Branched ears in wheat and yield determination

1972 ◽  
Vol 23 (4) ◽  
pp. 541 ◽  
Author(s):  
HM Rawson ◽  
KN Ruwali
Keyword(s):  
Unit Area ◽  
Field Conditions ◽  
Spikelet Number ◽  
Yield Production ◽  
Yield Determination ◽  
Very High

Differentiation of the branched ear of a semidwarf mutant wheat is described for plants grown under irrigated field conditions, and compared with cultivars bearing simple ears. With a very high spikelet number per ear (more than SO), and few grains per spikelet (a maximum of three), the branched ear offers a radically different concept for yield production. Yields per unit area of the current branched material were not as high as for Kalyan Sona, India's premier variety, but did exceed those for Late Mexico 120. Better yields could be expected if the random sterility of spikelets within the branched ear, first apparent early in spikelet differentiation, were reduced. However, individual fertile ears filled up to 128 grains weighing 4.8 g in the better plants.

Land for Food & Land for Nature?

Daedalus ◽  
2015 ◽  
Vol 144 (4) ◽  
pp. 57-75 ◽  
Author(s):  
Andrew Balmford ◽  
Rhys Green ◽  
Ben Phalan
Keyword(s):  
Ecosystem Services ◽  
Empirical Evidence ◽  
Wild Species ◽  
Unit Area ◽  
Environmental Externalities ◽  
Natural Habitats ◽  
Land Sparing ◽  
Yield Production ◽  
The Cost ◽  
Coupling Yield

Opinions on how to limit the immense impact of agriculture on wild species are divided. Some think it best to retain as much wildlife as possible on farms, even at the cost of lowering yield (production per unit area). Others advocate the opposite: increasing yield so as to limit the area needed for farming, and then retaining larger areas under natural habitats. Still others support a mixture of the two extremes, or an intermediate approach. Here we summarize a model designed to resolve this disagreement, and review the empirical evidence available to date. We conclude that this evidence largely supports the second, so-called land-sparing approach to reconciling agriculture and biodiversity conservation, but that important questions remain over the generality of these findings for different biota and for ecosystem services, how best to increase yields while limiting environmental externalities, and whether there are effective, socially just, and practical mechanisms for coupling yield growth to habitat retention and restoration.

scholarly journals Skin friction of the wind on the Earth's surface

1916 ◽  
Vol 92 (637) ◽  
pp. 196-199 ◽  
Keyword(s):  
Flat Plate ◽  
Skin Friction ◽  
Solid Surface ◽  
Unit Area ◽  
Tangential Force ◽  
Mean Velocity ◽  
Small Surface ◽  
The Mean ◽  
General Velocity ◽  
Very High

The mechanism by means of which momentum is transmitted to a solid surface, in order that it may exert a drag on a fluid flowing past it, is at present understood only very imperfectly. It seems certain, however, that the law of dynamical similarity is applicable to skin friction; if therefore it were possible to measure the tangential force exerted by the wind as it blows over a large tract of land, it should be equal to the skin friction on a similar small surface when subjected to the action of the very high wind which would correspond with the same value of l V/ v . In reducing the tract of land to a similar small flat plate, the trees and houses would be reduced to a mere roughness on the plate. It is to be expected therefore that, if the skin friction on unit area of the earth's surface be expressed in the form F = kp Q 2 s , (1) Q s being the wind velocity near the surface and p the density of air, the constant k will be the same as the constant which would be found in the laboratory by experimenting with a small, slightly roughened plate, if a sufficiently high value of l V/ v , could be obtained. It should be noticed, however, that the velocity which should be compared with is the velocity close to the solid surface and not the general velocity of the air in the case of a flat plate, or the mean velocity over a cross section in the case of flow in a pipe.

scholarly journals Climate Data to Predict Geometry of Cracks in Expansive Soils in a Tropical Semiarid Region

2022 ◽  
Vol 14 (2) ◽  
pp. 675
Author(s):  
Jacques Carvalho Ribeiro Filho ◽  
Eunice Maia de Andrade ◽  
Maria Simas Guerreiro ◽  
Helba Araujo de Queiroz Palácio ◽  
José Bandeira Brasil
Keyword(s):  
Environmental Factors ◽  
Potential Evapotranspiration ◽  
Expansive Soils ◽  
Clay Content ◽  
Field Conditions ◽  
Semiarid Region ◽  
Climate Change Scenarios ◽  
Climate Data ◽  
Morphometric Characteristics ◽  
Very High

The nonlinear dynamics of the determining factors of the morphometric characteristics of cracks in expansive soils make their typification a challenge, especially under field conditions. To overcome this difficulty, we used artificial neural networks to estimate crack characteristics in a Vertisol under field conditions. From July 2019 to June 2020, the morphometric characteristics of soil cracks (area, depth and volume), and environmental factors (soil moisture, rainfall, potential evapotranspiration and water balance) were monitored and evaluated in six experimental plots in a tropical semiarid region. Sixty-six events were measured in each plot to calibrate and validate two sets of inputs in the multilayer neural network model. One set was comprised of environmental factors with significant correlations with the morphometric characteristics of cracks in the soil. The other included only those with a significant high and very high correlation, reducing the number of variables by 35%. The set with the significant high and very high correlations showed greater accuracy in predicting crack characteristics, implying that it is preferable to have fewer variables with a higher correlation than to have more variables of lower correlation in the model. Both sets of data showed a good performance in predicting area and depth of cracks in the soils with a clay content above 30%. The highest dispersion of modeled over predicted values for all morphometric characteristics was in soils with a sand content above 40%. The model was successful in evaluating crack characteristics from environmental factors within its limitations and may support decisions on watershed management in view of climate-change scenarios.

Analysis of a Uniformity Trial on Cassava

1968 ◽  
Vol 4 (2) ◽  
pp. 135-141
Author(s):  
Biyi Afonja
Keyword(s):  
Coefficient Of Variation ◽  
Unit Area ◽  
Plot Size ◽  
Methods Of Analysis ◽  
Area Basis ◽  
Very High

SummaryThe analysis of a uniformity trial on cassava is briefly discussed, mentioning possible effects of plant losses on the methods of analysis. Two methods of calculating comparable variances, on a per plant and per unit area basis, gave very high values for the index of heterogeneity, with a mean of 0·94. When the ratio of overall cost per plot to cost per unit area lies between one and two, an optimum plot size of between 16 and 32 plants is obtained. The comparable plot sizes would range from 192 to 385 sq. ft and give a coefficient of variation less than twenty.

scholarly journals Evaluation of different wheat cultivars under salinity stress

2018 ◽  
Vol 10 (1) ◽  
pp. 479-481
Author(s):  
Balkaran Singh Sandhu ◽  
Nirmaljit Singh Dhaliwal
Keyword(s):  
Grain Yield ◽  
High Salinity ◽  
Unit Area ◽  
Triticum Aestivum L ◽  
Well Water ◽  
Wheat Cultivars ◽  
Experimental Site ◽  
Saline Irrigation ◽  
Salinity Condition ◽  
Very High

A field experiment was conducted to study the response of different 11 wheat (Triticum aestivum L.) cultivars under saline condition and by applying saline irrigation water during rabi 2016-17 at Krishi Vigyan Kendra, Sri Muktsar Sahib (Punjab). Experiment site was chosen with high salinity condition (EC=1.87 dS/m) to check the response of particular cultivars in these conditions. The field was only irrigated with tube well water having very high EC (4630 micro mhos/cm). Results showed that the grain yield was recorded higher in KH 65 (5648 kg/ha), KRL 210 (5440 kg/ha), KRL 386 (5290 kg/ha) and DBW 246 (5048 kg/ha) as compared to lower grain yield recorded with KRL 384 (4353 kg/ha), KRL 19 (4423 kg/ha), KRL 370 (4538 kg/ha), DBW 248 (4608 kg/ha),WH 1316 (4838 kg/ha), DBW 247 (4860 kg/ha) and KRL 377 (4895 kg/ha). The experimental site was slightly saline in nature, so the cultivar KH 65, KRL 210, KRL 386 and DBW 246 are very suitable for the area as these were less affected due to salinity. Grain yield among these varieties were higher due higher number of effective tiller per unit area and due to large number of grains per ear. Whereas, KH 65, KRL 377 and KRL 386 also produced significantly higher straw yield from WH 1316, DBW 248, DBW 247, KRL 210, KRL 384, DBW 246, KRL 370 and KRL 19.

scholarly journals Compact and Integrated High-Power Pulse Generation and Forming System

Energies ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 99
Author(s):  
Mikołaj Nowak ◽  
Kazimierz Jakubiuk ◽  
Daniel Kowalak ◽  
Marek Pikoń ◽  
Józef Czucha ◽  
...  
Keyword(s):  
Experimental Research ◽  
High Power ◽  
Pulse Generation ◽  
Field Conditions ◽  
Design Stage ◽  
Power Pulse ◽  
Flux Compression ◽  
Explosive Forming ◽  
Very High ◽  
High Power Pulse

This paper presents comprehensive analytical, numerical and experimental research of the compact and integrated high-power pulse generation and forming system based on the flux compression generator and the electro-explosive forming fuse. The paper includes the analysis of the presented solution, starting from the individual components studies, i.e., the separate flux compression generator tests in field conditions and the forming fuse laboratory test, through the formulation of the extended quasi-empirical components models aimed at enabling their optimal parameters determination at the early design stage and ending with the description of the integrated system studies in field conditions. Based on detailed research, it was possible to achieve very high parameters of the generated pulses, i.e., overvoltages of up to 340 kV with the available source power reaching 25 GW. A very high convergence of the simulation and the results of experimental research has been obtained. The parameters of the presented system have been compared with other literature solutions and the selected topology of the high power pulse generation and forming system has been distinguished against other available ones, e.g., based on Marx generators and forming lines.

scholarly journals Effective Cutting Methods and Media for Hardwood Cuttings in `Sunaga Wase' Peaches

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 497D-497
Author(s):  
Kyong Ho Lim ◽  
Wol Soo Kim ◽  
Hyung Kee Lim ◽  
Byeong Sam Kim
Keyword(s):  
Prunus Persica ◽  
Tree Height ◽  
Field Conditions ◽  
Bottom Part ◽  
Trunk Diameter ◽  
Survival Percentage ◽  
Bottom Heating ◽  
The Media ◽  
Nursery Trees ◽  
Very High

This experiment was carried out to investigate the effective cutting methods and media for hardwood cuttings in `Sunaga Wase' peach (Prunus persica L.). Using 1-year-old peach stems out of winter pruning, the cutting stems were procurred through several steps on 16 Feb. 1995 and 1996. i) Cut 30 cm in length by pruning scissors and bundled to 10 stems; ii) 1-cm bottom part of cutting stem dipped into IBA (1000 ppm solution) for 5 s and then powdering with Captan WP; iii) upper part of cutting stem coated with Topsin paste; iv) standing the bundled cutting stems in the cutting bench filled with cutting media; v) the temperature maintained at 20 ± 1°C under the level of cutting media by bottom heating and at 5 to 10°C above the media level. Among the cutting media, vermiculite showed the highest rooting percentage, as much as 93.2%, followed by Jiffy pot and rockwool cube. High transplanting survival percentage under field conditions was obtained by the treatment of vermiculite of media + cutting duration for 35 days. Although the treatment of cutting duration for 55 days showed very high percentage of rooting, such as 96.4% in vermiculite, 78.3% in Jiffy pots, and 83.3% of rockwool cube, their percentage of nursery survival after transplanting were reduced remarkably less than 10% in nursery fields covered with black polyethylene film. The nursery trees obtained from each treatment were characteristically 136 to 146 cm in tree height and 22.9 to 26.8 cm in trunk diameter.

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