scholarly journals FACTORS INFLUENCING PREEMERGENCE DAMPING-OFF AND SEEDLING BLIGHT OF SH-2 SWEET CORN CAUSED BY PENICILLIUM OXALICUM

HortScience ◽  
1994 ◽  
Vol 29 (7) ◽  
pp. 743b-743
Author(s):  
Nancy W. Callan ◽  
Don E. Mathre ◽  
James B. Miller
Keyword(s):  
Seed Germination ◽  
Sweet Corn ◽  
Seedling Emergence ◽  
Penicillium Oxalicum ◽  
Damping Off ◽  
Seedling Blight ◽  
Seedling Mortality ◽  
Factors Influencing ◽  
Visible Growth ◽  
Soil Temperatures

Penicillium oxalicum is a seed- and soilborne fungal pathogen that causes preemergence damping-off and postemergence seedling blight of sweet corn, While seed infection and infestation by P. oxalicum is common, the amount of injury observed in the field is variable. Our objective was to determine factors influencing the occurrence and severity of disease due to P. oxalicum. Inoculation of sh-2 sweet corn seeds with conidia of P. oxalicum reduced seedling emergence and resulted in seedling mortality. Disease severity in the greenhouse and the field was greater as inoculum density increased from ≈ 102 to 106 conidia per seed. Increasing soil temperatures after planting inoculated seed resulted in more preemergence damping-off. Penicillium oxalicum is capable of growth and sporulation in soil that is too dry for seed germination. Nontreated (naturally infected) sh-2 sweet corn seeds or seeds inoculated with P. oxalicum were incubated in pasteurized soil that had been adjusted to various moisture levels-all too low for seed germination. Increasing soil moisture was associated with visible growth of Penicillium spp. on seed after incubation, and greater levels of damping-off and seedling blight when the seed was planted.

scholarly journals Soil Moisture and Temperature Effects on shrunken2 Sweet Corn Seed Decay and Seedling Blight Caused by Penicillium oxalicum

1996 ◽  
Vol 121 (1) ◽  
pp. 83-90 ◽  
Author(s):  
Nancy W. Callan ◽  
James B. Miller ◽  
Don E. Mathre ◽  
S. Krishna Mohan
Keyword(s):  
Soil Moisture ◽  
Fungal Pathogens ◽  
Sweet Corn ◽  
Seedling Emergence ◽  
Penicillium Oxalicum ◽  
Inoculum Density ◽  
Damping Off ◽  
Seedling Blight ◽  
Corn Seed ◽  
Seed Decay

Sweet corn (Zea mays L.) seed is commonly infected or infested with fungi that can impair stand establishment. Among these, Penicillium oxalicum Currie and Thorn is known to cause preemergence damping-off or postemergence seedling blight. Supersweet, or shrunken2 (sh2), sweet corn cultivars are particularly affected by seedborne fungal pathogens, although the effects of seed infection on seedling emergence and stand are variable under field conditions. This study was conducted to examine factors that could influence the impact of P. oxalicum on seedling stand, including P. oxalicum inoculum density on seed and in soil, soil moisture, soil temperature, and control of seed decay caused by soilborne Pythium ultimum Trow. Seed surface disinfestation usually had no effect on seedling stand under conditions favoring infection by P. ultimum. Inoculation of sh2 sweet corn seeds or infestation of soil with conidia of P. oxalicum resulted in increasing severity of damping-off and seedling blight as inoculum density increased. In pasteurized soil in the greenhouse, an inoculum density of 102 P. oxalicum conidia per seed reduced emergence and induced seedling blight. In the field, where P. ultimum was also a factor, 106 conidia per seed were needed to reduce emergence and 105 conidia per seed to reduce healthy seedling stand. When pythium seed decay was controlled by metalaxyl seed treatment, seedling emergence and healthy seedling stand were both reduced at 1 × 106 P. oxalicum conidia per seed. When sh2 sweet corn seed was inoculated with conidia of P. oxalicum and incubated in soil at subgermination moisture contents (4.2 to -7.8 MPa) for 2-4 weeks before planting and irrigating, P. oxalicum reduced seedling emergence at all soil moisture levels, but caused the greatest amount of injury after planting when seeds were incubated in soil above -5.1 MPa. As soil temperature increased from 9-25C, seedling emergence from seed inoculated with P. oxalicum was progressively reduced, with a decrease of nearly 50% at 25 C. Penicillium oxalicum has the greatest potential to reduce seedling stand when infected sweet corn seeds are planted in warm, dry soil, but the effects of this and other seedborne fungal pathogens may be masked under conditions favoring infection by P. ultimum.

Seed Germination Ecophysiology of Meadow Salsify (Tragopogon pratensis) and Western Salsify (T. dubius)

Weed Science ◽  
1993 ◽  
Vol 41 (3) ◽  
pp. 362-368 ◽  
Author(s):  
Meiqin Qi ◽  
Mahesh K. Upadhyaya
Keyword(s):  
Seed Germination ◽  
Storage Temperature ◽  
Seedling Emergence ◽  
Separate Study ◽  
Optimum Temperature ◽  
Seedling Mortality ◽  
Secondary Dormancy ◽  
Persistence Strategies

To understand persistence strategies of meadow and western salsify, ecophysiological characteristics of their seed germination were studied. Anaerobiosis (immersion in deoxygenated water) induced secondary dormancy in seeds of both species. Dormancy could be induced in 86% of meadow salsify seeds and in 65% of western salsify seeds by a 1-d anaerobiosis treatment. The induced dormancy was gradually released during storage of air-dried secondary dormant meadow salsify seeds, and the rate of this release was influenced by storage temperature; 30 C was more effective than 10 or 20 C in releasing secondary dormancy. These results suggest that the two species may rely on induced dormancy as an option in their persistence strategy. The optimum temperature for germination of nondormant seeds of both species was 15 C. Maximum germination percentages for both species were established within 4 to 6 d of incubation at 15 C and within 14 to 28 d of incubation at 25 C. Nondormant seeds did not germinate below 10 or above 30 C. Stratification (at 5 C for 2 to 10 wk) stimulated germination of secondary dormant seeds of meadow salsify. This stratification requirement can be important in preventing germination of dormant salsify seeds in the fall, thereby avoiding high seedling mortality in the winter. Light (red and far-red) had no effect on germination of seeds in secondary dormancy. In a separate study, seeds of both species were planted in pots at depths of 2 to 14 cm and seedling emergence was observed. Maximum emergence occurred when seeds were buried 2 cm deep. Seeds planted 8 cm or deeper germinated but did not emerge.

scholarly journals FIELD PERFORMANCE OF BIO-PRIMING FOR PROTECTION OF sh2 SWEET CORN FROM PREEMERGENCE DAMPING-OFF CAUSED BY PYTHIUM ULTIMUM.

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1110f-1110
Author(s):  
Nancy W. Callan ◽  
James B. Miller ◽  
Don E. Mathre
Keyword(s):  
Pseudomonas Fluorescens ◽  
Seed Treatment ◽  
Field Experiments ◽  
Sweet Corn ◽  
Seedling Emergence ◽  
Field Performance ◽  
Pythium Ultimum ◽  
Damping Off ◽  
Corn Seed ◽  
Seed Bacterization

Shrunken-2 supersweet (sh2) sweet corn is susceptible to preemergence damping-off caused by Pythium ultimum, especially when planted into cold soil. Bio-priming, a seed treatment which combines the establishment of a bioprotectant on the seed with preplant seed hydration, was developed to protect seeds from damping-off.In a series of field experiments conducted in Montana's Bitterroot and Gallatin Valleys, bio-priming or seed bacterization with Pseudomonas fluorescens AB254 protected sweet corn from P. ultimum damping-off. Bio-priming corn seed with P. fluorescens AB254 was comparable to treatment with the fungicide metalaxyl in increasing seedling emergence. Seedlings from bio-primed seeds emerged from the soil more rapidly than from nontreated seeds and were larger at three weeks postplanting. Seeds of sh 2 and sugary enhancer (se) sweet corn, as well as that of several sh 2 cultivars, were protected from damping-off by bio-priming.

scholarly journals High-temperature Inhibition of Seed Germination and Seedling Emergence of Broccoli

1992 ◽  
Vol 2 (3) ◽  
pp. 417-419 ◽  
Author(s):  
Marshall K. Elson ◽  
Ronald D. Morse ◽  
Dale D. Wolf ◽  
David H. Vaughan
Keyword(s):  
High Temperature ◽  
Seed Germination ◽  
Seedling Emergence ◽  
Soil Temperatures ◽  
Summer Temperatures ◽  
Direct Seeded ◽  
Warm Climates

High summer temperatures may reduce plant stands of direct-seeded fall broccoli (Brassica oleracea var. italica Plenck). The influence of constant and diurnally alternating temperatures in the range of 5 to 42C on germination and emergence of `Packman' broccoli was evaluated. Germination was defined as protrusion of the radicle from the seedcoat, and emergence as 10 mm elongation of the radicle. The range of constant temperatures from 10 to 30C for 14 days was satisfactory for 90% germination and 75% emergence. However, alternating temperatures extended the acceptable emergence range to 5/17 through 20/32C. Since soil temperatures in warm climates often exceed 20/32C during the summer, high-temperature inhibition of seed germination and seedling emergence is a potentially important factor limiting direct-seeded broccoli stands.

Effect of soil moisture and temperature on seedling emergence and incidence of Pythium damping-off in safflower (Carthamus tinctorius L.)

1995 ◽  
Vol 75 (2) ◽  
pp. 505-509 ◽  
Author(s):  
H.-H. Mündel ◽  
H. C. Huang ◽  
G. C. Kozub ◽  
D. J. S. Barr
Keyword(s):  
Soil Moisture ◽  
Seedling Emergence ◽  
Moisture Stress ◽  
Pythium Ultimum ◽  
Carthamus Tinctorius ◽  
Infested Soil ◽  
Damping Off ◽  
Seedling Blight ◽  
Sterile Soil ◽  
Canadian Prairies

The effects of soil moisture, soil temperature and Pythium ultimum Trow var. ultimum, on the emergence of safflower seedlings were investigated. The effect on emergence of safflower cultivar, Saffire, in Pythium-infested and in sterile soil was tested at three moisture stress levels (1500 kPa, 30 kPa, or 0 kPa), and five temperatures (5, 10, 15, 20, and 25 °C). Both factors affected emergence. At 0 kPa, emergence of safflower seedlings in both the Pythium-infested and sterile soil treatments averaged 4%. In sterile soil, at both 30 kPa and 1500 kPa, seedling emergence exceeded 85% at all temperatures. In Pythium-infested soil at 30 kPa, emergence was greater than 85% at 5 and 10 °C, but only 67, 49, and 27% at 15, 20 and 25 °C, respectively. Within the temperature range, 10–25 °C, seedling emergence in Pythium-infested soil was significantly less at 30 kPa than at 1500 kPa. In fields in the southern Canadian prairies infested with Pythium ultimum, safflower seeded into warm soil is likely to have poor stand establishment due to damping-off, especially if soil is wet. Thus it is advisable to plant safflower early, when soil is cool. Key words:Carthamus tinctorius, Pythium ultimum var. ultimum, Pythium sp. "group G", damping-off, seedling blight, soil moisture, temperature

Novel Liquid Mycofungicide: An Ideal Approach in Protecting Tomato from the Damping-off Disease in Nursery

2020 ◽  
Author(s):  
Kishor Kumhar ◽  
Kuldeep Kumar ◽  
Indu Arora ◽  
Arun Kumar Bhatia ◽  
Vinod Kumar Batra
Keyword(s):  
Seed Germination ◽  
Vegetative Growth ◽  
Root Length ◽  
Growth Parameters ◽  
Disease Incidence ◽  
Block Design ◽  
First Year ◽  
Damping Off ◽  
Seedling Mortality ◽  
Second Year

Abstract Background: A novel liquid formulation of Trichoderma asperellum was prepared and its effectiveness was assessed by different methods for the management of tomato damping-off in the nursery. The experiments were conducted for two consecutive years in a randomized block design with three replications. Results: T. asperellum formulation improved seed germination and management of tomato damping-off when compared with control. All the treatments performed better over control, in the first year, the antagonist’s application enhanced seed germination up to 75.75 percent, however, it was 60.13 percent in control. There was 10.93 to 20.38 percent seedling mortality due to damping off which was comparatively lower than the control (26.98%). A similar trend of seed germination and disease incidence was observed in the second year. In addition to managing the disease, the antagonist certainly promoted the vegetative growth which was reflected as increased shoot and root length in comparison to control during both years. During the first year, shoot length ranged 10.90 – 12.85 cm as compared to the control (8.72 cm) and root length ranged from 3.21 to 3.65 cm which was greater than the control. Almost a similar trend in the vegetative growth parameters of seedling was observed during the second year. Conclusion: The present investigation showed that the tested antagonist’s formulation could efficiently managed the tomato damping-off as well as encouraged the vegetative growth of seedlings which ultimately ensured better and healthy seedling. And this formulation can successefully used through different methods to take care of tomato damping off.

Damping-off disease of pine seedlings on soils treated with simulated acidic rain

1995 ◽  
Vol 25 (5) ◽  
pp. 838-844 ◽  
Author(s):  
George A. Schier ◽  
Roy L. Patton
Keyword(s):  
Seedling Emergence ◽  
Fungal Species ◽  
Pine Barrens ◽  
Damping Off ◽  
Seedling Mortality ◽  
Solution Ph ◽  
Pine Seedlings ◽  
Early Seedling ◽  
Acidic Rain ◽  
Solution Acidity

Damping-off during seed germination and early seedling growth of Pinusrigida Mill., Pinusechinata Mill., Pinustaeda L., and Pinusstrobus L. were observed for 28 days on three New Jersey (U.S.A.) Pine Barrens soils (Atsion, Downer, Lakewood) treated with simulated acidic rain solutions of pH 4.2, 3.5, or 3.0 (SO42−:Cl−:NO3−, 2.2:1.4:1.0). The soils were sandy, highly acidic, and deficient in mineral nutrients. Treatment with rain solution was started 53 days before planting the pine seeds and continued during germination. Seedling emergence and seedling mortality were affected significantly by solution pH, soils, and species. Seedling emergence of all pine species on Atsion and Lakewood soils decreased with increasing solution acidity. On Downer soil seedling emergence was unaffected by solution acidity probably because the buffering action of the soil decreased the acidity of the rain solution. Seedling mortality of all species increased with increasing treatment acidity on all soils and was significantly higher on Atsion (100% at pH 3.0) than on the other soils. Although solution acidity significantly increased the concentration of Al in the soil solution, there was no evidence of Al toxicity. Two isolated fungal species, a Trichoderma and a Penicillium, significantly reduced seedling emergence and increased seedling mortality of P. rigida in sterile, acid-washed quartz sand; however, neither seedling emergence nor seedling mortality was affected significantly by solution acidity.

scholarly journals Stand Establishment in Plasticulture Systems

1996 ◽  
Vol 6 (3) ◽  
pp. 181-185 ◽  
Author(s):  
Michael D. Orzolek
Keyword(s):  
Seed Germination ◽  
Sweet Corn ◽  
Seedling Emergence ◽  
Warm Season ◽  
Fruit Crops ◽  
Plant Establishment ◽  
Snap Bean ◽  
Stand Establishment ◽  
Growing Seasons ◽  
Soil Temperature And Moisture

Plasticulture enables growers to optimize establishment of vegetable and fruit crops under nonoptimum conditions and in locations with short growing seasons. Generally, warm-season crops such as muskmelon, pepper, and tomato, are established from transplants to decrease the time to maturity in the field. Directly seeding vegetables such as sweet corn, cucumber, and snap bean through plastic allows for optimum soil temperature and moisture to ensure maximum seed germination and subsequent seedling emergence. Mechanized transplanting or seeding of vegetables in plasticulture is available and successful if a firm, flat bed with plastic firmly stretched over the bed is formed and specific crop requirements are followed during establishment. Common mistakes made with plant establishment in plasticulture are discussed.

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