scholarly journals Multimodel Inference for the Prediction of Disease Symptoms and Yield Loss of Potato in a Two-Year Crop Rotation Experiment

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Wim Van den Berg ◽  
Jan Vos ◽  
Johan Grasman
Keyword(s):  
Soil Ph ◽  
Verticillium Dahliae ◽  
Information Criterion ◽  
Nematode Species ◽  
Globodera Pallida ◽  
Water Soluble ◽  
Yield Reduction ◽  
Disease Symptoms ◽  
Ph Values ◽  
Soil Infestation

The second order Akaike information criterion was used for the assessment of 139 regression models for three responses of potato test crops: (a) incidence ofSpongospora subterraneaon the harvested tubers, (b) percentage of haulms infected withVerticillium dahliae,and (c) tuber yield. Six variables that are likely related to the response variables were taken into consideration: soil infestations of the fungusVerticillium dahliaeand of three nematode species (Globodera pallida,Trichodoridae,andMeloidogynespp.) and, furthermore, soil pH and water soluble phosphor (P). Interactions betweenV. dahliaeand the three nematode species were included as well. Based on multimodelling, predictors are given a weight from which one may decide about the need to include them in a prediction of crop yield. The most important predictors were soil infestation levels ofV. dahliaeandG. pallidaand soil pH. The outcome also showed that tubers suffered more fromS. subterraneafor higher soil pH values. Finally, yield reduction from the presence ofV. dahliaewas enhanced by the presence of higher densities ofG. pallida.

LABORATORY AND GREENHOUSE STUDIES ON EFFECT OF LIME AND OTHER AMENDMENTS ON WATER-SOLUBLE BORON IN SOIL

1958 ◽  
Vol 38 (1) ◽  
pp. 27-35 ◽  
Author(s):  
R. F. Bishop ◽  
R. L. Cook
Keyword(s):  
Sodium Hydroxide ◽  
Soil Ph ◽  
Laboratory Experiments ◽  
Boron Content ◽  
Magnesium Carbonate ◽  
Water Soluble ◽  
Plant Analysis ◽  
Laboratory Studies ◽  
Ph Values ◽  
Calcium And Magnesium

Greenhouse and laboratory experiments were used to study the effect of various soil amendments on the water-soluble boron content of a strongly acid soil.In the greenhouse, using ladino clover as the test crop, liming reduced boron availability as measured by soil and plant analysis. Calcium-boron ratios in the clover ranged from approximately 550:1 to 2000:1 and there was a significant correlation between the water-soluble boron in the soil and the boron content of the clover.In the laboratory studies calcium and magnesium carbonates were equally effective in decreasing water-soluble boron in soil. Gypsum was ineffective. Manure or alfalfa hay increased the water-soluble boron content of soil in proportion to the amounts applied. Applications of sodium hydroxide, resulting in a range of soil pH values from 4.82 to 9.72, were accompanied by decreases in water-soluble boron until a pH of approximately 8.0 was reached. Above this point water-soluble boron increased. At comparable pH values of approximately 7.0 or less, sodium hydroxide caused a smaller reduction in water-soluble boron than did either calcium or magnesium carbonate.

WATER-SOLUBLE AND EXCHANGEABLE ALUMINUM IN ACID SOILS AS AFFECTED BY LIMING AND FERTILIZATION

1967 ◽  
Vol 47 (3) ◽  
pp. 203-210 ◽  
Author(s):  
L. B. MacLeod ◽  
L. P. Jackson
Keyword(s):  
Soil Ph ◽  
Surface Soil ◽  
Acid Soils ◽  
Water Soluble ◽  
Ph Values ◽  
Exchangeable Al ◽  
Exchangeable Aluminum ◽  
High Fertilization ◽  
Surface Soil Ph ◽  
Representative Samples

The concentration of water-soluble and exchangeable aluminum was determined in the 0–15-, 15–23-, 23–30- and 30–45-cm depths of a Podzol limed to provide surface soil pH values ranging from 4.5 to 7.2. Both soluble and exchangeable Al decreased with increasing soil pH. Soluble Al ranged from 5.7 ppm at pH 4.4 with high fertilization to 0.3 ppm at pH 6.5 with similar fertilization. Increasing the rate of fertilization at pH 4.5 raised the soluble Al from 2.6 to 5.7 ppm. Fertilization still doubled the soluble Al in soil at pH 5.1 but had little effect as the pH was raised further to 5.8 and 6.5. Soluble Al in the subsoil samples was less than in surface soil samples at the same pH, while with exchangeable Al, the concentration was greater in the subsoil than in the surface soil samples.There was not a direct relationship between pH and soluble Al, although the highest soluble Al concentrations occurred at lowest soil pH levels. Analyses of 30 representative samples of surface soil taken from farmers' fields showed that the soluble Al concentration at pH 4.0 ranged from 3.5 to 4.8 ppm, while at a pH of 5.0 it ranged from 0.2 to 2.8 ppm. The concentrations of soluble Al in many of these soils exceeded the levels previously shown by nutrient solution experiments to severely restrict growth of legumes and some varieties of barley.

Soil acidity in 1970 and 1989 in a coniferous forest in southwest Finland

1998 ◽  
Vol 78 (3) ◽  
pp. 477-479 ◽  
Author(s):  
C. J. Westman ◽  
S. Jauhiainen
Keyword(s):  
Key Words ◽  
Soil Ph ◽  
Soil Acidity ◽  
Mineral Soil ◽  
Coniferous Forest ◽  
Soil Layers ◽  
Water Suspension ◽  
Ph Values ◽  
Humus Layer ◽  
Repeated Sampling

Forest soil pH in southwest Finland was measured with identical sampling and analysing methods in 1970 and 1989. The acidity of the organic humus layer increased significantly as pH values measured on water and on salt suspensions decreased between the two sampling dates. For the mineral soil layers, no unambiguous trend was found. pH values measured on salt suspension tended to be unchanged or lower, while pH on water suspension in some soil layers were even higher in 1989 than in 1970. Key words: pH, repeated sampling

The ability of rhizosphere bacteria isolated from nematode host and non-host plants to influence the hatch in vitro of the two potato cyst nematode species, Globodera rostochiensis and G. pallida

Nematology ◽  
2004 ◽  
Vol 6 (3) ◽  
pp. 375-387 ◽  
Author(s):  
N. Aileen Ryan ◽  
Peter Jones
Keyword(s):  
Sugar Beet ◽  
Host Plant ◽  
Host Plants ◽  
Nematode Species ◽  
Cyst Nematode ◽  
Potato Cyst Nematode ◽  
Globodera Pallida ◽  
Bacterial Isolates ◽  
Bacillus Spp

AbstractSeventy bacteria, isolated from the rhizosphere of the potato cyst nematode (PCN) host plant, potato, were cultured in the presence and absence of potato root leachate (PRL) and the resultant culture filtrates were analysed for their ability to affect the hatch in vitro of the two PCN species. Of the isolates tested, nine had a significant effect on PCN hatch. Six affected Globodera pallida hatch and three affected G. rostochiensis hatch. Five of the isolates significantly increased hatch only when cultured in the presence of PRL. Three of the isolates decreased PCN hatch significantly in PRL. Only one isolate increased hatch significantly in the absence of PRL. No isolate affected the hatch of both species. Six of the nine isolates that significantly affected PCN hatch had been pre-selected by culturing on PRL. Bacterial isolates from PCN non-hosts (14 from wheat, 17 from sugar beet) were also tested for hatching activity. The principal effect of the hatch-active isolates from the PCN non-host plants was to increase PCN hatch in the presence of PRL. In contrast to the host bacteria results, the isolates from non-host plants affected only G. rostochiensis hatch (three wheat isolates and four sugar beet isolates significantly increased G. rostochiensis hatch); no such isolate affected G. pallida hatch significantly in the presence of PRL. Ten isolates (32%) from non-host plants had the ability to increase significantly the hatch of PCN in the absence of PRL (eight of these affected G. rostochiensis hatch and four affected G. pallida hatch), compared to only one bacterial isolate (1%) from a host plant. The majority of the isolates from non-hosts produced PCN species-specific effects, as with the bacteria isolated from potatoes, although two wheat isolates increased the hatch of both species significantly in the absence of PRL. Of 20 hatch-active bacterial isolates (from all three plants) identified, 70% were Bacillus spp. Other genera identified were Arthrobacter , Acinetobacter and Staphylococcus .

Changes in phosphorus and nitrogen availability on recessional moraines of the Athabasca Glacier, Alberta

1987 ◽  
Vol 65 (1) ◽  
pp. 210-213 ◽  
Author(s):  
A. H. Fitter ◽  
W. F. J. Parsons
Keyword(s):  
Ground Water ◽  
Soil Ph ◽  
Nitrogen Availability ◽  
Water Soluble ◽  
Bare Ground ◽  
Early Stages ◽  
Leaf P

Soil pH and concentrations of N and P in leaves of Dryas drummondii were measured on recessional moraines of the Athabasca Glacier, Alberta. Soil pH declined by 0.5 units per 100 years under Dryas but remained steady on bare ground. Water-soluble N and P levels in soil remained low at all stages, but N was higher under Dryas patches. Leaf P and N declined in the early stages of succession but increased later. This increase may represent the initiation of biotic N and P cycles in soil. These patterns contrast with those reported for other moraine successions.

Key Insights and Research Prospects at the Dawn of the Population Genomics Era for Verticillium dahliae

2021 ◽  
Vol 59 (1) ◽  
Author(s):  
Jie-Yin Chen ◽  
Steven J. Klosterman ◽  
Xiao-Ping Hu ◽  
Xiao-Feng Dai ◽  
Krishna V. Subbarao
Keyword(s):  
Population Structure ◽  
Verticillium Dahliae ◽  
Plant Pathogens ◽  
Population Genomics ◽  
Population Divergence ◽  
Annual Review ◽  
Publication Date ◽  
Disease Symptoms ◽  
Historical Perspectives ◽  
Characteristic Features

The genomics era has ushered in exciting possibilities to examine the genetic bases that undergird the characteristic features of Verticillium dahliae and other plant pathogens. In this review, we provide historical perspectives on some of the salient biological characteristics of V. dahliae, including its morphology, microsclerotia formation, host range, disease symptoms, vascular niche, reproduction, and population structure. The kaleidoscopic population structure of this pathogen is summarized, including different races of the pathogen, defoliating and nondefoliating phenotypes, vegetative compatibility groupings, and clonal populations. Where possible, we place the characteristic differences in the context of comparative and functional genomics analyses that have offered insights into population divergence within V. dahliae and the related species. Current challenges are highlighted along with some suggested future population genomics studies that will contribute to advancing our understanding of the population divergence in V. dahliae. Expected final online publication date for the Annual Review of Phytopathology, Volume 59 is August 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

A STUDY OF A WATER-SOLUBLE COMPLEX OF PRODIGIOSIN PRODUCED BY A STRAIN OF SERRATIA MARCESCENS

1962 ◽  
Vol 40 (1) ◽  
pp. 1019-1024 ◽  
Author(s):  
Seiichi Yoshida
Keyword(s):  
Molecular Weight ◽  
Light Scattering ◽  
Serratia Marcescens ◽  
Average Molecular Weight ◽  
Electrophoretic Analysis ◽  
Water Soluble ◽  
Soluble Complex ◽  
Ph Values ◽  
Scattering Measurements ◽  
Water Soluble Complex

A water-soluble pigment excreted from Serratia marcescens has been purified by precipitation with ammonium sulphate, dialysis, and ultracentrifugation at different pH values. The purified pigment showed a single band in the ultracentrifuge and by electrophoretic analysis at several pH values. An average molecular weight of 5 × 106 was calculated from light-scattering measurements. This pigment is composed of carbohydrate and protein combined with prodigiosin, and several properties of the complex are described.

scholarly journals Adsorption of Heavy Metals on Soil Collected from Lixisol of Typical Karst Areas in the Presence of CaCO3 and Soil Clay and Their Competition Behavior

2020 ◽  
Vol 12 (18) ◽  
pp. 7315
Author(s):  
Guandi He ◽  
Zhenming Zhang ◽  
Xianliang Wu ◽  
Mingyang Cui ◽  
Jiachun Zhang ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Soil Sample ◽  
Soil Ph ◽  
Clay Content ◽  
Guizhou Province ◽  
Metal Exposure ◽  
Risk Area ◽  
High Risk Area ◽  
Ph Values ◽  
Pseudo Second Order

The content of heavy metals in the soil in Guizhou Province, which is a high-risk area for heavy metal exposure, is significantly higher than that in other areas in China. Therefore, the objective of this study was to evaluate the ability of CaCO3 and clay to accumulate heavy metals in topsoil sample collected from Lixisol using the method of indoor simulation. The results showed that the contents of Cu, Zn, Cd, Cr, Pb, Hg and As in the soil sample were 10.8 mg/kg, 125 mg/kg, 0.489 mg/kg, 23.5 mg/kg, 22.7 mg/kg, 58.3 mg/kg and 45.4 mg/kg, respectively. The soil pH values increased with the CaCO3 concentration in the soil, and the fluctuation of the soil pH values was weak after the CaCO3 concentrations reached 100 g/kg. The adsorption capacity of lime soil increased by approximately 10 mg/kg on average, and the desorption capacity decreased by approximately 300 mg/kg on average. The desorption of all heavy metals in this study did not change with increasing clay content. Pseudo-second-order kinetics were more suitable for describing the adsorption kinetics of heavy metals on the soil material, as evidenced by the higher R2 value. The Freundlich model can better describe the adsorption process of As on lime soil. The process of As, Cr, Cd and Hg adsorption on the soil sample was spontaneous and entropy-driven. Additionally, the process of Cu and Pb adsorption on the soil materials was spontaneous and enthalpy-driven. Generally, the adsorption and desorption of heavy metals in polluted soil increased and decreased, respectively, with increasing CaCO3 content. The effect of calcium carbonate on the accumulation of heavy metals in soil was greater than that of clay. In summary, CaCO3 and pH values in soil can be appropriately added in several areas polluted by heavy metals to enhance the crop yield and reduce the adsorption of heavy metals in soils.

scholarly journals Occurrence and molecular characterization of cyst nematode species (Globodera spp.) associated with potato crops in Colombia

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0241256
Author(s):  
Daniela Vallejo ◽  
Diego A. Rojas ◽  
John A. Martinez ◽  
Sergio Marchant ◽  
Claudia M. Holguin ◽  
...  
Keyword(s):  
Management Strategies ◽  
Nematode Species ◽  
Globodera Pallida ◽  
Rrna Gene ◽  
Potato Cyst Nematodes ◽  
28S Rrna ◽  
Cyst Nematodes ◽  
Nucleotide Substitutions ◽  
Internal Transcribed Spacer Region ◽  
The Status

Potato cyst nematodes (PCN) from the genus Globodera spp. cause major losses in the potato (Solanum tuberosum) industry worldwide. Despite their importance, at present little is known about the status of this plant pathogen in cultivated potatoes in Colombia. In this study, a total of 589 samples collected from 75 geographic localities in nine potato producing regions of Colombia (Cundinamarca, Boyacá, Antioquia, Nariño, Santander, Norte de Santander, Tolima, Caldas and Cauca) were assayed for the presence of potato cyst nematodes. Fifty-seven percent of samples tested positive for PCN. Based on phylogenetic analysis of the internal transcribed spacer region (ITS1-5.8S-ITS2) of the rRNA gene and D2-D3 expansion segments of the 28S rRNA gene, all populations but one were identified as Globodera pallida. Sequences of G. pallida from Colombia formed a monophyletic group closely related to Peruvian populations, with the lowest average number of nucleotide substitutions per site (Dxy = 0.002) and net nucleotide substitutions per site (Da = 0.001), when compared to G. pallida populations from Europe, South and North America. A single sample formed a well-supported subclade along with G. rostochiensis and G. tabacum from Japan, USA and Argentina. To our knowledge this is the first comprehensive survey of Globodera populations from Colombia that includes genetic data. Our findings on species diversity and phylogenetic relationships of Globodera populations from Colombia may help elucidate the status and distribution of Globodera species, and lead to the development of accurate management strategies for the potato cyst nematodes.

scholarly journals Vertical distribution of soil nutrients under different land use systems in Bangladesh

2020 ◽  
pp. 6-12
Author(s):  
Tahsina Sharmin Hoque ◽  
Shafia Afrin ◽  
Israt Jahan ◽  
Md. Joinul Abedin Mian ◽  
Mohammad Anwar Hossain
Keyword(s):  
Electrical Conductivity ◽  
Land Use ◽  
Organic Matter ◽  
Soil Ph ◽  
Soil Depth ◽  
Organic Matter Content ◽  
Soil Samples ◽  
Water Soluble ◽  
Exchangeable K ◽  
Land Use Systems

Soil depth can significantly influence the availability of nutrients in soil. An experiment was conducted with seven soil samples from seven land use types to observe the effect of soil depth on soil properties under various land use systems. Soil pH, electrical conductivity (EC), organic matter, available phosphorus (P), available sulphur (S) and different forms of potassium (K) such as water soluble, exchangeable and non-exchangeable were determined from the soil samples collected from four soil depths (viz. 0-10, 10-20, 20-30 and 30-40 cm). Soil pH varied from 6.30-7.39 irrespective of depths and land uses and it increased with increasing soil depth. Electrical conductivity of the soils ranged from 42-310 µS cm-1 and organic matter status of most of the soils was very low to medium in level. Both EC and organic matter content decreased with the increase of soil depth. Available P concentration showed no specific changing trend with soil depth whereas available S concentration under different land use systems decreased with increasing soil depth. The concentrations of water soluble, exchangeable and non-exchangeable K in soils varied from 12.30-39.60, 20.90-53.16 and 163.30-684.30 mg kg-1, respectively and showed no specific changing pattern with soil depth. Water soluble K content was higher in rice growing fertilizer and manure-treated soil but higher exchangeable and non-exchangeable K contents were observed in banana growing soil. In rice growing soils, nutrient concentration is mostly higher in nitrogen (N), P and K + farm yard manure (FYM) - treated plots compared to rice growing control plots.

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