CHEMICAL AND BIOLOGICAL CONTROL OF PHYTOPHTHORA ROOT AND STALK ROT OF SOYBEAN

1979 ◽  
Vol 59 (2) ◽  
pp. 307-311 ◽  
Author(s):  
O. VAARTAJA ◽  
R. I. BUZZELL ◽  
L. G. CRAWFORD ◽  
R. E. PITBLADO
Keyword(s):  
Biological Control ◽  
Field Tests ◽  
Short Term ◽  
Phytophthora Megasperma ◽  
Plant Survival ◽  
Stalk Rot ◽  
Low Degree ◽  
Gliocladium Virens ◽  
Glycine Max L ◽  
Fungal Antagonist

Chemical and biological control of root and stalk rot of soybean (Glycine max (L.) Merr.) caused by Phytophthora megasperma Drechs. var. sojae Hildebr. (Pms) was attempted in greenhouse and field tests. In-furrow spray-drench and granular treatments of the experimental compound CGA 48988 (Ciba-Geigy), applied at planting time at rates ranging from 0.5 to 2.0 kg a.i./ha, greatly reduced loss of plants from the disease and doubled the yield of the cultivar Steele, which has a low degree of field tolerance to Pms race 6. An in-furrow spray-drench treatment with thiram at 1.0 kg a.i./ha significantly reduced loss of plants, but not as much as CGA 48988 and not sufficiently to increase yield. Captan and CGA 48988 applied to Harosoy 63 seeds (at 0.13 and 0.33 g a.i./kg of seed, respectively) by a pelleting technique gave short-term control in the greenhouse, but did not significantly increase plant survival and yield in the field. CGA 48988, which is systemic in soybeans, increased plant survival and. yield in the field at 1.65 g a.i./kg of seed in seed pellets. Inclusion of the fungal antagonist Gliocladium virens Miller, Giddens and Foster in seed pellets did not significantly control Pms either alone or in combination with a low rate of captan or CGA 48988.

A ROOT AND STALK ROT OF SOYBEANS CAUSED BY PHYTOPHTHORA MEGASPERMA DRECHSLER VAR. SOJAE VAR. NOV.

1959 ◽  
Vol 37 (5) ◽  
pp. 927-957 ◽  
Author(s):  
A. A. Hildebrand
Keyword(s):  
Root Rot ◽  
The United States ◽  
Sweet Clover ◽  
Phytophthora Megasperma ◽  
Breeding Lines ◽  
Disease Reaction ◽  
Stalk Rot ◽  
Causal Fungus ◽  
Glycine Max L ◽  
Marked Specificity

Since 1954, a destructive root and stalk rot of soybeans, identical with one reported from several of the soybean-growing areas in the United States, has been prevalent in southwestern Ontario. It is proposed that Phytophthora megasperma Drechsler var. sojae nov. var. replace P. cactorum (Lib. and Cohn) Schroet., and P. sojae Kaufmann and Gerdemann, as the more correct taxonomic designation of the causal fungus. P. megasperma var. sojae comprises strains which though indistinguishable morphologically, differ physiologically and pathologically. Artificial inoculation of varieties and of breeding lines and selections of soybeans with the causal fungus, chiefly by the highly reliable toothpick method, indicated two well-defined types of disease reaction, resistance and susceptibility. Harosoy, the variety which currently is grown most extensively in Ontario, is highly susceptible to the disease. Pathogenicity trials involving many possible wild and cultivated hosts emphasized the marked specificity of P. megasperma var. sojae to Glycine max L. Merrill. The soybean Phytophthora, having been called P. cactorum and thereby associated nomenclaturally with a representative of that species causing a root rot of sweet clover in Ontario, was found to be quite different from the sweet clover pathogen.

Penetration and growth of compatible and incompatible races of Phytophthora megasperma var. sojae in soybean hypocotyl tissues differing in age

1980 ◽  
Vol 58 (24) ◽  
pp. 2594-2601 ◽  
Author(s):  
P. Stössel ◽  
G. Lazarovits ◽  
E. W. B. Ward
Keyword(s):  
Glycine Max ◽  
Epidermal Cells ◽  
Mechanisms Of Resistance ◽  
Hypocotyl Growth ◽  
Phytophthora Megasperma ◽  
Cell Layers ◽  
Glycine Max L ◽  
Incompatible Reaction ◽  
Race 4 ◽  
Incompatible Interactions

Intact 6-day old soybean hypocotyls (Glycine max L., cv. Altona) were inoculated with zoospores of Phytophthora megasperma Drechs. var. sojae Hildeb. either at the top (susceptible to compatible races, resistant to incompatible races) or the bottom (resistant to both compatible and incompatible races) and, after a 22-h incubation, were examined by light microscopy. Penetration at the top and bottom by both compatible (race 6) and incompatible (race 4) P. megasperma var. sojae was predominantly between anticlinal walls of epidermal cells. Both races, but especially race 4, also penetrated directly into the outer walls of epidermal cells, but epidermal cells rarely were invaded. Both races grew mainly intercellularly, but race 6 produced haustoria more frequently than race 4. Race 6 haustoria at the top of the hypocotyl were usually encased, those of race 4 were not. Growth of both races was equally dense in the first few cell layers, but the numbers of race 4 hyphae decreased rapidly while those of race 6 became more abundant in the deeper layers. With race 4, but not with race 6, most cells in the infected tissue were necrotic. Differences between the compatible and the incompatible interactions were not absolute; there were many unsuccessful invasion attempts by race 6 and individual hyphae of race 4 spread deeply into the tissue. At the bottom of the hypocotyl, growth of both races was more restricted. Race 6 produced fewer haustoria than at the top, and similarities to the incompatible reaction with race 4 at the top suggest that similar mechanisms of resistance may be involved.

scholarly journals Methodical issues of the monitoring for ammonium in indoors air

2019 ◽  
Vol 95 (10) ◽  
pp. 917-922 ◽  
Author(s):  
I. Sh. Iakubova ◽  
Yu. V. Dadaly ◽  
A. V. Mel’Tser ◽  
Lilia A. Alikbayeva ◽  
A. Yu. Zhirnov ◽  
...  
Keyword(s):  
Indoor Air ◽  
Standard Method ◽  
Field Tests ◽  
Air Sampling ◽  
State Standards ◽  
Comparative Assessment ◽  
Sampling Time ◽  
Short Term ◽  
Material Costs ◽  
Iso 5725

Introduction. To perform mass studies of the indoors air environment of the ammonium content the actual issues are the shortening of the sampling time and material costs for their implementation, reduction of adverse effects of ammonium with keeping of the objectivity of results. Aim. The elaboration of the method of short-term air sampling for indoors ammonium and comparative assessment ofdifferent methods of sampling in the course of modeling and field tests. Materials and Methods. Air sampling for ammonium was carried out according to the developed program and standard method, under the average daily 4-fold taking according to State Standards (GOST) 17.2.3.01-86 andRD 52.04.186-89. The evaluation of the significance of deviations of analysis results was carried out in accordance with GOST R ISO 5725-6-2002 and Recommendations of the Interstate Standardization RMG - 61-2003. Results. There were executed model and field tests of air sampling for ammonium according to the standard method and the program of short-term sampling. There were obtained significantly comparable results of ammonium content in the indoor air in the course of model and field tests. Conclusions. Sampling according to the developed program has a number of advantages, including: the shortening of sampling time, material costs, increasing in productivity in the analysis of indoor airfor the ammonium content. The execution oftest sampling according to the developed program allows to reduce the time of ammonium exposure to personnel carrying out the test sampling.

OAC Musca soybean

1991 ◽  
Vol 71 (2) ◽  
pp. 497-498 ◽  
Author(s):  
W. D. Beversdorf ◽  
D. J. Hume ◽  
P. Gostovic ◽  
J. C. Muscat ◽  
S. Pararajasingham
Keyword(s):  
Glycine Max ◽  
Key Words ◽  
Soybean Cultivar ◽  
Clay Soils ◽  
Phytophthora Megasperma ◽  
Low Field ◽  
Glycine Max L ◽  
Cultivar Description

OAC Musca is a soybean (Glycine max (L.) Merr.) cultivar which is 3 d earlier than Hodgson and 2% higher in yield in Ontario trials. It has exhibited low field losses to Phytophthora megasperma f. sp. glycinea in Ontario testing, is a tall cultivar and is intended for use on clay soils. Key words: Soybean, cultivar description

Biological control of Eutypa armeniacae. 4. Design and performance of an applicator for metered delivery of protective aerosols during pruning

1978 ◽  
Vol 18 (91) ◽  
pp. 287 ◽  
Author(s):  
MV Carter ◽  
LF Mullett
Keyword(s):  
Biological Control ◽  
Laboratory Tests ◽  
Field Tests ◽  
Piston Pump ◽  
Light Weight ◽  
Biological Matter ◽  
And Performance ◽  
Time Required ◽  
Aerosol Form ◽  
Three Components

The paper describes the development of a prototype applicator for delivery of protective mixtures, in aerosol form, to the wounded sapwood surfaces exposed during pruning. The equipment has three components : a 2 litre day-service tank, a light weight belt-mounted piston pump, and a modification of a standard pneumatic-powered pruning handgun. Laboratory tests of the applicator have proved its ability to deliver, repeatedly, a uniform dose of aerosol containing sufficient particulate chemical and/or biological matter to protect apricot sapwood from invasion by Eutypa armeniacae. Field tests of the equipment in two orchards demonstrated that from 90-100 per cent of wounds can be treated for the addition of less than 20 per cent to the time required to prune a tree. Over a period of three weeks' use no mechanical defects developed. Estimated volume of protective fluid required per day, treating up to 90 per cent of wounds, is less than two litres.

scholarly journals Evaluation of genetic diversity in 19 Glycine max (L.) Merr. accessions included in the Czech National Collection of soybean genotypes

2012 ◽  
Vol 38 (No. 2) ◽  
pp. 69-74 ◽  
Author(s):  
M. Baránek ◽  
M. Kadlec ◽  
J. Raddová ◽  
M. Vachůn ◽  
M. Pidra
Keyword(s):  
Genetic Diversity ◽  
Glycine Max ◽  
Random Amplified Polymorphic Dna ◽  
Breeding Programs ◽  
Low Level ◽  
Low Degree ◽  
Soybean Genotypes ◽  
Glycine Max L ◽  
Rapd Polymorphism ◽  
Selection Of

The random amplified polymorphic DNA (RAPD) technique was used to evaluate both genetic diversity among 19 soybean accessions included in the Czech National Collection of Soybean Genotypes and their potential as a new source of genetic variations for soybean breeding programs. Only 22 of all the 40 random primers used in RAPD reactions showed polymorphism acceptable for an effective characterisation of these accessions. Altogether 122 highly reproducible RAPD fragments were generated, 55 of them were polymorphic (46%). However, because of the previously observed low degree of RAPD polymorphism in the case of Glycine max, fragments with low level of informativeness were evaluated, too. Presented results enable the selection of genetically distinct individuals. Such information may be useful to breeders willing to use genetically diverse introductions in soybean improvement process. 

RCAT Persian soybean

1991 ◽  
Vol 71 (1) ◽  
pp. 175-176
Author(s):  
G. R. Ablett ◽  
W. D. Beversdorf
Keyword(s):  
Glycine Max ◽  
Root Rot ◽  
Yield Potential ◽  
Maturity Group ◽  
Phytophthora Megasperma ◽  
Phytophthora Root Rot ◽  
Group I ◽  
Glycine Max L ◽  
Cultivar Description ◽  
Late Maturity

RCAT Persian is a mid-late Maturity Group I soybean [Glycine max L. (Merr.)] cultivar with excellent yield potential, good lodging tolerance and resistance to most races of phytophthora root rot caused by Phytophthora megasperma f. sp. glycinea (Pmg) found in Ontario. Key words: Soybean, cultivar description

scholarly journals Evidence for a Pythium sp. as a Chronic Yield Reducer in a Continuous Grain Sorghum Field

Plant Disease ◽  
2001 ◽  
Vol 85 (7) ◽  
pp. 780-784 ◽  
Author(s):  
M. A. Davis ◽  
W. W. Bockus
Keyword(s):  
Seed Treatment ◽  
Field Experiments ◽  
Field Tests ◽  
Grain Sorghum ◽  
Causal Organism ◽  
Grain Yields ◽  
Stalk Rot ◽  
Negative Effect ◽  
Seed Rot ◽  
Sorghum Production

Pythium spp. have been reported to reduce stands and cause stalk rot of grain sorghum. Evidence is presented that it also can cause a serious seed and root rot in the field under a continuous grain sorghum production system. Experiments were conducted for 4 years in a field that had been cropped continuously to grain sorghum for at least 10 years. Effects of seed treatments with captan and metalaxyl on plant stands, early to mid-season plant vigor, and grain yields were evaluated. In five field experiments, seed treatment with metalaxyl (73 g a.i./100 kg) increased grain yields by an average of 24.0% compared with nontreated seed. In three out of four field experiments, seed treatment with metalaxyl increased grain yields by an average of 13.1% above seed treated with captan (73 g a.i./100 kg). The yield increases could not always be explained in terms of differences among treatments in plant stands or in visual estimates of the amount of top growth 26 to 72 days after sowing. Apparently, the Pythium sp. causes a chronic root and seed rot that has a significant negative effect on grain production without necessarily affecting stands or early to mid-season growth. P. ultimum var. ultimum was the fungus most commonly isolated from roots and seeds collected from the field. Tests for Koch's postulates conducted in a greenhouse verified it as the causal organism. In the greenhouse, treatment with metalaxyl protected seeds and roots from attack by P. ultimum var. ultimum for at least 28 days after planting.

Sign in / Sign up

Export Citation Format

Share Document