Effect of plastic mulches on growth and yield of potato (Solanum tuberosum L.) in Dadeldhura, Nepal

A field experiment was conducted from February to June, 2020 at Bhatkanda, Dadeldhura, Nepal to assess the effectiveness of plastic mulches in potato production. The experiment was laid out in Randomized Complete Block Design (RCBD) with four replications comprising of five treatments viz: T1: white plastic mulch (white on black colored), T2: silver plastic mulch (silver on black colored), T3: perforated black plastic mulch, T4: black plastic mulch and T5: control (without mulch). Results revealed that the black plastic mulch significantly increased the rate of emergence while perforated black plastic exhibited highest values of all other studied growth parameters, yield components and quality parameters. The highest marketable tuber yield was obtained in perforated black plastic (6.05 kg/m2) followed by silver plastic (5.62 kg/m2), white plastic (5.46 kg/m2), black plastic (5.14 kg/m2) and lowest marketable tuber yield was obtained in control condition (4.07 kg/m2). Similarly, temperature difference between controlled and mulched condition at 15 cm depth of soil was observed up to 2.8°C with its highest value in black plastic mulch and lowest in control condition. The perforated black plastic mulch was found most economical with maximum value of net return (NRs. 1904.31 thousands/ha) and B: C ratio (5.83). This study concludes that the use of perforated black plastic mulch is most economical with optimum plant growth and yield, producing best quality potatoes under climatic condition of Dadeldhura, Nepal

Unusual magnetic and transport properties in HoMn6_6Sn6_6 kagome magnet

With intricate lattice structures, kagome materials are an excellent platform to study various fascinating topological quantum states. In particular, kagome materials, revealing large responses to external stimuli such as pressure or magnetic field, are subject to special investigation. Here, we study the kagome-net HoMn$_6$Sn$_6$ magnet that undergoes paramagnetic to ferrimagnetic transition (below 376 K) and reveals spin-reorientation transition below 200 K. In this compound, we observe the topological Hall effect and substantial contribution of anomalous Hall effect above 100 K. We unveil the pressure effects on magnetic ordering at a low magnetic field from the pressure tunable magnetization measurement. By utilizing high-resolution angle-resolved photoemission spectroscopy, Dirac-like dispersion at the high-symmetry point K is revealed in the vicinity of the Fermi level, which is well supported by the first-principles calculations, suggesting a possible Chern-gapped Dirac cone in this compound. Our investigation will pave the way to understand the magneto-transport and electronic properties of various rare-earth-based kagome magnets

Regenerative callus induction and biochemical analysis of Stevia rebaudiana Bertoni

Stevia Leaves are the principal source of stevioside, which is estimated to be 100-300 times sweeter than table sugar. Stevioside has clinical significance as they are reported to maintain glucose levels in human blood. Owing to the difficulties in propagation of stevia through seeds and vegetative methods, callus culture has been an efficient alternative for generation of stevioside. The aim of this study is to develop an efficient and standardized protocol for maximum induction and multiplication of callus from a leaf. Callus culture was established from leaves in MS basal media fortified with various combinations (BAP, NAA, 2,4-D, KN, IBA) and concentrations of phytohormones. The best callusing (100%) was recorded in MS media supplemented with (2,4-D 1.0mg/l + NAA 1.0mg/l). The callus was harvested after 4 weeks and screened for the presence of various bioactive compounds. The qualitative results showed that the extracts of callus contained bioactive compounds like flavonoids, glycosides, phenol, tannins, sterols and saponins thereby making callus one of the sources for extraction of various secondary metabolites

Observation of anisotropic Dirac cones in the topological material Ti2Te2P

Anisotropic bulk Dirac (or Weyl) cones in three dimensional systems have recently gained intense research interest as they are examples of materials with tilted Dirac (or Weyl) cones indicatig the violation of Lorentz invariance. In contrast, the studies on anisotropic surface Dirac cones in topological materials which contribute to anisotropic carrier mobility have been limited. By employing angle-resolved photoemission spectroscopy and first-principles calculations, we reveal the anisotropic surface Dirac dispersion in a tetradymite material Ti2Te2P on the (001) plane of the Brillioun zone. We observe the quasi-elliptical Fermi pockets at the M -point of the Brillouin zone forming the anisotropic surface Dirac cones. Our calculations of the Z2 indices confirm that the system is topologically non-trivial with multiple topological phases in the same material. In addition, the observed nodal-line like feature formed by bulk bands makes this system topologically rich.Comment: 21 pages, 17 figures, Supplementary Information include