REPRODUCTION OF PRATYLENCHUS PENETRANS AND GROWTH OF BIRDSFOOT TREFOIL AS INFLUENCED BY SOIL MOISTURE AND CUTTING MANAGEMENT

1970 ◽  
Vol 50 (4) ◽  
pp. 499-504 ◽  
Author(s):  
L. S. THOMPSON ◽  
C. B. WILLIS
Keyword(s):  
Soil Moisture ◽  
Field Capacity ◽  
Early Flowering ◽  
Birdsfoot Trefoil ◽  
Pratylenchus Penetrans ◽  
Root Yield ◽  
Flowering Stage ◽  
Nematode Reproduction ◽  
Lesion Nematode ◽  
Cutting Management

Significantly less root and foliage growth of Empire birdsfoot trefoil, Lotus corniculatus L., was recorded at a soil moisture level of approximately 50% of field capacity (FC) when compared with that at 70–100% FC. The root lesion nematode, [Pratylenchus penetrans (Cobb) Filip. and Stekh], significantly reduced root and foliage yields of plants growing in soil at 70–100% FC, but there was no effect at 50% FC. The nematode population increased gradually throughout the experiment in plants at low soil moisture, whereas, at the higher soil moisture, population development was more rapid early in the experiment. Root and foliage yields were reduced significantly by cutting at early flowering and cutting at 2.5 cm above soil every 3 weeks. Nematodes reduced foliage yields significantly in all cutting management treatments, with the greatest reduction recorded when plants were cut at the early flowering stage. Nematode numbers per gram of rootlets increased more rapidly with more severe cutting. Total nematode reproduction was proportional to root yield.

RELATIONSHIP BETWEEN EVAPOTRANSPIRATION BY WHEAT AND THE STAGE OF CROP DEVELOPMENT, BELLANI-PLATE EVAPORATION, AND SOIL MOISTURE CONTENT

1965 ◽  
Vol 45 (1) ◽  
pp. 33-38 ◽  
Author(s):  
W. S. Ferguson
Keyword(s):  
Soil Moisture ◽  
Soil Moisture Content ◽  
Surface Soil ◽  
Field Capacity ◽  
Moisture Stress ◽  
Flowering Stage ◽  
Stage Of Development ◽  
Total Soil ◽  
Crop Development ◽  
Semi Arid Region

Mean weekly evapotranspiration by spring wheat at Brandon, Man. (1955–1959) was dependent on the stage of development of the crop. It increased from 0.70 in. per week at the 3-leaf stage to 1.45 in. per week at the flowering stage and decreased to 0.60 in. per week as the crop reached maturity. Evapotranspiration was correlated positively with Bellani-plate evaporation when the soil was moist to the surface and correlated negatively when the surface soil was dry, but total soil moisture was greater than 50% of field capacity. When the soil moisture was less than 50% of field capacity evapotranspiration was not correlated with Bellani-plate evaporation. Evapotranspiration was correlated positively with total soil moisture plus rainfall. This emphasizes the importance of moisture stress in limiting evapotranspiration in a semi-arid region.

scholarly journals Study of Growing Flue-cured Tobacco in Croatia under Various Conditions of Irrigation and Nitrogen Nutrition

2006 ◽  
Vol 22 (2) ◽  
pp. 125-132 ◽  
Author(s):  
M Cavlek ◽  
I Tursic ◽  
T Cosic
Keyword(s):  
Soil Moisture ◽  
Field Experiments ◽  
Nitrogen Nutrition ◽  
Sugar Content ◽  
Reducing Sugar ◽  
Early Flowering ◽  
Flowering Stage ◽  
Nicotine Content ◽  
The Third ◽  
Sugar Levels

AbstractThree field experiments were conducted at the experimental station of the Tobacco Institute Zagreb in Pitomaca during the years 1990 and 1992, 1993-1996 and 1999-2000 to determine the effects of irrigation at different soil moisture levels [40-100%, 60-100%, 80-100% of plant available water, (PAW)], of different starting times of irrigation (vegetative phase, early flowering stage, continuously), and of irrigation combined with nitrogen nutrition (0, 20, 40, 60 kg/ha N) on the yields and quality of flue-cured tobacco. The first two experiments involved block methods, the third involved the split-plot method.In the first experiment, irrigation led to an increase in yield (3-38%), in price/kg (15-69%) and in reducing sugar content (18-89%) and a reduction of nicotine content (20-39%) in the flue-cured leaves. Additional irrigation at the early flowering stage and constant maintenance of soil moisture at a higher level resulted in somewhat lower yields but better visually estimated tobacco quality and, as expected, had a marked influence on the contents of nicotine and reducing sugars.In the second experiment, irrigated tobacco gave higher yields in two of the four trial years, which were significant in 1995 (13-21%), higher reducing sugar levels in 1994 (20-34%) and a marked reduction of nicotine content in cured leaves in all years (11-56%). Under conditions identical with or similar to those used in this research, irrigation may be started at the early flowering stage.In the third experiment, in both years irrigated tobacco showed significantly higher yields, price/kg and reducing sugar levels and significantly lower nicotine content. Averaging the two years indicated increases of 17%, 12% and 26% and a decrease of 29%, respectively. Higher amounts of nitrogen fertilizer promoted yield (up to 32%) and nicotine content (up to 76%), while decreasing reducing sugar levels (by up to 52%). Also, the price/kg of tobacco fertilized with more than 20 kg/ha of nitrogen dropped by as much as 26%.

scholarly journals Invasion and reproduction of Pratylenchus penetrans in birdsfoot trefoil cultivars

2005 ◽  
Vol 80 (3) ◽  
pp. 179-184 ◽  
Author(s):  
J. Kimpinski ◽  
Y.A. Papadopoulos ◽  
B.R. Christie ◽  
K.B. McRae ◽  
C.E. Gallant
Keyword(s):  
Genetic Variability ◽  
Lotus Corniculatus ◽  
Birdsfoot Trefoil ◽  
Pratylenchus Penetrans ◽  
Root Lesion Nematode ◽  
Population Densities ◽  
Lesion Nematodes ◽  
Lesion Nematode ◽  
Root Lesion Nematodes ◽  
Screening Trial

Greenhouse trials were conducted to determine the levels of invasion of birdsfoot trefoil(Lotus corniculatus) cultivars and lines by the root-lesion nematode (Pratylenchuspenetrans). Numbersof nematodesin roots grown in 50-cm3 polystyrene starter pots were determined 6 weeks after planting. Nematodes were detected in the roots of all cultivars and lines, though the degree of invasion varied significantly. In the first screening trial, carried out in 1994 on 23 cultivars and lines, NB90-104, Upstart, and Viking harbored the lowest population densities of nematodes with levels below 1 000 g-1 of dry root, while Fergus and EPF had population densities over 30 000 g-1 of dry root. In the second screening trial conducted in 1995, all nine cultivars and lines tested, including NB90-104, Upstart, and Viking, had nematode levels greater than 7 900 g-1 of dry root. The results indicated that the cultivars and lines tested in this study exhibited wide genetic variability for invasion by root-lesion nematodes.

Soil moisture and temperature affect condensed tannin concentrations and growth in Lotus corniculatus and Lotus pedunculatus

1993 ◽  
Vol 44 (7) ◽  
pp. 1667 ◽  
Author(s):  
M Anuraga ◽  
P Duarsa ◽  
MJ Hill ◽  
JV Lovett
Keyword(s):  
Soil Moisture ◽  
Growth Rates ◽  
Condensed Tannin ◽  
Field Capacity ◽  
Moisture Stress ◽  
Birdsfoot Trefoil ◽  
Dry Matter Accumulation ◽  
Cultivar Development ◽  
Slight Elevation ◽  
Lotus Pedunculatus

Maku big trefoil and Dewey birdsfoot trefoil were grown at 14/10, 20/16, 26/22 and 32/28�C (14/10 h) in growth cabinets. Growth rates and condensed tannin (CT) concentrations were measured as soil moisture was changed from field capacity (FC) to 20% FC to FC again in three regrowth cycles. Seasonal dry matter accumulation and CT concentrations were also measured on these cultivars together with Sharnee big trefoil, Monarch cicer milkvetch, Chemung crownvetch and WL605 lucerne at two sites in the field. Condensed tannin concentrations were not greatly affected by temperature alone. However, moisture stress induced proportionately larger reductions in growth rates of big trefoil as temperature increased, and correspondingly larger rises in CT concentrations. Condensed tannin concentrations in birdsfoot trefoil were largely unaffected by these factors. In big trefoil, the responses in CT levels and growth rates continued even when soil moisture was returned to FC. Low temperature did not appear to affect CT concentrations in big trefoil, but caused some slight elevation in concentrations in birdsfoot trefoil. In the field, CT levels in the big trefoil cultivars, and in birdsfoot trefoil, were elevated in summer and autumn, when temperatures were high and periods of soil moisture stress occurred. The potential for elevated CT levels in big trefoil appears to be enhanced when growth rates are reduced by moisture stress and temperaturs are high. Big trefoil should be carefully screened for CT concentrations in the process of cultivar development. High CT levels are not a problem in birdsfoot trefoils such as Dewey.

EFFETS DU pH ET DES REGIMES HYDRIQUES DES SOLS SUR LES RENDEMENTS ET LA TENEUR EN Mn DE LA LUZERNE ET DU LOTIER CULTIVES EN SERRE

1976 ◽  
Vol 56 (4) ◽  
pp. 919-928 ◽  
Author(s):  
J. L. DIONNE ◽  
A. R. PESANT
Keyword(s):  
Soil Moisture ◽  
Soil Ph ◽  
Acid Soil ◽  
Manganese Content ◽  
Field Capacity ◽  
Soil Conditions ◽  
Birdsfoot Trefoil ◽  
Moisture Regime ◽  
Soil Moisture Regime ◽  
Moisture Regimes

Alfalfa (Medicago sativa L.) and birdsfoot trefoil (Lotus corniculatus L.) were grown under greenhouse conditions, on Ste-Rosalie clay and St-Jude sand adjusted at pH of 5.0, 6.5 and 7.5, in order to determine the effect of soil pH and soil moisture regimes on the yields of the two legumes. Three soil moisture regimes were used: (1) humid (H1), with soil moisture between saturation point and field capacity; (2) optimum (H2), with soil moisture between field capacity and 70% of this value; (3) dry (H3), with soil moisture between 50% of field capacity and wilting point. Under the dry soil moisture regime (H3), birdsfoot trefoil behaved in the same way as did alfalfa. Their drought resistance decreased as the soil pH increased. Dry matter yields were reduced by 61.5% when soils were limed at the pH of 7.5. Under the humid soil moisture regime (H1), the productivity of alfalfa decreased much more than that of birdsfoot trefoil. The effect of excess soil moisture on alfalfa was mostly observed on the unlimed soils. Under these wet and acid soil conditions, alfalfa was intoxicated and suffocated due to high exchangeable manganese content and poor soil aeration. Liming soils to the pH of 7.5 decreased exchangeable Mn in soils to a non-toxic level and alfalfa could then grow well enough to transpire off the excess of soil water. Birdsfoot trefoil was much less influenced by soil acidity and poor drainage than alfalfa was.

EFFETS DES DOSES DE BORE, DES REGIMES HYDRIQUES ET DU pH DES SOLS SUR LES RENDEMENTS DE LA LUZERNE ET DU LOTIER ET SUR L’ASSIMILABILITE DU BORE

1978 ◽  
Vol 58 (3) ◽  
pp. 369-379 ◽  
Author(s):  
J. L. DIONNE ◽  
A. R. PESANT
Keyword(s):  
Soil Moisture ◽  
Soil Ph ◽  
Field Capacity ◽  
Soil Conditions ◽  
Birdsfoot Trefoil ◽  
Moisture Regime ◽  
Yield Increase ◽  
Soil Moisture Regime ◽  
Moisture Regimes ◽  
Wilting Point

Alfalfa (Medicago sativa L. cv. Vernal) and birdsfoot trefoil (Lotus corniculatus L. cv. Leo) were grown under greenhouse conditions in order to determine changes in boron response and availability following variations in soil pH and soil moisture regimes. Three rates of boron applications were selected: 0, 1.5, and 3.0 ppm of B. Soil pH was adjusted to 5.0, 6.5 and 7.5, respectively. The soil moisture regimes were fixed as following: (1) very dry (H1) with soil moisture between 50% of field capacity and wilting point, (2) dry (H2), with soil moisture between field capacity and wilting point. (3) optimum (H3), with soil moisture between field capacity and 70% of this value. Boron fertilization was more useful to alfalfa than to birdsfoot trefoil. Optimum rate was found to be 1.5 ppm of B. On Ste-Rosalie clay, the yield increase due to boron was 22% on soils under the dry regime (H2) but was almost non-existant at the very dry (H1) and optimum water regime (H3). Boron application on Greensboro loam was more efficient on soils undergoing dry (H2) and very dry soil moisture regime (H1) than on soils where moisture conditions were optimum (H3). Dry matter yields were increased by a factor of 10 under dry (H2) and very dry (H1) soil moisture regimes compared to a factor of 4 under optimum soil moisture regime (H3). Under acid soil conditions, no yield increase was obtained following boron applications. Boron availability and response of the two legumes to B was also decreased by overliming soils to pH 7.4. The cyclic drought periods that happened under dry (H2) and very dry (H1) soil moisture regime produced similar effects. Boron availability and efficiency as plant nutrient was greatly reduced, if not annihilated, by the combined effect of repeated drought cycles and by either excessive soil acidity or overliming.

scholarly journals The root lesion nematode effector Ppen10370 is essential for parasitism of Pratylenchus penetrans

2021 ◽  
Author(s):  
Paulo Vieira ◽  
Claudia SL Vicente ◽  
Jordana Branco ◽  
Gary Buchan ◽  
Manuel Mota ◽  
...  
Keyword(s):  
Plant Pathogens ◽  
Potato Virus X ◽  
Pratylenchus Penetrans ◽  
Root Lesion Nematode ◽  
Migratory Species ◽  
Nematode Reproduction ◽  
Genes Encoding ◽  
Lesion Nematode

The root lesion nematode, Pratylenchus penetrans, is a migratory species that attacks a broad range of crops. Like other plant pathogens, P. penetrans deploys a battery of secreted protein effectors to manipulate plant hosts and induce disease. Although several candidate effectors of P. penetrans have been identified, detailed mechanisms of their functions and particularly their host targets remain largely unexplored. In this study, a repertoire of candidate genes encoding pioneer effectors of P. penetrans was amplified from mixed life stages of the nematode, cloned and subjected to transient expression in a heterologous host Nicotiana benthamiana using potato virus X-based gene vector. Among seven analyzed genes, the candidate effector designated as Ppen10370 triggered pleiotropic phenotypes substantially different from those produced by wild type infection. Transcriptome analysis of plants expressing Ppen10370 demonstrated that observed phenotypic changes were likely related to disruption of core biological processes in the plant due to effector-originated activities. Cross-species comparative analysis of Ppen10370 identified homologue gene sequences in five other Pratylenchus species and their transcripts were found to be localized specifically in the nematode esophageal glands by in situ hybridization. RNA silencing of the Ppen10370 resulted in a significant reduction of nematode reproduction and development, demonstrating an important role of the esophageal gland effector for parasitism.

Soil Moisture Deficits in South-Central Sweden

1989 ◽  
Vol 20 (2) ◽  
pp. 109-122 ◽  
Author(s):  
Lotta Andersson
Keyword(s):  
Soil Moisture ◽  
Field Capacity ◽  
Interannual Variations ◽  
Neutron Probe ◽  
South Central ◽  
Normal Ranges ◽  
Moisture Fluxes ◽  
In The Beginning ◽  
Probe Measurements ◽  
Different Parts

Some commonly used assumptions about climatically induced soil moisture fluxes within years and between different parts of a region were challenged with the help of a conceptual soil moisture model. The model was optimised against neutron probe measurements from forest and grassland sites. Five 10 yrs and one 105 yrs long climatic records, from the province of Östergötland, situated in south-central Sweden, were used as driving variables. It was concluded that some of the tested assumptions should not be taken for granted. Among these were the beliefs that interannual variations of soil moisture contents can be neglected in the beginning of the hydrological year and that soils usually are filled up to field capacity after the autumn recharge. The calculated climatic induced dryness was estimated to be rather insensitive to the choice of climatic stations within the region. Monthly ranges of soil moisture deficits (1883-1987) were shown to be skewed and it is therefore recommended to use medians and standard deviations in statistical analyses of “normal” ranges of soil moisture deficits.

scholarly journals Effect of Three Ca Sources Applied On Peanuts I. Productivity and Seed Quality1

1980 ◽  
Vol 7 (1) ◽  
pp. 19-25 ◽  
Author(s):  
D. L. Hallock ◽  
A. H. Allison
Keyword(s):  
Crop Yields ◽  
Relative Effectiveness ◽  
Correlation Coefficients ◽  
Early Flowering ◽  
Lower Yield ◽  
Flowering Stage ◽  
Arachis Hypogaea L ◽  
Dry Conditions ◽  
Increase Productivity ◽  
The Relationship

Abstract The relative effectiveness of United States Gypsum granular 420 Landplaster Bulk (420-Bulk) and Texasgulf Gypsum (Tg Gypsum) were compared with finely ground anhydrite (Bagged-LP) as sources of supplemental Ca for Florigiant peanuts (Arachis hypogaea L.). Treatments included the above sources at rates of 605 kg/ha banded (61 cm) or 907 kg/ha broadcast (91-cm wide rows) of CaSO4 equivalent per unit area covered (double these rates of 420-Bulk and Bagged-LP also were applied in 1977). Times of application were planting, planting + ca 30 days, and early flowering stage. The experiments were located on Kenansville lfs (Arenic Hapludult) in 1977 and on Rumford lfs (Typic Hapludult) in 1978. The Ca treatments increased crop yields from 360 to 1,200 kg/ha and crop value (yield × price) from $343 to $889/ha over the check in 1977. Slightly lower yield increases were obtained in 1978 when dry conditions prevailed during fruit maturation. Kernel size grades were improved markedly by all Ca treatments in 1977. There was a definite trend both years (significant in 1978) toward higher productivity when the Ca sources were applied at the early flowering stage compared to earlier applications. No difference was noted between methods of application of Bagged-LP or Tg Gypsum in 1978. Double rates of Bagged-LP or 420-Bulk in 1977 did not increase productivity over the low rates. A single application of Bagged-LP was as effective as split applications in the 1978 test. Germinability of seed in 1977 averaged 85% or higher for all Ca treatments. Seed germination in 1978 averaged 75%, 69% and 74% in plots where Tg Gypsum, 420-Bulk or Bagged-LP was applied, respectively. Germination was lowest in the check plots both years. Germinability and seed-Ca contents were significantly higher in 1978 when the Ca sources were applied at the early flowering stage (ca July 1) than 15 days earlier. Seed-Ca contents both years and K contents in 1978 were significantly correlated with germinability. The correlation coefficients were only 0.4 in each case and the relationship was negative for K. In general, 420-Bulk, Tg Gypsum, or Bagged-LP were equally effective sources of supplemental Ca for peanuts. However, when fruit mature under very dry conditions 420-Bulk may be somewhat inferior to the other Ca sources especially when applied before early flowering.

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