Mechanism of Sunlight Damage on Drip Tape by Pendant Droplets in Mulched Drip Irrigation

2018 ◽  
Vol 61 (6) ◽  
pp. 1969-1975
Author(s):  
Yan Mo ◽  
Guangyong Li ◽  
Dan Wang ◽  
Jiandong Wang ◽  
Haidong Chai ◽  
...  
Keyword(s):  
Drip Irrigation ◽  
Focal Length ◽  
Contact Angles ◽  
Geometric Parameters ◽  
Plastic Mulch ◽  
Light Gathering Power ◽  
Hydrophobic Materials ◽  
Length Range ◽  
Light Gathering ◽  
Clear Plastic

Abstract. Drip irrigation under mulch has been applied in China for nearly 20 years, but sunlight damage from the lens effect through droplets beneath clear plastic mulch is always a problem that cannot be ignored. Droplet volume and mulch wettability affect the geometric parameters of the pendant droplets. Changes in geometric parameters were experimentally investigated by analyzing side-view images of droplets. Models were built to predict droplet focal length and light-gathering power based on the geometric parameters. A comparison between numerical and optical experimental results suggested that the focal length model was accurate and reliable. The effective incident area of the parallel light proposed in this study could also be used to represent the light-gathering power, which had a relationship with the drip tape burning rate. The increase in wettability of the clear mulch considerably increased the focal length of the pendant droplets, expanded the focal length range, enhanced the light-gathering power, and thus increased the risk of drip tape burning. In practice, pendant droplets with a wetting radius of 3 to 5 mm, with corresponding focal lengths of 5 to 12 mm, have a high probability of emergence. Therefore, the distance between the mulch and drip tape should be beyond this focal length range to reduce the risk of drip tape burning by pendant droplets. In addition, filming the mulch surface with hydrophobic materials to increase the contact angles of droplets can also protect the drip tape from sunlight damage. Keywords: Drip irrigation under mulch, Drip tape burning, Effective incident area of parallel light, Focal length, Pendant droplet.

Effect of Irrigation Methods and Mulching on Growth and Seed Yield of Semialata

2020 ◽  
Vol 7 (01) ◽  
Author(s):  
SK SRIVASTAVA ◽  
PAWAN JEET
Keyword(s):  
Seed Yield ◽  
Drip Irrigation ◽  
Growth Parameters ◽  
Block Design ◽  
Water Requirement ◽  
Furrow Irrigation ◽  
Plastic Mulch ◽  
Randomized Block Design ◽  
Daily Water ◽  
Black Plastic

A study was conducted to assess the effect of drip irrigation and plastic mulch on growth and seed yield of Semialata. Two types of plastic mulch (green and silver/black) were tested at three levels of irrigation (120%, 100% and 80%) by drip irrigation and one level (100%) by furrow irrigation. The daily water requirement of Semialata was estimated by the equation ETcrop= ETox crop factor. ETcrop is crop water requirement mm/day. ETo (reference evapotranspiration, mm/day) was calculated by FAO calculator which uses temperature and humidity data. In this experiments there were twelve treatments were considered. The treatments were replicated thrice. The experiment was laid in randomized block design. It was observed that drip irrigation with or without plastic mulch is yielding better results in terms of growth parameters and seed yield as compared to furrow irrigation without plastic mulch. It was also observed that maximum suppression (67.58%) of weeds resulted with drip irrigation and silver/black plastic mulch at 80% level of irrigation.

scholarly journals Design of spherical aberration free liquid-filled cylindrical zoom lenses over a wide focal length range based on ZEMAX

2020 ◽  
Vol 28 (5) ◽  
pp. 6806 ◽  
Author(s):  
Licun Sun ◽  
Shuwu Sheng ◽  
Weidong Meng ◽  
Yuanfangzhou Wang ◽  
Quanhong Ou ◽  
...  
Keyword(s):  
Spherical Aberration ◽  
Focal Length ◽  
Length Range

scholarly journals Effect of plastic mulch, drip irrigation and fertigation on vegetative growth and chemical attributes of guava in Tarai region

2019 ◽  
Vol 7 (6) ◽  
pp. 214-218
Author(s):  
Manpreet Singh Preet ◽  
Rajesh Kumar ◽  
VP Singh ◽  
Jitendra Kumar ◽  
AK Singh ◽  
...  
Keyword(s):  
Drip Irrigation ◽  
Vegetative Growth ◽  
Plastic Mulch ◽  
Chemical Attributes

Measurement of contact angles of microscopic droplets by focal length method

2017 ◽  
Vol 88 (8) ◽  
pp. 083701
Author(s):  
Daniel Geiger ◽  
Kirsten Geiger ◽  
Tobias Neckernuss ◽  
Othmar Marti ◽  
Masoud Amirkhani
Keyword(s):  
Focal Length ◽  
Contact Angles

Effect of plastic mulch and row covers on photosynthesis and yield of watermelon

2005 ◽  
Vol 45 (12) ◽  
pp. 1653 ◽  
Author(s):  
L. Ibarra-Jiménez ◽  
J. Munguía-López ◽  
A. J. Lozano-del Río ◽  
A. Zermeño-González
Keyword(s):  
Total Yield ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Bare Soil ◽  
Plastic Mulch ◽  
Row Covers ◽  
Number Of Leaves ◽  
Clear Plastic ◽  
Black Plastic ◽  
Growing Conditions

The effect of row covers on watermelon (Citrullus vulgaris) grown on plastic mulch is well documented. However, row covers have not been adequately evaluated under Mexican growing conditions. Watermelon plants were grown on plastic mulch alone or with row covers to study their effect on photosynthesis, and early and total yields. Treatments were clear plastic mulch (C); black plastic mulch (B); B plus a Vispore cover of polypropylene (BV); B plus a white cover of perforated polyethylene (BW); B plus a clear cover of perforated polyethylene (BC); B plus an Agribon cover of polypropylene (BA); and bare soil as the control. For plants grown in treatment C, B or B combined with row covers, plant dry weight and number of leaves 40 days after seeding (DAS) were higher than the control (P<0.05), except BC which was comparable to the control. Total yields of treatments C, B, BV, BW and BA differed (P<0.05) from BC and the control. Total yields increased by 46.1, 43.2, 35.7, 41.6, 13.3, 15.4 and 35.8 t/ha for the C, B, BV, BW, BC and BA treatments, respectively, over the control, which yielded 27.1 t/ha. Total yield was highest for the C and the B treatment suggesting that there was no need for additional covers. The number of leaves per plant or dry weight per plant better explains the changes in yield than net photosynthesis rate. Stomatal conductance was explained in part by changes in photosynthesis.

Merging Data from Large and Small Telescopes – Good or Bad? And: How Useful is the Application of Statistical Weights to Time-Series Photometric Measurements?

2003 ◽  
Vol 12 (2) ◽  
Author(s):  
G. Handler
Keyword(s):  
Fourier Transforms ◽  
Light Curves ◽  
Data Sets ◽  
Effective Number ◽  
Spectral Window ◽  
Light Gathering Power ◽  
Data Weighting ◽  
Light Gathering ◽  
Data Points ◽  
Photometric Measurements

AbstractI have investigated the value of the contribution of small telescopes to the success of a whole WET run. To this end, I have applied different data weighting schemes to two extreme WET test data sets. I find that weights proportional to the inverse local scatter in the light curves produce Fourier Transforms of best signal-to-noise. Weighting data stronger than their inverse scatter does not yield optimal results because of the reduction of the effective number of data points.The contribution of the small telescopes to the combined WET results was found to be very important. They do not only improve the spectral window, but they can reduce the noise in the total FT by more than their light gathering power would imply. Some suggestions for the optimal use of small telescopes in the WET are given.

scholarly journals Water use efficiency of different production techniques for zucchini

2019 ◽  
Vol 41 (1) ◽  
pp. 42604
Author(s):  
Anita Cristina Costa da Silva ◽  
Willian Fernandes de Almeida ◽  
Luiz Antonio Lima ◽  
Mayra Carolina De Oliveira ◽  
Alexandre Lasmar Guimarães
Keyword(s):  
Water Use Efficiency ◽  
Factorial Design ◽  
Water Use ◽  
Drip Irrigation ◽  
Drip Line ◽  
First Year ◽  
Line Position ◽  
Plastic Mulch ◽  
Use Efficiency ◽  
Subsurface Drip

 The effects of pulse drip, drip line position and soil mulch on water use efficiency in yields of zucchini cv. Clarinda were evaluated. The experiment was conducted in the experimental area of the Engineering Department of the Federal University of Lavras, Lavras, Minas Gerais State, Brazil, for two years. For the first year of the experiment, the experimental design was a randomized block design with a 2 x 2 x 2 factorial design (continuous and pulse drip irrigation, surface and subsurface dripping, with and without plastic mulch), with four replications. For the second year of the experiment, the design was completely randomized in a 2 x 2 x 2 factorial design with eight treatments and five replications. In relation to the position of the drip line, the subsurface drip line was installed at a 0.15-m depth, and the soil mulch was made with double-sided plastic (white/black). The results indicated that pulse drip irrigation did not affect the yield of zucchini and that soil mulch increased the yield and water use efficiency. In terms of the drip line position, the subsurface drip line increased the yield in the first year, but it had no effect on water use efficiency.

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