Random Versus Systematic Arrangements in Non‐Latin Square Field Experiments

1955 ◽  
Vol 47 (7) ◽  
pp. 289-294 ◽  
Author(s):  
S. C. Salmon
2017 ◽  
Vol 66 (3) ◽  
pp. 360-366 ◽  
Author(s):  
Kolima Peña Calzada ◽  
Juan Carlos Rodríguez Fernández ◽  
Martín Santana Sotolongo ◽  
Dilier Olivera Viciedo ◽  
Cesar Danilo Valle Expósito ◽  
...  

In order to evaluate the effect of a growth promoter on the productivity performance and seed-quality in bean (Phaseolus vulgaris L.) crops, two experiments were carried out, one in the field and under controlled conditions. In the field experiments, a Latin square design was used for four treatments as follows: control, 0.5, 0.8 and 1.0 l.ha-1, respectively, where yield components were evaluated. The seeds used in the controlled conditions experiment were from prior trials, in a totally randomized design, at the dosages above mentioned. Seed germination and seedling growth were evaluated. In the field experiments, the product had a stimulating effect on the production. The highest yields were reached with the 0.8 and 1.0 l.ha-1 dosages in number 1, with values of 3.09 and 3.02 t.ha-1, and in number 2, the treatment with the best results was 1.0 l.ha-1, with a yield of 2.07 t.ha-1. In germination, there were significant differences among variables only in the first assessment at three days after planting. The best performance in seedling growth and in dry matter production was the treatment with seeds from the 0.5 l.ha-1 dosage in experiment 1. In addition, in number 2, performance among variables was similar. Therefore, VIUSID agro improved the bean yield performance and did not affect later seed germination nor initial seedling growth.


1930 ◽  
Vol 20 (3) ◽  
pp. 399-406 ◽  
Author(s):  
F. E. Allan ◽  
J. Wishart

In cases of field experiments when one plot is missing, a method has been developed for furnishing an estimate of the yield of the missing plot, based on all the other values. The calculation is given for (a) a Randomised Block experiment, and (b) a Latin Square arrangement. In both cases the actual arithmetic is very simple.The steps in the procedure are:(1) Determine the desired value by an application of the equation (A) or (B) according as the experiment was arranged in Randomised Blocks or in a Latin Square.(2) Proceed as usual with the analysis of variance, using the estimated figure for the missing yield, and remembering to deduct one from the number of degrees of freedom ascribable to error.


1999 ◽  
Vol 133 (4) ◽  
pp. 427-431 ◽  
Author(s):  
R. J. LONG ◽  
S. K. DONG ◽  
X. B. CHEN ◽  
E. R. ØRSKOV ◽  
Z. Z. HU

Field experiments were conducted at the farm of Qinghai Academy of Animal and Veterinary Science, Xining, China during 1996/97 to determine the effects of level of food intake on the urinary excretion of purine derivatives (PD), creatinine and nitrogen in yaks (Bos grunniens). Two experiments were carried out with three female yaks (initial body weight 173–187 kg, age 5 years). For Expt 1 a 3×3 Latin square experimental design was used with three levels of oat hay (nitrogen 13·5 g/kg dry matter (DM)) intake treatments, i.e. 0·3, 0·6 and 0·9 of voluntary intake (1·3–3·5 kg DM/d). Each treatment lasted for 17 days and the samples were collected during the last 7 days of each period. For Expt 2 the animals were fed the same oat hay as in Expt 1 for 3 weeks at a level equivalent to the estimated energy maintenance requirement (M) (1·5–2·2 kg DM/d). The intake was then reduced to 0·6 M on day 1, 0·3 M on day 2 and zero from day 3 until day 10. The animals were re-fed in the reverse order for 3 days. Of the PD, only allantoin and uric acid were present in the urine. The proportions of allantoin and uric acid were 0·86 and 0·14 respectively for both experiments. There was no response of creatinine and nitrogen excretions to feed intake. The rates of PD excretion per kg digestible organic matter (DOM) or digestible dry matter (DDM) were 13·5 and 13·6 mmol respectively. As expected, urinary PD excretion increased significantly (P<0·001) with increasing intake of DDM and DOM. The daily fasting PD, creatinine and nitrogen excretions amounted to 0·22±0·02 (S.E.), 0·25±0·01 mmol/kg W0·75 and 314±24·2 mg/kg W0·75 respectively. The results suggest that it is possible to establish a method for estimating intestinal microbial protein flow based on PD excretion in yaks.


1938 ◽  
Vol 28 (2) ◽  
pp. 299-306 ◽  
Author(s):  
John Wishart

A recent paper by A. E. Brandt (1937) goes into the details of a type of design in field experimental procedure, where two or more factors are under examination, which has been much elaborated since 1928, when the first 2 × 2 × 2 experiment, involving two levels of each of three factors, nitrogen, potash and phosphate, was carried out at Woburn (Rothamst. Rep. 1927–8) with four-fold replication. Similar experiments, of the 3 × 2 × 2 type, had in fact been conducted at Rothamsted (Rep. 1925–6) two years earlier, but there was here the further complication that no differentiation was possible for two of the factors at one level (no manure) of the third. Details have been given by Fisher (1937) and Yates (1937) of, among others, experiments of the 2n and 3 × 2n types, and it may be said that the recent work has been in the direction of systematizing the lay-out and analysis of such experiments. Further features have been the device of confounding, which dates back to 1927 (Rothamst. Rep. 1927–8), i.e. it is almost contemporaneous with the first introduction by Fisher of randomized blocks and Latin square experiments, and the suggestion that replication may even be dispensed with entirely, a much more recent innovation. Confounding is a method of enlarging the number of blocks between which elimination of soil heterogeneity is possible by sacrificing information on certain of the higher-order interactions, which are considered unlikely to be real effects; with absence of replication an estimate of the experimental error is found by grouping together a number of these higher-order interactions.


1931 ◽  
Vol 21 (3) ◽  
pp. 547-573 ◽  
Author(s):  
T. Eden

1. A uniformity trial of 144 plots of mature tea plucked on 42 occasions is examined with a view to determining an adequate technique for field experiments.2. Yields are expressed as dry matter; the necessity for, and accuracy of, this procedure is examined.3. Using the latin square and statistical analysis of variance, a maximum diminution of error up to the plot sizes of acre is found; the elimination of positional variance is shown to be inferior to that generally obtained on annual crops in temperate climates, but this inferiority corresponds with similar experience on other tropical crops.


Author(s):  
M. Jose Yacaman

In the Study of small metal particles the shape is a very Important parameter. Using electron microscopy Ino and Owaga(l) have studied the shape of twinned particles of gold. In that work electron diffraction and contrast (dark field) experiments were used to produce models of a crystal particle. In this work we report a method which can give direct information about the shape of an small metal particle in the amstrong- size range with high resolution. The diffraction pattern of a sample containing small metal particles contains in general several systematic and non- systematic reflections and a two-beam condition can not be used in practice. However a N-beam condition produces a reduced extinction distance. On the other hand if a beam is out of the bragg condition the effective extinction distance is even more reduced.


2020 ◽  
Vol 36 (2) ◽  
pp. 296-302 ◽  
Author(s):  
Luke J. Hearne ◽  
Damian P. Birney ◽  
Luca Cocchi ◽  
Jason B. Mattingley

Abstract. The Latin Square Task (LST) is a relational reasoning paradigm developed by Birney, Halford, and Andrews (2006) . Previous work has shown that the LST elicits typical reasoning complexity effects, such that increases in complexity are associated with decrements in task accuracy and increases in response times. Here we modified the LST for use in functional brain imaging experiments, in which presentation durations must be strictly controlled, and assessed its validity and reliability. Modifications included presenting the components within each trial serially, such that the reasoning and response periods were separated. In addition, the inspection time for each LST problem was constrained to five seconds. We replicated previous findings of higher error rates and slower response times with increasing relational complexity and observed relatively large effect sizes (η2p > 0.70, r > .50). Moreover, measures of internal consistency and test-retest reliability confirmed the stability of the LST within and across separate testing sessions. Interestingly, we found that limiting the inspection time for individual problems in the LST had little effect on accuracy relative to the unconstrained times used in previous work, a finding that is important for future brain imaging experiments aimed at investigating the neural correlates of relational reasoning.


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