Importance of seed-borne inoculum in the etiology of the Ascochyta blight complex of field peas (Pisum sativum L.) grown in Victoria

1995 ◽  
Vol 35 (4) ◽  
pp. 525 ◽  
Author(s):  
TW Bretag ◽  
TV Price ◽  
PJ Keane
Keyword(s):  
Pisum Sativum ◽  
Ascochyta Blight ◽  
Mycosphaerella Pinodes ◽  
Seed Infection ◽  
Seeding Rate ◽  
Pisum Sativum L ◽  
Field Peas ◽  
Ascochyta Pisi ◽  
Growing Region ◽  
Seed Infestation

Fungi associated with the ascochyta blight complex of field peas were isolated from 436 of 691 seedlots tested. Of the fungi detected, 94.8% of isolates were Mycosphaerella pinodes, 4.2% Phoma medicaginis, and 1.0% Ascochyta pisi. The levels of infestation of seed varied considerably from year to year and between seedlots, depending on the amount of rainfall between flowering and maturity. Within a particular pea-growing region, the level of seed-borne infection was often highest in seed from crops harvested latest. In addition, crops sown early were usually more severely affected by disease than late-sown crops, and this resulted in higher levels of seed infection. There was no correlation between the level of seed infestation by M. pinodes and the severity of ascochyta blight; however, where the level of seed infection was high (>11%) there was a significant reduction in emergence, which caused a reduction in grain yield. It may therefore be possible to use seed with high levels of seed-borne ascochyta blight fungi, provided the seeding rate is increased to compensate for poor emergence.

The epidemiology and control of ascochyta blight in field peas: a review

2006 ◽  
Vol 57 (8) ◽  
pp. 883 ◽  
Author(s):  
T. W. Bretag ◽  
P. J. Keane ◽  
T. V. Price
Keyword(s):  
Current Knowledge ◽  
Ascochyta Blight ◽  
Mycosphaerella Pinodes ◽  
Sources Of Resistance ◽  
New Crops ◽  
Field Peas ◽  
Ascochyta Pisi ◽  
Almost All ◽  
The Cost ◽  
And Control

Ascochyta blight is one of the most important diseases affecting field peas. The disease occurs in almost all pea-growing regions of the world and can cause significant crop losses when conditions are favourable for an epidemic. Here we review current knowledge of the epidemiology of the disease. Details are provided of disease symptoms, the disease cycle and the taxonomy of the causal fungi, Ascochyta pisi, Mycosphaerella pinodes and Phoma pinodella. The importance of seed-, soil- and air-borne inoculum is discussed along with the factors that influence survival of the causal fungi in soil, on seed or associated with pea trash. Many studies have been reviewed to establish how the fungi responsible for the disease survives from year to year, how the disease becomes established in new crops and the conditions that favour disease development. Evidence is provided that crop rotation, destruction of infected pea trash and chemical seed treatments can significantly reduce the amount of primary inoculum. Later sowing of crops has been shown to reduce the incidence and severity of disease. Fungicides have been used successfully to control the disease, although the cost of their application can significantly reduce the profitability of the crop. The best long-term strategy for effective disease control appears to be the development of ascochyta blight resistant pea varieties. Reports of physiological specialisation in ascochyta blight fungi are also documented. Despite extensive screening of germplasm, relatively few sources of resistance to ascochyta blight fungi have been found in Pisum sativum. However, the discovery of much better sources of resistance in closely related species and the development of advanced breeding methods offer new possibilities for developing useful resistance.

Fungicidal control of ascochyta blight of field pea

1996 ◽  
Vol 76 (1) ◽  
pp. 67-71 ◽  
Author(s):  
T. D. Warkentin ◽  
K. Y. Rashid ◽  
A. G. Xue
Keyword(s):  
Pisum Sativum ◽  
Key Words ◽  
Untreated Control ◽  
Seed Weight ◽  
Ascochyta Blight ◽  
Field Pea ◽  
Mycosphaerella Pinodes ◽  
Yield Increase ◽  
Pisum Sativum L

The use of fungicides for the control of ascochyta blight in field pea was investigated. Four fungicides were applied to the cultivars AC Tamor and Radley at two locations in Manitoba in 1993 and 1994. Fungicides were applied either once, twice, or three times at 10-d intervals, beginning at the initiation of flowering. Chlorothalonil and benomyl were effective m reducing the severity of ascochyta blight and increasing the yield and seed weight of field pea. The triple application of chlorothalonil resulted in a mean yield increase of 33% over that of the untreated control. Iprodione and propiconazole were relatively ineffective in controlling ascochyta blight. The percentage of seedborne ascochyta was not significantly affected by fungicide treatments. The severity of ascochyta blight was greater in 1993 that in 1994, resulting in greater benefits of chlorothalonil and benomyl applications in 1993. Key words: Field pea, Pisum sativum L., ascochyta blight, Mycosphaerella pinodes, fungicide

Effect of sowing date on the severity of ascochyta blight in field peas (Pisum sativum L.) grown in the Wimmera region of Victoria

2000 ◽  
Vol 40 (8) ◽  
pp. 1113 ◽  
Author(s):  
T. W. Bretag ◽  
P. J. Keane ◽  
T. V. Price
Keyword(s):  
Pisum Sativum ◽  
Field Experiments ◽  
Average Length ◽  
Ascochyta Blight ◽  
Sowing Date ◽  
Small Reduction ◽  
Average Percentage ◽  
Severity Of Disease ◽  
Pisum Sativum L ◽  
Field Peas

Field experiments were established at Horsham, in the Wimmera region ofVictoria, in 1987, 1988 and 1989 to compare the severity of ascochyta blightand grain yield of field peas sown in May, June and July. In each year, theseverity of ascochyta blight on all the pea cultivars studied was greatest onthe May-sown plots and least severe on the July-sown plots. The level of seedinfestation by ascochyta blight fungi was also highest in grain harvested fromthe plots sown earliest. In 1987, the average length of lesions girdling themain stem was 28.7 cm in the May-sown plots and 1.0 cm in the July-sown plots.In 1988, the average percentage of stem area affected by ascochyta ranged from 60.2% in the May-sown plots to 13.1% in the July-sown plots,while in 1989 the range was from 38.3% in the May-sown plots to5.8% in the July-sown plots. In 1988, delaying sowing until Julyresulted in a significant reduction in disease with only a small reduction inyield. However, in 1989 while July sowing reduced the severity of disease by 17%, compared to a June sowing, the later sowing also reduced grainyields by 40%.In a separate trial at Horsham in 1988, using cv. Buckley, disease progresswas most rapid on the April-sown plots and slowest on the August-sown plots.The final disease levels ranged from 100% of stem area affected (Aprilsowing) to 2% of stem area affected (August sowing). The yield lossescaused by the disease were greater the earlier the plots were sown.These studies suggest that the severity of disease in commercial crops may bereduced by delaying sowing until after mid-June, thus avoiding exposure ofyoung plants to high levels of primary inoculum.

DS Admiral field pea

2002 ◽  
Vol 82 (4) ◽  
pp. 751-752 ◽  
Author(s):  
L. Andersen ◽  
T. Warkentin ◽  
O. Philipp ◽  
A. Xue ◽  
A. Sloan
Keyword(s):  
Powdery Mildew ◽  
Pisum Sativum ◽  
Powdery Mildew Resistance ◽  
Field Pea ◽  
Western Canada ◽  
Mildew Resistance ◽  
Pisum Sativum L ◽  
Cultivar Description ◽  
Good Yielding ◽  
Growing Region

DS Admiral, a yellow cotyledon field pea (Pisum sativum L.) cultivar, was released in 2000 by Agriprogress Inc., Morden, Manitoba. DS Admiral has a semileafless leaf type, powdery mildew resistance, medium sized, round seeds, and good yielding ability. DS Admiral is adapted to the field-pea-growing region of western Canada. Key words: Field pea, Pisum sativum L., cultivar description, powdery mildew resistance

Assessment of the feeding value of South Dakota-grown field peas (Pisum sativum L.) for growing pigs12

2004 ◽  
Vol 82 (9) ◽  
pp. 2568-2578 ◽  
Author(s):  
H. H. Stein ◽  
G. Benzoni ◽  
R. A. Bohlke ◽  
D. N. Peters
Keyword(s):  
Pisum Sativum ◽  
South Dakota ◽  
Pisum Sativum L ◽  
Field Peas ◽  
Feeding Value
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