Role of macronutrients in cotton production

Sound nutrition plays a key role in enhancing cotton yield. As cotton undergoes vegetative and reproductive growth at the same time, its nutritional requirements are dissimilar, compared to other field crops. Cotton is grown as an annual crop with an indeterminate growth pattern. The vegetative branching provides a potential fruiting place except under abiotic and biotic stresses. Moreover, cotton has a deep root system with low density of roots in the surface layer of soils where availability of nutrients is high. The rooting system makes cotton crop more dependent on the subsoil for nutrition. A continuous supply of nutrients is required to sustain morphogenesis. The rate of both nutrients absorption and dry matter production increases progressively during the seedling, vegetative, and fruiting periods and peaks near the end of the bloom period. Nitrogen, phosphorus, and potassium are required in large quantities and are limited in many soils. The deficiencies of macro-and micronutrients decrease plant growth and development, and consequently seed cotton yield is reduced. The deficiency of phosphorous (P), calcium (Ca), potassium (K), boron (B), magnesium (Mg), and zinc (Zn) affects fruit production in cotton than vegetative growth, while the deficiencies of nitrogen (N), sulfur (S), molybdenum (Mo), and manganese (Mn) affect equally vegetative and reproductive growth of cotton. A bevy of literature concerning the role of macronutrients in growth and development is presented in the following paragraphs. © Springer Nature Singapore Pte Ltd. 2020. All rights reserved

The electrical and optical properties of liquid devices for adaptive optics

The use of adaptive optics (AO) for wavefront compensation other than for atmospheric turbulence is an emerging, exciting field. The required system specifications will obviously be dependent on the particular application, and indeed may not be well-characterized for many of the potential uses. Liquid crystal spatial light modulators (LC-SLMs) are also an emerging technology within the field of AO. With this in mind we present here a summary of the specifications of both currently available and predicted LC-SLMs which may be used as wavefront correctors, and discuss how they may be particularly suited for use in non-astronomical AO systems.</jats:p

A wide-field K-band survey — I. Galaxy counts in B, V, I and K

We present bright galaxy number counts measured with linear detectors in the B, V, I, and K bands in two fields covering nearly 10 square degrees. All of our measurements are consistent with passive evolution models, and do not confirm the steep slope measured in other surveys at bright magnitudes. Throughout the range 16 < B < 19, our B-band counts are consistent with the "high normalization" models proposed to reduce the faint blue galaxy problem. Our K-band counts agree with previous measurements, and have reached a fair sample of the universe in the magnitude range where evolution and K-corrections are well understood.Comment: Accepted for publication in MNRAS. 5 pages in LaTex, including 4 postscript figures, requires mn.sty and epsf.sty. Postscript version available from ftp://star-ftp.dur.ac.uk/pub/preprints/bviknumct.ps.g

High Quality Liquid Crystal Spatial Light Modulators for Adaptive Optics

Our work involves investigating adaptive wavefront correctors which may be used as alternatives to the deformable mirror in an adaptive optics system. Liquid crystal spatial light modulators (LC–SLMs) have several advantages over deformable mirrors, and also some problems of their own, as discussed in ref [1]. Much of the past work on LCs has centered around using modified LG displays which were not designed as high quality optical elements. In this paper we describe results produced using a LC-SLM which was designed specifically for wavefront correction and shaping.</jats:p