The effect of seed size, seed treatment, seeding date and depth on Rhizoctonia seedling blight of canola

2014 ◽  
Vol 94 (2) ◽  
pp. 311-321 ◽  
Author(s):  
S. F. Hwang ◽  
H. U. Ahmed ◽  
G. D. Turnbull ◽  
B. D. Gossen ◽  
S. E. Strelkov
Keyword(s):  
Seed Size ◽  
Seed Yield ◽  
Seed Treatment ◽  
Seedling Emergence ◽  
Dry Weight ◽  
Field Trials ◽  
Seedling Blight ◽  
Substantial Impact ◽  
Seeding Date ◽  
The Impact

Hwang, S. F., Ahmed, H. U., Turnbull, G. D., Gossen, B. D. and Strelkov, S. E. 2014. The effect of seed size, seed treatment, seeding date and depth on Rhizoctonia seedling blight of canola. Can. J. Plant Sci. 94: 311–321. Rhizoctonia solani can have a substantial impact on seedling establishment and productivity of canola (Brassica napus). The effects of seeding date, seeding depth, seed size, and seed treatment on seedling blight of canola were evaluated under greenhouse and field conditions. Early seeding resulted in higher seedling emergence in one trial year and higher seed yield in all trial years relative to a late-seeded treatment. Mid-sized seed (range 0.7–2.0 mm diam.) had greater seedling emergence in R. solani-inoculated growth medium in a greenhouse trial and higher seed yield in one of two field trials compared with smaller seed (<0.7 mm). In the greenhouse study, sowing of large seed resulted in greater plant height and shoot weight compared with sowing of smaller seed. The effect of seeding depth was significant only on shoot dry weight, which increased at a seeding depth of 2.6 cm. Seed treatment with Helix Xtra (thiamethoxam+difenconazole+metalaxyl+fludioxonil), and Prosper FX (clothianidin+carboxin+trifloxystrobin+metalaxyl) resulted in a significant increase in seedling emergence and yield compared with the inoculated control. These results indicate that fungicidal seed treatment can minimize the impact of R. solani on canola.

Effect of seeding date and depth, seed size and fungicide treatment on Fusarium and Pythium seedling blight of canola

2015 ◽  
Vol 95 (2) ◽  
pp. 293-301 ◽  
Author(s):  
S. F. Hwang ◽  
H. U. Ahmed ◽  
G. D. Turnbull ◽  
B. D. Gossen ◽  
S. E. Strelkov
Keyword(s):  
Seed Size ◽  
Seed Yield ◽  
Seed Treatment ◽  
Seedling Emergence ◽  
Pythium Ultimum ◽  
Seedling Blight ◽  
Substantial Impact ◽  
Fungicide Treatment ◽  
Stand Establishment ◽  
Seeding Date

Hwang, S. F., Ahmed, H. U., Turnbull, G. D., Gossen, B. D. and Strelkov, S. E. 2015. Effect of seeding date and depth, seed size and fungicide treatment on Fusarium and Pythium seedling blight of canola. Can. J. Plant Sci. 95: 293–301. Seedling blight has a substantial impact on stand establishment and productivity of canola (Brassica napus) on the Canadian prairies. The effects of seeding date, seed size, seeding depth, and seed treatment fungicides on seedling blight of canola caused by Fusarium avenaceum and Pythium ultimum were evaluated under field conditions. In the trials inoculated with P. ultimum, early seeding reduced seedling emergence and seed yield in all 3 yr of the study. However, the interaction of F. avenaceum with seeding date was not consistent; inoculation with F. avenaceum reduced seedling emergence in early seeded canola in 1 of 4 yr, but emergence was higher in early than in mid-seeded treatments in 2 yr and there was no difference among seeding dates in 1 yr. Late seeding reduced seed yield in 2 of 4 yr in the F. avenaceum study. Seed size and seeding depth generally did not have an effect on seedling establishment or seed yield for either pathogen. Seed treatment with Helix Xtra (thiamethoxam+difenconazole+metalaxyl+fludioxonil) and Prosper FX (clothianidin+carboxin+trifloxystrobin+metalaxyl) fungicides increased seedling emergence and yield compared with the F. avenaceum-inoculated control. Seed treatment with Helix Xtra also increased seedling emergence and seed yield compared with the P. ultimum-inoculated control. Manipulation of seeding date did not substantially improve stand establishment or yield of canola when inoculum pressure was high. Seed treatment was the most effective strategy for reducing losses caused by seedling blight of canola in fields infested with F. avenaceum or P. ultimum.

Effect of seed damage and metalaxyl seed treatment on pythium seedling blight and seed yield of field pea

2001 ◽  
Vol 81 (3) ◽  
pp. 509-517 ◽  
Author(s):  
S. F. Hwang ◽  
B. D. Gossen ◽  
K. F. Chang ◽  
G. D. Turnbull ◽  
R. J. Howard
Keyword(s):  
Seed Yield ◽  
Seed Treatment ◽  
Effective Means ◽  
Seedling Emergence ◽  
Field Pea ◽  
Laboratory Studies ◽  
Seed Vigour ◽  
Stand Establishment ◽  
Seed Damage ◽  
The Impact

When cool, wet conditions persist after planting, Pythium spp. can be an important constraint to stand establishment in field pea. Laboratory studies and field trials were conducted over 3 yr to assess the impact and evaluate the interactions of Pythium spp., metalaxyl seed treatment and damage to seed on seedling establishment, root rot severity and seed yield of field pea. Seedling emergence, seedling size, and seed yield were reduced by inoculation with Pythium spp. and by mechanical damage to the seed. Fungicide seed treatment reduced the impact of seed damage, but did not always restore seedling emergence and seed yield to the same level as from undamaged seed. Undamaged seed treated with metalaxyl was not affected by inoculation with Pythium spp. Differences among cultivars, although often significant, were small relative to the effect of seed injury. Laboratory studies showed a negative linear relationship between inoculum concentration and emergence from untreated seed. They also showed that Pythium spp. had a similar impact on seedling emergence in cool (20/10°C day/night) and cold (12/6°C) soils. This study showed that planting fungicide-treated, high-quality field seed was an effective means of maximizing emergence and stand establishment for commercial field pea production. Key words: Pisum sativum, seed vigour, metalaxyl, Pythium, seed damage

Management strategies to reduce losses caused by rhizoctonia seedling blight of field pea

2007 ◽  
Vol 87 (1) ◽  
pp. 145-155 ◽  
Author(s):  
S. F. Hwang ◽  
B. D. Gossen ◽  
R. L. Conner ◽  
K. F. Chang ◽  
G. D. Turnbull ◽  
...  
Keyword(s):  
Seed Yield ◽  
Seedling Establishment ◽  
Root Rot ◽  
Seed Treatment ◽  
Dry Weight ◽  
Field Pea ◽  
Seeding Density ◽  
Seedling Blight ◽  
Highly Pathogenic ◽  
Pea Seedlings

Seedling blight can cause substantial reductions in stand density of field pea on the Canadian prairies. Ninety-four isolates of Rhizoctonia solani were obtained from soil samples collected from 37 pea fields in 1999 in Alberta, Canada. Sixty isolates were characterized as anastomosis group (AG)-4 and 12 isolates as AG-2-1. Some of these isolates caused severe pre-emergence damping-off and were classified as highly pathogenic; 41 of the 44 highly pathogenic isolates were AG-4 and three were AG-2-1. Two highly pathogenic AG-4 isolates were used to assess the effect of inoculum density on survival and growth of field pea seedlings, and the impact of seeding date, seeding depth, soil temperature, seed damage, seed treatments and seeding density on seedling blight and root rot injury. As inoculum density increased, so did root rot severity, while seedling establishment, shoot dry weight and root dry weight declined. Under controlled conditions, seedling establishment in the noninoculated control increased as soil temperatures increased, but establishment and growth declined in inoculated treatments. In a temperature gradient study, seedling infection was highest when mean daily temperatures were 17.5°C or higher. In field trials over 8 station years, delayed seeding often resulted in reduced seedling establishment in inoculated treatments, although this trend was not consistent across sites or years. Seed yield consistently declined with later seeding dates. Seed treatment with fungicides (carbathiin + thiram, metalaxyl) improved establishment and productivity in inoculated treatments, especially where seed was damaged prior to planting. Seeding depth had no impact on root rot severity. Emergence and seed yield increased with seeding density, but increasing density beyond 90 seeds m-2 did not result in proportionately higher yields. These results indicate that a combination of seed treatment and early seeding can reduce Rhizoctonia injury to pea seedlings under field conditions. Key words: Pisum sativum, Rhizoctonia solani (AG-4), management, seeding depth, seeding rate

Effects of soil-borne Rhizoctonia solani on canola seedlings after application of glyphosate herbicide

2013 ◽  
Vol 93 (1) ◽  
pp. 97-107 ◽  
Author(s):  
A. Rashid ◽  
S. F. Hwang ◽  
H. U. Ahmed ◽  
G. D. Turnbull ◽  
S. E. Strelkov ◽  
...  
Keyword(s):  
Rhizoctonia Solani ◽  
Weed Management ◽  
Management Practice ◽  
Seedling Emergence ◽  
Dry Weight ◽  
Field Trials ◽  
Shoot Dry Weight ◽  
Subsequent Crop ◽  
Glyphosate Herbicide ◽  
The Impact

Rashid, A., Hwang, S. F., Ahmed, H. U., Turnbull, G. D., Strelkov, S. E. and Gossen, B. D. 2013. Effects of soil-borne Rhizoctonia solani on canola seedlings after application of glyphosate herbicide. Can. J. Plant Sci. 93: 97–107. Application of glyphosate (N-phosphonomethyl glycine) prior to seeding is a common weed management practice in many agricultural systems. However, there are concerns that this practice may increase the impact of soil-borne diseases on the crop, even in cultivars that are resistant to glyphosate. In the current study, the effects of pre-plant applications of glyphosate on seedling blight of canola caused by Rhizoctonia solani and subsequent crop growth were examined under field and greenhouse conditions. Under greenhouse conditions in soil inoculated with R. solani, glyphosate application 15 d before seeding reduced seedling emergence, increased damping-off, and decreased plant height and shoot dry weight of canola relative to a glyphosate-free control. However, the adverse effects were substantially reduced when the crop was seeded 33 d after glyphosate application. This indicates that glyphosate application prior to planting may increase the impact of R. solani on canola seedlings, but that this effect diminishes quite rapidly. Soil populations of R. solani declined over the 33-d period regardless of glyphosate treatment. Glyphosate application 10 d before seeding increased seedling emergence and seed yield (1 of 2 yr) of canola in field trials inoculated with R. solani.

The effect of seed size, seed treatment, seeding date and depth on Rhizoctonia seedling blight of canola

2013 ◽  
pp. 150113084625001
Author(s):  
Sheau-Fang Hwang ◽  
Hafiz U. Ahmed ◽  
George D. Turnbull ◽  
Bruce Gossen ◽  
Stephen Strelkov
Keyword(s):  
Seed Size ◽  
Seed Treatment ◽  
Seedling Blight ◽  
Seeding Date

Effects of inoculum density, temperature, seeding depth, seeding date and fungicidal seed treatment on the impact of Rhizoctonia solani on lentil

2008 ◽  
Vol 88 (4) ◽  
pp. 799-809 ◽  
Author(s):  
K. F. Chang ◽  
S. F. Hwang ◽  
B. D. Gossen ◽  
G. D. Turnbull ◽  
H. Wang ◽  
...  
Keyword(s):  
Rhizoctonia Solani ◽  
Seedling Establishment ◽  
Root Rot ◽  
Seed Treatment ◽  
Field Experiments ◽  
Seedling Survival ◽  
Seedling Emergence ◽  
Inoculum Density ◽  
Seeding Date ◽  
The Impact

Rhizoctonia solani causes seedling blight and root rot in lentil, which reduces plant populations and the vigour and yield of surviving plants. Factors in the seedling environment, such as inoculum density, temperature, seeding depth, seeding date, and fungicidal seed treatment were studied to determine the degree to which they affect the impact of R. solani on lentil seedlings. Survival of lentil plants was evaluated after planting into soil artificially inoculated with various concentrations of a highly aggressive isolate of R. solani (AG-4). Emergence, seedling survival and shoot dry matter production decreased with increasing inoculum density, but these declines varied with temperature. Low soil temperatures delayed the emergence of lentil seedlings in non-inoculated soil, but in inoculated soils, emergence was inhibited with increasing temperatures. Depth of seeding did not affect seedling establishment, but root rot severity increased with depth of seeding in a growth cabinet trial. Root nodulation was reduced as root rot severity increased. In field experiments carried out over 3 station years, seeding date had a substantial effect on seedling emergence and yield of inoculated treatments, but the trends were not consistent between sites. In field assessments of fungicide efficacy, treatment of seed with thiabendazole plus carbathiin (Crown) and carbathiin plus thiram (Vitaflo 280) improved seedling establishment relative to the inoculated control. Key words: Lens culinaris, damping-off, root rot, seeding date, fungicide seed treatment depth of seeding, thiabendazole, carbathiin, thiram

Response of kabuli chickpea to seed size and planting depth

2003 ◽  
Vol 83 (1) ◽  
pp. 39-46 ◽  
Author(s):  
Y. T. Gan ◽  
P. R. Miller ◽  
C. L. McDonald
Keyword(s):  
Cicer Arietinum ◽  
Seed Size ◽  
Seed Yield ◽  
Seedling Emergence ◽  
Dry Weight ◽  
Production Costs ◽  
Planting Depth ◽  
Cicer Arietinum L ◽  
Shoot Dry Weight ◽  
Small Seed

The use of small seed can reduce the production costs of kabuli chickpea (Cicer arietinum L.) 15 to 25% by reducing the amount of seed needed per unit area, but little is known about the effects of seed size on stand establishment, plant growth, and seed yield in semiarid environments. We conducted a field study in southwest Saskatchewan from 1998 to 2000 and determined the chickpea responses to seed size under different planting depths. Crops grown from small (7.1–9.0 mm) diameter seed required the same number of days to emerge (16.7 d) and mature (106 d) as those from large (9.1–11.0 mm) diameter seed. There were no differences in plant establishment, shoot dry weight, pod production, or seed yield between the two seed sizes when planted at a 50-mm depth. However, the small-seeded crop produced 7% lower plant stand, 4% lower seed yield, and 3% less seed 1799-mm diameter compared to the large-seeded crop when planted at a 100-mm depth (P < 0.05). Large-seed ed chickpea plants were 20 mm (4%) taller, and the height of the lowest pods from the soil surface was 11 to 13 mm (5%) higher than those from the small seed, suggesting an improvement of harvestability. In general, planting depth did not affect seedling emergence, shoot dry weight, or seed yield, but when small seed was used, chickpea sown at the 50-mm depth increased seed yield by 6% compared to that at the 100-mm depth. Kabuli chickpea produced an average of >20 pods plant-1, with 77% of them containing one seed per pod, 10% with two seeds per pod, and the remainder containing no seed; this ratio of pod fertility was independent of seed size or planting depth. Our results indicate that the use of small seed and shallow planting can reduce the production costs of chickpea by $31 to $52 ha-1 without a seed yield penalty. This level of saving in production far exceeds the otherwise increased value of $4 to $6 ha-1 with the use of large seed which produces a higher (3%) proportion of ≥ 9-mm diameter seed. Key words: Seedling emergence, seed mass, pod production, Cicer arietinum L.

Effect of temperature, seeding date, fungicide seed treatment and inoculation with Fusarium avenaceum on seedling survival, root rot severity and yield of lentil

2000 ◽  
Vol 80 (4) ◽  
pp. 899-907 ◽  
Author(s):  
S. F. Hwang ◽  
B. D. Gossen ◽  
G. D. Turnbull ◽  
K. F. Chang ◽  
R. J. Howard ◽  
...  
Keyword(s):  
Seed Yield ◽  
Root Rot ◽  
Seed Treatment ◽  
Seedling Survival ◽  
Maximum Yield ◽  
Fusarium Avenaceum ◽  
Effect Of Temperature ◽  
Seeding Date ◽  
Wide Range ◽  
The Impact

Early seeding of lentil is necessary on the northern prairies to ensure that the crop has time to mature. However, planting into cold soils in spring results in slow germination, which may predispose seedlings to infection by soil-borne pathogens. In a controlled-environment study of the impact of temperature on infection of lentil seedlings (cv. Eston) byFusarium avenaceum, root rot symptoms were most severe at warm temperatures (20° to 27.5 °C) and declined in warmer or cooler soils. Field plots were seeded on three dates, which were spaced about 2 wk apart between early May and early June in four station years. Seedling emergence was most consistent and seed yield was highest in three of four sites at the second seeding date. Emergence and yield were substantially lower for the latest seeding date. Inoculation with F. avenaceum reduced establishment and seed yield. Seed treatment with Crown (thiabendazole and carbathiin) improved seedling survival, reduced root rot severity and increased seed yield relative to the inoculated control. Vitaflo-280 (thiram and carbathiin) also improved establishment and yield, but the effect was not as strong or consistent. Treatment with Raxil (tebuconazole) and Apron (metalaxyl) had no effect. The pathogenicity of aggressive isolates of F. avenaceum from lentil on a range of crop species was evaluated. All crops were susceptible to some degree, which indicates that the pathogen, once established, is likely to persist in a field for some time. This study demonstrated that early planting was required for maximum yield, that certain isolates of F. avenaceum were pathogenic on a wide range of hosts, and that seed treatment can be used to minimize losses from seedling blight and root rot in lentil. Key words: Lentil (Lens culinaris Medikus), Fusarium avenaceum, root rot, seeding date, thiabendazole, carbathiin, thiram, tebuconazole

Seedbed preparation, timing of seeding, fertility and root pathogens affect establishment and yield of alfalfa

2002 ◽  
Vol 82 (2) ◽  
pp. 371-381 ◽  
Author(s):  
S. F. Hwang ◽  
B. D. Gossen ◽  
G. D. Turnbull ◽  
K. F. Chang ◽  
R. J. Howard
Keyword(s):  
Seed Treatment ◽  
Fungal Pathogens ◽  
Plant Density ◽  
Seedling Emergence ◽  
Stand Density ◽  
Pathogenic Fungi ◽  
Field Trials ◽  
Forage Yield ◽  
Seedbed Preparation ◽  
The Impact

Invasion by grasses and weedy species occurs when plant density in alfalfa fields falls below critical levels. Several soil-borne fungal pathogens can reduce stand density in alfalfa by impeding seedling establishment and by killing older plants weakened by other stresses. Surveys of alfalfa fields were conducted in 1997, and pathogenic fungi from rotted roots were isolated and identified. Isolates of selected pathogens were applied with the seed in field trials to assess the impact of fertilizer and seeding system (conventional vs. sod-seeding, spring vs. dormant-fall seeding) on seedling emergence and subsequent productivity when disease pressure was high. The impact of various fungicide seed treatments was also assessed. Seed treatment improved seedling emergence and initial forage productivity in one of three trials; however, it had little effect on long-term forage yield. Addition of sulphur fertilizer had little effect on seedling emergence or survival, but improved forage productivity at all three trial sites. Sod-seeded plots suffered more winterkill and were less vigorous than plots seeded into a tilled seedbed. Seedling emergence was lower when seedlings were planted in the fall than in the spring. However, fall-seeded treatments showed a less adverse response to inoculum treatments and, in some cases, these seedlings were able to take advantage of early-season moisture to produce higher yields than their spring-seeded counterparts. Key words: Medicago, Fusarium, Pythium, Phoma, fungicide, seed treatment, fertilizer, tillage

Etiology, impact and control of rhizoctonia seedling blight and root rot of chickpea on the Canadian prairies

2003 ◽  
Vol 83 (4) ◽  
pp. 959-967 ◽  
Author(s):  
S. F. Hwang ◽  
B. D. Gossen ◽  
K. F. Chang ◽  
G. D. Turnbull ◽  
R. J. Howard ◽  
...  
Keyword(s):  
Rhizoctonia Solani ◽  
Seed Yield ◽  
Root Rot ◽  
Seed Treatment ◽  
Seedling Survival ◽  
Root Mass ◽  
Seedling Blight ◽  
Inoculum Concentration ◽  
Seed Damage ◽  
The Impact

Studies were undertaken to assess the impact of seedling blight and root rot caused by Rhizoctonia solani AG-4 on nodulation and seed yield of chickpea. The effects of pathogen inoculum concentration and seed damage on disease severity were also measured. Chickpea seedlings were grown under controlled-environment conditions in sterilized soil amended with pathogenic isolates of R. solani and in field plot experiments where the inoculum was incorporated with the seed at planting. In greenhouse experiments, emergence and dry matter production declined and root rot severity increased with increasing inoculum concentration. Root rot reduced nodulation where lesions covered more than 25% of the root surface. For chickpea cultivar Sanford this level of infection was sufficient to reduce root mass, but for the cultivar Tyson, more than half of the root was covered with lesions before root mass began to decline. In a comparison of seed treatment fungicides, thiram + carbathiin (Vitaflo 280) and carbathiin + thiabendazole (Crown at 6 mL of product kg-1 seed) significantly increased seedling emergence and seed yield compared to the inoculated control. In an assessment of the effects of seed damage, seedling survival and seed yield were similar for both healthy and mechanically damaged seed. Rhizoctonia solani has the potential to be an important constraint to chickpea production in the prairie region of western Canada. Key words: Rhizoctonia solani, Cicer arietinum, seed treatment, fungicide, seeding date

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