Light interception and yield response of cotton varieties to high density planting and fertilizers in sub-tropical India

Plant density and optimum fertilization are two important agronomic practices to enhance productivity of cotton (Gossypium hirsutum L.) varieties. The objective of this study was to investigate the effect of high density planting (HDPS) and fertilization rate, especially their interactions, on yield, yield components of cotton varieties in sub-tropical India. Split-split plot design was adopted and replicated thrice. The main plots were assigned to low, medium and high plant densities (16.7, 13.3 and 11.1 plants/m2). Pre released cotton varieties TCH-1705 and LH-2298 were tested in low, moderate and high rates of fertilizers recommended for the region (100, 125 and 150 %) in sub-sub plots. Significantly higher seed cotton yield (1148 kg/ha) was achieved in narrow inter row spaced at 60 cm over normal plant row spacing of 90 cm (1025 kg/ha). Compact genotype TCH-1705 was out yielded (1146 kg/ha) over LH 2298(1044 kg/ha). Application of fertilizers at higher rate improved seed cotton yield (1232 kg/ha) Leaf area index (3.8) and light interception (0.98) over blanket recommendation. The results of the study inferred that seed cotton yield improvement was possible under HDPS production system with compact varieties grown at narrow spacing and higher fertilizer dose

Modified planting geometry and fertilizer rate on productivity of corn (Zea mays L.) in Vertisols

A field experiment was conducted at Raichur, Karnataka with an objective to find out production potential of grain corn planted in clumps and rate of fertilizer application. Design followed was split plot and repeated thrice with rate of fertilizer application as main factor and planting geometry as sub factor. Treatments consists of planting corn at 2, 3, 4 seeds/hill compared with single seeds/hill (60 cm x 20 cm) and farmers practice uneven spacing. In clumped plants inter row spacing is similar (60 cm) and intra row distance is differ to maintain uniform plant density (83,333 plants/ha) in each treatment. Recommended dose of fertilizers (RDF) was applied in 2 splits and 150% RDF in 3 splits. Results revealed that planting 2 seeds /hill at 60 cm x 40 cm recorded significantly higher yield, economics of corn as compared to 3 and 4 seeds/hill and farmers practice. As increased plant population per hill maintains higher soil moisture at 75 days after planting (7.5-9.4%) and lower dry matter per plant at harvest (236.3 to 185.5 g) as compared to conventional planting. Application of higher (150%) fertilizers in 3 splits recorded higher dry matter production, grain yield, and economic returns over RDF. This may be useful strategy for corn productivity enhancement by clump planting with higher fertilizer rate

On‐surface synthesis of porous graphene nanoribbons containing nonplanar [14]annulene pores

The precise introduction of nonplanar pores in the backbone of graphene nanoribbon represents a great challenge. Here, we explore a synthetic strategy toward the preparation of nonplanar porous graphene nanoribbon from a predesigned dibromohexabenzotetracene monomer bearing four cove-edges. Successive thermal annealing steps of the monomers indicate that the dehalogenative aryl-aryl homocoupling yields a twisted polymer precursor on a gold surface and the subsequent cyclodehydrogenation leads to a defective porous graphene nanoribbon containing nonplanar [14]annulene pores and five-membered rings as characterized by scanning tunneling microscopy and noncontact atomic force microscopy. Although the C–C bonds producing [14]annulene pores are not achieved with high yield, our results provide new synthetic perspectives for the on-surface growth of nonplanar porous graphene nanoribbons

Neutral organic radical formation by chemisorption on metal surfaces

Organic radical monolayers (r-MLs) bonded to metal surfaces are potential materials for the development of molecular (spin)electronics. Typically, stable radicals bearing surface anchoring groups are used to generate r-MLs. Following a recent theoretical proposal based on a model system, we report the first experimental realization of a metal surface-induced r-ML, where a rationally chosen closed-shell precursor 3,5-dichloro-4-[bis(2,4,6-trichlorophenyl)methylen]cyclohexa-2,5-dien-1-one (1) transforms into a stable neutral open-shell species () via chemisorption on the Ag(111) surface. X-ray photoelectron spectroscopy reveals that the >C=O group of 1 reacts with the surface, forming a C-O-Ag linkage that induces an electronic rearrangement that transforms 1 to . We further show that surface reactivity is an important factor in this process whereby Au(111) is inert towards 1, whereas the Cu(111) surface leads to dehalogenation reactions. The radical nature of the Ag(111)-bound monolayer was further confirmed by angle-resolved photoelectron spectroscopy and electronic structure calculations, which provide evidence of the emergence of the singly occupied molecular orbital (SOMO) of 1

Highly Oxidized States of Phthalocyaninato Terbium(III) Multiple‐Decker Complexes Showing Structural Deformations, Biradical Properties and Decreases in Magnetic Anisotropy

Presented here is a comprehensive study of highly oxidized multiple‐decker complexes composed of Tb$_{III}$ and Cd$_{III}$ ions and two to five phthalocyaninato ligands, which are stabilized by electron-donating n-butoxy groups. From X-ray structural analyses, all the complexes become axially compressed upon ligand oxidation, resulting in bowl-shaped distortions of the ligands. In addition, unusual coexistence of square antiprism and square prism geometries around metal ions was observed in +4e charged species. From paramagnetic $^{1}$H NMR studies on the resulting series of triple, quadruple and quintuple-decker complexes, ligand oxidation leads to a decrease in the magnetic anisotropy, as predicted from theoretical calculations. Unusual paramagnetic shifts were observed in the spectra of the +2e charged quadruple and quintuple-decker complexes, indicating that those two species are actually unexpected triplet biradicals. Magnetic measurements revealed that the series of complexes show single-molecule magnet properties, which are controlled by the multi-step redox induced structural changes

π-Extended peri-Acenes: Recent Progress in Synthesis and Characterization

In memory of François Diederich.Nanographenes (NGs) with open-shell character have gained intense attention due to their potential applications in future organic nanoelectronics and spintronics. Among them, NGs bearing a pair of parallel zigzag edges, such as acenes and periacenes (PAs) bestow unique (opto)electronic and magnetic properties owing to their localized non-bonding π-state. However, their reactive zigzag edges impart intrinsic instability, leading to the challenging synthesis. The recent development of synthetic strategies provided access to several π-extended PAs, which were considered unrealistic for decades. Notably, their laterally π-extended structures of zigzag-edged graphene nanoribbons was realised via on-surface synthesis. However, synthesis of π-extended PAs in solution is still in its infancy, more intensive scientific efforts are needed to surpass the existing challenges regarding stability and solubility. This Review provides an overview of recent progress in the synthesis and characterization of PAs through a bottom-up synthetic strategy, including on-surface and solution-phase chemistry. In addition, views on existing challenges and the future prospects are also provided

Light interception and yield response of cotton varieties to high density planting and fertilizers in sub-tropical India

Plant density and optimum fertilization are two important agronomic practices to enhance productivity of cotton (Gossypium hirsutum L.) varieties. The objective of this study was to investigate the effect of high density planting (HDPS) and fertilization rate, especially their interactions, on yield, yield components of cotton varieties in sub-tropical India. Split-split plot design was adopted and replicated thrice. The main plots were assigned to low, medium and high plant densities (16.7, 13.3 and 11.1 plants/m2). Pre released cotton varieties TCH-1705 and LH-2298 were tested in low, moderate and high rates of fertilizers recommended for the region (100, 125 and 150 %) in sub-sub plots. Significantly higher seed cotton yield (1148 kg/ha) was achieved in narrow inter row spaced at 60 cm over normal plant row spacing of 90 cm (1025 kg/ha). Compact genotype TCH-1705 was out yielded (1146 kg/ha) over LH 2298(1044 kg/ha). Application of fertilizers at higher rate improved seed cotton yield (1232 kg/ha) Leaf area index (3.8) and light interception (0.98) over blanket recommendation. The results of the study inferred that seed cotton yield improvement was possible under HDPS production system with compact varieties grown at narrow spacing and higher fertilizer dose

Core-Modified Naphthalenediimides Generate Persistent Radical Anion and Cation: New Panchromatic NIR Probes

The generation of the first persistent radical cation of naphthalenediimide with Cu²⁺/Fe³⁺ under ambient conditions is reported. An alternate anionic trigger generates a persistent radical anion within the same motif. Steric protection and H-bonding enhances the half-life of radical cation by 290-fold. The radical anion and cation have orthogonal spin density, panchromatic and NIR optical bands, which can be applied as attractive multichannel probes

Farmers’ Perception towards Climate Change and its Effect on Agriculture in Kolar District of Karnataka, India

This study aimed to assess farmers' perception of climate change and its implications for agriculture in Kolar district, Karnataka, during the year 2021-22. Data from 80 respondents were collected using a multi-stage random sampling technique, employing a well-structured, pre-tested questionnaire administered through personal interviews. Descriptive statistics, regression analysis, and Garret's ranking technique were employed for data analysis. The results revealed that 40% of the respondents had been aware of climate change for the past five years, with farmers' personal observations being a primary source of information. Most farmers identified climate change through rising temperatures, irregular rainfall patterns, and increased overall rainfall. Respondents also noted climate change effects on agriculture, such as increased pest and disease occurrences, altered sowing periods, and heightened competition from weeds. Regression analysis indicated that factors such as education, the use of social media, sources of weather information, and farming experience had a positive and significant influence on farmers' perception levels. As a result, this study suggests the development of climate-based advisory services, including weather alerts, climate-resilient crop varieties, adaptation strategies, and enhanced weather forecasting systems by relevant government departments to mitigate the impacts of climate change on agriculture in the region

Extraordinary Stability of Naphthalenediimide Radical Ion and Its Ultra-Electron-Deficient Precursor: Strategic Role of the Phosphonium Group

Stabilization of radical ions and highly electron-deficient systems under ambient conditions is of great significance. A new design concept is presented that applies the multifaceted features of the phosphonium group to achieve isolation of (a) the first naphthalenediimide (NDI) radical ion [(<b>1a</b>^•+)­BPh₄^–] as single crystals and (b) an ultra-electron-deficient NDI [(<b>1a</b>²⁺)­2BF₄^–] having the lowest LUMO level recorded for an NDI, overwhelming the formative tetracyanoquinodimethane (<b>TCNQ</b>) molecule. Both <b>1a</b>^•+ and <b>1a</b>²⁺ exhibit unprecedented stability to normal workup procedures, chromatography, and anion metathesis in open air. To our knowledge, this is the first instance where radical ions stable toward chromatography have been obtained, which is a noteworthy development in the field of synthetic radical chemistry. The crucial components of thermodynamic and kinetic stabilization, namely, the nonbonded P···O interaction, hypervalency, and propeller-like shape of the phosphonium groups in <b>1a</b>²⁺ and <b>1a</b>^•+, were substantiated by crystallography and theoretical studies. Natural bond orbital (NBO) calculations validated the P···O contact to be an n_O → σ_P–C^* orbital interaction. Spontaneous electron transfer reactions of <b>1a</b>²⁺ even in nonpolar solvents, anion−π interactions of <b>1a</b>²⁺ with the naphthalene core, and panchromism of <b>1a</b>^•+ are the other emergent properties. The high-yielding (∼90%) in situ synthesis of <b>1a</b>^•+ and the extraordinary stability fostered by the phosphonium group have the potential to turn hitherto unstable organic systems into a new genre of stable <i>off-the-shelf</i> systems