Biological control of Pythium damping-off of pea and sugar beet by Rhizobium leguminosarum bv. viceae

2004 ◽  
Vol 82 (3) ◽  
pp. 291-296 ◽  
Author(s):  
Sylvie D Bardin ◽  
Hung-Chang Huang ◽  
Joanna Pinto ◽  
Eric J Amundsen ◽  
R Scott Erickson
Keyword(s):  
Biological Control ◽  
Sugar Beet ◽  
Untreated Control ◽  
Rhizobium Leguminosarum ◽  
Field Experiments ◽  
Biological Control Agent ◽  
Root Nodules ◽  
Seedling Emergence ◽  
Field Pea ◽  
Damping Off

Rhizobium leguminosarum Jordan bv. viceae strains from pea and lentil root nodules were tested for control of damping-off of pea (Pisum sativum L., host) and sugar beet (Beta vulgaris L., nonhost) crops caused by Pythium sp. "group G". Of the 18 Rhizobium isolates tested, only strain R5 inhibited mycelial growth of Pythium sp. "group G". None of the strains showed any protease activity. Results of indoor experiments in soil artificially infested with Pythium sp. "group G" showed that 10 strains of R. leguminosarum bv. viceae were effective in increasing sugar beet emergence compared with the untreated control, when bacteria were coated onto seeds. Three of the most promising strains, R12, R20, and R21, were further tested for control of damping-off of field pea and sugar beet in a field naturally infested with Pythium spp. R12 and R20 significantly increased seedling emergence of field pea in the two field tests, compared with the untreated control. The efficacy of strains R12 and R20 was similar to that of Pseudomonas fluorescens Migula 708, a biological control agent of Pythium sp. "group G". Rhizobium leguminosarum bv. viceae strains R12 and R21 were the most effective biological control agents for control of sugar beet damping-off in the field experiments. They were as effective as seed treatment with the fungicide ThiramTM in one field experiment. The present study reveals that some R. leguminosarum bv. viceae strains, in addition to their use as biofertilizer, also have the potential to be used for biological control of Pythium damping-off of field pea and sugar beet.Key words: Rhizobium leguminosarum bv. viceae, Pythium sp. "group G", damping-off, biological control, sugar beet, pea.

Damping-off of sugar beet in Finland: II. Disease control 

1983 ◽  
Vol 55 (5) ◽  
pp. 431-450
Author(s):  
Mauritz Vestberg ◽  
Risto Tahvonen ◽  
Kyösti Raininko
Keyword(s):  
Sugar Beet ◽  
Disease Control ◽  
Field Experiments ◽  
Damping Off ◽  
Good Protection ◽  
Great Damage

In pot and field experiments carried out in 1979-1981, the systemic funqicide hymexazol prevented satisfactorily soil borne damping-off of sugar beet caused mainly by the fungus Pythium debaryanum auct. non Hesse. The results with the combination hymexazol + thiram were still better. This treatment gave very good protection against the disease up to about two to three weeks after emergence, increased the yield on the average by 5-10 % and produced considerably thicker and denser stands. Thereafter a large number of beets may have become infected, but no great damage was caused as only few died. Band spraying at emergence using hymexazol with a large amount of water as well as spraying into the seed furrow prevented the outbreak of the disease almost completely. Liming had little effect on damping-off.

Efficacy of Clonostachys rosea strain ACM941 and fungicide seed treatments for controlling the root rot complex of field pea

2003 ◽  
Vol 83 (3) ◽  
pp. 519-524 ◽  
Author(s):  
A. G. Xue
Keyword(s):  
Root Rot ◽  
Untreated Control ◽  
Seedling Emergence ◽  
Field Trials ◽  
Field Pea ◽  
Seed Treatments ◽  
Clonostachys Rosea ◽  
Pea Root ◽  
Pea Root Rot ◽  
Better Than

The efficacy of seed treatments with bioagent ACM941 (a strain of Clonostachys rosea), its formulated products GB116 and ACM941-Pro, and common fungicides for the control of pea root rot complex were examined in six field trials in western Canada from 1996 to 2000. The effects on seedling emergence, root rot severity, and yield varied among years. In trials 1 and 2 (1996–1997), none of the treatments significantly reduced root rot severity or increased yield. ACM941 + Thiram 75WP was the most effective treatment, increasing emergence by 17.4% and was significantly better than that of the untreated controls. In trials 3 and 4 (1997–1998), Apron FL alone and ACM941 + Apron FL were significantly better than the untreated control, increasing emergence by 6.2 and 7.7%, and yield by 10.8 and 11.5%, respectively. In trials 5 and 6 (1999–2000), AC M 941 and GB116 were equally the most effective treatments, increasing emergence by 11.5 and 12.2%, and yield by 8.2 and 6.3%, respectively. These effects were significantly greater than that of the untreated control, but not significantly different from those of Apron FL or Vitaflo-280. ACM941-Pro was developed and tested in 2000 only, and it increased emergence by 17.1% and reduced root rot severity by 29.6%. Key words: Bioagent, Clonostachys rosea, field pea, Pisum sativum, pea root rot complex (PRRC), seed treatment, fungicide

Grading monogerm sugar-beet seed and its influence on performance

1974 ◽  
Vol 83 (1) ◽  
pp. 125-133 ◽  
Author(s):  
P. C. Longden ◽  
R. K. Scott ◽  
D. W. Wood
Keyword(s):  
Sugar Beet ◽  
Seed Weight ◽  
Field Experiments ◽  
Plant Density ◽  
Seedling Emergence ◽  
Growth And Yield ◽  
Viable Seed ◽  
True Seed ◽  
High Plant Density ◽  
Fruit Diameter

SUMMARYFrom monogerm sugar-beet seed as harvested non-viable fruits have to be eliminated, multigerm ones rejected and the size made sufficiently uniform for use in precision drills. Seed which had been gently rubbed to remove some of the cortex was graded for diameter, thickness and by aspiration, either singly or in combination. Effects of grading were determined by laboratory germination tests, radiography and field sowings in which seedling emergence and crop growth and yield were recorded.Grading by thickness was effective in removing multigerm fruits. Grading by aspiration and diameter rejected non-viable seed and reduced the variation in size. By combining all three grading methods, samples of seed of 80% germination and 90% monogermity were produced, provided the seed lot as threshed gave at least 50% germination. True seed weight increased with fruit diameter but only the first aspiration was effective in removing light true seeds. Radiography showed that both aspiration and, to a less extent, grading by diameter were effective in removing most empty fruits but neither eliminated those with shrivelled seed. The field experiments confirmed that increase in fruit diameter or aspiration gave more seedlings. Even at uniform, high plant density, sugar yields were less from the smallest (less than 3 mm diameter) than from the other grades of seed. The initial aspiration also improved sugar yield but further aspiration decreased yield.

Biological control of damping-off of sugar-beet and cotton with Chaetomium globosum or a fluorescent Pseudomonas sp.

1988 ◽  
Vol 34 (5) ◽  
pp. 631-637 ◽  
Author(s):  
D. Walther ◽  
D. Gindrat
Keyword(s):  
Biological Control ◽  
Sugar Beet ◽  
Seed Treatment ◽  
Pythium Ultimum ◽  
Chaetomium Globosum ◽  
Pseudomonas Sp ◽  
Damping Off ◽  
Antifungal Metabolites ◽  
Fluorescent Pseudomonas

Seed treatment with ascospores of Chaetomium globosum reduced damping-off of sugar-beet caused by seed-borne Phoma betae and soil-borne Pythium ultimum or Rhizoctonia solani in growth chamber experiments. Seed treatment with a fluorescent Pseudomonas sp. controlled Ph. betae and P. ultimum but not R. solani. Coating cotton seeds with ascospores controlled P. ultimum and R. solani damping-off. In some experiments, biological seed treatments were equally or more effective than seed treatment with captan. However, greater variability in disease control occurred with the antagonists than with captan. Fifty percent of freshly harvested ascospores of C. globosum germinated in 8 h on water agar. When ascospores were stored under air-dried conditions for 3 days to 2.5 years, germination increased to > 90%. Under same storage conditions, survival of Pseudomonas sp. was detected after 4 months. Antagonistic activities observed in vitro were hyphal coiling of C. globosum on R. solani, and mycostasis was induced by C. globosum or Pseudomonas sp. on agar and soil. The presumed cause of mycostasis is the diffusible antifungal metabolites which may also be involved in the biological control of damping-off.

scholarly journals Regression Analyses for Evaluating the Influence of Bacillus cereus on Alfalfa Yield Under Variable Disease Intensity

2000 ◽  
Vol 90 (6) ◽  
pp. 657-665 ◽  
Author(s):  
Elizabeth R. Kazmar ◽  
Robert M. Goodman ◽  
Craig R. Grau ◽  
David W. Johnson ◽  
Erik V. Nordheim ◽  
...  
Keyword(s):  
Bacillus Cereus ◽  
Untreated Control ◽  
Field Experiments ◽  
Seedling Emergence ◽  
Field Trials ◽  
Forage Yield ◽  
Regression Methods ◽  
Control Response ◽  
Treated Seed ◽  
Yield Gain

We developed and tested regression methods to exploit the variability in disease inherent in field experiments, and applied the methods to evaluate strains of Bacillus cereus for biocontrol efficacy. Four B. cereus strains were tested for their effect on alfalfa (Medicago sativa) performance in 16 field trials planted during 1993 to 1996 at multiple sites in Wisconsin. To evaluate performance of the strains, we used the ratio of (metalaxyl response)/(untreated control response) as a measure of disease intensity within the experiments. The ratio of (Bacillus response)/(untreated control response) was then regressed as a function of disease intensity. The slope of the resulting line provides a statistical test to compare performance of the Bacillus strain with that of the untreated seed (Ho: slope = 0) and metalaxyl controls (Ho: slope = 1). Under conditions in which disease occurred, forage yield of plots planted with seed treated with B. cereus strain AS4–12 exceeded yield from the untreated control plots (P = 0.002) and was similar to yield of plots planted with metalaxyl-treated seed (P = 0.14). Yield gain associated with AS4–12 and metalaxyl seed treatment averaged 6.1 ± 2.8% (±standard error) and 3.0 ± 2.8%, respectively. In contrast to the regression approach, means analysis by analysis of variance did not detect differences among treatments. Three other B. cereus strains either did not increase alfalfa yield or increased yield less than did AS4–12. Metalaxyl and three of the Bacillus strains increased seedling emergence, but the improved stands were not predictive of increased forage yield. In six additional studies conducted for one season in 1997, AS4–12 enhanced yield of two cultivars at diverse locations in Wisconsin, but there was an apparent cultivar-location interaction. A strong correlation between response to AS4–12 and metalaxyl treatment suggests that these treatments controlled similar pathogens, most likely the oomycete pathogens Phytophthora medicaginis and Pythium spp.

Sodium and Potassium Fertilizer in Relation to Soil Physical Properties and sugar-beet yield

1976 ◽  
Vol 87 (3) ◽  
pp. 633-642 ◽  
Author(s):  
A. P. Draycott ◽  
M. J. Durrant ◽  
D. B. Davies ◽  
L. V. Vaidyanathan
Keyword(s):  
Sugar Beet ◽  
Physical Properties ◽  
Soil Structure ◽  
Field Experiments ◽  
Sandy Loam ◽  
Seedling Emergence ◽  
Fine Sand ◽  
Clay Loam ◽  
Potassium Fertilizer ◽  
Visual Assessments

SummaryDespite much experimental evidence showing that sodium fertilizer increases sugar–beet yield and decreases need for potassium, there is resistance to its use on some soil types through fears of deterioration in soil structure. Twelve field experiments with sugar beet were made in Eastern England, testing all combinations of autumn and spring applications of 0, 150 and 300 kg Na/ha and 0, 83 and 333 kg K/ha. Fields were chosen with soils of loamy very fine sand, very fine sandy loam, sandy clay loam and clay loam textures. Micro–plot and controlled environment studies were also made with the same soils to examine effects of sodium on seedling emergence and growth.Visual assessments of soil physical state following sodium application revealed no effect in the year sugar beet was grown nor in the following spring when cereals were grown. Measurements of physical properties of soils treated with sodium suggested that applications of several times the recommended amounts of sodium fertilizer would not damage soil structure. However, sodium fertilizer increased the osmotic suction of soil solution which, under some circumstances, e.g. dry springs or giving the fertilizer close to the time of sowing, decreased germination and seedling growth. For this reason and not because it has a detrimental effect on soil physical condition, sodium fertilizer best given in the autumn or some weeks before sowing.

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