PRACTICAL USE OF NEIGHBOR METHODS AND ALTERNATIVES IN THE ANALYSIS OF FIELD TRIALS

1987 ◽  
Vol 67 (2) ◽  
pp. 477-489 ◽  
Author(s):  
M. R. BINNS

Neighbor methods for the analysis of field experiments are described with the minimum of mathematical detail. Using actual field data, two popular methods are compared with standard blocking, row and column elimination, and covariance analysis. It is shown that simple randomized block analysis is likely to give biased treatment effects when there is a fertility trend. For large experiments, row and column analysis is likely to be inferior to covariance analysis using well-chosen covariates. Neighbor analysis can be more precise than standard methods based on well-designed experiments with appropriate blocking. Situations where neighbor methods may not work well are suggested, but since the methods are easy to use they are recommended when fertility trends are suspected and a simple detective tool is required.Key words: Neighbor analysis, covariate analysis, lattice design, fertility trends

2010 ◽  
Vol 3 (1) ◽  
pp. 91 ◽  
Author(s):  
M. Kashif ◽  
M. I. Khan ◽  
M. Arif ◽  
M. Anwer ◽  
M. Ijaz

Two rice trials were conducted from 2005 to 2006 in rice research institute, Kala Shah Kako Pakistan to evaluate the efficiency of alpha lattice design in field experiments. The average standard error of difference between genotypes mean is used to calculate relative efficiency of alpha lattice design. Both experiments clearly identified the advantages of small blocks. The average gain in efficiency was 119% with maximum 128%. Mean ranks comparison for both randomized complete block and alpha lattice design were performed. It was observed that the ranks were not constant across the experiments. The results emphasize that the traditional randomized complete block designs (RCBD) should be replaced by alpha lattice in the agricultural field experiments when number of varieties to be tested in an experiment increases to more than five or ten. In such a situation finding a homogeneous block is quite difficult in field experiments.Keywords: Rice; Alpha lattice design; RCBD; Pakistan.© 2011 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi:10.3329/jsr.v3i1.4773                 J. Sci. Res. 3 (1), 91-95 (2011)


Author(s):  
R. N.F. Abdelkawy ◽  
A. Z. Turbayev ◽  
A. A. Soloviev

Twenty genotypes triticale were evaluated in an alpha lattice design and RCBD for eight characters to a comparison of the relative efficiency (RE) of alpha-lattice design and RCBD. Two experiments were analyzed according to alpha lattice design and RCB design. Average estimated (RE) was 12.97, 5.93, 21.79, 35.50, 21.53, 23.96 and 26.69% for number of plants / m2, tillering fertility, plant height (cm), spike length (cm), number of spikelets / spike, 1000-grain weight (g) and grain yield (g / m2), respectively, the high precision is obtained significantly to estimate treatment effects indicating that using an alpha lattice design in place of RCBD. Mean comparisons for both RCBD and alpha lattice design were performed and two designs confirmed to Dublet, Ulyana, 131/1656 and C259 genotypes were the highest yield (g / m2). Cluster analysis showed that genotypes were isolated into three principle groups and one of these contains one variety (Dublet). This variety was characterized by a high yield over two years. The results showed that alpha lattice more efficient and it can be used it instead of traditional RCB design in the agricultural field trials.


Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 789
Author(s):  
Klára Kosová ◽  
Miroslav Klíma ◽  
Ilja Tom Prášil ◽  
Pavel Vítámvás

Low temperatures in the autumn induce enhanced expression/relative accumulation of several cold-inducible transcripts/proteins with protective functions from Late-embryogenesis-abundant (LEA) superfamily including dehydrins. Several studies dealing with plants grown under controlled conditions revealed a correlation (significant quantitative relationship) between dehydrin transcript/protein relative accumulation and plant frost tolerance. However, to apply these results in breeding, field experiments are necessary. The aim of the review is to provide a summary of the studies dealing with the relationships between plant acquired frost tolerance and COR/LEA transcripts/proteins relative accumulation in cereals grown in controlled and field conditions. The impacts of cold acclimation and vernalisation processes on the ability of winter-type Triticeae to accumulate COR/LEA proteins are discussed. The factors determining dehydrin relative accumulation under controlled cold acclimation treatments versus field trials during winter seasons are discussed. In conclusion, it can be stated that dehydrins could be used as suitable indicators of winter survival in field-grown winter cereals but only in plant prior to the fulfilment of vernalisation requirement.


Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1269
Author(s):  
David K. Mfuti ◽  
Amanuel Tamiru ◽  
William D. J. Kirk ◽  
Adeyemi O. Akinyemi ◽  
Heather Campbell ◽  
...  

The potential of semiochemicals to lure insect pests to a trap where they can be killed with biopesticides has been demonstrated as an eco-friendly pest management alternative. In this study, we tested two recently characterized male-produced aggregation pheromones of the bean flower thrips Megalurothrips sjostedti (Trybom), namely (R)-lavandulyl 3-methylbutanoate (major) and (R)-lavandulol (minor), for their field efficacy. Moreover, compatibility of these pheromones and two other thrips attractants, Lurem-TR and neryl (S)-2-methylbutanoate, with the entomopathogenic fungus (EPF) Metarhizium anisopliae ICIPE 69 has been determined. Our study revealed that the M. sjostedti aggregation pheromones have dose-dependent antifungal effects on the EPF viability, but showed no fungistatic effect at a field-realistic dose for attraction of thrips. (R)-lavandulyl 3-methylbutanoate had similar antifungal effects as neryl (S)-2-methylbutanoate 8 days after exposure; whereas, Lurem-TR had a stronger antifungal effect than other thrips attractants. In the semi-field experiments, all autoinoculation devices maintained at least 86% viability of M. anisopliae conidia after 12 days of exposure. Field trials demonstrated for the first time that (R)-lavandulyl 3-methylbutanoate increases trap catches. Our findings pave a way for designing a lure-and-kill thrips management strategy to control bean flower thrips using autoinoculation devices or spot spray application.


Plant Disease ◽  
2019 ◽  
Vol 103 (8) ◽  
pp. 1991-1997 ◽  
Author(s):  
Xiaoxue Ji ◽  
Jingjing Li ◽  
Zhen Meng ◽  
Shouan Zhang ◽  
Bei Dong ◽  
...  

Gray mold caused by Botrytis cinerea can be a severe disease of tomato infecting leaves and fruits of tomato plants. Chemical control is currently the most effective and reliable method; however, application of fungicides has many drawbacks. The combination of biological control agents with newly developed fungicides may be a practicable method to control B. cinerea. Fluopimomide is a newly developed fungicide with a novel mode of action. Bacillus methylotrophicus TA-1, isolated from rhizosphere soil of tomato, is a bacterial strain with a broad spectrum of antimicrobial activities. Little information is currently available about the effect of fluopimomide and its integrated effect on B. cinerea. Therefore, laboratory, pot, and field experiments were carried out to determine the effects of fluopimomide alone and in combination with B. methylotrophicus TA-1 against gray mold on tomato. The in vitro growth of B. methylotrophicus TA-1 was unaffected by 100 mg liter−1 fluopimomide. Inhibition of B. cinerea mycelial growth was significantly increased under combined treatment of fluopimomide and B. methylotrophicus TA-1. In greenhouse experiments, efficacy against gray mold was significantly greater by an integration of fluopimomide and B. methylotrophicus TA-1 than by either alone; control efficacy of fluopimomide at 50 and 100 g ha−1 in combination with B. methylotrophicus TA-1 at 108 colony-forming units (cfu) ml−1 reached 70.16 and 69.32%, respectively, compared with the untreated control. In both field trials during 2017 and 2018, control efficacy was significantly higher for the combination of fluopimomide at 50 and 100 g ha−1 in combination with B. methylotrophicus TA-1 than for either treatment alone. The results from this study indicated that integration of the new fungicide fluopimomide with the biocontrol agent B. methylotrophicus TA-1 synergistically increased control efficacy of the fungicide against gray mold of tomato.


1986 ◽  
Vol 26 (6) ◽  
pp. 745 ◽  
Author(s):  
PA Taylor ◽  
SP Flett ◽  
RFde Boer ◽  
D Marshall

The period of susceptibility of potato tubers to powdery scab (Spongospora subterranea) was studied by inoculating potato plants with spores, or by watering plants in infested soil, at different stages of plant development in greenhouse conditions. Maximum susceptibility began about 1 week before the stage when 50% of stolons had swollen to at least 5-mm diameter (tuber set), and ended 3-4 weeks later. With holding irrigation water during this period reduced the severity of powdery scab by 65-75% in field experiments in 1981-82 and 1982-83, but had no apparent effect on disease severity in 3 out of 6 large-scale field trials during 1984-85.


2013 ◽  
Vol 93 (4) ◽  
pp. 619-625 ◽  
Author(s):  
K. F. Chang ◽  
S. F. Hwang ◽  
H. U. Ahmed ◽  
B. D. Gossen ◽  
G. D. Turnbull ◽  
...  

Chang, K. F., Hwang, S. F., Ahmed, H. U., Gossen, B. D., Turnbull, G. D. and Strelkov, S. E. 2013. Management strategies to reduce losses caused by fusarium seedling blight of field pea. Can. J. Plant Sci. 93: 619–625. Fusarium seedling blight can cause substantial reductions in the stand density of field pea in western Canada. In greenhouse experiments, emergence decreased and root rot severity rose with increasing inoculum density. In field trials in 2007 and 2008 near Edmonton, AB, seeding at different depths and seeding dates did not consistently affect emergence or yield in Fusarium-infested soils. In field experiments, emergence declined significantly with each increase in inoculum level. Also, seed yield were reduced at high levels of disease pressure. Treatment of seed with Apron Maxx improved emergence, nodulation and yield of treatments challenged with inoculum of F. avenaceum in both greenhouse and field experiments. This research demonstrates the need to prevent seedling blight and root rot through proper seed treatment.


2020 ◽  
Vol 13 (2) ◽  
pp. 235-246
Author(s):  
W.Q. Shi ◽  
L.B. Xiang ◽  
D.Z. Yu ◽  
S.J. Gong ◽  
L.J. Yang

Fusarium graminearum causes Fusarium head blight (FHB), a devastating disease that leads to extensive yield and quality loss in wheat and barley production. Integrated pest management (IPM) is required to control this disease and biofungicides, such as tetramycin, could be a novel addition to IPM strategies. The current study investigated in vitro tetramycin toxicity in Fusarium graminearum and evaluated its effectiveness for the control of Fusarium head blight FHB. Tetramycin was shown to affect three key aspects of Fusarium pathogenicity: spore germination, mycelium growth and deoxynivalenol (DON) production. The in vitro results indicated that tetramycin had strong inhibitory activity on the mycelial growth and spore germination. Field trials indicated that tetramycin treatment resulted in a significant reduction in both the FHB disease index and the level of DON accumulation. The reduced DON content in harvested grain was correlated with the amount of Tri5 mRNA determined by qRT-PCR. Synergistic effects between tetramycin and metconazole, in both the in vitro and field experiments were found. Tetramycin could provide an alternative option to control FHB.


<p>The purpose of this paper is the presentation of the results compiled from self weighing of household food waste and self filling of waste collection diaries that took place in Greece. A diary was compiled and given to 101 urban households in various areas of the country. The participants were asked to weigh and write down in the diary every food item wasted in their households for two full weeks (i.e., 14 days). The total per capita food waste generation in Greece is estimated to be 76.1 (±68.3) kg/inh.y. This figure is divided into the avoided food waste fraction which equals to 25.9 (±34.9) kg/inh.y, and the unavoidable fraction which is estimated to be 50.2 (±47.1) kg/inh.y. The use of diaries for recording food that is thrown away from households is a methodology that underestimates the food wasted in households because households tend to be cautious when they know that they have to weigh and report the amount of food that they throw away. The current research is the first of its kind, presenting actual field data for food waste generation by households in Greece.</p>


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