scholarly journals VARIATION IN DIGESTIBILITY DECLINE WITH ADVANCE IN MATURITY AMONG TIMOTHY (Phleum pratense L.) GENOTYPES

1986 ◽  
Vol 66 (2) ◽  
pp. 323-328 ◽  
Author(s):  
A. R. McELROY ◽  
B. R. CHRISTIE
Keyword(s):  
Forage Quality ◽  
Phleum Pratense ◽  
In Vitro Digestibility ◽  
Single Population ◽  
Population Mean ◽  
Unit Increase ◽  
Selection For ◽  
Phleum Pratense L

The in vitro digestibility (IVD) of timothy (Phleum pratense L.) declines with advance in maturity. Forage quality reductions resulting from late harvesting could be minimized by developing cultivars with reduced IVD decline during maturation. This study examines variation for IVD decline among timothy genotypes. Clones originating from a single population were grown in simulated swards (100 plants m−2) at two Ontario locations in 1980 and 1981. Harvests were made every 5–6 d from early heading to late anthesis. Relative IVD declines were determined by regressing genotype performance on the population mean over several harvests. Considerable variation was found for relative IVD decline, but this parameter was not associated with IVD at early heading. Genotypes were identified which showed high IVD at heading and a 20% reduction in digestibility decline from heading to late anthesis. Changes in IVD were not associated with changes in the leaf content of forage. It is concluded that selection for reduced IVD decline, in addition to high digestibility at heading, might result in a 2–3% unit increase at anthesis.Key words: Timothy, Phleum pratense L., in vitro digestibility, IVD, IVD decline

GENOTYPE × ENVIRONMENT INTERACTIONS FOR IN VITRO DIGESTIBILITY OF TIMOTHY (Phleum pratense L.) GENOTYPES

1986 ◽  
Vol 66 (2) ◽  
pp. 315-321 ◽  
Author(s):  
A. R. McELROY ◽  
B. R. CHRISTIE
Keyword(s):  
Zea Mays L ◽  
Genetic Material ◽  
Phleum Pratense ◽  
In Vitro Digestibility ◽  
Environment Interaction ◽  
Important Goal ◽  
Genotype Environment Interaction ◽  
Selection For ◽  
Phleum Pratense L

Improved in vitro digestibility (IVD) is an important goal in timothy (Phleum pratense L.) breeding. This study examines the effect of genotype × environment (GE) interactions on individual genotypes and examines two methods for identifying superior parental genotypes. Fifteen genotypes of similar maturity were grown in simulated swards (100 plants m−2) at five locations. IVD was determined at early heading. Highly significant effects were found for genotype, year, location and all their interactions. A regression stability analysis indicated that most genotypes responded in a predictable manner to environment. Genotypes which performed relatively well in all environments were identified. However, some useful genetic material, being "unstable", would be discarded using this approach. Genotypes with consistently high IVD were identified using a technique developed for grouping corn (Zea mays L.) hybrids. This approach is considered the more efficient for identifying superior parental genotypes. Although genotype (IVD should be based on performance in several environments, it is suggested that selection for IVD stability is important in developing narrow-based but not wide-based synthetics.Key words: Timothy, Phleum pratense L., genotype × environment interaction, in vitro digestibility, IVD

INFLUENCE OF HARVEST SYSTEMS AND NITROGEN RATES ON YIELDS, QUALITY AND PERSISTENCE OF CHAMP TIMOTHY IN THE SEEDING AND POSTSEEDING YEARS

1976 ◽  
Vol 56 (3) ◽  
pp. 715-723 ◽  
Author(s):  
H. T. KUNELIUS ◽  
M. SUZUKI ◽  
K. A. WINTER
Keyword(s):  
Full Range ◽  
Phleum Pratense ◽  
In Vitro Digestibility ◽  
N Application ◽  
System A ◽  
Yield Quality ◽  
N Rates ◽  
Nitrogen Rates ◽  
Phleum Pratense L

The interaction effects of harvest systems and rates of N on yield, quality and persistence of Champ timothy (Phleum pratense L.) were studied in a 4-yr field experiment. In the seeding year, total dry matter (DM) yields were highest (4.41 tons/ha) for the harvest taken 12 wk after seeding. Total DM yields increased with increasing N application up to 148 kg N/ha/yr. During the 3 postseeding yr, timothy was harvested four (system A), three (B) or two (C) times per season. Nitrogen was applied at five rates from 33 to 165 kg/ha; three times for systems A and B and twice per season for system C. Total DM yields showed increases for the full range of N application for systems A and B, but up to 132 kg/ha/application for system C. The tissue N concentrations were increased by increasing rates of fertilizer N while the in vitro digestibility of DM (IVDDM) was not generally changed. Forage with high IVDDM of 68.0 to 72.0% was produced under systems A and B whereas under C, IVDDM ranged from 55.9 to 65.1% during the season. The NO3-N concentrations of tissue frequently exceeded 0.15% levels at N rates above 132 kg/ha/application. High rates of N tended to thin the stand, but weeds were most prevalent where the lowest N rate was used.

EFFECTS OF 25 YEARS OF N, P AND K FERTILIZATION ON YIELD, PERSISTENCE AND NUTRITIVE VALUE OF A TIMOTHY SWARD

1989 ◽  
Vol 69 (2) ◽  
pp. 501-512 ◽  
Author(s):  
G. BÉLANGER ◽  
J. E. RICHARDS ◽  
R. B. WALTON
Keyword(s):  
Crude Protein ◽  
Nutritive Value ◽  
Maximum Yield ◽  
Phleum Pratense ◽  
In Vitro Digestibility ◽  
Botanical Composition ◽  
Phleum Pratense L ◽  
K Fertilization

The effects of over 25 yr of levels of applied N, P and K on forage DM yield, crude protein content, in vitro digestibility (IVD), botanical composition and persistence of a timothy (Phleum pratense L.) sward were assessed in a long-term field experiment on an acidic Riverbank L. Ammonium nitrate (0, 90, 180, 270 kg N ha−1), superphosphate (0, 15, 29, 44 kg P ha−1) and muriate of potash (0, 47, 94, 141 kg K ha−1) were applied annually in all possible combinations to a timothy sward since 1960. In the first 3 yr of the experiment, only N and K were required for maximum yield and persistence of timothy. The requirement for applied P, however, increased with time; in the last 3 yr (1985–1987) of the trial, the highest level of applied P resulted in profitable forage DM yield increases. After 25 yr, the productivity of the timothy sward was dependent upon a balanced application of all three macronutrients; absence of any one nutrient resulted in little or no response to applications of the other nutrients. The long-term persistence of timothy was solely dependent on K fertilization. The proportion of bentgrass and bluegrass species declined with increasing levels of applied K while that of timothy increased. The change in botanical composition due to applied N and K significantly affected IVD and crude protein content.Key words: N, P, K, fertilization, yield, persistence, timothy

THE EFFECT OF NURSERY CONDITIONS ON THE IN VITRO DIGESTIBILITY OF TIMOTHY (Phleum pratense L.)

1986 ◽  
Vol 66 (2) ◽  
pp. 307-313 ◽  
Author(s):  
A. R. McELROY ◽  
B. R. CHRISTIE
Keyword(s):  
Predictive Value ◽  
Phleum Pratense ◽  
Relative Performance ◽  
In Vitro Digestibility ◽  
Whole Plant ◽  
Growth Room ◽  
Growing Conditions ◽  
Phleum Pratense L

Fifteen timothy (Phleum pratense L.) genotypes of similar maturity were grown in simulated sward (100 plants m−2), spaced-plant (1 plants m−2) and growth room nurseries for 2 yr or harvests. The whole plant in vitro digestibility (IVD) was determined at early heading. IVD values were strongly influenced by growing conditions and highly significant [Formula: see text] year × genotype and harvest × genotype interactions were found. The precision of IVD determination was similar in all nurseries. Correlation between genotype means of simulated sward and other nurseries, although significant [Formula: see text] is some cases, was too low to be of predictive value. Some genotypes tended to rank relatively high in all nurseries, but the relative performance of most genotypes was inconsistent. It is concluded that the choice of nursery techniques used to predict the sward performance of timothy genotypes is more critical than is generally assumed.Key words: Timothy, Phleum pratense L., in vitro digestibility, IVD, nursery competition

scholarly journals COMBINING ABILITY OF FORAGE WATERMELON ( Citrullus lanatus var. citroides ) GERMPLASM

2017 ◽  
Vol 30 (3) ◽  
pp. 768-775 ◽  
Author(s):  
ROBERTA MACHADO SANTOS ◽  
NATONIEL FRANKLIN DE MELO ◽  
MARIA ALDETE JUSTINIANO DA FONSECA ◽  
MÁRIO ADRIANO ÁVILA QUEIROZ
Keyword(s):  
Protein Content ◽  
Dry Matter ◽  
Citrullus Lanatus ◽  
Fruit Yield ◽  
F1 Hybrids ◽  
In Vitro Digestibility ◽  
Ethereal Extract ◽  
Selection For ◽  
Number Of Seeds

ABSTRACT The aim of this study was to identify parents and promising hybrid combinations for the improvement of forage watermelon. Five parents were evaluated: BGCIA 996 (1), BGCIA 997 (2), BGCIA 998 (3), BGCIA 228 (4), Jojoba (5) and ten F1 hybrids, which were obtained from balanced diallel crosses. The experimental design was in a complete randomized block, with three replications. The morphoagronomic and bromatological traits were evaluated. The highlights were the progenitors BGCIA 997, BGCIA 998, BGCIA 228 and Jojoba for protein content, fruit yield, in vitro digestibility of dry matter and number of seeds, respectively. The hybrid 1x4 stood out for fruit length, seed number, and ethereal extract. The hybrid 2x3 stood out for rind and pulp thickness while the hybrids 3x4, 3x5 and 4x5 had exceptional digestibility, protein content and fruit yield, respectively. The analysis of the standard deviation of the SCA estimates of both SD (Sij- Sik) and SD (Sij- Skl) indicated that no hybrids were found that had SCA estimates twice that of SD (Sij- Sik) or SD (Sij- Skl), except for the hybrid 1x4 for the number of seeds per fruit. These results suggest that the parents were more promising than the hybrids. Similarly, the GCA estimates favor the intrapopulation method, which will promote greater efficiency in selection for genetic gains.

BARREN RING, A DESCRIPTION AND STUDY OF CAUSAL RELATIONSHIPS

1965 ◽  
Vol 43 (9) ◽  
pp. 1043-1054 ◽  
Author(s):  
J. I. Toohey ◽  
C. D. Nelson ◽  
G. Krotkov
Keyword(s):  
Bacterial Culture ◽  
Test Organism ◽  
Phleum Pratense ◽  
Pseudomonas Aureofaciens ◽  
Phytotoxic Activity ◽  
Number Of Microorganisms ◽  
Barren Soil ◽  
Bacteria And Fungi ◽  
Phleum Pratense L

A description is given of a rare soil disease, called "barren ring", which occurs in some old, deserted pastures. It is an expanding ring-shaped area of diameter up to 17 meters in which the vegetation is killed. Regeneration of normal vegetation occurs in the center of the ring. A number of microorganisms were isolated from the barren soil and tested for phytotoxicity in vitro. Of 24 pure strains of bacteria and fungi isolated, only one bacterium showed phytotoxicity to the test organism, Phleum pratense L. It was identified as a strain of Pseudomonas aureofaciens Kluyver. Bioautography of extracts of the bacterial culture showed that there are two compounds extractable in benzene which have both antibiotic and phytotoxic activity. However, it has not been established that this bacterium is the sole causal agent of the disease and it is suggested that it is caused by an association of microorganisms.

Selection for crude protein content in Phalaris tuberosa L. I. Response to selection and preliminary studies on correlated responses

1969 ◽  
Vol 20 (4) ◽  
pp. 643 ◽  
Author(s):  
RJ Clements
Keyword(s):  
Crude Protein ◽  
Nutritive Value ◽  
Breeding Population ◽  
In Vitro Digestibility ◽  
Seedling Vigour ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Selection For ◽  
Pasture Plant

In a highly variable breeding population of P. tuberosa, marked responses were obtained to three generations of selection for high and low crude protein concentration (percentage nitrogen x 6.25) in whole tillers at heading. Total response was similar in each direction, and realized heritability estimates were h2 = 0.25 and h2 = 0.20 in the high and low directions respectively. The responses were accompanied by positively correlated changes in in vitro digestibility and in characters commonly used as indicators of nutritive value of herbage. However, there were large negatively correlated changes in seedling vigour, relative growth rates, and other morphological and physiological characters. The implications of the results for pasture plant breeding are discussed.

Cutting frequency and cutting height effects on forage quality of rough fescue and Parry oat grass

1991 ◽  
Vol 71 (1) ◽  
pp. 87-96 ◽  
Author(s):  
W. D. Willms ◽  
K. A. Beauchemin
Keyword(s):  
Crude Protein ◽  
Forage Quality ◽  
Ground Level ◽  
In Vitro Digestibility ◽  
First Year ◽  
Repeated Treatment ◽  
Acid Detergent Fiber ◽  
Cutting Frequency ◽  
Rough Fescue

An experiment was conducted to determine the qualitative response of rough fescue (Festuca scabrella var. campestris) and Parry oat grass (Danthonia parryi) to five cutting frequencies and three cutting heights Beginning in mid-May, the same plants were cut every 1, 2, 4, 8, or 16 wk. during a 16-wk period, at heights of either 5, 10, or 15 cm above ground level. The treatments were repeated in 3 consecutive years on the same plants. Crude protein (CP), lignin, and calcium (Ca) were significantly greater for Parry oat grass than for rough fescue, which had greater acid detergent fiber (ADF) and phosphorus (P) concentrations. Increasing cutting frequency in the first year reduced acid detergent-insoluble nitrogen (ADIN), ADF, and lignin but increased CP and in vitro digestibility of dry matter (IVD) in both forages. Repeated treatment over 3 yr tended lo increase ADF and Ca but reduce CP, P, and IVD. In the first year of treatment, CP yields in rough fescue and Parry oat grass were greatest with 2 or 4 cuts during the growing season. However, in the second year of treatment, CP yield was greatest with one or two cuts in rough fescue and with four cuts in Parry oat grass. The data confirm the benefits of repeated grazing within a year to maintain high quality forage but demonstrate the need to limit the frequency of repeated grazing to avoid deterioration and maximize nutrient yield. Nutrient yields and, presumably, benefits to livestock would be greater at a lower grazing frequency on rough fescue than on Parry oat grass. Key words: Festuca scabrella var. campestris, Danthonia parryi, crude protein, acid detergent fiber, in vitro digestibility, forage quality

Leaf and stem nutritive value of timothy grown with varying N nutrition in spring and summer

1999 ◽  
Vol 79 (2) ◽  
pp. 223-229 ◽  
Author(s):  
G. Bélanger ◽  
R. E. McQueen
Keyword(s):  
Cell Wall ◽  
Nutritive Value ◽  
Nitrogen Deficiency ◽  
Phleum Pratense ◽  
Shoot Biomass ◽  
Negative Effect ◽  
N Deficiency ◽  
Rate Of Decline ◽  
Phleum Pratense L

Nitrogen fertilization is known to have a limited effect on the digestibility of grasses. In a previous paper, however, we reported that N deficiency increased the proportion of leaves in the shoot biomass, and hence, indirectly increased the digestibility of timothy (Phleum pratense L). This was mitigated by the direct negative effect of N deficiency on the digestibility of leaves or stems or both early in the regrowth. The objective of this study was to determine the direct effect of N deficiency on three parameters of nutritive value of leaves and stems of timothy cv. Champ. The evolution of leaf and stem in vitro true digestibility (IVTD), in vitro cell wall digestibility (IVCWD), and neutral detergent fiber (NDF) concentration of field-grown timothy fertilized with four rates of N was studied during a spring and summer regrowth cycle by sampling at weekly intervals. The rate of decline in leaf nutritive value in spring was greater than that in summer, and was less than the rate of decline in stem nutritive value during spring. Nitrogen deficiency consistently increased the NDF concentration of leaves but had a lesser effect on the NDF concentration of stems. Nitrogen deficiency decreased leaf IVCWD when the leaf-to-weight ratio (LWR) was high early in the spring and summer regrowth cycles. At the end of regrowth when LWR values were low, leaf IVCWD was greatest when no N was applied. As a result, the negative effect of N deficiency on the leaf IVTD during the early part of the spring and summer regrowth cycles diminished as the regrowth cycles progressed. Nitrogen deficiency had a limited effect on stem IVCWD. We concluded that the direct negative effect of N deficiency on the digestibility of the timothy shoot biomass can be attributed primarily to its effect on the NDF concentration and cell wall digestibility of leaves. Key words: Phleum pratense L., grasses, digestibility, cell wall, nitrogen

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