scholarly journals Efficacy of Fungicide Seed Treatments in Controlling Blackleg of Canola

2019 ◽  
Vol 20 (3) ◽  
pp. 160-164
Author(s):  
Sudha GC Upadhaya ◽  
Venkataramana Chapara ◽  
Mukhlesur Rahman ◽  
Luis E. del Río Mendoza
Keyword(s):  
Seed Treatment ◽  
Leaf Growth ◽  
Disease Incidence ◽  
Leptosphaeria Maculans ◽  
Field Trials ◽  
Management Tool ◽  
Blackleg Disease ◽  
Seed Treatments ◽  
Spring Canola ◽  
Plant Stand

The efficacy of five fungicide seed treatments as a management tool against blackleg on spring canola was evaluated under greenhouse and field conditions in North Dakota. Blackleg, caused by Leptosphaeria maculans, inflicts the greatest yield losses when infecting seedlings before they reach the six-leaf growth stage. In greenhouse studies, 10-day-old seedlings were inoculated with L. maculans spore suspensions and evaluated 12 days later and at maturity or inoculated 12, 20, or 28 days after planting and evaluated at maturity. In field trials conducted in 2017 and 2018, severity was assessed at maturity. In the greenhouse, all fungicide seed treatments reduced (P = 0.05) disease severity at the seedling stage, but only the protection provided by Obvius (fluxapyroxad + pyraclostrobin + metalaxyl) and Helix Vibrance (mefenoxam + fludioxonil + sedaxane + difenoconazole + thiamethoxam) reduced (P < 0.05) severity at the adult stage; however, none of them provide effective protection when plants were inoculated 20 days after planting or later. In field trials, none of the treatments significantly (P > 0.05) improved plant stand and yield or reduced disease incidence and severity. Although fungicide seed treatment is a valuable tool, it should not be used as the only method to manage blackleg disease.

scholarly journals Plant Population and Replant Method Effects on Peanut Seeded in Single Rows

2016 ◽  
Vol 43 (2) ◽  
pp. 126-132
Author(s):  
J.M. Sarver ◽  
R.S. Tubbs ◽  
J.P. Beasley ◽  
A.K. Culbreath ◽  
T.L. Grey ◽  
...  
Keyword(s):  
Linear Trend ◽  
Disease Incidence ◽  
Block Design ◽  
Field Trials ◽  
Yield Potential ◽  
Seeding Rate ◽  
Seed Addition ◽  
University Of Georgia ◽  
Plant Stand ◽  
Reduced Rate

ABSTRACT The University of Georgia Extension recommendation for optimum plant stand in peanut (Arachis hypogaea L.) is 13.1 plants/m, although previous work has shown that yield potential can be maintained at lower plant stands. The unpredictable and often extreme weather and the ubiquity of pathogens in the region often contribute to poor emergence and poor plant stands. When plant stand is adversely affected, replanting the field may be a practical option. The objectives of this study were to determine i) the effect of plant stand on yield, grade and disease incidence, ii) at what plant stand peanut gains an advantage from replanting and iii) the best method for replanting peanut when an adequate stand is not achieved. Field trials took place in Plains, GA in 2011, 2012, and 2013; and Tifton, GA in 2012 and 2013 to evaluate peanut production at six plant stands (3.3, 4.9, 6.6, 8.2, 9.8, and 11.5 plants/m, in addition to a 13.1 plants/m control) in combination with three replant practices; i) no replant, ii) destroy the original stand and replant at a full seeding rate, and iii) add a reduced rate of seed to supplement the original stand) in a randomized complete block design. A positive linear trend for yield and a negative linear trend for tomato spotted wilt Tospovirus incidence were discovered as plant stand increased. Yield advantages from replanting occurred via supplemental seed addition to initial stands of 3.3 and 8.2 plants/m. Destroying the initial stand and completely replanting was never beneficial when compared to the other two replant practices. Replanting is warranted via supplemental seed addition at plant stands equal-to or below 8.2 plants/m.

Prevalence of blackleg (Leptosphaeria maculans) on canola (Brassica napus) in Western Australia

2001 ◽  
Vol 41 (1) ◽  
pp. 71 ◽  
Author(s):  
R. K. Khangura ◽  
M. J. Barbetti
Keyword(s):  
Western Australia ◽  
Disease Incidence ◽  
Leptosphaeria Maculans ◽  
Sowing Date ◽  
Blackleg Disease ◽  
The Mean ◽  
Seed Yields ◽  
Blackleg Fungus ◽  
Western Australian

Canola crops were monitored throughout the Western Australian wheatbelt during 1996–99 to determine the incidence and severity of crown cankers caused by the blackleg fungus (Leptosphaeria maculans). All crops surveyed had blackleg. The incidence of crown canker was 48–100%, 15–100%, 9–94% and 48–100% during 1996, 1997, 1998 and 1999, respectively. The mean incidence of crown cankers statewide was 85, 63, 55 and 85% in 1996, 1997, 1998 and 1999, respectively. The severity of crown canker (expressed as percentage disease index) ranged between 30 and 96%, 3 and 94%, 5 and 78% and 21 and 96% during 1996, 1997, 1998 and 1999, respectively. These high levels of blackleg can possibly be attributed to the accumulation of large amounts of infested canola residues. In 1999, there were effects of variety, application of the fungicide Impact, distance to last year’s canola residues and rainfall on the incidence and severity of blackleg. However, there were no effects of sowing date or region on the disease incidence or severity once the other factor effects listed above had been considered. In 1995, an additional survey of 19 sites in the central wheatbelt of Western Australia assessed the survival of the blackleg fungus on residues from crops grown in 1992–94. The residues at all sites carried blackleg. However, the extent of infection at any particular site varied from 12 to 100% of stems with the percentage of stems carrying pseudothecia containing ascospores varying between 7 and 96%. The high levels of blackleg disease found in commercial crops are indicative of significant losses in seed yields, making it imperative that management of blackleg be improved if canola is to remain a viable long-term cropping option in Western Australia.

Evaluation of seed, stem and soil applications of procymidone to control white rot (Sclerotium cepivorum Berk.) of onions

1991 ◽  
Vol 31 (3) ◽  
pp. 401 ◽  
Author(s):  
IJ Porter ◽  
JP Maughan ◽  
GB Towers
Keyword(s):  
Seed Treatment ◽  
Disease Incidence ◽  
Soil Surface ◽  
White Rot ◽  
Effective Control ◽  
Plant Establishment ◽  
Seed Treatments ◽  
Stem Base ◽  
Sclerotium Cepivorum ◽  
Plant Emergence

The effects of different methods of applying procymidone, either alone or combined, were evaluated for control of white rot (caused by Sclerotium cepivorum Berk.) in onions at 2 sites in Victoria.Field trials at Colac showed that seed treatments combined with sprays to the soil surface gave the most effective control of white rot, reducing disease from 78 to 16% and increasing yields from 5.7 to 14.6 t/ha in brown onions. Sprays applied to the soil surface at 2.5 kg a.i./ha had no effect on emergence and reduced disease incidence from 65.3 to 21.7%. Seed treatment at 25 g procymidone/kg seed delayed the onset of disease by 80 days and reduced disease incidence by 30%. The same treatment also reduced plant emergence by more than 27% and, therefore, did not increase yields. Dispersible granules (5 or 10%; at 2.5 kg procymidone/ha) were as effective as the soil sprays at sowing. Stem base sprays applied 11 and 19 weeks after sowing reduced disease incidence slightly but did not increase yields. Procymidone applied with bands of fertiliser 2 or 5 cm below the seed was not effective. Two formulations of procymidone, Sumisclex 500 (50% a.i.) and 275 Flocol (27.5% a.i.), were equally effective in controlling white rot. At Lang Lang, root-dips of 14-week-old seedlings in 5 g procymidone/L reduced white rot in transplanted white globe onions. Procymidone concentrations of 0.05-50 g a.i./L applied for periods ranging from 2 s to 30 min had no effect on plant establishment in a glasshouse.

scholarly journals Dehydrated pork manure by-product: effect of a chitosan amendment on bacterial community and common scab incidence

2011 ◽  
Vol 90 (3) ◽  
pp. 107-115
Author(s):  
Julie Roy ◽  
Pierre J. Lafontaine ◽  
Rock Chabot ◽  
Carole Beaulieu
Keyword(s):  
Bacterial Community ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Seed Treatment ◽  
Common Scab ◽  
Disease Incidence ◽  
Anaerobic Bacteria ◽  
Field Trials ◽  
Potato Seed ◽  
Rrna Gene

Chitosan amendment modified the composition of a microbial community associated with dehydrated pork manure by-product. The amended product (biosolid PC) contained a lower number of anaerobic bacteria than the non-amended product (biosolid P). Chitosan also significantly reduced the fungal population. A 16S rRNA gene bank constructed from DNA extracted from the bacterial community associated with both P and PC biosolids revealed that bacterial ordersXanthomonodales,Pseudomonadales,Enterobacteriales,Burkholderiales,Actinomycetales,Bacillales,ClostridialesandLactobacillaleswere found in both biosolids. Bacteria from theStenotrophomonasgenus were abundant in both biosolids. However, the addition of chitosan appeared to induce changes in the population of some bacterial genera. For example, clones carrying a 16S rRNA gene corresponding to theBacillusgenus were doubled in biosolid PC. In field trials carried out to test their effect on common scab incidence, biosolids P and PC were applied as potato seed treatment. Biosolid P increased disease incidence by a factor of 1.33 and 2.85 in two independent experiments. However, when chitosan was added to the seed treatment, the stimulating effect of biosolid P on common scab was cancelled out.

scholarly journals Evaluating Plant Population and Replant Method Effects on Peanut Planted in Twin Rows

2017 ◽  
Vol 44 (1) ◽  
pp. 19-25 ◽  
Author(s):  
J.M. Sarver ◽  
R.S. Tubbs ◽  
J.P. Beasley ◽  
A.K. Culbreath ◽  
T.L. Grey ◽  
...  
Keyword(s):  
Disease Incidence ◽  
Field Trials ◽  
Yield Potential ◽  
Seeding Rate ◽  
Pod Yield ◽  
Arachis Hypogaea L ◽  
Method Effects ◽  
Plant Stand ◽  
Reduced Rate ◽  
Disease Pressure

ABSTRACT Achieving and maintaining an adequate plant stand is a major priority when making planting and early season management decisions in peanut (Arachis hypogaea L.). Unpredictable and often extreme weather and high disease pressure in the southeastern United States can contribute to poor emergence and below-optimum plant stands. When plant stand is affected, replanting may be agronomically justified. This study was designed to determine i) the effect of plant stand on pod yield, market grade, and disease incidence in peanut seeded in a twin row pattern, (ii) if replanting is a viable option in a field with a below adequate stand and, iii) the best method for replanting peanut when an adequate stand is not achieved. Field trials were established at two locations in south Georgia in 2012 and 2013 to evaluate peanut production at four plant stands (7.4, 9.8, 12.3, and 14.8 plants/m [total plants/m across both units, or ‘twins' of the twin row pattern) and four replant methods (no replant, destroy the original stand and replant at a full seeding rate, add a reduced rate of seed to supplement the original stand with a single row between the original rows, and supplement with two additional rows with one between and the other next to the original rows). Replanting occurred when the stand had been established, an average of 24 days after initial planting. Pod yield at a stand of 12.3 plants/m was 6.6 and 5.8% greater than at a stand of 7.4 and 9.8 plants/m, respectively, with no benefit from increasing plant stand beyond 12.3 plants/m. Market grade was also maximized at 12.3 plants/m. Disease incidence was unaffected by plant stand. Yield was increased by supplementing an initial stand of 9.8 plants/m in both a single additional row and in two additional rows by 8.3 and 6.6%, respectively. A full replant of the original stand always resulted in lower yield, while grade was slightly increased in the full replant treatment. While an initial stand of 12.3 plants/m was needed in order to maintain yield potential, replanting via supplemental seed addition can recover lost yield at stands below this level.

scholarly journals Field assessment of neonicotinoids against three aphid species and their natural enemies on wheat crop in Ismailia, egypt

2017 ◽  
Vol 32 (1) ◽  
pp. 41-49 ◽  
Author(s):  
Farag Mahmoud ◽  
Mohamed Osman ◽  
Kariman Mahmoud
Keyword(s):  
Natural Enemies ◽  
Seed Treatment ◽  
Foliar Application ◽  
Rhopalosiphum Padi ◽  
Field Trials ◽  
Wheat Crop ◽  
Chrysoperla Carnea ◽  
Seed Treatments ◽  
Significant Difference ◽  
The Mean

Aphids are the most important pests on wheat in Egypt and worldwide. Field trials were conducted to assess the efficacy of the neonicotinoid insecticides imidacloprid (Nufidor 60% FS; at the doses of 2.1, 1.05 and 0.525 g a.i./kg of seeds) and thiamethoxam (Cruiser 70% WS; at the rates of 14.4, 7.2 and 3.6 g a.i./kg of seeds) as seed treatments, and thiamethoxam (Actara 25% WG; at the rates of 0.1, 0.05 and 0.025 g a.i./l) as foliar application, against three wheat aphids: bird cherry oat aphid, Rhopalosiphum padi (L.), greenbug, Schizaphis graminum (Rondani), and corn leaf aphid, Rhopalosiphum maidis (Fitch). Their effects on the aphids? natural enemies: lacewings, Chrysoperla carnea Stephens, ladybird beetles, Coccinella spp., and syrphid flies Syrphus spp. were assessed as well. The trials were conducted on the farm of the Faculty of Agriculture, Suez Canal University, Ismailia Governorate, during 2013/14 and 2014/15 seasons. Our results showed significant differences between the tested insecticides at all concentrations and clearly indicated that the recommended doses of all insecticides were more efficient against aphids on wheat plants than half- and quarter-doses. Also, the data revealed significant differences between the two seed treatments at all doses before and after foliar application, as compared to the control at all time intervals of inspection regarding the mean number of aphids on wheat plants, from the 3rd until 13th week after sowing, except in the 8th week after seed treatment before foliar application. The results clearly indicated that the weekly reduction of infestation and the general efficacy was higher at the recommended doses of Nufidor, Cruiser and Actara than the half and quarter doses in both seasons. Also, reduction in infestation decreased over the following weeks until the 8th week, when Actara insecticide was sprayed. Data revealed that there were no significant differences between treatments and control in the mean number of Chrysoperla carnea and Syrphus spp., while a significant difference in the mean number of coccinellids was observed on wheat plants treated with imidacloprid seed treatment before foliar application 6 and 7 weeks after sowing, and also after foliar application with thiamethoxam 9, 10, 11, 12 and 13 weeks after sowing. Regarding thiamethoxam seed treatment, significant differences were revealed in the ladybird population on wheat plants 3, 4, 7 and 8 weeks before foliar application, and only in the 10th week after spraying with thiamethoxam.

scholarly journals Polymerase Chain Reaction-Assisted Evaluation of the Efficacy of Seed-Treatment Prevention of Sporisorium reilianum Infection in Sorghum Seedlings

2021 ◽  
Vol 12 ◽  
Author(s):  
Zhi Zhang ◽  
Juan Fan ◽  
Mucai Feng ◽  
Hongbo Qiu ◽  
Anlong Hu
Keyword(s):  
Polymerase Chain Reaction ◽  
Seed Treatment ◽  
Early Stage ◽  
Disease Incidence ◽  
Infected Plant ◽  
Seed Treatments ◽  
Chain Reaction ◽  
Pcr Assay ◽  
Sporisorium Reilianum ◽  
Polymerase Chain

Head smut, caused by Sporisorium reilianum [(Kuhn) Langdon and Fullerton], is a major disease of sorghum. Seed treatment is considered to be the most effective way to control the disease; however, the pathogen can infect at the seedling stage and the infected plant will not display symptoms until the reproductive stage is reached. The evaluation of the efficacy of seed treatments is time consuming and is dependent upon visible symptoms. Polymerase chain reaction (PCR) methods have the ability to identify pathogens and diagnose their presence at an early stage of infection. In this study, the S. reilianum-specific primer SR3 was used for PCR detection pathogen. We optimized temperature, humidity, and spore quantity test conditions and were able to achieve &gt;88% infection incidence in sorghum seedlings. Sorghum seeds were soaked in various concentrations of tebuconazole and planted for 7 days in soil containing 0.2% teliospores. The efficacy of tebuconazole against S. reilianum was evaluated by PCR and recorded as disease incidence. Results indicated that the reduction in disease incidence after exposure to 0.15, 0.30, 0.45, 0.60, and 0.75 μg/mL tebuconazole was 6.24, 37.48, 67.74, 81.24, and 93.74%, respectively. Significant differences between the concentrations of tebuconazole were observed. The PCR assay represents a valuable tool for evaluating the efficacy of fungicide seed treatments for the control of S. reilianum in sorghum under laboratory conditions.

scholarly journals Insecticide Seed Treatments Reduced Crop Injury from Flumioxazin, Chlorsulfuron, Saflufenacil, Pyroxasulfone, and Flumioxazin + Pyroxasulfone + Chlorimuron in Soybean

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
N. R. Steppig ◽  
J. K. Norsworthy ◽  
R. C. Scott ◽  
G. M. Lorenz
Keyword(s):  
Seed Treatment ◽  
Residual Activity ◽  
Unintentional Injury ◽  
Field Trials ◽  
Soybean Seeds ◽  
Seed Treatments ◽  
Injury Reduction ◽  
Crop Injury ◽  
Postemergence Herbicides ◽  
Weed Resistance

With increased instances of weed resistance to applications of postemergence herbicides, the use of soil-applied herbicides that offer residual activity is becoming popular. Unfortunately, under some conditions, the use of residual herbicides can result in unintentional injury to crops. However, there are a number of ways to reduce these risks, including the use of in-crop herbicide safeners. Based on previous research conducted on rice, the potential may exist for crop injury from certain soil-applied herbicides to be reduced (safened) in seeds treated with insecticides. Field trials were conducted in Marianna, Arkansas, in 2015 and 2016, and near Colt, Arkansas, in 2016, to explore this possibility in soybean. Soybean seeds were treated with the insecticide thiamethoxam and subsequently the herbicides metribuzin, saflufenacil, pyroxasulfone, sulfentrazone, chlorimuron, flumioxazin, flumioxazin + pyroxasulfone + chlorimuron, mesotrione, and chlorsulfuron were applied immediately after planting. Of the nine herbicides evaluated, the insecticide reduced crop injury for flumioxazin, chlorsulfuron, saflufenacil, pyroxasulfone, and flumioxazin + pyroxasulfone + chlorimuron. The highest degree of injury reduction was seen 1 week after emergence (WAE) at Marianna, where injury from flumioxazin + pyroxasulfone + chlorimuron was reduced from 15% to 5%. Based on the results from this study, the insecticide seed treatment thiamethoxam may have the potential to safen soybean to applications of some soil-applied herbicides.

Effect of benomyl on 'blackleg' disease of rape in Western Australia

1976 ◽  
Vol 16 (79) ◽  
pp. 276 ◽  
Author(s):  
AGP Brown ◽  
MJ Barbetti ◽  
PM Wood
Keyword(s):  
Western Australia ◽  
Maximum Rate ◽  
Field Experiments ◽  
Natural Infection ◽  
Leptosphaeria Maculans ◽  
Blackleg Disease ◽  
Seed Treatments ◽  
Poor Control ◽  
Rape Seedlings

Seed treatments using the fungicide benomyl at 1.1 and 2.2 per cent w/w protected seedling rape from infection by Leptosphaeria maculans under glasshouse conditions but in field experiments with natural infection no worthwhile control of the disease was obtained. Benomyl applied as a spray to rape seedlings in field experiments gave variable but mainly poor control At the maximum rate tried it increased yields at only three out of eight experiment sites.

Effect of seed treatments on emergence, yield, and root rot severity of soybean under Rhizoctonia solani inoculated field conditions in Ontario

2007 ◽  
Vol 87 (1) ◽  
pp. 167-174 ◽  
Author(s):  
A. G. Xue ◽  
E. Cober ◽  
M. J. Morrison ◽  
H. D. Voldeng ◽  
B. L. Ma
Keyword(s):  
Rhizoctonia Solani ◽  
Root Rot ◽  
Seed Treatment ◽  
Bacillus Pumilus ◽  
Field Trials ◽  
Natural Soil ◽  
Seed Treatments ◽  
Untreated Seed ◽  
Plant Emergence ◽  
Better Than

Field trials were conducted with soybean at two sites each year from 2001 to 2003 in Ottawa, ON, to determine the effect of seed treatments with various combinations of seven formulated fungicides and the bioagent Yield Shield (Bacillus pumilus GB34) under Rhizoctonia solani inoculated conditions. Controls were untreated seed planted into both non-inoculated (natural) soil and soil inoculated with R. solani. Compared with the non-inoculated control, inoculation significantly increased root rot severity and reduced emergence by 27%, and yield by 31%. Under the inoculated conditions, none of the seed treatments significantly increased emergence or yield in all of the six trials when compared with the control. Allegiance (metalaxyl) plus Vitaflo-280 (carbathiin plus thiram) and Vitaflo-280 alone were the most effective seed treatments, increasing emergence in by 20 and 19% and yield by 21 and 26%, which were significantly better than the control in four and five trials for emergence and three and four trials for yield, respectively. Allegiance plus HEC5725 (HEC5725), Apron Maxx RTA (fludioxonil plus metalaxyl), and Maxim 480FS (fludioxonil) increased both emergence and yield in two trials and TFL RTU (metalaxyl plus triflox ystrobin) plus Yield Shield in one trial. There was no difference between seed treatment with Allegiance and the untreated control for all parameters, confirming that metalaxyl is ineffective to R. solani. It is concluded that carbathiin, thiram, HEC5725, fludioxonil an trifloxystrobin are effective active ingredients protecting soybean from soil-borne R. solani and increasing plant emergence and yield. Key words: Rhizoctonia solani, seed treatment, soybean, Glycine max, fungicide, bioagent

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