T1 Minimum Research Articles

Influence of Mn on dry yield and nutrient uptake by new jute variety BJRI Tossa-7

A field experiment was conducted during the year 2018-2019 at the vital place of Bangladesh Jute Research Institute (BJRI), Dhaka. The aim of the study was to evaluate the influence of Mn fertilizer on the dry matter yield and potential nutrient uptake of the newly developed jute variety BJRI Tossa jute-7. The treatments used in the experiments were T1: Control, T2: RDF sole (N90P10 K30 S20kg/ha), T3: RDF + 1 kg Mn/ha, T4: RDF + 2 kg Mn/ha, T5: RDF + 3 kg Mn/ha and T6: RDF + 4 kg Mn/ha. Mn application had a favorable effect on the dry matter yield of jute. Among the fertilizers of Mn with RDF, interaction promoted the dry yield biomass compared to sole RDF and control. Maximum dry matter yield (leaves + shoots + roots) achieved (20000 kg/ha) with T5 (RDF + 3 kg Mn/ha) and minimum (6421 kg/ha) in T1 (control). Study indicated that it needs to apply Mn to obtain optimum yield production. The interaction effect of Mn, NPK and S fertilizer significantly influenced nutrient uptake by the jute plant. The uptake of nutrient found highest N (218.9 kg/ha) in T5, P (92.75 kg/ha) in T3, K (239.73 kg/ha) with T6, S (19.59 kg/ha) in T4, Fe (0.64 kg/ha) in T5, Zn (0.38 kg/ha) in T5 and Mn (0.63 kg/ha) recorded in T6. The amount of micro nutrient uptake may be arranged in the order of Mn >Zn> Fe. Considering the highest uptake of major element, it can be kept as in the order of K > N>P>S. Study indicated that a higher rate of nutrient uptake was promoted dry matter accumulation in jute. Research revealed that the rate of nutrient uptake maximized with the addition of Mn in the RDF treatment. Hence, it could be concluded that applying RDF + 3 kg Mn/ha may be a suitable dose for optimum yield production of jute. Yet, in order to draw a sound conclusion, repeating the experiment is needed. In the future, the study will be a guideline for further investigation. Int. J. Agril. Res. Innov. Tech. 14(1): 87-95, June 2024

Unveiling the potential of cellulose nanofibre based nitrogen fertilizer and its transformative effect on Vigna radiata (Mung Bean): nanofibre for sustainable agriculture.

Fertilizer management is crucial to maintaining a balance between environmental health, plant health, and total crop yield. Farmers are overutilizing fertilizers with a mind set to enhance the productive capacity of the field, which adversely impacts soil fertility and causes serious environmental hazards. To mitigate the issues of over-utilization of fertilizers, controlled-release fertilizers were developed using nitrogen fertilizer (ammonium chloride) loaded on cellulose nanofibres (named CNF*N). In this study, the effects of CNF*N were compared with commercial nitrogen fertilizer (ammonium chloride) on Vigna radiata (Mung) under greenhouse conditions. The pot experiment was conducted using six treatments: first treatment was control, where the plant was cultivated (T1); second treatment was T2, where the plant was cultivated with CNF to determine the impact of CNF on the plant; third was T3 where commercial ammonium chloride (24 mg/ 2 kg soil) was added to the plant; fourth was T4, where the plant was loaded with CNF, viz. CNF*N contains 4.8 mg of nitrogen; fifth was T5 CNF*N pellet contains 12 mg of nitrogen, and the last sixth treatment (T6) where CNF*N pellet containing 24 mg of nitrogen. It indicated that the growth parameters were best achieved in T6 treatment. Plant height was at its maximum in the T6 treatment (44.4 ±0.1cm) after the second harvest, whereas the minimum plant height was observed in T1, which was 39.1 ±0.1 cm. Root-to-shoot weight ratio was also maximum in T6 (0.183± 0.02) and minimum in T1 (0.07± 0.01) after second harvesting. The significant difference among the treatments was determined with Tukey's honestly significant difference (HSD). The nitrogen content (available and total) was significantly higher in the T4, T5, and T6 treatments (0.22, 0.25, and 0.28%) as compared to the control treatments (T1 (0.12%), T2 (0.13%), and T3 (0.14%) during the second harvesting stage (90 days), as nitrogen plays a crucial role in the development of vegetative growth in Vigna radiata. The rate of controlled-release nitrogen-fertilizer was found to be optimal in terms of plant growth and soil nutrients; hence, it could potentially play a crucial role in improving soil health and the yield of the crop.

Compatibility Analysis of Mushroom with different Botanicals in In vitro Condition

White button mushroom [Agaricus bisporus (Lange) Imbach] is the most popular cultivated edible mushroom, fetching high price and still dominating in Indian and International market. However, the limiting factor for its successful cultivation is the occurrence of competitor moulds. The present investigations were carried out in the laboratory Department of Plant Pathology, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj, Uttar Pradesh. In this experiment different botanical (seed extract) viz., Trachyspermum ammi (Ajwain), Foeniculum vulgare (Saunf), Anethum graveolens (Soa), Trigonella foenumgraecum (Methi) were evaluated to test their compatibility with Agaricus bisporus. The botanicals (seed extract) were evaluated in vitro through poison food technique at 10, 20 and 30% concentrations and 24, 48 & 72 hours of incubation. The maximum radial growth of Agaricus bisporus was observed in T0-Control (Agaricus bisporus) (16.45mm), (17.12 mm) and (17.22 mm) and minimum in T1 - Trachyspermum ammi (Ajwain) (1.46mm), (0.83mm) and (0.60mm) at 10, 20 and 30 percent concentration respectively. Maximum percentage of inhibition was observed in T1 - Trachyspermum ammi (Ajwain) (91.11%), (95.13%) and (96.50%) at 10, 20 and 30 percent concentration respectively.

Quantum mechanics/molecular mechanics studies on the excited-state decay mechanisms of cytidine aza-analogues: 5-azacytidine and 2'-deoxy-5-azacytidine in aqueous solution.

The excited state properties and deactivation pathways of two DNA methylation inhibitors, i.e., 5-azacytidine (5ACyd) and 2'-deoxy-5-azacytidine (5AdCyd) in aqueous solution, are comprehensively explored with the QM(CASPT2//CASSCF)/MM protocol. We systematically map the feasible decay mechanisms based on the obtained excited-state decay paths involving all the identified minimum-energy structures, conical intersections, and crossing points driving the different internal conversion (IC) and intersystem crossing (ISC) routes in and between the 1ππ*, 1nπ*, 3ππ*, 3nπ*, and S0 states. Unlike the 1nπ* state below the 1ππ* state in 5ACyd, deoxyribose group substitution at the N1 position leads to the 1ππ* state becoming the S1 state in 5AdCyd. In 5ACyd and 5AdCyd, the initially populated 1ππ* state mainly deactivates to the S0 state through the direct 1ππ* → S0 IC or mediated by the 1nπ* state. The former nearly barrierless IC channel of 1ππ* → S0 occurs ultrafast via the nearby low-lying 1ππ*/S0 conical intersection. In the latter IC channel of 1ππ* → 1nπ* → S0, the initially photoexcited 1ππ* state first approaches the nearby S2/S1 conical section 1ππ*/1nπ* and then undergoes efficient IC to the 1nπ* state, followed by the further IC to the initial S0 state via the S1/S0 conical intersection 1nπ*/S0. The 1nπ*/S0 conical intersection is estimated to be located 6.0 and 4.9 kcal mol-1 above the 1nπ* state minimum in 5ACyd and 5AdCyd, respectively, at the QM(CASPT2)/MM level. In addition to the efficient singlet-mediated IC channels, the minor ISC routes would populate 1ππ* to T1(ππ*) through 1ππ* → T1 or 1ππ* → 1nπ* → T1. Relatively, the 1ππ* → 1nπ* → T1 route benefits from the spin-orbit coupling (SOC) of 1nπ*/3ππ* of 8.7 cm-1 in 5ACyd and 10.2 cm-1 in 5AdCyd, respectively. Subsequently, the T1 system will approach the nearby T1/S0 crossing point 3ππ*/S0 driving it back to the S0 state. Given the 3ππ*/S0 crossing point located above the T1 minimum and the small T1/S0 SOC, i.e., 8.4 kcal mol-1 and 2.1 cm-1 in 5ACyd and 6.8 kcal mol-1 and 1.9 cm-1 in 5AdCyd, respectively, the slow T1 → S0 would trap the system in the T1 state for a while. The present work could contribute to understanding the mechanistic photophysics and photochemistry of similar aza-nucleosides and their derivatives.

Study of seed germination of Cordia dichotoma G. Forst. under laboratory condition

The seeds of Cordia dichotoma were collected from trees with the ideal phenotypical characters of good height, large crown and medium aged with abundant seed production. The fresh seeds were collected manually and the extracted seeds were cleaned and thoroughly hand mixed to improve the homogeneity during the sampling. The seeds based on their diameter were graded into three classes i.e. small (L1) (1.4 cm). The graded seeds were subjected to five different pre-sowing treatments for germination viz., Control (T1) (untreated seeds), Cold water treatment for 72 hours (T2), Cow dung treatment for 7 days (T3), Concentrated H2SO4 for 20 minutes followed by rinsing under running tap water (T4) and Hot water treatment (80 °C) followed by 24 hours soaking (T5). The graded and treated seeds were kept in seed germinator for four week. Watering and spray of fungicide was carried out manually when necessary. The effects of seed size and pre-sowing treatments on germination of seeds were explored periodically through counting the germinated seeds. The study revealed that seed parameters of the Cordia dichotoma were significantly influenced by seed size categories. The weight of 100 seeds was recorded maximum (209.22 g) in large size (L3) seed category which is significantly differed from L2 (medium) and L1 (small). However no significant difference has been observed among seed viability. The highest germination per cent (68.54%), germination capacity (74.08) and germination energy (41.47%) was recorded in concentrated H2SO4 for 20 minutes followed by rinsing under running tap water (T4) pre-sowing treatment while the lowest germination per cent (56.67%), germination capacity (64.08%) and germination energy minimum (30.75%) in T1(control). All treatments were significantly different from each other. On the other hand, among three seed category, large seed category (L3) was recorded maximum per cent germination (76.23%), germination capacity (83.56%) and germination energy (47.11%) while the minimum germination per cent (46.24%) germination capacity (54.46%) and germination energy (25.34%) was found in small seed category (L1). But all three seed size categories differed significantly from each other. Among the treatment combinations, germinability parameters were recorded maximum in T4L3 (concentrated H2SO4 for 20 minutes followed by rinsing under running tap water+ large seed category). The seed size and pre sowing treatments often controls the germination and initial seedling growth in many tree species. Pre-sowing treatment methods are employed for overcoming seed dormancy and are used not only to ensure the rapid germination but it also decreases labour, cost and time for nursery production.

Effect of Different Growing Media on Growth, Establishment and Survival of Passion Fruit (Passiflora edulis Sims.) cv. Coorg Purple

The current study was conducted in the Research Field at the SHUATS, Prayagraj, Department of Horticulture, from 2020 to 2021. Seven treatments were used in the experiment, which included growing media (farm yard manure, vermicompost, and poultry manure) on passion fruit. The experiment was carried out using a Randomized Block Design (RBD). the treatments were T1 Control (RDF 100% NPK)/ Plant, T2 Vermicompost (50%) +Poultry Manure (25%) + FYM (25%), T3 Vermicompost (25%) +Poultry Manure (50%) + FYM (25%), T4 Vermicompost (25%) + Poultry Manure (25%) + FYM (50%), T5 Poultry Manure (50%) + FYM (50%), T6 Poultry Manure (50%) + Vermicompost (50%) and T7 FYM (50%) + Vermicompost (50%). The results from the present investigation revealed that treatment T7 followed by T4 and T5 was found superior in terms of Survival percentage and growth parameters of Passion fruit in growing media i.e. (Vermicompost, Poultry manures, and Farm yard manures), in an agro-climatic condition of Prayagraj in terms of cost of cultivation maximum cost was recorded in treatment T3 and minimum in treatment T1.

Molecular motion of imidazolium cations and phase transitions in (ImH)2KCo(CN)6 with double perovskite structure

Temperature dependence of 1H nuclear magnetic resonance spin–lattice relaxation time T1 of (ImH)2KCo(CN)6, ImH+: imidazolium cation, is reported. The asymmetric T1 minimum observed in intermediate-temperature phase between 198 and 112 K is analyzed assuming the Cole-Davidson distribution of correlation time. Temperature dependences of 14N nuclear quadrupole resonance frequencies and spin–lattice relaxation times are also reported. The phase transitions at 198 and 112 K are shown to be of second and first order, respectively. The 14N relaxation is shown to be governed by the electric field gradient fluctuation due to the in-plane reorientational motion of the imidazolium cations.

Impact of different spacing on production of pole type lima bean (Phaseolus lunatus L.) with intercropping of brinjal crop

Lima beans are very nutritious underutilized legume crops. It is two types; bush type and pole type or vine varieties. Pole lima beans are grown for their distinctive flavour prized by local cooks (Namkeen) and high value as a fresh market crop in the district Farrukhabad. The pods are picked when they semi mature and seed sold for namkeen making. The experiment consisted three plant spacing (T1 S-1x1m Farmers practice without trellis, T2 S-2x2m+trellis, T3 S-3x3 trellis) and that effect on growth, yield and quality of lima bean and additional crop of brinjal as an intercrop at initial stage of lima beans. Flowering parameters Days to first flowering significantly earliest flowering was observed in the treatment T3 (S-3.0m x 3.0m + trellis), with minimum days for first flowering (72.50) and 50% flowering (92.50) at days after sowing. The number of pods per cluster (7.20) was found to be superior among all the treatment in spacing T3 followed by T2 and minimum in T1. Green Seed yield per hectare (q) as influenced by different spacing was found to be significant. The green seed yield per hectare (185q) was found significantly superior in the treatment T3 followed by (178q) in T2 and minimum (129q) in T1. The economics of the lima bean and intercrop of brinjal was found superior in treatment T3 with highest BC ratio.

Comprehensive Effects of Different Chemical Preservatives On Dehydrated Diced Radish During Storage

This study aimed to the effect of chemical preservatives on dehydrated diced radish, as well as their effect on the taste, nutritional value and shelf life of the final product. Before dehydration turnip diced were treated with different chemical preservatives and their different concentrations viz. The eight samples were added T1 = 0.1% potassium metabisulphite, T2 = 0.1% sodium benzoate, T3 = 0.1% potassium sorbate, T4 = 0.05% potassium metabisulphite + 0.05% sodium benzoate, T5 = 0.05% potassium metabisulphite + 0.05% potassium sorbate, T6 = 0.05% sodium benzoate + 0.05% potassium sorbateT7 = 0.05% potassium metabisulphite + 0.025% sodium Benzoate + 0.025% potassium sorbate, T0 = no chemical preservative. Samples were evaluated for physiochemical (moisture, pH, total solid, titratable acidity, ash and ascorbic acid), sensory (color, texture, taste and overall acceptability) and total bacterial count at 15 days interval of 90 days storage. Moisture value was decreased during storage. Maximum decreased was found in T0 (8.65) 3.52% while minimum decrease was observed in T1 (9.23)1.40%. pH was decreased during storage. The maximum decrease was observed in T0 (5.44) 16.10%. While minimum decreased found in T1 (5.64) 6.36%. Titratable acidity value was increased during storage. Maximum increase was observed in T0 (1.96) 17.78% while minimum increase was observed in T1 (1.81) 8.05%. Total solid was increased during storage. Maximum increase was found in T0 (91.35) 0.34 % and lower limit was detected in T1 (90.77) 0.14%. Ash content was increased with storage interval. Maximum increased in T0 (6.57) 2.31% while minimum in T1 (6.08) 0.99%. Ascorbic acid was decreased during storage. Maximum decreased in T0 (6.15)80.48% while minimum in T1 (9.05) 37.79%. Color, Texture, Taste and Overall acceptability were decreased with storage interval. Color maximum score was found in T1 (7.70) while minimum score was found in T0 (3.97). Texture maximum score was found in T1 (8.06) and minimum score in T0 (2.97). Taste maximum score was found in T1 (7.56) while minimum was noticed in T0 (3.33). Maximum score of overall acceptability was found in T1 (7.77) while minimum score obtained by T0 (3.42). Total bacterial count was increased with storage interval. Maximum increased in T0 (24.43x107) 800% while minimum increased in T1 (10.57x107cfu/g) 375%. Both chemical preservatives and storage intervals resulted in highly significant (p < 0.000) differences for all parameters. When comparing the chemical preservatives, the best acceptability among all the treatments was obtained by T1 which was treated with 0.1% potassium metabisulphite.

Mechanistic Photophysics of Tellurium-Substituted Uracils: Insights from Multistate Complete-Active-Space Second-Order Perturbation Calculations.

The photophysical mechanisms of tellurium-substituted uracils were studied at the multistate complete-active-space second-order perturbation level with a particular focus on how the position and number of tellurium substitutions affect their nonadiabatic relaxation processes. Electronic structure analysis reveals that the lowest several excited states are closely concerned with the n and π orbitals at the Te7-C2 [Te8-C4] moiety of 2-tellurouracil (2TeU) [4TeU and 24TeU]. Both planar and twisted minima were optimized for 2TeU, whereas only planar ones were obtained for 4TeU and 24TeU, except for a twisted T1 minimum of 4TeU. Based on intersection structures and linearly interpolated internal coordinate paths, we proposed several feasible excited-state deactivation paths. It is found that the relaxation channels for 2TeU are more complicated than those of 4TeU and 24TeU. The electronic population transfer to the T1 state for 2TeU is easier than that for 4TeU and 24TeU in consideration of the barrier heights from the S2 Franck-Condon point to the S2/S1 or S2/T2 intersections. In addition, the recovery of the ground state from the T1 state for 2TeU will be more efficient than that for the other two systems as well.

On the Importance of Ligand-Centered Excited States in the Emission of Cyclometalated Ir(III) Complexes.

The photophysical behavior of the cyclometalating Ir(III) complexes [Ir(ppy)2(bpy)]+, where Hppy is 2-phenylpyridine and bpy is 2,2′-bipyridine (complex 1), and [Ir(diFppy)2(dtb-bpy)]+, where diFppy is 2-(2,4-difluorophenyl)pyridine and dtb-bpy is 4,4′-di-tert-butyl-2,2′-bipyridine (complex 2), has been theoretically investigated by performing density functional theory calculations. The two complexes share the same molecular skeleton, complex 2 being derived from complex 1 through the addition of fluoro and tert-butyl substituents, but present notable differences in their photophysical properties. The remarkable difference in their emission quantum yields (0.196 for complex 1 in dichloromethane and 0.71 for complex 2 in acetonitrile) has been evaluated by characterizing both radiative and nonradiative decay paths. It has emerged that the probability of decaying through the nonradiative triplet metal-centered state, normally associated with the loss of the emission quantum yield, does not appear to be the reason behind the reported substantially different emission efficiency. A more critical factor appears to be the ability of complex 2 to emit from both the usual metal-to-ligand charge-transfer state and from two additional ligand-centered states, as supported by the fact that the respective minima belong to the potential energy surface of the lowest triplet T1 state and that their phosphorescence lifetimes are in the same order of magnitude. In contrast, the emission of complex 1 can be originated only from the metal-to-ligand charge-transfer state, being the only emissive T1 minimum. The results constitute a significant case in which the emission from ligand-centered states is the key for determining the high emission quantum yield of a complex.

Excited-State Properties and Relaxation Pathways of Selenium-Substituted Guanine Nucleobase in Aqueous Solution and DNA Duplex.

The excited-state properties and relaxation mechanisms after light irradiation of 6-selenoguanine (6SeG) in water and in DNA have been investigated using a quantum mechanics/molecular mechanics (QM/MM) approach with the multistate complete active space second-order perturbation theory (MS-CASPT2) method. In both environments, the S11(nSeπ5*) and S21(πSeπ5*) states are predicted to be the spectroscopically dark and bright states, respectively. Two triplet states, T13(πSeπ5*) and T23(nSeπ5*), are found energetically below the S2 state. Extending the QM region to include the 6SeG-Cyt base pair slightly stabilizes the S2 state and destabilizes the S1, due to hydrogen-bonding interactions, but it does not affect the order of the states. The optimized minima, conical intersections, and singlet–triplet crossings are very similar in water and in DNA, so that the same general mechanism is found. Additionally, for each excited state geometry optimization in DNA, three kind of structures (“up”, “down”, and “central”) are optimized which differ from each other by the orientation of the C=Se group with respect to the surrounding guanine and thymine nucleobases. After irradiation to the S2 state, 6SeG evolves to the S2 minimum, near to a S2/S1 conical intersection that allows for internal conversion to the S1 state. Linear interpolation in internal coordinates indicate that the “central” orientation is less favorable since extra energy is needed to surmount the high barrier in order to reach the S2/S1 conical intersection. From the S1 state, 6SeG can further decay to the T13(πSeπ5*) state via intersystem crossing, where it will be trapped due to the existence of a sizable energy barrier between the T1 minimum and the T1/S0 crossing point. Although this general S2 → T1 mechanism takes place in both media, the presence of DNA induces a steeper S2 potential energy surface, that it is expected to accelerate the S2 → S1 internal conversion.

Reorientation Times for Solid-State Electrolyte Solvents and Electrolytes from NMR Spin-Lattice Relaxation Studies.

Ionic and molecular plastic crystals have been studied recently as solid electrolytes or solvents, but the specific role of molecular reorientation has not been clarified. We use NMR spin-lattice relaxation times (T1 minima) to compare the time scale for magnetic fluctuations in a plastic crystal solvent to the molecular reorientation times, as established by dielectric spectroscopy. We focus on a mixture of succinonitrile and glutaronitrile, in which the rotationally disordered phase is stabilized against crystallization. Reorientation times can then be studied over 13 orders of magnitude, down to the glass transition temperature at 144 K. For each nucleus, 1H and 13C, the most probable magnetic fluctuation time is found to be slightly shorter than the reorientation time, but with practically indistinguishable temperature dependence. This facilitates investigation of the relation of solvent reorientation to ion conductivity relaxation times in ionic conducting systems in which the conductivity swamps the dielectric signature of solvent reorientation.

Effect of potassium and zinc on growth, physiological and yield attributes in sweet orange (Citrus sinensis Osbeck) cv. “mosambi” under high density planting

The present investigation was carried out to study the effect of potassium and zinc on Sweet orange (Citrus sinensis Osbeck) cv. “Mosambi” during the year 2018. Eight years old uniformly grown Mosambi Sweet orange plants, grafted on Karna Khatta rootstock and planted at a distance of 3.0 x 2.5m were used in this investigation. The investigation was carried out in high density planting area of Bihar Agricultural College, Sabour, Bhagalpur, under the Department of Fruit & Fruit Technology. Twelve different treatments of K and Zn in a simple randomized block design were used. Various treatments showed significant effect on physiological, vegetative and yield parameters. The maximum leaf area (23.53cm2), total chlorophyll content (3.04mg/g), leaf relative water content (75.82%), specific leaf weight (0.0164g/cm2) were observed in T12 (K2O @500g +Zinc sulphate @200 g) whereas minimum in T1(control). The maximum increase in current season shoot length (13.22cm), canopy spread (64.17cm), trunk girth (1.93cm) and plant height (36.67cm) were also recorded in T12 (500g K2O and 200g ZnSO4) whereas minimum in control. The maximum number of fruits per tree was counted (92.67) in T8.

Screening Rice Germplasm against Sheath Blight Disease of Rice and its Integrated Management in Bangladesh

Fifty-seven rice germplasm collected from BRRI Genebank were screened against sheath blight (ShB) by artificial inoculation in field and laboratory conditions in T. Aman 2012. Significant differences on relation to lesion height (RLH) among the germplasm were observed, where the highest (83%) was recorded in susceptible check, BR11 and the lowest (8.33%) was in Orgoja. Severity score of ShB was recorded maximum (9) in Dudhsail, Basi, Chaula mari, Holdemota, Calendamota, Semmua, Kotijira, Halisail, Horakani, Kalisura, Ashfuli, Huglapata and BR11 as highly susceptible to ShB, whereas it was minimum (1) in Orgoja. Gopal ghosh was observed as moderately tolerant with 27.33% RLH and severity score 3, while Kala binni, Khazur chari, Binni, Kalagora, Patjait and Dorkumur found moderately tolerant with severity score 5. In detached sheath inoculation method in test tube, most of the germplasms found highly susceptible, except Orgoja as resistant and Gopal ghosh as moderately tolerant. However, Orgoja showed resistance in both field inoculation and detached sheath inoculation methods. But, Dorkumur was found moderately tolerant in field and highly susceptible in detached sheath inoculation in laboratory. The experiment of Integrated Disease Management (IDM) packages was conducted in the farmer’s field with BR11 at Fulpur, Mymensingh during T. Aman 2013. The IDM practices of rice ShB resulted profound effect. Relative lesion height, percent disease index, tiller infection and hill infection were maximum (68%, 69%, 86% and 79% respectively) in T6 (control) and minimum in T1 [FDR (removal of floating debris) + 30 July transplanting + Potash (K) fertilizer (202 g decimal-1) + Top dressing of urea (247 kg ha-1) in four equal splits at 15 days interval + single spray of fungicides of Azoxystrobin 10% (0.17 kg ha-1) + Tebuconazole 90% (500 ml ha-1)]. Moreover, the highest number of panicles per m2, filled grains per panicle and grains yield were recorded in T1 (160, 150 and 6.25 t ha-1 respectively) and the minimum in T6 (227, 120 and 3.6 t ha-1 respectively). Therefore, the best IDM package was T1 for its effective control of ShB disease as well as yield maximization of rice. Finally, Orgoja could be used in resistance breeding for varietal improvement and the IDM package of T1 need to be recommended to prescribe in the farmer’s field after simulation in different AEZs and seasons with different varieties of Bangladesh.
 Bangladesh Rice j. 2018, 22(2): 1-12

MS-CASPT2 Studies on the Photophysics of Selenium-Substituted Guanine Nucleobase.

The MS-CASPT2 method has been employed to optimize minimum-energy structures of 6-selenoguanine (6SeGua) and related two- and three-state intersection structures in and between the lowest five electronic states, i.e., S2(1ππ*), S1(1nπ*), T2(3nπ*), T1(3ππ*), and S0. In combination with MS-CASPT2 calculated linearly interpolated internal coordinate paths, the photophysical mechanism of 6SeGua has been proposed. The initially populated S2(1ππ*) state decays to either S1(1nπ*) or T2(3nπ*) states through a three-state S2/S1/T2 intersection point. The large S2/T2 spin–orbit coupling of 435 cm–1, according to the classical El-Sayed rule, benefits the S2 → T2 intersystem crossing process. The S1(1nπ*) state that stems from the S2 → S1 internal conversion process at the S2/S1/T2 intersection point can further jump to the T2(3nπ*) state through the S1 → T2 intersystem crossing process. This process does not comply with the El-Sayed rule, but it is still related to a comparatively large spin–orbit coupling of 39 cm–1 and is expected to occur relatively fast. Finally, the T2(3nπ*) state, which is populated from the above S2 → T2 and S1 → T2 intersystem crossing processes, decays to the T1(3ππ*) state via an internal conversion process. Because there is merely a small energy barrier of 0.11 eV separating the T1(3ππ*) minimum and an energetically allowed two-state T1/S0 intersection point, the T1(3ππ*) state still can decay to the S0 state quickly, which is also enhanced by a large T1/S0 spin–orbit coupling of 252 cm–1. Our proposed mechanism explains experimentally observed ultrafast intersystem crossing processes in 6SeGua and its 835-fold acceleration of the T1 state decay to the S0 state compared with 6tGua. Finally, we have found that the ground-state electronic structure of 6SeGua has more apparent multireference character.

Photosensitized Retinal Isomerization in Rhodopsin Mediated by a Triplet State

AbstractDirect 11‐cis to all‐trans retinal photoisomerization within rhodopsin is well known to be the initial chemical reaction triggering the process of vision in mammalians, such as bovine. Nevertheless, deep‐sea fish are known to use chlorophyll derivatives as photosensitizers in order to see deep‐red light, at wavelengths where retinal does not absorb. Also, some photodynamic therapy treatments were shown to enhance the vision of patients in dim light conditions. Energy transfer from the photosensitizer to rhodopsin was therefore proposed as a mechanism to populate the triplet state of the retinal chromophore. Herein, by means of hybrid quantum mechanics‐coupled‐molecular mechanics modeling techniques, we give insights into the possible energy mechanism and describe the retinal isomerization mediated by the lowest‐lying triplet state. Especially, we show how a few kcal/mol energy barrier separates a T1 minimum from a S0/T1 intersection region, hence proposing an equilibrium between phosphorescence and isomerization processes. Moreover, the eventual self‐production of singlet oxygen, constituting a potential danger for the integrity of rhodopsin, is discussed.

Curious Case of 2-Selenouracil: Efficient Population of Triplet States and Yet Photostable.

Excited-state MS-CASPT2 and ADC(2) quantum chemical calculations and nonadiabatic dynamics simulations show that 2-selenouracil is able to both efficiently populate and depopulate reactive triplet states in an ultrashort time scale. Thus, the heavier homologue of 2-thiouracil unites the ultrafast, high-yield intersystem crossing of 2-thiouracil with the short excited-state lifetime and photostability of the parent nucleobase uracil-two properties that have been traditionally thought to be diametrically opposed. Remarkably, while the S2 → S1 → T2 → T1 deactivation dynamics of 2-selenouracil is analogous to that of 2-thiouracil, the calculations show that the triplet lifetime of 2-selenouracil should decrease by up to 3 orders of magnitude in comparison to that 2-thiouracil, possibly down to the few-picosecond time scale. The main reasons for this decrease are the lack of a second T1 minimum, the enhanced spin-orbit coupling, and the reduction of the energy barrier to access the T1/ S0 crossing-in particular in aqueous solution-compared to 2-thiouracil. Such unusual photophysical properties, together with its significant red-shifted absorption spectrum, could make 2-selenouracil a useful specialized photosensitizer for photodynamical therapy.

Theoretical insight in highly luminescent properties of Eu(III) complex with phenanthroline

The complete photophysical process, from absorption in the UV region, excited state energy transitions, ligand → Eu(III) energy transfer to luminescence of Eu(phen)2(NO3)3 in Vis region, is elucidated by means of two theoretical approaches and in close relation to the experiment. The energy diagram, S1 and T1 excited state character and the concurrent energy transitions in phen and its Eu(III) complex in gas phase and in DMF solution are predicted by DFT-TDDFT/PBE1PBE calculations. The contributions of phen and NO3 ligands to the excited state energies are evaluated in detail. The high population of T1 state (due to effective intersystem crossing) and its closeness in energy to the 5D0 level of the Eu(III) (0.4 eV), make T1 state the key donor for the excited state ligand-to-metal ion energy transfer. The T1 state energy of phen chromophore determines this one in its Eu(III) and Gd(III) complexes. The solvent DMF effect on the lowest triplet excited state is insignificant. Providing similar accuracy for the vertical excited state energy as the estimates for the TDDFT/PBE1PBE energy of T1 minimum and the experimental phosphorescence data, INDO/S-CIS method could be reliably used for further prediction of the luminescent properties. A computational strategy based on Sparkle/RM1 geometry, INDO/S-CIS excitation energies, Judd-Ofelt parameters, obtained with the QDC model and energy transfer rates predicted T1 → 5D0 as the most probable channel of the energy transfer process and luminescent quantum yield of 32% close to the experimental result of 35%.

Development of low field NMR technique for analyzing segmental mobility of crosslinked polymers

ABSTRACTThis low field NMR study established the correlation between the degree of crosslinking in rigid model systems to the proton spin lattice relaxation time (T1) measured. For three model epoxy samples, our data have shown that as the number of crosslinks increases the T1 minima shift toward higher temperatures. In addition, the magnitude of the T1 minimum is also observed to shift to higher values as a function of crosslinks formed. These trends are consistent with the predictions of the Bloembergen, Purcell, and Pound analysis. For these highly crosslinked systems, it was necessary to incorporate the Fuoss Kirkwood distribution function for describing the coupled dynamics of the connected individual monomer units of each crosslink. By fitting the spin lattice relaxation data at different temperatures to the Fuoss Kirkwood modified BPP theory, the average activation energy for the molecular motion and the breadth of the relaxation spectrum were obtained. For these model systems, the increase in the activation energy to achieve mobility and the broadening of relaxation distribution have also been determined quantitatively. The results of this study provide the foundation for using T1 to analyze the crosslinking process of polymeric systems. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018, 56, 639–642