Mechanism for the Suppression of pea (Pisum sativum) Root Rot by Dinitroaniline Herbicides

Weed Science ◽  
1979 ◽  
Vol 27 (2) ◽  
pp. 195-201 ◽  
Author(s):  
J. R. Teasdale ◽  
R. G. Harvey ◽  
D. J. Hagedorn
Keyword(s):  
Pisum Sativum ◽  
Root Rot ◽  
Solution Culture ◽  
Spore Production ◽  
Aphanomyces Euteiches ◽  
Sensitive Stage ◽  
Zoospore Production ◽  
Asexual Spore ◽  
Pea Roots ◽  
Dinitroaniline Herbicides

Pea (Pisum sativumL. ‘Elf’) root rot suppression by dinitroaniline herbicides could not be explained by a direct effect on the host. Pre-incubation of pea roots with 0.1 ppmw of oryzalin (3,5-dinitro-N4,N4-dipropylsulfanilamide) or trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine) in solution culture did not alter their resistance to root rot. Furthermore, 0.1 ppmw of oryzalin or trifluralin did not alter the exudation of electrolytes or α-amino compounds from pea roots. Most of the dinitroaniline herbicides significantly inhibited mycelial radial growth of pathogen,Aphanomyces euteichesDrechs., at 1.0 ppmw and inhibited asexual spore production at 0.1 to 1.0 ppmw. Dinitramine (N4,N4-diethyl-α,α,α-trifluoro-3,5-dinitrotoluene-2,4-diamine), fluchloralin [N-(2-chloroethyl)-2,6-dinitro-N-propyl-4-(trifluoromethyl)aniline], and oryzalin inhibitedA. euteichesmycelial growth and asexual reproduction more effectively than the other dinitroaniline herbicides studied. The production of motile zoospores, the infecting propagule of the pathogen, was the most sensitive stage in the life cycle and was completely inhibited by 0.01 ppmw of all dinitroaniline herbicides tested. Since this concentration is below that estimated in the soil solution at registered rates of application, inhibition of motile zoospore production is sufficient to explain root rot suppression. Inhibition of pathogen motility resulted in a 2-week delay in the infection of pea roots. This delay allowed sufficient additional plant growth that the peas could better withstand the effects of subsequent disease development.

Suppression of Pea(Pisum sativum)Root Rot by Dinitroaniline Herbicides

Weed Science ◽  
1978 ◽  
Vol 26 (6) ◽  
pp. 609-613 ◽  
Author(s):  
J. R. Teasdale ◽  
R. G. Harvey ◽  
D. J. Hagedorn
Keyword(s):  
Pisum Sativum ◽  
Root Rot ◽  
Aphanomyces Euteiches ◽  
Average Yield ◽  
Fresh Weight ◽  
Common Root ◽  
Common Root Rot ◽  
Herbicide Treatments ◽  
Plant Stand ◽  
Dinitroaniline Herbicides

Nine substituted dinitronaline herbicides were studied to determine their effectiveness in controlling common root rot of peas(Pisum sativumL.) caused byAphanomyces euteichesDrechs. under field conditions. Most of the dinitroaniline herbicide treatments increased plant stand, plant fresh weight, and shelled pea yield due to root rot suppression in each of the three years studied. Weed control was good in all plots and did not contribute to yield differences. Root rot suppression and crop injury were the primary determinants of yields. The greatest yield increases when compared with the weeded control were 82% for 0.56 kg/ha of dinitramine(N4,N4-diethyl-α,α,α-trifluoro-3,5-dinitrotoluene-2,4-diamine) in 1974, 80% for 0.84 kg/ha of fluchloralin [N-(2-chloroethyl)-2,6-dinitro-N-propyl-4-(trifluoromethyl) aniline] in 1975, and 26% for 1.68 kg/ha of pendimethalin [N-(1-ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzenamine] in 1976. The best average yield increases over all years were 54% for the combination of trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine) and oryzalin (3,5-dinitro-N4,N4-dipropylsulfanilamide) at 0.56 + 0.56 kg/ha, 49% for fluchloralin at 0.84 kg/ha, and 43% for pendimethalin at 0.84 kg/ha. Annual applications of 0.84 kg/ha of trifluralin delayed the rate of pathogen infestation of a field repeatedly planted to peas.

Suppression of Root Diseases and Weeds in Peas(Pisum sativum)Treated with Dinitrophenol and Dinitroaniline Herbicides

Weed Science ◽  
1978 ◽  
Vol 26 (6) ◽  
pp. 589-593
Author(s):  
R. F. Sacher ◽  
H. J. Hopen ◽  
B. J. Jacobsen
Keyword(s):  
Pisum Sativum ◽  
Weed Control ◽  
Disease Severity ◽  
Root Rot ◽  
Fungal Pathogens ◽  
Severity Index ◽  
Disease Severity Index ◽  
Aphanomyces Euteiches ◽  
Root Diseases ◽  
Dinitroaniline Herbicides

Dinoseb (2-sec-butyl-4,6-dinitrophenol) and certain dinitroaniline herbicides suppressed root rot caused byAphanomyces euteichesDrechs. and other fungal pathogens in peas(Pisum sativumL.). Dinoseb was the most effective. At 6.72 kg/ha pre-plant incorporated (PPI) it reduced the disease severity index (DSI) in glasshouse bioassays to the level considered safe for general use by commercial growers. In fields tests disease severity was reduced and yield of peas was increased with dinoseb. Dinitroaniline herbicides reduced DSI values to the level considered safe for early crop peas. A simplified DSI method of measuring root rot based on mid-season root symptoms was found to be effective. Weed control was superior with the dinitroanilines and propachlor (2-chloro-N-isoproylacetanilide). Dinoseb significantly reduced weed populations relative to untreated plots. Several dinitroaniline treatments caused stunting and stand reduction.

Factors Affecting the Suppression of Pea(Pisum sativum)Root Rot(Aphanomyces euteiches)by Dinitroaniline Herbicides

Weed Science ◽  
1979 ◽  
Vol 27 (4) ◽  
pp. 467-472 ◽  
Author(s):  
J. R. Teasdale ◽  
R. G. Harvey ◽  
D. J. Hagedorn
Keyword(s):  
Soil Moisture ◽  
Pisum Sativum ◽  
Root Rot ◽  
Severe Disease ◽  
Field Capacity ◽  
Field Studies ◽  
Aphanomyces Euteiches ◽  
Greenhouse Study ◽  
Maximum Root ◽  
Dinitroaniline Herbicides

Field and greenhouse studies have shown that dinitroaniline herbicides suppress root rot of peas (Pisum sativumL.) caused by the fungusAphanomyces euteichesDrechs. This investigation was conducted to identify factors which could enhance root rot suppression. In a temperature-soil moisture growth chamber study, dinitroaniline herbicides significantly reduced disease severity symptoms at all temperature and soil moisture regimes except 32 C and 0.75 field capacity. Dinitroaniline herbicides increased pea fresh weight significantly only under those conditions which favored severe disease development. Maximum root rot suppression occurred at 24 C and 1.25 field capacity. In a greenhouse study of the interaction of root rot suppression with pea varieties, dinitroaniline herbicides significantly increased growth of all 12 pea varieties tested including a root rot tolerant wild type of pea. A series of experiments explored the effect of uniformity, time, and depth of dinitroaniline herbicide incorporation on root rot suppression. In greenhouse studies, non-uniform incorporation significantly reduced root rot suppression indicating the need for thorough incorporation to achieve maximum root rot suppression. The combination of trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine) + oryzalin (3,5-dinitro-N4,N4dipropylsulfanilamide) was more effective than either trifluralin or oryzalin alone under non-uniform incorporation conditions but not under uniform incorporation conditions. Field studies showed that herbicide incorporation 2 weeks prior to planting may improve pea yield by 1.12 kg/ha of trifluralin or 0.56 + 0.56 kg/ha of trifluralin + oryzalin but not by 0.56 kg/ha of trifluralin. Herbicide incorporation to 15.2 cm rather than the normal 7.6 cm, increased pea yield at the 1.12 kg/ha rate of trifluralin or oryzalin or at 0.56 + 0.56 kg/ha of trifluralin + oryzalin. At the 0.56 kg/ha rate of trifluralin or oryzalin, herbicide dilution offset any benefit from deeper soil incorporation.

scholarly journals Identification of Pisum sativum Germ Plasm with Resistance to Root Rot Caused by Multiple Strains of Aphanomyces euteiches

Plant Disease ◽  
1999 ◽  
Vol 83 (1) ◽  
pp. 51-54 ◽  
Author(s):  
D. K. Malvick ◽  
J. A. Percich
Keyword(s):  
Pisum Sativum ◽  
Root Rot ◽  
Plant Introduction ◽  
Aphanomyces Euteiches ◽  
Sources Of Resistance ◽  
Breeding Programs ◽  
Pea Seedlings ◽  
Biomass Loss ◽  
Serious Disease ◽  
Multiple Strains

Aphanomyces root rot is a serious disease of pea (Pisum sativum), and additional sources of resistance are needed for development of disease-resistant cultivars. Accessions (n = 123) from the P. sativum Plant Introduction (PI) collection with the highest relative levels of resistance to one strain of Aphanomyces euteiches were previously identified from among approximately 2,500 accessions evaluated. The chosen 123 accessions were evaluated in this study for resistance to root rot caused by multiple strains of this pathogen. Five strains representing different US geographical locations and pathogenicity characteristics were used to evaluate pea seedlings in a greenhouse. Disease severity (DS) and percent loss of fresh biomass (inoculated vs. non-inoculated plants) were determined 15 days after inoculation. Significant differences (P = 0.05) in levels of DS and biomass loss (BL) occurred among the accessions after inoculation individually with the five strains. The relative rank of accessions based on DS and BL varied with the strain of A. euteiches used for inoculations. The 20 accessions with the lowest DS after inoculation with each strain were identified. Based on lowest DS, two accessions were among the 20 identified with all five individual strains, and four other accessions were among the 20 identified with four of the five strains. The results suggest that the P. sativum PI collection contains useful accessions for breeding programs aimed at developing pea varieties with resistance to A. euteiches.

Response of Aphanomyces euteiches mycelia, zoospore, and oospore to oat extract

2004 ◽  
Vol 84 (2) ◽  
pp. 687-690
Author(s):  
M. A. Chandler ◽  
V. A. Fritz ◽  
R. R. Allmaras
Keyword(s):  
Pisum Sativum ◽  
Root Rot ◽  
Green Manure ◽  
Mycelial Growth ◽  
Late Summer ◽  
Aphanomyces Euteiches ◽  
Economic Threat ◽  
Pisum Sativum L ◽  
Production Research ◽  
Reduce Disease Severity

Root rot (Aphanomyces euteiches Drechs.) is a serious economic threat to pea (Pisum sativum L.) production. Research has shown a late-summer-seeded oat (Avena sativa L .) crop can reduce disease severity. A. euteiches was exposed to extracts of oat cvs. Bay and Ogle. Oat extract significantly enhanced mycelial growth of the pathogen. Key words: Root rot, biological control, green manure, Pisum sativum

scholarly journals Use of One Cycle of Recurrent Selection per Year for Increasing Resistance to Aphanomyces Root Rot in Peas

1992 ◽  
Vol 117 (4) ◽  
pp. 638-642 ◽  
Author(s):  
Mark E. Lewis ◽  
Earl T. Gritton
Keyword(s):  
Pisum Sativum ◽  
Seed Yield ◽  
Root Rot ◽  
Recurrent Selection ◽  
Control Line ◽  
Aphanomyces Euteiches ◽  
Field Screening ◽  
Phenotypic Recurrent Selection ◽  
Selection Intensities

The effectiveness of one cycle (C) per year of phenotypic recurrent selection was evaluated for improving tolerance of peas (Pisum sativum L.) to aphanomyces root rot (Aphanomyces euteiches Drech.). Each cycle included field-screening a population of F2 lines (summer), diallel intermating among lines selected from the field (fall greenhouse), and one generation of selfing F1 plants (spring greenhouse) to produce F2 lines for the next cycle. The schedule is repeated for each cycle. A blocks-within-replicates design was employed in the field screening of C1 and C2 to improve within-block homogeneity. Selection intensities were 12.4%, 11.1%, and 10.6% for C0, C1, and C2, respectively. Using the performance of a tolerant control line, Mn 108, as a basis of comparison, the realized gain in dry seed yield and survival was 32% and 68% from C0 to C1 and 22% and 115% from C1 to C2, respectively.

scholarly journals Is a Fully Established Arbuscular Mycorrhizal Symbiosis Required for Bioprotection of Pisum sativum Roots against Aphanomyces euteiches?

2000 ◽  
Vol 13 (2) ◽  
pp. 238-241 ◽  
Author(s):  
Sophie Slezack ◽  
Eliane Dumas-Gaudot ◽  
Michel Paynot ◽  
Silvio Gianinazzi
Keyword(s):  
Pisum Sativum ◽  
Arbuscular Mycorrhizal Fungus ◽  
Mycorrhizal Fungus ◽  
Arbuscular Mycorrhizal ◽  
Arbuscular Mycorrhizal Symbiosis ◽  
Mycorrhizal Symbiosis ◽  
Aphanomyces Euteiches ◽  
Chitinolytic Enzymes ◽  
Pea Roots

Bioprotection of pea roots against Aphanomyces euteiches by the arbuscular mycorrhizal fungus G. mosseae was demonstrated to depend on a fully established symbiosis. This was related with induction of mycorrrhiza-related chitinolytic enzymes. Possible mechanisms implicated in bioprotection are discussed.

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