scholarly journals Optimal Plot Dimensions for Performance Testing of Hybrid Potato in the Field

2021 ◽  
Author(s):  
Julia E. Stockem ◽  
George Korontzis ◽  
Stefan E. Wilson ◽  
Michiel E. de Vries ◽  
Fred A. van Eeuwijk ◽  
...  
Keyword(s):  
Potato Breeding ◽  
Tuber Yield ◽  
Performance Testing ◽  
Field Trials ◽  
Genetic Differences ◽  
Field Variation ◽  
Tuber Shape ◽  
Plot Size ◽  
Trial Field ◽  
New Varieties

Abstract Field trials to evaluate the performance of new varieties are an essential component of potato breeding. Besides the genetic differences, environmental factors can lead to variation in a trial. In variety trials, the observed differences amongst varieties should reflect genetic differences, without a large impact of the random or systematic variation in the field. One way to reduce within-field variation is to adjust the plot size and its shape in a trial. Two years of field trials in which individual plants in 90-plant plots of both diploid hybrid and tetraploid varieties were measured provided data to derive relationships between LSD% and plot size and shape. We provide a method to estimate the equations to calculate the expected variation when using different plot dimensions in a relatively homogeneous trial field for tuber yield, tuber volume, tuber count, tuber shape and the standard deviations of tuber volume and shape. Compared with the yield traits, the variation for tuber shape was relatively small. The effect of plot shape was minor. With these equations, breeders can determine what plot dimensions are needed to reach the desired precision for each trait.

scholarly journals Automating Uniformity Trials to Optimize Precision of Agronomic Field Trials

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1254
Author(s):  
Marcus Jones ◽  
Marin Harbur ◽  
Ken J. Moore
Keyword(s):  
Web Application ◽  
Unit Area ◽  
Field Trials ◽  
State University ◽  
Iowa State University ◽  
Plot Size ◽  
Maize Field ◽  
Process Uniformity ◽  
Field Plots ◽  
Uniformity Trials

Plot size has an important impact on variation among plots in agronomic field trials, but is rarely considered during the design process. Uniformity trials can inform a researcher about underlying variance, but are seldom used due to their laborious nature. The objective of this research was to describe variation in maize field trials among field plots of varying size and develop a tool to optimize field-trial design using uniformity-trial statistics. Six uniformity trials were conducted in 2015–2016 in conjunction with Iowa State University and WinField United. All six uniformity trials exhibited a negative asymptotic relationship between variance and plot size. Variance per unit area was reduced over 50% with plots 41.8 m2 in size and over 75% when using a plot size >111.5 m2 compared to a 13.9 m2 plot. Plot shape within a fixed plot size did not influence variance. The data illustrated fewer replicates were needed as plot size increased, since larger plots reduced variability. Use of a Shiny web application is demonstrated that allows a researcher to upload a yield map and consider uniformity-trial statistics to inform plot size and replicate decisions.

scholarly journals Modified Humic Substances as Soil Conditioners: Laboratory and Field Trials

Agronomy ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 150
Author(s):  
Natalia A. Kulikova ◽  
Alexander B. Volikov ◽  
Olga I. Filippova ◽  
Vladimir A. Kholodov ◽  
Nadezhda V. Yaroslavtseva ◽  
...  
Keyword(s):  
Humic Substances ◽  
Soil Aggregates ◽  
Field Tests ◽  
Performance Testing ◽  
Field Trials ◽  
Soil Conditioner ◽  
Model Soil ◽  
Substrate Induced Respiration ◽  
And Performance ◽  
Survival Of Seedlings

The paper is devoted to the development and performance testing of a soil conditioner based on leonardite humic substances (LHS) modified with 3-aminopropyltriethoxysilane (APTES). The modified HS were obtained by adding APTES to LHS solution at different mass ratios of LHS and APTES, followed by the investigation of siloxane structures using 31Si NMR spectroscopy. The Urbic Technosol was used as a model soil. The size and amount of water-stable soil aggregates were estimated using wet sieving and laser diffraction, respectively. Toxicity was evaluated by monitoring microbial substrate-induced respiration (SIR) and seedling bioassay. Laboratory column experiments demonstrated an increase in water-stability of the 3–5 mm soil aggregates after LHS-APTES application. Field tests showed an increase in the average weighted diameter of micro aggregates (from 59 to 73 μm) and water-stable macroaggregates (from 1.6 to 2.9 mm) due to the LHS-APTES amendment. A substantial increase in SIR from 5 to 9 mg CO2 (kg h)−1 was detected. Better survival of seedlings was observed. The obtained beneficial results indicate that APTES-modified HS can be successfully used as a soil conditioner. The formation of extended siloxane networks was suggested as the main mechanism of the observed improvement in the structure of the amended soils.

Season-Long Dose–Response of Potato to Sulfometuron

Weed Science ◽  
2007 ◽  
Vol 55 (5) ◽  
pp. 521-527 ◽  
Author(s):  
Pamela J. S. Hutchinson ◽  
Don W. Morishita ◽  
William J. Price
Keyword(s):  
Return Loss ◽  
Tuber Yield ◽  
Logistic Models ◽  
Field Trials ◽  
Tuber Quality ◽  
Initial Attempt ◽  
Single Degree Of Freedom ◽  
Net Return ◽  
Agronomic Practices ◽  
Effect Level

Field trials were conducted to determine potato response to parts per trillion (ppt) per weight concentrations of sulfometuron in soil. The herbicide was applied to achieve targeted, 0-d soil concentrations of 0, 7.5, 15, 30, 60, 120, 240, 480, and 960 ppt. Russet Burbank potatoes were planted immediately after application using standard agronomic practices. Based on midseason visual evaluations, root and tuber injury occurred with 0-d concentrations of only 7.5 ppt. Concentrations at or above 120 ppt caused a significant increase in number of tubers with deformities compared with the control. By the end of the growing season, 0-d concentrations between 120 and 240 ppt resulted in higher percentages of tubers with deformities, such as cracks, knobs, or folds. Using logistic models fit to U.S. No. 1 tuber yield and net return data, doses of 74, 156, and 324 ppt are predicted to result in 5, 10, and 20% U.S. No. 1 yield reductions, respectively. The model predicted a 20% net return loss, approximately $160/ha, occurring at 262 ppt, which is near the 240 ppt concentration determined by standard ANOVAs and means comparisons with single degree of freedom contrasts causing significant tuber quality and yield reductions in our study. Growers using the 240 ppt concentration as an indicator of a no-effect level would encounter actual losses too great to withstand. This modeling approach provides an initial attempt at giving growers the tools necessary for assessing potential losses.

Evaluating the EPA's Comparative Product Performance Testing Guidelines for Herbicides in Snap Bean (Phaseolus vulgaris)

1998 ◽  
Vol 12 (2) ◽  
pp. 215-222
Author(s):  
Robin R. Bellinder ◽  
Marija Arsenovic ◽  
Jonathan J. Kirkwyland ◽  
Russell W. Wallace
Keyword(s):  
Weed Control ◽  
Environmental Protection Agency ◽  
Performance Testing ◽  
Good Control ◽  
Field Trials ◽  
Weed Species ◽  
Snap Bean ◽  
Common Lambsquarters ◽  
Redroot Pigweed ◽  
Product Comparison

Following suggested guidelines developed by the Environmental Protection Agency (EPA), comparative snap bean herbicide performance field trials were conducted from 1993 to 1995 in New York. Data were obtained on crop injury, weed control, and weed biomass, and crop yield, quality, and losses during harvest. Trifluralin, EPTC, and pendimethalin applied preplant incorporated (PPI) and applications of metolachlor applied preemergence (PRE) provided less than adequate control of redroot pigweed, common lambsquarters, and hairy galinsoga. Cultivation improved weed control with PPI and PRE applications. Metolachlor + fomesafen PRE provided good control of hairy galinsoga, adequate redroot pigweed control, and marginal control of common lambsquarters. Fomesafen applied postemergence (POST), combinations of metolachlor applied PRE with fomesafen or bentazon applied POST, and fomesafen + bentazon applied POST adequately controlled the three weed species without cultivation. Herbicide treatments had little measurable impact on snap bean quality or losses during harvest. Information from product comparison trials may be useful in developing recommendations for growers but may prove less than adequate in providing data necessary for a thorough evaluation of the relative benefits of individual herbicides as intended by EPA guidelines. Difficulties were encountered in following the guidelines, and costs of conducting the product comparison trials for a single crop in one growing region exceeded $90,000 over 3 yr.

Yield response of barley germplasm to field variation in salinity quantified using the EM-38

1990 ◽  
Vol 30 (4) ◽  
pp. 551 ◽  
Author(s):  
PG Slavich ◽  
BJ Read ◽  
BR Cullis
Keyword(s):  
Soil Salinity ◽  
Field Trials ◽  
Yield Response ◽  
Soil Conditions ◽  
Yield Reduction ◽  
Field Variation ◽  
Secondary Salinisation ◽  
Salinity Response ◽  
Unit Increase ◽  
Barley Germplasm

Five field trials to screen a range of barley germplasm for tolerance to saline soil conditions were conducted on irrigation farms in southern New South Wales, in areas affected by secondary salinisation from shallow watertables. Three trials were located on heavy grey clay soils and 2 on red-brown earth soils. An electromagnetic soil conductivity meter (EM-38) was used to quantify the salinity of individual field plots. Cultivars were compared in terms of their grain yield response to soil salinity. Yields were significantly reduced by soil salinity at all sites except 1 on red-brown earth. Both genetic and site differences in salinity response were identified. The reduction in yield per unit increase in electrical conductivity of the saturated paste (EC,), averaged across sites, varied from 4.7% for Forrest to 6.6% for Schooner. However, the yield reduction per unit increase in EC,, averaged across cultivars, varied from 4.1% in a red-brown earth to 6.4% in heavy clays.

scholarly journals Effects of Crop Rotation and Biocontrol Amendments on Rhizoctonia Disease of Potato and Soil Microbial Communities

Agriculture ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 128 ◽  
Author(s):  
Robert P. Larkin ◽  
Marin T. Brewer
Keyword(s):  
Microbial Communities ◽  
Tuber Yield ◽  
Soil Microbial Communities ◽  
Stem Canker ◽  
Field Trials ◽  
Interactive Effects ◽  
Soil Microbial ◽  
Complex Interactions ◽  
Rhizoctonia Disease ◽  
Rotation Crops

Rotation crops and biocontrol amendments were investigated for suppression of Rhizoctonia solani on potato (Solanum tuberosum) and their interactive effects on soil microbial communities. Greenhouse trials were conducted to evaluate selected rotation crops, including barley, common and “Lemtal” ryegrass, clover, potato, and combinations of barley with ryegrass or clover, for their effects on populations of R. solani and Rhizoctonia disease. Potato and clover preceding potato resulted in higher disease severity than most other rotations, whereas ryegrass reduced stem canker severity. In addition, all ryegrass treatments resulted in substantially higher populations of R. zeae. Field trials evaluating selected biocontrol treatments in combination with different rotations were conducted at two locations in Maine. Potatoes were treated with the biocontrol organisms Laetisaria arvalis, Trichoderma virens, or Bacillus subtilis and planted following rotation crops of barley and ryegrass, barley and clover, or potato. The barley/ryegrass rotation significantly reduced incidence and severity of stem canker and increased tuber yield at one location. Efficacy of the biocontrol treatments varied by rotation and location, with L. arvalis and T. virens reducing black scurf in some rotations and increasing some aspects of tuber yield at one location. Soil microbial community characteristics differed among rotation crops and biocontrol treatments. Significant crop by biocontrol interactions were observed demonstrating the complex interactions among rotation crops, biocontrol treatments, and soil microbial communities, as well as indicating that biocontrol can be enhanced within beneficial rotations.

scholarly journals Characterisation of resistance genes resources against late blight available for Czech potato breeding by means of selected DNA markers

2011 ◽  
Vol 51 (No. 2) ◽  
pp. 82-86 ◽  
Author(s):  
P. Sedlák ◽  
P. Vejl ◽  
M. Melounová ◽  
P. Křenek ◽  
J. Domkářová ◽  
...  
Keyword(s):  
Resistance Genes ◽  
Dna Markers ◽  
Marker Assisted Selection ◽  
Potato Breeding ◽  
Potato Research ◽  
Plant Production ◽  
Potato Chromosome ◽  
Research Institutes ◽  
New Varieties ◽  
Developing Area

Marker assisted selection (MAS) in potato breeding is the most developing area at present time. Methods of DNA markers are developed in all top world potato research institutes and universities oriented on plant production. This paper presents results obtained from the testing of gene resources encompassing different resistance genes against Phytophthora infestans potentially exploitable for Czech potato breeding. Three different DNA markers were studied that are linked to R1 locus in the potato chromosome V operating as a resistance against some races of P. infestans. Markering capability and frequencies of these markers was evaluated with respect to their usage in practical Czech plant breeding that has vital importance in finding the tools as a prerequisite for creating new varieties efficiently.

scholarly journals PLOT SIZE AND SHAPE FOR FIELD TRIALS WITH FORAGE CACTUS PEAR

2021 ◽  
Vol 39 (2) ◽  
pp. 334-349
Author(s):  
Bruno Vinícius Castro GUIMARÃES ◽  
Sérgio Luiz Rodrigues DONATO ◽  
Ignacio ASPIAZÚ ◽  
Alcinei Místico AZEVEDO ◽  
Abner José de CARVALHO
Keyword(s):  
Soil Heterogeneity ◽  
Field Trials ◽  
Production Cycle ◽  
Index Number ◽  
Cactus Pear ◽  
Area Index ◽  
Size And Shape ◽  
Plot Size ◽  
Relative Information ◽  
Federal Institute

This study aimed to determine the size and shape of experimental plots that provide maximum precision using relative information method. This trial was conducted at the Federal Institute of Bahia. Plant height, cladode length, cladode width, cladode thickness, cladode area, cladode area index, number of cladodes, cladode total area and yield were measured in the third production cycle, 930 days after planting. The plants, defined as basic units, were arranged in 39 plot sizes so that the crop would fill the whole experimental area. Then, plot shapes with higher relative information and equal plot size in basic units were selected. The experimental plot with eight basic units in size ensures higher efficiency in the experimental evaluation. This combination between size and shape, besides meeting all evaluation requirements of the characteristics normally assessed in studies with forage cactus pear, has the maximum control of soil heterogeneity, thereby decreasing experimental error and significantly increasing precision.

scholarly journals Optimum Plot Size for Field Trials of Taro (Colocasia esculenta)

HortScience ◽  
2013 ◽  
Vol 48 (4) ◽  
pp. 435-443 ◽  
Author(s):  
Susan C. Miyasaka ◽  
Charles E. McCulloch ◽  
Graham E. Fogg ◽  
James R. Hollyer
Keyword(s):  
Linear Relationship ◽  
Statistical Power ◽  
Unit Cost ◽  
Field Trials ◽  
Colocasia Esculenta ◽  
Test Plot ◽  
Plot Size ◽  
Maximum Curvature ◽  
Natural Logarithm ◽  
Maximum Test

Taro (Colocasia esculenta L. Schott) is a root crop widely grown in the Tropics. To determine the optimum plot size for taro field trials, fresh and dry weights of individual corms were collected from two field trials conducted under flooded culture and two conducted under upland culture. For a given maximum test plot with a single border row surrounding inner measured plants, all possible combinations of smaller plot sizes were investigated. A plot size was defined as a given number of adjacent plants. A strong linear relationship was found between the natural logarithm of variance of yield and the natural logarithm of plot size. Expressed on the non-log-transformed scale, the point of maximum curvature in this relationship indicates a sudden decrease in advantage to larger plot sizes and is taken as optimum. Calculating maximum curvature mathematically, optimum plot size was 21 inner plants (5.7 m2) for the second flooded trial and 18 inner plants (4.9 m2) for the second upland trial. Another method of estimating optimum plot size minimized the cost per unit of research data by using the index of degree of correlation between neighboring plots. In three of four trials, the optimum plot size ranged from 16 to 24 inner plants (4.3 to 6.5 m2). In this second method, we calculated a non-linear relationship between plot size and outer border plants to estimate the fixed and per-unit cost of a single border row surrounding the inner measured plants. Both methods of calculating optimal plot size sometimes resulted in estimates that exceeded the maximum test plot size for particular field trials, indicating limitations of each method and the importance of managing field trials to ensure uniformity across treatments. No evidence of spatial autocorrelation was found in the corm yield of taro, indicating that the two methods used were adequate in calculating optimum plot size. In addition, we conducted an analysis based on statistical power but found that plot size did not materially affect the power to detect differences between treatments. To our knowledge, this is the first report of optimum plot size for field trials of taro.

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