Competition for nodule occupancy of introduced Bradyrhizobium japonicum strains in a Wisconsin soil with a low indigenous bradyrhizobia population

1990 ◽  
Vol 36 (12) ◽  
pp. 839-845 ◽  
Author(s):  
T. J. McLoughlin ◽  
S. Hearn ◽  
S. G. Alt
Keyword(s):  
Bradyrhizobium Japonicum ◽  
Growing Season ◽  
Field Trials ◽  
Enzyme Linked Immunosorbent Assay ◽  
Nodule Occupancy ◽  
Antibiotic Resistant ◽  
Growing Seasons ◽  
Low Incidence ◽  
One Year ◽  
Successful Inoculation

The population dynamics of six introduced Bradyrhizobium japonicum strains were measured over three growing seasons in a Wisconsin soil with a low incidence of indigenous B. japonicum (10 cells/gm). Four antibiotic-resistant members of the 123 serocluster (which were either spectinomycin resistant or streptomycin resistant), USDA 110, and USDA 138 were inoculated using liquid inoculum, at a rate of 1 × 108 cells per 2.5-cm row, on two soybean cultivars in 1985. Nodule occupants were identified using an enzyme-linked immunosorbent assay (ELISA), fluorescent antibodies, and antibiotic-resistant mutants. In the first growing season, 100% of the nodules were formed by the introduced strains. The nodules from the uninoculated plots were occupied by an indigenous 110 serogroup. In the second and the third season at the same site (without further inoculation), a high percentage (> 60%) of the nodules from all the plots were nodulated by the 123 serocluster (either alone or as mixed infections). However, < 25% of the nodules in the 123-inoculated plots and < 9% in the other plots were formed by any of the antibiotic-marked 123 inoculum strains introduced in 1985. The main conclusions are (i) that it is possible to successfully introduce inoculum strains in soils where the indigenous Bradyrhizobium population is low and to obtain 100% nodule occupancy in the first growing season, and (ii) that successful inoculation in one year in soils with a low incidence of Bradyrhizobium does not ensure that the introduced inoculum strains will form nodules in subsequent years. Key words: Bradyrhizobium japonicum, indigenous bradyrhizobia, interstrain competition, field trials.

Persistence of introduced Bradyrhizobium japonicum strains in forming nodules in subsequent years after inoculation in Wisconsin soils

1990 ◽  
Vol 36 (11) ◽  
pp. 794-800 ◽  
Author(s):  
T. J. McLoughlin ◽  
S. G. Alt ◽  
P. A. Merlo
Keyword(s):  
Key Words ◽  
Bradyrhizobium Japonicum ◽  
Field Experiments ◽  
Field Trials ◽  
Phage Typing ◽  
Antibiotic Resistant ◽  
Almost All ◽  
Successful Inoculation ◽  
Japonicum Strain ◽  
Different Soils

Nodulation of soybeans by indigenous and inoculum strains of Bradyrhizobium japonicum was studied in field experiments in Wisconsin from 1983 to 86. Aqueous suspensions of bacteria were applied to seeds at the time of planting at levels of 7 × 107–1010 bacteria per 2.5-cm row. The predominant indigenous serogroup was 123 in these soils. Six different inoculum strains were used (two from serocluster 123, two from serogroup 110, and one each from serogroups 122 and C1). Nodule occupants were identified using spontaneous antibiotic-resistant mutations in the inoculum strains, phage typing, and serotyping. In the 1983 experiment, the majority of nodules were formed by the inoculum strains in almost all cases (up to 100% in some cases), in two different soils containing 3.5 × 105 indigenous B. japonicum per gram. After 2 years without inoculation at the same two site, the inoculum strains did not form many nodules on uninoculated soybeans (less than 10% in most cases; less than 30% in all cases). In inoculation experiments carried out in 1985 and 1986, four inoculum strains were used (3 members of 123 serocluster and USDA 110str); inocula containing 108 bacteria per 2.5-cm row formed less than42%ofthe nodules in soils containing 1 × 104–4 × 104B. japonicum per gram. The major conclusions are (i) the success of inoculation in Midwestern U.S. soils is highly variable, even with members of the (highly competitive) 123 serocluster, and (ii) successful inoculation in 1 year in a Wisconsin soil does not ensure that the inoculated strain will persist in forming nodules in that field in subsequent years without further inoculation. Key words: Bradyrhizobium japonicum, strain persistence, field trials.

Third-Year Growth Response of Loblolly Pine to Eight Levels of Competition Control

1987 ◽  
Vol 11 (2) ◽  
pp. 91-95 ◽  
Author(s):  
Catherine G. Bacon ◽  
Shepard M. Zedaker
Keyword(s):  
Loblolly Pine ◽  
Growth Response ◽  
Volume Growth ◽  
Growing Season ◽  
Control Treatment ◽  
Growing Seasons ◽  
Best Response ◽  
Competition Control ◽  
Pinus Taeda L ◽  
One Year

Abstract The growth response of young loblolly pine (Pinus taeda L.) to different amounts of competition control was studied in plantations of three ages in the Virginia Piedmont. Eight competition control treatments involved the removal of all, two-thirds, one-third, or none of the hardwoodstems either with or without herbaceous weed control. Results after three growing seasons showed a significant increase in pine diameter and volume growth with competition control. Treatments combining woody and herbaceous control resulted in better pine growth than the same treatments withoutherbaceous control, in the two youngest stands. The best response, obtained with the two-thirds woody plus herbaceous control treatment, resulted in: a 100% increase in volume growth over the check plots in seedlings treated at the beginning of their second growing season in the field; a 93% increase in one-year-old seedlings; and a 53% increase in the growth of seedlings treated before the third growing season. South. J. Appl. For. 11(2):91-95.

Competition for nodulation of field-grown soybeans by strains of Rhizobium fredii

1986 ◽  
Vol 32 (2) ◽  
pp. 183-186 ◽  
Author(s):  
Thomas J. McLoughlin ◽  
Scott G. Alt ◽  
P. Ann Owens ◽  
Corrine Fetherston
Keyword(s):  
Bradyrhizobium Japonicum ◽  
Indigenous Population ◽  
Growing Season ◽  
Indigenous Populations ◽  
First Year ◽  
Antibiotic Resistant ◽  
Rhizobium Fredii ◽  
Glycine Max L ◽  
Resistant Mutants ◽  
Antibiotic Resistant Mutants

Nodulation of Glycine max (L) Merr. by six Rhizobium fredii strains was measured in two Midwestern fields containing high indigenous populations of Bradyrhizobium japonicum (3 × 105/gm soil). The soils were inoculated with antibiotic-resistant mutants using liquid inoculum at two levels on soybean cv. Peking and cv. Jacques 130. Strain establishment was measured 40 days after planting. In the first year, USDA206, USDA217, and USDA257 were the most competitive strains, occupying greater than 50% of the nodules on cv. Peking in both soils. None of the strains were competitive on Jacques 130. In the second growing season, all nodules were formed by the indigenous population on both cultivars, suggesting that these fast-growing strains do not persist in Midwestern soils.

EFFICACY OF THREE DINITROANILINE HERBICIDES IN PROCESSING PEAS AND THEIR RESIDUES IN SOILS

1983 ◽  
Vol 63 (3) ◽  
pp. 687-693 ◽  
Author(s):  
K. I. N. JENSEN ◽  
E. R. KIMBALL ◽  
J. A. IVANY
Keyword(s):  
Weed Control ◽  
Sandy Loam ◽  
Growing Season ◽  
Field Trials ◽  
Soil Types ◽  
Crop Tolerance ◽  
Pisum Sativum L ◽  
Light Soil ◽  
One Year ◽  
Dinitroaniline Herbicides

The efficacy and relative persistence of dinitramine (N′,N′-diethyl-α,α,α-trifluoro-3,5-dinitrotoluene-2-4-diamine), ethalfluralin [N-ethyl-N-(2-methyl-2-propenyl)-2,6-dinitro-4(trifluoromethyl) benzenamine], and trifluralin (α,α,α -trifluoro-2,6-dinitro-N,N-diproply-p-toluidine) were studied in a series of field trials conducted on a Charlottetown fine sandy loam (P.E.I.) and on a Somerset loamy sand (N.S.). Phytotoxicity, as reflected by weed control and injury to the peas (Pisum sativum L.), was greater on the sandy soil and herbicide rates recommended for the region may reduce yields on light soil types. The margin of crop tolerance was also reduced in one year characterized by an extremely wet growing season. Under field conditions, there was little practical difference in weed control obtained with the three herbicides. Dinitramine and ethalfluralin were more persistent in the Somerset sand than in the Charlottetown sandy loam. The order of decreasing persistence was trifluralin>ethalfluralin>dinitramine, except in the Somerset sand where the persistence of ethalfluralin and trifluralin was similar. Significant detectable levels of all three herbicides remained 320 days after application.Key words: Processing peas, dinitramine, ethalfluralin, trifluralin, residue

Selective chemical control of doublegee (Emex australis) in legume pasture

1977 ◽  
Vol 17 (84) ◽  
pp. 80 ◽  
Author(s):  
DJ Gilbey
Keyword(s):  
Chemical Control ◽  
Growth Stage ◽  
Leaf Growth ◽  
Growing Season ◽  
Field Trials ◽  
Emex Australis ◽  
Selective Control ◽  
Selective Chemical ◽  
One Year ◽  
Clover Seed

Seven chemicals were evaluated for selective control of doublegee (Emex australis) in legume pasture in 14 field trials conducted at several sites in Western Australia over three years. The effect of removing doublegee on pasture growth was studied in four field trials over the same period. Three hundred and fifty to 700 g a.i. methabenzthiazuron ha-1 gave good selective control of this weed except at Chapman and Wongan Hills in 1974 where the beginning of the growing season was poorly defined. The selectivity of bromoxynil and WL 6361 1 in one year of trials was similar to methabenzthiazuron but that of asulam and metoxuron was too restricted for practical use when doublegees were sprayed at the 2-4 leaf growth stage, 2,4-DB showed selectivity on doublegees with 12 leaves, and no herbicides were satisfactory on doublegees with more than 12 leaves at the time of spraying. Pasture growth and clover seed production was not substantially increased by controlling doublegee.

scholarly journals Budset and Growth of Eastern White Pine Following Application of 6-Benzylaminopurine to Seedlings Fertilized with Different Levels of Nitrogen

1988 ◽  
Vol 6 (2) ◽  
pp. 42-45
Author(s):  
L. Eric Hinesley ◽  
Robert D. Wright
Keyword(s):  
Irrigation Water ◽  
Pinus Strobus ◽  
Dry Weight ◽  
Growing Season ◽  
First Year ◽  
White Pine ◽  
Eastern White Pine ◽  
Growing Seasons ◽  
One Year ◽  
Different Levels

Eastern white pine (Pinus strobus L.) were potted and solution fed once weekly during 2 growing seasons with 5 levels of N in the irrigation water: 50, 100, 200, 300 and 400 ppm. Leaders were treated with 750 ppm 6-benzylaminopurine (BA) in late June of the first year. The higher N levels resulted in greater stem diameter, greater foliage dry weight, longer and heavier needle fascicles, better foliage color, greater budset after application of BA, and more and longer branches on the BA-treated leader the second growing season. BA should be applied to trees with N concentration ≥ 1.5% in one-year-old foliage.

scholarly journals Epiphytic Microbiome of Grapes Berries Varies Between Phenological Timepoints, Growing Seasons and Regions

2019 ◽  
Author(s):  
Megan E. Hall ◽  
Isabelle O’Bryon ◽  
Wayne F. Wilcox ◽  
Michael V. Osier ◽  
Lance Cadle-Davidson
Keyword(s):  
New York ◽  
Growing Season ◽  
Phenological Stage ◽  
Phenological Stages ◽  
Growing Seasons ◽  
Single Region ◽  
Finger Lakes ◽  
Primary Focus ◽  
One Year

AbstractExtensive research into the microbial ecology of grapes near harvest, with a primary focus on yeasts, has improved our understanding of some components of variation that influence grapevine terroir. Metagenomic tools enable a broader exploration of the plant microbiome and components of variability due to such factors as year, location, management, and phenological stage. In 2014, to characterize the microbial changes of the grape surface over the course of the growing season in the Finger Lakes region of New York, we examined the epiphytic microbiome of grapes at five key phenological stages: pea-sized, bunch closure, Veraison, 15 Brix and harvest. This experiment was repeated in two subsequent years in the Finger Lakes, New York in 2015, and in Tasmania, Australia in 2016, to examine variability of regional terroir. We found significant shifts in taxa presence and relative taxa abundance between phenological timepoints, and determined that the epiphytic microbiome differed significantly not just between regions but also within a single region from one year to the next. These findings call into question the role of the phytobiome in the expression of terroir, as the phytobiome is dynamically responding to its environment, within and between years and locations. On the berry surface in particular, these dynamics are complicated by weather and management. Understanding that the grape surface microbiome is consistently changing may influence how we manage the berry epiphytic microbiome, potentially affecting disease management and vinification decisions.

Soil Solarization Controls Broomrapes (Orobanchespp.) in Host Vegetable Crops in the Jordan Valley

1991 ◽  
Vol 5 (3) ◽  
pp. 575-581 ◽  
Author(s):  
B. E. Abu-Irmaileh
Keyword(s):  
Crop Yields ◽  
Growing Season ◽  
Field Trials ◽  
Soil Solarization ◽  
Soil Tillage ◽  
Vegetable Crops ◽  
Jordan Valley ◽  
Deep Soil ◽  
Growing Seasons ◽  
Tomato Field

The effectiveness of soil solarization with black (BPE) and clear polyethylene mulches (CPE), 0.04 and 0.06 mm thick, respectively, was tested during the 1986 to 1990 growing seasons for controlling Egyptian broomrape, hemp broomrape and nodding broomrape in heavily infested fields. Solarization for 6 wk reduced or eliminated broomrape infestation and improved crop yields. The CPE started to show splitting and deterioration after 4 to 5 wk of solarization. The BPE lasted in usable conditions throughout the growing season. Deep soil tillage with the hand hoe, after solarization, caused broomrape to reappear. Crops grew best in plots after solarization with BPE if they were planted through the same mulch after it was perforated. Soil solarization with BPE or CPE in large tomato field trials, completely eliminated both nodding and hemp broomrapes during the growing season. However, greenhouse pot experiments indicated that solarization significantly reduced weed seedling numbers, but did not significantly reduce the dry weights of the broomrape plants that emerged in the soil samples taken from solarized plots.

scholarly journals Identification and use of actinomycetes for enhanced nodulation of soybean co-inoculated with Bradyrhizobium japonicum

2003 ◽  
Vol 49 (8) ◽  
pp. 483-491 ◽  
Author(s):  
A K Gregor ◽  
B Klubek ◽  
E C Varsa
Keyword(s):  
Bradyrhizobium Japonicum ◽  
Antibiotic Sensitivity ◽  
Nodule Occupancy ◽  
Antibiotic Resistant ◽  
Glycine Max L ◽  
Resistant Strains ◽  
Soybean Plants ◽  
Population Sensitivity ◽  
Germinated Soybean ◽  
Streptomyces Kanamyceticus

The utilization of actinomycetes as potential soybean (Glycine max (L.)) co-inoculants was evaluated. Soil samples from Carbondale and Belleville, Ill., were used to inoculate pre-germinated soybean plants to determine antibiotic sensitivity in the native Bradyrhizobium japonicum population. Sensitivity was in the order kanamycin > tetracycline > oxytetracycline > rifampicin > neomycin. Antagonism by five actinomycete cultures toward seven test strains of B. japonicum was also assessed. The ranking average inhibition (across all seven B. japonicum strains) by these actino mycetes was Streptomyces kanamyceticus = Streptomyces coeruleoprunus > Streptomyces rimosus > Streptomyces sp. > Amy colatopsis mediterranei. Ten antibiotic combinations were used to isolate antibiotic-resistant mutants of B. japonicum I-110 and 3I1B-110 via successive cycles of mutation. Eighty-one antibiotic-resistant strains were isolated and tested for symbiotic competency; nine of which were selected for further characterization in a greenhouse pot study. Few differences in nodule number were caused by these treatments. Nodule occupancy varied from 0% to 18.3% when antibiotic-resistant strains of B. japonicum were used as the sole inoculants. However, when three mutant strains of B. japonicum were co-inoculated with S. kanamyceticus, significant increases in nodule occupancy (up to 55%) occurred. Increases in shoot nitrogen composition (27.1%–40.9%) were also caused by co-inoculation with S. kanamyceticus. Key words: Bradyrhizobium japonicum, Streptomyces kanamyceticus, indigenous bradyrhizobia, co-inoculation, nodule occupancy.

scholarly journals Tolerance of Supina Bluegrass to Pre and Post-Emergence Herbicides

2002 ◽  
Vol 20 (2) ◽  
pp. 118-121 ◽  
Author(s):  
Kurt Steinke ◽  
John Stier
Keyword(s):  
Shade Tolerance ◽  
Herbicide Tolerance ◽  
Field Trials ◽  
Annual Bluegrass ◽  
Growing Seasons ◽  
Mature Stand ◽  
Poa Supina ◽  
One Year ◽  
Close Relatives ◽  
Herbicide Use

Abstract Supina bluegrass (Poa supina) is being increasingly used for shaded lawns and golf course tees due to its excellent shade tolerance. The herbicide tolerance, however, is undocumented because herbicide use on amenity turfs is banned in the European countries where supina bluegrass has been used for over 30 years. Several commonly used turf and ornamental herbicides are capable of harming or eradicating close relatives of supina bluegrass. In particular, Prograss (Ethofumesate) is used to selectively remove annual bluegrass (Poa annua) from mixed turf stands. Supina bluegrass is a putative ancestor of annual bluegrass and may have similar susceptibilities to chemicals. Fifteen pre and postemergence turf and ornamental herbicides were tested for their potential to damage or kill a mature stand of supina bluegrass. Field trials were conducted twice over two growing seasons. Herbicides with the active ingredients triclopyr, MCPP, quinclorac, and ethofumesate caused temporary phytotoxicity in at least one of the two years. Fall applications of Prograss (Ethofumesate) and Turflon Ester (Triclopyr) caused phytotoxicity the spring following autumn application in both years, while Strike 3 (Dicamba, MCPP, 2,4-D) and Confront (Triclopyr + Clopyralid) caused phytotoxicity in one year only. None of the compounds showed potential for selectively removing supina bluegrass from a mixed turf stand.

Sign in / Sign up

Export Citation Format

Share Document