Root and crown characteristics of alfalfas varying in fall dormancy

1994 ◽  
Vol 74 (1) ◽  
pp. 125-127 ◽  
Author(s):  
N. A. Juan ◽  
C. C. Sheaffer ◽  
D. K. Barnes
Keyword(s):  
Medicago Sativa ◽  
Key Words ◽  
Dry Weight ◽  
Nonstructural Carbohydrate ◽  
Shoot Number ◽  
Fall Dormancy ◽  
Crown Morphology ◽  
Medicago Sativa L ◽  
Crown Characteristics ◽  
Alfalfa Root

We compared root and crown characteristics of five alfalfa (Medicago sativa L.) entries which differed in fall dormancy. Alfalfas were subjected to bud or mid-bloom harvests. The most consistent entry effect occurred for root and crown dry weight and root total nonstructural carbohydrate (TNC) concentrations. Root TNC concentration was highest and root and crown weight were greatest for the nondormant and least in the most dormant entries. Entries did not consistently differ in crown bud numbers, shoot number, or shoot origin. In October, the number of elongated crown buds were greater for a non-fall dormant alfalfa Nitro than for the most fall dormant alfalfa. Key words: Alfalfa, root and crown morphology, fall dormancy, root carbohydrates

Exploration of Endophytes from Alfalfa (Medicago sativa L.) as Biocontrol Agents

2020 ◽  
pp. 1-8
Author(s):  
Beilei Wu ◽  
Beilei Wu ◽  
Mei Li ◽  
Xiaoli Chen ◽  
Xiliang Jiang ◽  
...  
Keyword(s):  
Medicago Sativa ◽  
Root Rot ◽  
Agricultural Production ◽  
Biocontrol Agents ◽  
Bacillus Spp ◽  
Medicago Sativa L ◽  
The Common ◽  
Seedling Germination ◽  
Germination Experiments ◽  
Alfalfa Root

Endophytes are increasingly investigated as biocontrol agents for agricultural production. The identification of new endophytes with high effectiveness against plant disease is very important. A total of 362 strains of endophytes, including fungi, bacteria, and actinomycete, were isolated from alfalfa (Medicago sativa L.) collected in Hebei, Inner Mongolia and Ningxia provinces of China. The three strains of endophytic bacteria (NA NX51R-5, NA NX90R-8, and NA NM1S-1) with strong biocontrol capability with >50% effectiveness were screened against the common alfalfa root rot pathogen Fusarium oxysporum F. sp. medicaginis in alfalfa seedling germination experiments on MS medium and pot experiments. Using phylogenetic analysis, the isolates of NA NM1S-1 and NA NX51R-5 were identified as Bacillus spp. by 16S rDNA, while NA NX90R-8 was found to be Pseudomonas sp.

Shearing force of alfalfa stems: Effects of genotype and year interactions

1998 ◽  
Vol 78 (4) ◽  
pp. 719-722
Author(s):  
A. D. Iwaasa ◽  
K. A. Beauchemin ◽  
S. N. Acharya ◽  
J. G. Buchanan-Smith
Keyword(s):  
Cell Wall ◽  
Medicago Sativa ◽  
Key Words ◽  
Chemical Constituents ◽  
Stem Segment ◽  
Shearing Force ◽  
Medicago Sativa L ◽  
Genotype Clustering ◽  
Force Characteristics

Shearing force of alfalfa (Medicago sativa L.) stems was measured to evaluate genotype-by-year interactions. Based on mean shearing force for each stem segment and genotype clustering criteria, several genotypes had similarly shearing forces among years. Therefore, selecting genotypes with desirable shearing force characteristics to improve digestibility or intake potential of forages may be possible. Key words: Genotype, environment, shearing force, cell wall chemical constituents

Comparative characteristics during wilting for alfalfa conditioned by maceration or by a conventional roller-conditioner

1999 ◽  
Vol 79 (4) ◽  
pp. 509-517 ◽  
Author(s):  
Suwarno Suwarno ◽  
K. M. Wittenberg ◽  
W. P. McCaughey
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Medicago Sativa ◽  
Key Words ◽  
Dry Matter ◽  
Microbial Count ◽  
Nutrient Profile ◽  
Conditioning Treatment ◽  
Acid Detergent Fibre ◽  
Medicago Sativa L

A study was conducted to monitor nutrient and microbial count changes during wilting of alfalfa (Medicago sativa L.) in response to varying degrees of maceration at mowing. Early bloom alfalfa was mowed with either a roller-conditioner (CONV) or a macerator set to deliver four degrees of maceration during alfalfa mowing: LIGHT, LIGHT+, SEVERE, and SEVERE+. Macerated alfalfa reached 80% dry matter in 9–11 h compared with alfalfa mowed by roller-conditioner, which required 54 h. The most rapid wilting rates were associated with LIGHT+, SEVERE, and SEVERE+ maceration treatments when alfalfa was not exposed to precipitation. The wilting coefficient in the first 24 h was increased by more than 100% for the SEVERE treatment compared with alfalfa mowed using a conventional roller-conditioner in alfalfa that was not exposed to precipitation. Precipitation at 1.5 h post-mowing increased wilting time by 8.3 h to achieve 45% DM, and by 17.5 to achieve 80% DM in the SEVERE+ maceration treatment relative to alfalfa from the same conditioning treatment that was not exposed to precipitation. Precipitation at 24 h post-mowing increased wilting time to reach 80% DM by 11 h and 21 h for the LIGHT and LIGHT+ maceration treatments relative to alfalfa of the same mowing treatments not exposed to precipitation. Maceration of alfalfa resulted in a 24.2 to 26.8 h shorter wilting time relative to the conventional roller-conditioner treatment when alfalfa was exposed to precipitation at 24 h post-mowing. SEVERE and SEVERE+ maceration treatments at mowing resulted in higher (P < 0.05) neutral detergent fibre and acid detergent fibre levels post-wilting. Lactic acid bacteria populations on alfalfa tended to be higher with maceration within 1 h post-mowing (P < 0.10) and post-wilting (P < 0.08). Key words: Alfalfa, maceration, precipitation, wilting time, bacteria, nutrient profile, compressibility

Identification and selection for salt tolerance in lucerne (Medicago sativa L.)

1984 ◽  
Vol 35 (2) ◽  
pp. 239 ◽  
Author(s):  
CL Noble ◽  
GM Halloran ◽  
DW West
Keyword(s):  
Salt Tolerance ◽  
Medicago Sativa ◽  
Recurrent Selection ◽  
Leaf Damage ◽  
Shoot Number ◽  
Two Generations ◽  
Medicago Sativa L ◽  
Selection For ◽  
Efficiency Of Selection ◽  
Chloride Concentrations

Variation existed between plants of the lucerne (Medicago sativa L.) cultivar CUF 101 for dry matter production, shoot number and length, and leaf damage when grown for 70 days under 250 mM NaCl (15 h photoperiod, 20�C day, 10�C night). Salt tolerance evaluation using the criteria percentage leaf damage (percentage of total number of leaves with complete or partial necrosis) and length of the main shoot, isolated plants which showed salt tolerance of reasonably high heritability (h2=0.41). Two generations of recurrent selection for tolerance significantly increased the mean population tolerance without decreasing production under non-saline conditions. While both sodium and chloride concentrations of the shoot were lower in the tolerant than in less tolerant plants, chloride was more closely associated with salt tolerance than sodium. Sodium and chloride concentrations in the roots did not vary with the level of salt tolerance. No association of shoot and root potassium concentration with tolerance was evident. Selection for salt tolerance in lucerne plants using percentage leaf damage of less than 10% as the main criterion should give a rapid response to selection. The efficiency of selection may be increased if selection is based on the efficiency of chloride exclusion from the shoots and/or the level of chloride tolerated by the shoots prior to leaf damage becoming evident.

The influence of the lucerne bud mite (Eriophyes medicaginis Keifer) on the growth of lucerne

1981 ◽  
Vol 32 (5) ◽  
pp. 773 ◽  
Author(s):  
PM Ridland ◽  
GM Halloran
Keyword(s):  
Medicago Sativa ◽  
Dry Weight ◽  
Stem Length ◽  
Infestation Level ◽  
Axillary Shoots ◽  
Two Temperatures ◽  
Medicago Sativa L ◽  
Extent Of Damage ◽  
Initial Infestation ◽  
Damage Symptoms

The influence of Eriophyes medicaginis on the growth of lucerne (Medicago sativa L.) was studied at four temperatures (15, 20, 25 and 29�C) at an initial infestation level of 10 mites per seedling, and at two temperatures (20 and 29�C) with four initial levels of infestation (2, 5, 10 and 20 mites per seedling). At 25� and 29�C, infestation with 10 mites per seedling significantly reduced dry weight of tops, stem length and the development of axillary shoots within 22 days of infestation. In this period, the numbers of mites increased 16-fold at 29OC, ninefold at 25�C and sixfold at 20�C, but there was no increase at 15�C. The extent of damage caused by mites at 20�C appeared to vary with the differences in growth of the plants under different photoperiods. Under a short photoperiod (10.3 h) where no axillary shoots developed on either infested or control plants, the extent of damage due to mite infestation was much higher than under a longer photoperiod (13.2 h) where axillary shoots developed on all seedlings. Damage symptoms on leaves of infested plants included chlorotic patches (mainly at 20� and 25�C), agate-like banding (29�C) and a waxy mottle (15�C).

scholarly journals Dynamics of aerial and perennial biomass of two lucerne cultivars with different fall dormancy subject to two severities of cutting during the establishment phase

2021 ◽  
Vol 120 (1) ◽  
pp. 072
Author(s):  
Leonela Analía García ◽  
Silvia Graciela Assuero ◽  
Gabriel Blain ◽  
Matías Ezequiel Pereyra ◽  
Germán Darío Berone
Keyword(s):  
Leaf Area ◽  
The Other ◽  
Randomized Design ◽  
Shoot Number ◽  
Fall Dormancy ◽  
Crown Biomass ◽  
Medicago Sativa L ◽  
Completely Randomized Design ◽  
The Impact ◽  
Establishment Phase

The aim of this study was to quantify the impact of two cutting severities on the dynamics of aerial and perennial (root plus crown) biomass of lucerne (Medicago sativa L.) plants of two cultivars of contrasting fall dormancy rating during the establishment phase. We worked at Unidad Integrada Balcarce with two cultivars of lucerne (non-winter dormant: FD10; semi-winter dormant: FD6) and two cutting severities (40 and 100 mm) defining four treatments (FD6-40 mm, FD6-100 mm, FD10-40 mm and FD10-100 mm) under a completely randomized design. In both cultivars, increasing cutting severity produced a reduction in leaf area and number of nodes in the residual, resulting in a reduced production of aerial biomass during regrowth, given a reduction on shoot number. On the other hand, the effect of increased cutting severity on perennial biomass was only observed in plants of FD10 cultivar. This cultivar showed less perennial biomass when cut at 40 mm than at 100 mm, while no differences were observed between cutting heights in FD6 cultivar.

EFFET DU MAGNÉSIUM ET DU pH DU SOL SUR LA LUZERNE CULTIVÉE EN SERRE DANS TROIS TYPES DE SOL DU QUÉBEC

1980 ◽  
Vol 60 (2) ◽  
pp. 275-284 ◽  
Author(s):  
J. L. DIONNE
Keyword(s):  
Medicago Sativa ◽  
Soil Ph ◽  
Dry Weight ◽  
Weight Basis ◽  
Soil Types ◽  
Yield Increase ◽  
Medicago Sativa L ◽  
Mg Content

Aflalfa (Medicago sativa L. ’Saranac’) was grown under greenhouse conditions in order to determine changes in magnesium (Mg) response and availability following variation in soil pH. The rates of Mg applications were 0, 25, 50, 100 and 200 ppm of Mg calculated on soil dry weight basis. Soil pH was adjusted to 5.0 (or original) 6.0, 6.5 and 7.5. A 40% yield increase was recorded on Greensboro loam following Mg fertilization. The increase in yields due to Mg was 23% on the two others soil types. The Mg contents of plant and soil increased with rate of Mg applied to soil. In general, the response of alfalfa was increased by liming soils and the Mg content of alfalfa was decreased. The availability of Mg in soils was also lowered by liming. The Mg requirement of soils varied from 25 to 100 ppm depending upon pH and soil types.

Bloat in cattle fed alfalfa selected for a low initial rate of digestion

1994 ◽  
Vol 74 (3) ◽  
pp. 451-456 ◽  
Author(s):  
J. W. Hall ◽  
W. Majak ◽  
D. G. Stout ◽  
K.-J. Cheng ◽  
B. P. Goplen ◽  
...  
Keyword(s):  
Medicago Sativa ◽  
Protein Content ◽  
Key Words ◽  
Dry Matter ◽  
Initial Rate ◽  
Legume Species ◽  
The Third ◽  
Fourth Cycle ◽  
Medicago Sativa L

Investigations of legume species which do and do not cause bloat suggested that a bloat-safe alfalfa (Medicago sativa L.) might be produced by reducing its initial rate of digestion. This study compared a third cycle alfalfa synthetic selected for a low initial rate of digestion (LIRD) with a control cultivar (Beaver). The occurrence of bloat was not significantly lower when cattle were fed cycle 3 LIRD than when fed Beaver in three grazing trials or in two of three feedlot trials. The deviation of the results in the third trial could not be explained by differences in dry matter or protein content. When grown under irrigation, the 4 h dry matter disappearance (DMD) of cycle 3 LIRD was 89% to 96% of that for Beaver. This reduction was much less than has been hypothesized to prevent bloat. Without irrigation the 4 h DMD of both cultivars were reduced by 1–3% while cycle 3 LIRD continued to have a lower DMD than Beaver. LIRD may provide some protection against bloat on dry rangelands though the response may be variable in years when moisture is well supplied. Studies with a fourth cycle LIRD selection will investigate this further. Key words: Legumes, Medicago sativa L., nylon bag, digestion

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