the chromium (VI) induced phytoxicity and accumulation in the black gram (Vigna mungo L. cv. BVN-3) grown under refined sand pot culture. The phytotoxicity assessed with reference to growth behavior, water transport, metabolic alteration, yield, uptake and translocation of S, P, Fe and Cr under chromium (VI) stress. The black gram plants were treated with varied chromium (VI) at 0.00, 0.05, 0.10 and 0.25 mM concentration. After 5 d of Cr (VI) treatment, the foliar toxicity symptoms showed as loss of turgor and chlorosis of older leaves which also reflect in middle aged leaves later on at higher concentration of chromium (0.25 mM). At the later stage, chlorosis symptoms became critical and distorted to necrosis in patches with tapered lamina, thin tendrils and loosed coiling property. Cr (VI) induced toxicity observed on black gram as decreased growth and yield, impairment in photosynthesis activity, inhibition of metabolic and enzymatic activities and nutrient imbalances. Excess (0.25 mM) of Cr (VI) also caused a reduction in uptake and accumulation of iron in the leaves as compared to control (from 426.2 to 198.7 µg g-1 dw) with more uptake and accumulation of sulphur and phosphorus. Higher accumulation of Cr was recorded in the leaves (166.5 µg g-1 dw) followed by roots (123.4 µg g-1 dw) and stems (46.6 µg g-1 dw) at 0.25 mM after 29 d of treatment. Therefore, consumption of Cr containing black gram may have human health concern due to toxic Cr accumulation and nutrition imbalances.