scholarly journals Predispositional Effect of Soil Water Saturation on Infection of Chile Pepper by Phytophthora capsici

HortScience ◽  
2006 ◽  
Vol 41 (1) ◽  
pp. 172-175 ◽  
Author(s):  
S. Sanogo
Keyword(s):  
New Mexico ◽  
Soil Water ◽  
Growth Stage ◽  
Water Saturation ◽  
Phytophthora Capsici ◽  
Soil Conditions ◽  
Growth Stages ◽  
Chile Pepper ◽  
Disease Symptoms ◽  
Soil Water Saturation

Phytophthora capsici is a serious soilborne pathogen in chile pepper [Capsicum annuum L.] in New Mexico, and has been shown to spread under high soil moisture conditions and cause losses in a wide array of crops worldwide. This study was conducted to assess whether soil water saturation predisposes chile pepper to infection by P. capsici. Potted chile pepper plants of `Criollo de Morelos 334' (`CM334') and `New Mexico 6-4' (`NM6-4'), resistant and susceptible to P. capsici, respectively, were subjected to soil water saturation conditions (saturated and nonsaturated) for 3 and 6 days at two growth stages (six- to eight-leaf stage and one- to four-flower bud stage) prior to being inoculated or noninoculated with zoospores of P. capsici. Regardless of growth stage, no disease symptoms developed in `CM334' grown either under saturated or nonsaturated soil conditions at any of the two periods (3 or 6 days) of soil water saturation. In `NM6-4', disease symptoms consisting of stem necrosis, defoliation, and wilting were expressed. Plant growth stage at inoculation had a significant effect on disease severity (P < 0.0001). However, the response of `NM6-4' to P. capsici at each growth stage under saturated soil conditions was similar to that under nonsaturated conditions regardless of the period of saturation (P = 0.09). These results indicate that soil water saturation does not exert a significant predispositional effect on infection of chile pepper by P. capsici.

scholarly journals Incidence of Phytophthora Blight and Verticillium Wilt Within Chile Pepper Fields in New Mexico

Plant Disease ◽  
2006 ◽  
Vol 90 (3) ◽  
pp. 291-296 ◽  
Author(s):  
S. Sanogo ◽  
J. Carpenter
Keyword(s):  
New Mexico ◽  
Drip Irrigation ◽  
Phytophthora Capsici ◽  
Furrow Irrigation ◽  
Growth Stages ◽  
Phytophthora Blight ◽  
Chile Pepper ◽  
Plant Infection ◽  
Causative Agents ◽  
Pepper Plants

Statewide surveys of commercial chile pepper (Capsicum annuum) fields were conducted in New Mexico from 2002 to 2004 to gain information on the incidence of diseases with wilt symptoms and their causative agents. Fifty-nine fields were surveyed during the course of this 3-year study when chile pepper plants were at growth stages from green fruit to beginning red fruit. All fields were affected by diseases with wilt symptoms. The proportion of total field area exhibiting symptoms of wilt spanned from less than 1% to over 80%. Field diagnostics along with laboratory assays of wilted plants revealed that the wilting was caused by Phytophthora capsici and Verticillium dahliae. The two pathogens were both found in 80% of the fields, and occurred together in some wilted plants in 12% of the fields. Average incidence of plant infection (number of plants infected with P. capsici or V. dahliae out of 5 to 25 wilted plants sampled) varied from approximately 40 to 90% for P. capsici, and from 18 to 65% for V. dahliae. Incidence of plant infection by P. capsici was approximately 40% less in fields with drip irrigation than in fields with furrow irrigation. In contrast, incidence of plant infection by V. dahliae was approximately 32% greater under drip irrigation than under furrow irrigation. In pathogenicity tests, isolates of P. capsici and V. dahliae caused symptoms in inoculated chile pepper identical to those in field-grown chile pepper plants. Results indicate that diseases with wilt symptoms are well established in chile pepper production fields, with P. capsici and V. dahliae posing the most serious challenge to chile pepper producers in New Mexico.

scholarly journals Asexual Reproduction of Phytophthora capsici as Affected by Extracts from Agricultural and Nonagricultural Soils

2007 ◽  
Vol 97 (7) ◽  
pp. 873-878 ◽  
Author(s):  
S. Sanogo
Keyword(s):  
New Mexico ◽  
Chemical Composition ◽  
Discriminant Analysis ◽  
Phytophthora Capsici ◽  
Organic Matter Content ◽  
Discriminant Functions ◽  
Chile Pepper ◽  
Soil Extracts ◽  
Significant Difference ◽  
History Of

Formation of sporangia and zoospores in species of Phytophthora is known to be influenced by soil microbial and chemical composition. In Phytophthora capsici, the study of the relationship of soil chemical composition to production of sporangia and zoospores has been limited. P. capsici is a soilborne pathogen of a wide array of vegetable crops, including chile pepper (Capsicum annuum) in New Mexico. Production of sporangia and zoospores by P. capsici was evaluated in extracts of soils from three different environments in New Mexico: (i) agricultural environments with a long history of chile pepper cropping and occurrence of P. capsici (CP), (ii) agricultural environments with no history of chile pepper cropping and no occurrence of P. capsici (Non-CP), and (iii) nonagricultural environments consisting of forests and rangelands (Non-Ag). There was a significant difference in production of P. capsici asexual propagules, expressed as natural log (number of sporangia × number of zoospores), among the three environments (P = 0.0298). Production of propagules was 9 to 13% greater in Non-Ag than in CP or Non-CP environments. Stepwise multiple discriminant analysis and canonical discriminant analysis identified the edaphic variables Na, pH, P, organic matter content, and asexual propagule production as contributing the most to the separation of the three environments. Two significant (P < 0.0001) canonical discriminant functions were derived with the first function, accounting for ≈75% of the explained variance. Based on the two discriminant functions, ≈93, 86, and 89% of observations in CP, Non-CP, and Non-Ag environments, respectively, were classified correctly. Soils from agricultural and nonagricultural environments differentially influence production of sporangia and zoospores in P. capsici, and soil samples could be effectively classified into agricultural and nonagricultural environments based on soil chemical properties and the production of asexual propagules by P. capsici in soil extracts.

scholarly journals Erythrina speciosa (Leguminosae-Papilionoideae) under soil water saturation: morphophysiological and growth responses

2009 ◽  
Vol 104 (4) ◽  
pp. 671-680 ◽  
Author(s):  
Camilo L. Medina ◽  
Maria Cristina Sanches ◽  
Maria Luiza S. Tucci ◽  
Carlos A. F. Sousa ◽  
Geraldo Rogério F. Cuzzuol ◽  
...  
Keyword(s):  
Soil Water ◽  
Water Saturation ◽  
Growth Responses ◽  
Soil Water Saturation

scholarly journals Effect of soil water saturation on slope stability: Tomsk case study

2019 ◽  
Vol 98 ◽  
pp. 05005 ◽  
Author(s):  
Natalia Brakorenko ◽  
Anna Leonova ◽  
Aleksey Nikitenkov
Keyword(s):  
Shear Strength ◽  
Slope Stability ◽  
Soil Water ◽  
Water Saturation ◽  
Shear Strength Parameters ◽  
Strength Parameters ◽  
A Site ◽  
The Impact ◽  
Soil Water Saturation

We investigate in this article the impact of soil water saturation on the slope stability, using a site in Tomsk city as a case study. The dependency of the shear strength parameters of soil on the degree of soil water saturation has been demonstrated. The paper also provides equations for the calculation of slope stability coefficient under different values of soil water saturation.

Soil water saturation: Dielectric determination

1987 ◽  
Vol 23 (4) ◽  
pp. 591-595 ◽  
Author(s):  
A. Alharthi ◽  
J. Lange
Keyword(s):  
Soil Water ◽  
Water Saturation ◽  
Soil Water Saturation

Influence of continuous and periodic soil water conditions on root necrosis of holly caused by Pythium spp.

1970 ◽  
Vol 48 (9) ◽  
pp. 1641-1645 ◽  
Author(s):  
J. A. Biesbrock ◽  
Floyd F. Hendrix Jr.
Keyword(s):  
Soil Temperature ◽  
Soil Water ◽  
Water Saturation ◽  
Root Damage ◽  
Root Necrosis ◽  
Water Conditions ◽  
Prolonged Duration ◽  
Soil Temperatures ◽  
Soil Water Conditions ◽  
Soil Water Saturation

Root damage in Helleri holly induced by P. vexans was affected more by differences in soil water saturation capacities (70 and 90%) than by differences in mean soil temperatures (18, 24, and 30 °C). By contrast, root damage in Helleri holly induced by P. irregulare was affected more by differences in mean soil temperatures than by differences in soil water saturation capacities. Root damage in Convexa holly induced by P. vexans was affected more by a periodic saturation of prolonged duration than by differences in soil temperatures. By contrast, root damage in Convexa holly induced by P. irregulare was affected more by differences in soil temperature than by periodic saturations of prolonged and unprolonged durations.<

Relating the onset of reduction to degree of soil water saturation

2013 ◽  
Vol 30 (3) ◽  
pp. 157-161 ◽  
Author(s):  
Kimberly Smith ◽  
Cornelius W van Huyssteen
Keyword(s):  
Soil Water ◽  
Water Saturation ◽  
Soil Water Saturation
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