A Mathematical Model Of Reflectance And Transmittance Of Plant Leaves As A Function Of Chlorophyll Pigment Content

To obtain the maximum yield of winter wheat, it is necessary to further optimize the existing cultivation technologies in the direction of their adaptation to changing environmental conditions. One of the areas of adaptation of plants to adverse abiotic factors is the active functioning of the photosynthetic apparatus, which depends on the amount of nutrients introduced. The influence of fertilizer application on the condition of the pigment complex of winter wheat plants in the conditions of the Southern Steppe of Ukraine has been studied. Two varieties of winter wheat were selected for the study: Shestopalivka and Mason. The experiment scheme involved the application of fertilizers at sowing (K0; K12) and foliar treatment with various tank mixtures (urea; urea + magnesium sulfate; urea + magnesium sulfate + potassium monophosphate). The pigment content has been determined by grinding fresh leaves of winter wheat, followed by the addition of a solvent in the form of acetone. Measurements of pigments were performed using a spectrophotometer. According to the research results, it was established that before the foliar treatment the a-chlorophyll content and carotenoids was higher in the plant leaves of the Shestopalivka variety. At the same time, the b-chlorophyll content on the contrary was higher for plants of the Mason variety by 17%, which may be due to the adaptation of plants of this variety to lack of light. On the 3rd day after foliar treatment, a decrease in the pigment content in the plant leaves of all experimental variants has been observed, which was due to the active growth of the photosynthetic surface and a decrease in the total dry matter mass. There was no significant difference between the varieties of the content of photosynthetic pigments in this period. On the 10th day after foliar treatment, an increase in a- and b-chlorophyll content has been observed for both studied varieties, which may be the result of adaptation of the photosynthetic apparatus of winter wheat plants to lighting conditions. Foliar treatment of winter wheat plants with a tank mixture of urea with magnesium sulfate and potassium monophosphate contributed to a further increase in the content of a-chlorophyll by 12-23%, and b-chlorophyll by 5-37% depending on the variety compared to the control. The results of the research testify to the high efficiency of complex application of nitrogen-phosphorus-potassium fertilizers for foliar treatment of winter wheat plants in the BBCH 31 stage, both against the background of pre-sowing application of potassium fertilizers and without it.

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Research on Supporting Force of Several Models of Hydrophobic Plant Leaves

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.152-154.1112 ◽

2012 ◽

Vol 152-154 ◽

pp. 1112-1117

Author(s):

Qing Cheng Wang ◽

Xiao Dong Yang ◽

Guang Rui Shang ◽

Zhuo Juan Yang ◽

Guo Hua Cao ◽

...

Keyword(s):

Mathematical Model ◽

Contact Angle ◽

Water Surface ◽

Mechanical Analysis ◽

Contact Angles ◽

Adhesive Tape ◽

Plant Leaves ◽

Instrument Measuring ◽

Supporting Force ◽

The Mathematical Model

In this paper, the leaves of 5 kinds of hydrophobic plants including lotus, canna, green poplar, grape and pumpkin were selected, whose contact angles were 150.6º, 135.5 º, 110.4 º, 101.3 º and 94.8 º respectively by contact angle instrument measuring. These plant leaves were adhered to rectangular box by double-sided adhesive tape, as experimental model.The maximum supporting force of these models on water surface were measured by analytical balance, and the supporting force increases as contact angle, the dimple pressed by the model on water surface can increase its supporting force. Through mechanical analysis, the mathematical model of the supporting force was established, the relationship between depth of dimple and contact angle was analyzed by the mathematical model.

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Pigment Content in Plant Leaves as a Bio-Indicator of Adaptability to Growing Conditions

10.1201/9781003145424-14 ◽

2021 ◽

pp. 197-217

Author(s):

Eugene M. Lisitsyn

Keyword(s):

Pigment Content ◽

Plant Leaves ◽

Growing Conditions

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Ectodesmata as Revealed By Freeze-Etch Preparations of Plant Epidermal Cell Walls

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100072782 ◽

1973 ◽

Vol 31 ◽

pp. 468-469

Author(s):

N.C. Lyon ◽

W. C. Mueller

Keyword(s):

Electron Microscopy ◽

Acetic Acid ◽

Nitric Acid ◽

Oxalic Acid ◽

Light Microscopy ◽

Epidermal Cell ◽

Cell Walls ◽

Plant Viruses ◽

Plant Leaves ◽

Thin Sections

Schumacher and Halbsguth first demonstrated ectodesmata as pores or channels in the epidermal cell walls in haustoria of Cuscuta odorata L. by light microscopy in tissues fixed in a sublimate fixative (30% ethyl alcohol, 30 ml:glacial acetic acid, 10 ml: 65% nitric acid, 1 ml: 40% formaldehyde, 5 ml: oxalic acid, 2 g: mecuric chloride to saturation 2-3 g). Other workers have published electron micrographs of structures transversing the outer epidermal cell in thin sections of plant leaves that have been interpreted as ectodesmata. Such structures are evident following treatment with Hg++ or Ag+ salts and are only rarely observed by electron microscopy. If ectodesmata exist without such treatment, and are not artefacts, they would afford natural pathways of entry for applied foliar solutions and plant viruses.

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