An assessment of variation in Idaho fescue [Festuca idahoensis (Elmer)] in southern Alberta

2004 ◽  
Vol 84 (4) ◽  
pp. 1077-1084 ◽  
Author(s):  
K. W. May ◽  
W. D. Willms ◽  
Z. Mengli ◽  
T. J. Lysyk
Keyword(s):  
Genetic Variability ◽  
Environmental Variability ◽  
Large Range ◽  
Genetic Selection ◽  
Field Trials ◽  
Grazing Pressure ◽  
Grass Species ◽  
Test Location ◽  
Southern Alberta ◽  
Festuca Idahoensis

Idaho fescue (Festuca idahoensis Elmer) is a native grass species that has attracted interest for use in revegetation, reclamation and other applications. However, there is a serious shortage of commercially available seed and concern that germplasm used will not be adapted to the site. A component of adaptation is genetic variability that allows a species to occupy a greater range of environments. Field trials were conducted in southern Alberta to determine the genetic variability of phenotypic and performance characteristics among genotypes of Idaho fescue. Since grazing pressure may contribute to genetic selection and may therefore affect the variability within a population, we also compared genotypes taken from a heavily grazed paddock with those taken from a lightly grazed paddock. Forty-nine genotypes from three populations were randomly sampled in 1992, propagated vegetatively to produce plants for replicated trials and planted in four locations in 1993. Nine plant characteristics were observed from 1993 to 1997. Since the genotypes were grown in common environments, variation among them was assumed to be caused by genetic differences. All variables were affected (P < 0.05) by population, test location and year, while the effect of population was also influenced by test location and year for a few variables. While the Idaho fescue plants expressed differences (P < 0.05) among populations for all selected traits, they displayed considerable overlap in the range of values for all variables both within and among test locations. Therefore, while the populations may be different, individuals within populations exhibit common attributes over a large range. This suggests that sufficient genetic variability exists in all populations to allow successful establishment over a large range of environmental variability. Results from a secondary test suggest that selection pressure, induced by grazing, resulted in genotypes that were smaller in crown circumference, had less spring vigor, had shorter flowering tillers and produced less seed. However, this observation needs further validation with a more robust test. Key words: Morphology, genotypes, seed yield, winter kill, grazing response

An assessment of variation in foothills rough fescue [Festuca campestris (Rydb.)] in southern Alberta

2003 ◽  
Vol 83 (3) ◽  
pp. 541-550 ◽  
Author(s):  
K. W. May ◽  
W. D. Willms ◽  
Z. Mengli ◽  
T. J. Lysyk
Keyword(s):  
Genetic Variability ◽  
Environmental Variability ◽  
Field Trials ◽  
Collection Site ◽  
South Central ◽  
Test Location ◽  
Southern Alberta ◽  
Selected Traits ◽  
And Performance ◽  
Rough Fescue

The genetic diversity of native plants is thought to be an important consideration in the selection of appropriate material for reclamation. Field trials were c onducted in southern Alberta to determine the genetic variability, expressed through phenotypic and performance attributes, of several populations of foothills rough fescue [ Festuca campestris (Rydb.)] found in southern Alberta and south-central British Co lumbia. The objectives of this study were to determine the extent of genetic variability among plants of foothills rough fescue. Sixty-four plants from four populations were sampled in 1992, propagated vegetatively to produce clones for replicated trials a nd planted in four locations in 1993. Eleven plant characteristics, including phenotypic and performance variables, were observed from 1994 to 1997. Since the plants were grown in common environments, variations among them were assumed to be caused by gen etic differences. All variables were affected ( P < 0.05) by collection site and, with a few exceptions, test location, year and their two and three-way interactions. The most important factors specific to our objectives were collection site and its interact ions with test location and year. The rough fescue plants expressed differences ( P < 0.05) among populations for all selected traits but displayed considerable overlap in the range of values for all variables both within and among test sites. Therefore, wh ile the populations may be different, individuals within populations have common attributes that suggest sufficient genetic variability to allow successful establishment over a greater range of environmental variability than present at their origins. Resu lts from a secondary test suggest that selection pressure, induced by grazing, resulted in genotypes that were more winter-hardy. However, this observation needs further validation with a more robust test. Key words:

Evaluation and genetic analysis of common bean genotypes (Phaseolus vulgaris L.) at Dibatie and Mandura, Northwestern Ethiopia

2021 ◽  
Vol 7 (5) ◽  
pp. 82-90
Author(s):  
Gezahegn Tefera ◽  
Keyword(s):  
Genetic Variability ◽  
Common Bean ◽  
Coefficient Of Variation ◽  
Environmental Variability ◽  
Genetic Constitution ◽  
Genetic Advance ◽  
Breeding Programs ◽  
Days To Flowering ◽  
Lattice Design ◽  
Component Traits

Assessing and understanding the variations existing in crops due to genetic composition and environmental variability is very important in order to exploit the genetic constitution of crop plants. To this aim, variability measures such as phenotypic coefficient of variation (PCV) and genotypic coefficient of variation (GCV) are commonly used. Heritability and genetic advance are major concerns for common bean to identify important traits for common bean genetic improvement. The field experiment was conducted at Mandura and Dibatie research substations working with sixteen genotypes of the common bean during 2017/2018 in lattice design with three replications to evaluate the performance of common bean genotypes and estimate the genetic variability. Heritability and genetic advance were estimated in relation to yield and its component traits for future breeding programs. Combined analysis of variance across locations revealed highly significant variations among genotypes for all traits under study. The PCV ranged from 3.36% for days to flowering to 15.91% for a number of pods per plant while the GCV value ranged from 0.75% for days to flowering to 13.74% for the number of pods per plant. Broad sense heritability values ranged from 5.00% for days to flowering to 84.61% for a hundred seed weight. Generally, the result of the study showed that significant genetic variability among tested genotypes and a simple selection for effective improvement of these traits. Keywords: common bean, genetic variability, genetic advance, heritability

scholarly journals Exploring the genetic variability and diversity of pearl millet core collection germplasm for grain nutritional traits improvement

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Mahalingam Govindaraj ◽  
Kedar N. Rai ◽  
Anand Kanatti ◽  
Hari D. Upadhyaya ◽  
Harshad Shivade ◽  
...  
Keyword(s):  
Genetic Variability ◽  
Pearl Millet ◽  
Core Collection ◽  
Germplasm Collection ◽  
Nutrient Content ◽  
Field Trials ◽  
Essential Nutrient ◽  
Micronutrient Malnutrition ◽  
Diverse Origin ◽  
Lower Magnitude

AbstractImproving essential nutrient content in staple food crops through biofortification breeding can overcome the micronutrient malnutrition problem. Genetic improvement depends on the availability of genetic variability in the primary gene pool. This study was aimed to ascertain the magnitude of variability in a core germplasm collection of diverse origin and predict pearl millet biofortification prospects for essential micronutrients. Germplasm accessions were evaluated in field trials at ICRISAT, India. The accessions differed significantly for all micronutrients with over two-fold variation for Fe (34–90 mg kg−1), Zn (30–74 mg kg−1), and Ca (85–249 mg kg−1). High estimates of heritability (> 0.81) were observed for Fe, Zn, Ca, P, Mo, and Mg. The lower magnitude of genotype (G) × environment (E) interaction observed for most of the traits implies strong genetic control for grain nutrients. The top-10 accessions for each nutrient and 15 accessions, from five countries for multiple nutrients were identified. For Fe and Zn, 39 accessions, including 15 with multiple nutrients, exceeded the Indian cultivars and 17 of them exceeded the biofortification breeding target for Fe (72 mg kg−1). These 39 accessions were grouped into 5 clusters. Most of these nutrients were positively and significantly associated among themselves and with days to 50% flowering and 1000-grain weight (TGW) indicating the possibility of their simultaneous improvement in superior agronomic background. The identified core collection accessions rich in specific and multiple-nutrients would be useful as the key genetic resources for developing biofortified and agronomically superior cultivars.

Weed Efficacy Evaluations for Bromoxynil, Glufosinate, Glyphosate, Pyrithiobac, and Sulfosate

2004 ◽  
Vol 18 (2) ◽  
pp. 443-453 ◽  
Author(s):  
Jerry L. Corbett ◽  
Shawn D. Askew ◽  
Walter E. Thomas ◽  
John W. Wilcut
Keyword(s):  
Field Trials ◽  
Grass Species ◽  
Annual Grass ◽  
Common Lambsquarters ◽  
Yellow Nutsedge ◽  
Giant Foxtail ◽  
Green Foxtail ◽  
Herbicide Treatments ◽  
Rate Controlled ◽  
Prickly Sida

Thirteen field trials were conducted in 1999 and 2000 to evaluate postemergence (POST) weed control with single applications of bromoxynil at 420 or 560 g ai/ha, glufosinate at 291 or 409 g ai/ha, glyphosate at 1,120 g ai/ha, pyrithiobac at 36 or 72 g ai/ha, or sulfosate at 1,120 g ai/ha. Additional treatments evaluated included two applications with glufosinate at both rates in all possible combinations, two applications of glyphosate, and two applications of sulfosate. Weeds were 2 to 5 cm or 8 to 10 cm tall for annual grass and broadleaf weeds whereas yellow nutsedge and glyphosate-resistant corn were 8 to 10 cm tall. All herbicide treatments controlled 2- to 5-cm common cocklebur, Florida beggarweed, jimsonweed, ladysthumb smartweed, Pennsylvania smartweed, pitted morningglory, prickly sida, redroot pigweed, smooth pigweed, and velvetleaf at least 90%. All herbicide treatments except pyrithiobac at either rate controlled 2- to 5-cm common lambsquarters, common ragweed, and tall morningglory at least 90%; pyrithiobac at the lower rate was the only treatment that failed to control entireleaf and ivyleaf morningglory at least 90%. Bromoxynil and pyrithiobac at either rate controlled 2- to 5-cm sicklepod 33 to 68% whereas glufosinate, glyphosate, and sulfostate controlled ≥99%. Glyphosate and sulfosate applied once or twice controlled hemp sesbania less than 70% and volunteer peanut less than 80%. Bromoxynil and pyrithiobac were the least effective treatments for control of annual grass species and bromoxynil controlled Palmer amaranth less than 80%. Glufosinate controlled broadleaf signalgrass, fall panicum, giant foxtail, green foxtail, large crabgrass, yellow foxtail, seedling johnsongrass, Texas panicum, and glyphosate-resistant corn at least 90% but controlled goosegrass less than 60%. Glyphosate and sulfosate controlled all grass species except glyphosate-resistant corn at least 90%. In greenhouse research, goosegrass could be controlled with glufosinate POST plus a late POST-directed treatment of prometryn plus monosodium salt of methylarsonic acid.

Measuring Light Interception and the Efficiency of Light Utilization by the Coconut Palm (Cocos nucifera)

1992 ◽  
Vol 28 (3) ◽  
pp. 273-285 ◽  
Author(s):  
J. R. J. Moss
Keyword(s):  
Cocos Nucifera ◽  
Genetic Selection ◽  
Efficiency Index ◽  
Field Trials ◽  
Light Interception ◽  
Dry Season ◽  
Potassium Fertilizer ◽  
Sole Cropping ◽  
One Year

SummaryA mobile sampling method was used to measure the amount of photosynthetically active radiation (PAR) transmitted through the canopies of coconut palms in two long term field trials. PAR transmissions were measured at approximately monthly intervals for one year. Fractional interception of light was found to vary considerably between months, and to be associated with frond shedding caused by dry season water stress. Palms receiving potassium fertilizer intercepted more light and replaced leaf area lost during the dry season more rapidly than those receiving no potassium. Palms planted at a higher density intercepted more light and carried more fronds per palm, but intercepted less light per frond than those planted at a lower density. The ratio of moles of carbohydrate yield to moles of intercepted PAR quanta was calculated for six plots of hybrid palms, giving a dimensionless light efficiency index (LEI) comparable to harvest index. Mean LEI for all plots was 1.275 × 10−4 and was found to increase with increased light interception, results suggesting that there is a basal level of light interception below which no yield is produced. The potential for using LEI in agronomic experimentation on sole cropping and multicropping and as a criterion for genetic selection of coconut palms is discussed.

Effect of seeding date and rate on desi chickpea in southern Alberta

2006 ◽  
Vol 86 (3) ◽  
pp. 717-721
Author(s):  
R. H. McKenzie ◽  
A. B. Middleton ◽  
E. Bremer
Keyword(s):  
Cicer Arietinum ◽  
Plant Density ◽  
Field Trials ◽  
Cicer Arietinum L ◽  
Seeding Date ◽  
Large Yield ◽  
Southern Alberta ◽  
Plant Densities ◽  
Seed Yields ◽  
Target Plant

Field trials were conducted at 12 location-years (sites) over a 4-yr period (2000–2003) to determine the response of desi chickpea (Cicer arietinum L.) to seeding date and rate in southern Alberta. Desi chickpea, cv. Myles, was planted on three dates at approximately 10-d intervals at target plant densities of 20, 40, 60, 80 and 100 plants m-2. Seed yields were close to maximum at seeding dates ranging from late April till mid-May, but further delays in seeding resulted in modest yield declines at two sites during the drought years and large yield declines at two sites in the wet year. The economic optimum plant density for desi chickpea increased with moisture availability, from 26 to 79 plants m-2. Under typical conditions in southern Alberta, optimum yields of chickpea were obtained with seeding dates prior to May 15 and seeding rates of 30 to 40 plants m-2. Key words: Cicer arietinum, yield, planting, sowing

scholarly journals Increased signal to noise ratios within experimental field trials by regressing spatially distributed soil properties as principal components.

2021 ◽  
Author(s):  
Jeffrey C Berry ◽  
Mingsheng Qi ◽  
Balasaheb V Sonawane ◽  
Amy Sheflin ◽  
Asaph Cousins ◽  
...  
Keyword(s):  
Soil Properties ◽  
Degrees Of Freedom ◽  
Environmental Variability ◽  
Plant Traits ◽  
Experimental System ◽  
Environmental Variation ◽  
Field Studies ◽  
Field Trials ◽  
Spatially Distributed ◽  
Sorghum Genotypes

Environmental variability poses a major challenge to any field study. Researchers attempt to mitigate this challenge through replication. Thus, the ability to detect experimental signals is determined by the degree of replication and the amount of environmental variation, noise, within the experimental system. A major source of noise in field studies comes from the natural heterogeneity of soil properties which create micro-treatments throughout the field. To make matters worse, the variation within different soil properties is often non-randomly distributed across a field. We explore this challenge through a sorghum field trial dataset with accompanying plant, microbiome and soil property data. Diverse sorghum genotypes and two watering regimes were applied in a split-plot design. We describe a process of identifying, estimating, and controlling for the effects of spatially distributed soil properties on plant traits and microbial communities using minimal degrees of freedom. Importantly, this process provides a tool with which sources of environmental variation in field data can be identified and removed, improving our ability to resolve effects of interest and to quantify subtle phenotypes.

scholarly journals Influence of phosphate on the botanical composition and on the grade of quality of herbage.

1959 ◽  
Vol 7 (1) ◽  
pp. 40-50 ◽  
Author(s):  
F. Sonneveld ◽  
A.A. Kruijne ◽  
D.M. De Vries
Keyword(s):  
Field Trials ◽  
Grass Species ◽  
Botanical Composition ◽  
Average Increase ◽  
Herbage Quality ◽  
Different Soils

Results of 115 field trials are tabulated in respect of the average increase in herbage quality (as defined by six grade classes) by P fertilizing in general, by increasing applications of 20-160 kg/ha P2O5, and by P dressings on different soils ranging from sands to peats. The response to P of various species of grasses and forbs, and the P status of soils (five classes of 0-20 to >80 citric solubility) in relation to herbage quality and frequency of different grass species are also discussed. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Cinmethylin for Weed Control in Soybeans,Glycine max

Weed Science ◽  
1988 ◽  
Vol 36 (5) ◽  
pp. 678-682 ◽  
Author(s):  
Prasanta C. Bhowmik
Keyword(s):  
Glycine Max ◽  
Adverse Effects ◽  
Weed Control ◽  
Yield Components ◽  
Seed Weight ◽  
Field Trials ◽  
Grass Species ◽  
Plant Seed ◽  
Common Lambsquarters ◽  
Residual Control

A 3-yr study was conducted to evaluate efficacy and soybean tolerance of cinmethylin. Cinmethylin was applied preemergence alone at 0.6, 0.8, and 1.0 kg ai/ha or in combination with metribuzin at 0.3 kg/ha. These treatments did not injure soybeans in field trials in 1984, 1985, and 1986. The combination of cinmethylin at 0.7 kg/ha and metribuzin at 0.3 kg/ha controlled more than 90% of large crabgrass, fall panicum, and yellow foxtail. Redroot pigweed and common lambsquarters control was also excellent. Residual control of all grass species was excellent for 8 weeks after preemergence application, followed by reduced control in two of the three grasses. The combination of cinmethylin and metribuzin at 0.7 and 0.3 kg/ha, respectively, significantly increased soybean yields compared to those of untreated plots. These yields were comparable with those obtained from the combination of alachlor and metribuzin at 2.0 and 0.3 kg/ha, respectively. Cinmethylin treatments had no adverse effects on soybean yield components including pods/plant, seed/pod, and seed weight. Cinmethylin shows potential as a preemergence herbicide for full-season weed control in soybean production.

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