scholarly journals Seed Treatment Effects on Maize Seedlings Coinfected with Rhizoctonia solani and Pratylenchus penetrans

Plant Disease ◽  
2017 ◽  
Vol 101 (6) ◽  
pp. 957-963 ◽  
Author(s):  
M. P. da Silva ◽  
G. L. Tylka ◽  
G. P. Munkvold

The roots of maize seedlings typically are attacked by a complex of organisms that includes fungal pathogens and plant-parasitic nematodes but few studies have examined the effects of these organisms in combination. Rhizoctonia solani can be an important component of the seedling disease complex; like other fungi, its effect on the plant may be influenced by the activity of nematodes such as the root-lesion nematode Pratylenchus penetrans. In this study, we assessed the impact of seed treatments, including fungicide–nematicide combinations, on maize seedlings exposed to R. solani and P. penetrans alone or in combination. In growth-chamber and greenhouse experiments, seed treated with various active ingredient combinations were planted in an autoclaved sand-soil mixture with or without inoculum of R. solani. In some treatments, a suspension of P. penetrans adults and juveniles was added to the sand-soil mixture. In the greenhouse experiments, infection by R. solani caused dramatic reductions in root length, volume, surface area, and numbers of root tips and root forks, whereas P. penetrans infestation alone reduced only shoot fresh weight. Statistical interactions between the effects of the two organisms were not significant, although fungal infestation significantly reduced the numbers of nematodes extracted from roots. Seed treatments significantly improved most root development variables, and the combination that included four fungicides, thiamethoxam, and abamectin was the best treatment for most variables. Results were similar in the growth-chamber experiments, where R. solani caused significant reductions in nearly all shoot and root development measurements, and seed treatment with sedaxane, alone or combined with abamectin, consistently provided the best results. R. solani was more damaging to seedlings than P. penetrans, and the combination of the two organisms did not cause more damage than R. solani alone. Seed-treatment active ingredients that specifically targeted R. solani (sedaxane) and P. penetrans (abamectin) had large positive effects on seedling health, causing significant improvements in root and shoot growth and development compared with untreated seedlings exposed to these pathogens.

2007 ◽  
Vol 87 (1) ◽  
pp. 167-174 ◽  
Author(s):  
A. G. Xue ◽  
E. Cober ◽  
M. J. Morrison ◽  
H. D. Voldeng ◽  
B. L. Ma

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


Plant Disease ◽  
2016 ◽  
Vol 100 (2) ◽  
pp. 431-437 ◽  
Author(s):  
M. P. da Silva ◽  
G. L. Tylka ◽  
G. P. Munkvold

Seedling diseases of maize are caused by a complex of organisms, including fungi in the genus Fusarium. Root-lesion nematodes (Pratylenchus spp.) are common in fields where maize is grown, and they are known to interact with Fusarium spp. in several crops. The objectives of this study were to assess the impacts of seed treatment combinations on maize seedlings coinfected with Pratylenchus penetrans and two Fusarium spp. that cause seedling disease symptoms (Fusarium graminearum and F. verticillioides) and to determine whether there were interactions between P. penetrans and the Fusarium spp. Growth-chamber experiments were conducted with fungicide- or nematicide-treated or untreated maize seed planted in a sand-soil mixture infested with inoculum of either F. graminearum or F. verticillioides. A suspension of 4,000 P. penetrans (mixed stages) was added to the pots at the time of planting. After 30 days, shoot length and fresh and dry shoot and root weights were determined. Total root length and fine root length, root volume, numbers of root tips and forks, and root surface area were measured through analysis of digital images of the root systems. After 42 days, P. penetrans nematodes were extracted and quantified from roots and soil. There were significant effects of the treatments on root health with interactions between Fusarium spp. and P. penetrans. F. graminearum caused the greatest reductions in root and shoot growth, and interactions with P. penetrans were more evident for F. verticillioides than for F. graminearum. Image analysis of root system architecture showed that seed treatment significantly improved root system characteristics. Seed treatments containing the nematicide abamectin in combination with fungicides reduced root infection by P. penetrans and provided the healthiest root system when under attack by the Fusarium–Pratylenchus complex.


Plant Disease ◽  
2012 ◽  
Vol 96 (12) ◽  
pp. 1805-1817 ◽  
Author(s):  
C. S. Rothrock ◽  
S. A. Winters ◽  
P. K. Miller ◽  
E. Gbur ◽  
L. M. Verhalen ◽  
...  

The importance of fungicide seed treatments on cotton was examined using a series of standardized fungicide trials from 1993 to 2004. Fungicide seed treatments increased stands over those from seed not treated with fungicides in 119 of 211 trials. Metalaxyl increased stands compared to nontreated seed in 40 of 119 trials having significant fungicide responses, demonstrating the importance of Pythium spp. on stand establishment. Similarly, PCNB seed treatment increased stands compared to nontreated seed for 44 of 119 trials with a significant response, indicating the importance of Rhizoctonia solani in stand losses. Benefits from the use of newer seed treatment chemistries, azoxystrobin and triazoles, were demonstrated by comparison with a historic standard seed treatment, carboxin + PCNB + metalaxyl. Little to no stand improvement was found when minimal soil temperatures averaged 25°C the first 3 days after planting. Stand losses due to seedling pathogens increased dramatically as minimal soil temperatures decreased to 12°C and rainfall increased. The importance of Pythium increased dramatically as minimal soil temperature decreased and rainfall increased, while the importance of R. solani was not affected greatly by planting environment. These multi-year data support the widespread use of seed treatment fungicides for the control of the seedling disease complex on cotton.


2007 ◽  
Vol 97 (1) ◽  
pp. 66-71 ◽  
Author(s):  
Charles R. Howell

Good quality seeds of cotton cultivars often escaped pre-emergence damping-off incited by Pythium spp. and Rhizopus oryzae, and they were resistant to postemergence damping-off incited by Rhizoctonia solani. Poor quality seeds, however, were highly susceptible to both phases of seedling disease and required seed treatment in order to survive. Pre-emergence damping-off incited by Pythium spp. and Rhizopus oryzae could be controlled by seed treatment with biocontrol preparations of a number of Trichoderma spp., but these treatments were much less effective in controlling postemergence disease incited by Rhizoctonia solani. Postemergence seedling disease can be controlled by fungicides, but they were much less effective in controlling the pre-emergence phase of the disease. Combination seed treatments of poor quality cotton seeds with fungicides and Trichoderma spp. preparations, followed by planting in pathogen-infested soil, indicated that this technique will control both phases of seedling disease. Seed treatment with either the fungicides or the biocontrol agents alone did not achieve this goal. The optimum combination treatment for disease control was that of chloroneb plus Trichoderma spp., followed by chloroneb plus metalaxyl (Deltacoat AD) plus T. virens strain G-6.


2017 ◽  
Author(s):  
◽  
Blake Remington Barlow

Field research experiments were conducted in 2015 and 2016 in Missouri to determine whether interactions are present between herbicides sprayed prior to planting and seed treatments in soybean. Two varieties of soybean were chosen, one that was known to be tolerant to the herbicides sprayed and one that was known to be sensitive to these herbicides. Each of these soybean varieties were treated with a commonly used seed treatment and sprayed with three commonly used herbicides. The results of these experiments indicate that there were larger interactions present between herbicides and varieties than herbicides and seed treatments or seed treatments and varieties. Greenhouse and field research experiments were conducted in 2015 and 2016 to investigate a waterhemp population with suspected resistance to multiple herbicides including 2,4-D. Results form the field experiment suggested resistance to six of the eight herbicides screened. The only two herbicides that had effective control were dicamba and glufosinate. Greenhouse experiments confirmed the waterhemp population to be resistant to 2,4-D, atrazine, chlorimuron, fomesafen, glyphosate, and mesotrione making this population the third 2,4-D-resistant waterhemp population identified in the U.S., and the first population resistant to six different herbicidal modes of action.


2014 ◽  
Vol 94 (4) ◽  
pp. 693-700 ◽  
Author(s):  
K. F. Chang ◽  
R. L. Conner ◽  
S. F. Hwang ◽  
H. U. Ahmed ◽  
D. L. McLaren ◽  
...  

Chang, K. F., Conner, R. L., Hwang, S. F., Ahmed, H. U., McLaren, D. L., Gossen, B. D. and Turnbull, G. D. 2014. Effects of seed treatments and inoculum density of Fusarium avenaceum and Rhizoctonia solani on seedling blight and root rot of faba bean. Can. J. Plant Sci. 94: 693–700. Production of faba bean cultivars with tannin-free seed on the Canadian prairies has potential for use in human food and as a feedstock for livestock and aquaculture. However, root rot is a major constraint to production. The effects of fungicide seed treatments on root rot caused by Fusarium avenaceum and Rhizoctonia solani, and the effect of inoculum density on seedling emergence, nodulation, root rot severity and yield of faba bean were examined across 12 station years from 2009 to 2011 at sites in Manitoba and Alberta. Fusarium avenaceum reduced seedling emergence more than R.solani, but both pathogens had a similar impact on seed yield. The effects of inoculum density and seed treatment were generally significant for seedling emergence, root rot severity and seed yield for both pathogens. The interaction effects of inoculum density×seed treatment for F.avenaceum and R.solani were only significant for seed yield and seedling emergence. Seedling emergence and seed yield declined with increasing inoculum level for both F. avenaceum and R.solani. Fungicidal seed treatments with Apron Maxx (fludioxonil+metalaxyl) and Vitaflo 280 (carbathiin+thiram) consistently improved emergence and seed yield in trials inoculated with F.avenaceum or R.solani. This study demonstrated that seed treatment to manage root rot of faba bean is warranted.


2016 ◽  
Vol 17 (4) ◽  
pp. 223-228 ◽  
Author(s):  
Jean C. Batzer ◽  
Yuba R. Kandel ◽  
Carl A. Bradley ◽  
Martin I. Chilvers ◽  
Albert U. Tenuta ◽  
...  

Early season brown spot caused by Septoria glycines was compared in Illinois, Indiana, Iowa, Michigan, and Ontario, Canada, soybean fields planted with differing commercial seed treatments. Seed treatments that included fluopyram significantly reduced brown spot (P < 0.001). A greenhouse mist chamber experiment revealed that fluopyram seed treatment reduced the Area Under Disease Progress Curve of brown spot over a 6-week period (P < 0.001). Brown spot severity was unaffected by plant age at inoculation for the control treatment without fluopyram (P = 0.911); however, severity increased with plant age at inoculation for the fluopyram treatment (P = 0.009). The sensitivity of two S. glycines isolates to fluopyram was assessed by determining the effective concentration required to reduce its colony diameter growth in culture by 50% (EC50). Both isolates had an EC50 of 0.41 μg/ml of fluopyram. These results demonstrate that fluopyram seed treatment is effecttive at controlling early season brown spot in soybean. Accepted for publication 19 September 2016.


2021 ◽  
Vol 10 (3) ◽  
pp. 206-210
Author(s):  
Bhut JB ◽  
◽  
Jethva DM ◽  
Naggana R ◽  
◽  
...  

Field experiment on evaluation of insecticidal seed treatments against white grub Holotrichia consanguinea Blachard infesting groundnut was conducted during kharif 2018 and 2019 at farmers field. The nine insecticides evaluated as seed treatment against white grub infesting groundnut, the lowest per cent plant morality and number of grub/m2 was observed in treatment of clothianidin 50 WDG @ 2 g a.i. /kg and imidacloprid 40 + fipronil 40 WG @ 3 g a.i. /kg. These treatments were produced 2329 and 2296 yield of pod, 3970 & 3780 kg/ha yield of halum, respectively. Increased in yield over control in these treatments was recorded 57.79 and 55.56 per cent in pod, 76.29 and 64.65 per cent in halum. Whereas avoidable yield loss recorded of these treatments was recorded 36.63 and 35.71 per cent in pod, 43.27 and 39.27 per cent in halum. However, the highest 1:28.32 NICRB was recorded in treatment of chlorpyriphos 20 EC @ 30 ml a.i. /kg. The NICRB of clothianidin 50 WDG @ 2 g a.i. /kg and imidacloprid 40 + fipronil 40 WG @ 3 g a.i. /kg were recorded 1:14.95 and 1:9.20, respectively. The evaluated insecticides had no adverse effect on seed germination


2020 ◽  
Vol 7 (3) ◽  
pp. 138-143
Author(s):  
A. J. Deshmukh ◽  
◽  
A. N. Sabalpara ◽  
R. P. Bambharolia ◽  
◽  
...  

The experiment was conducted to perceive the effect of fungicidal seed treatment on seed borne diseases of green gram on susceptible cv. GM-3 with nine different fungicides. Results revealed that dry seed treatment with either mix formulation of carbendazim + mancozeb or thiophanate methyl or carbendazim @ 2.5 g kg-1 seeds is very effective in field to control Macrophomina leaf blight, Alternaria leaf spot and Anthracnose diseases. Two years pooled data indicated that PDI of Macrophomina leaf bilght was significantly lower in dry seed treatment with carbendazim + mancozeb (0.99%, 12.90%) which was statistically at par with thiophanate methyl (1.54%, 13.80%) followed by carbendazim (0.99%, 14.06%) at 35 and 65 DAS, respectively. Two years pooled data of Alternaria leaf spot indicated that the PDI of was significantly lower in dry seed treatment with carbendazim + mancozeb (2.64%, 11.15%) which was statistically at par with thiophanate methyl (2.74%, 11.30%) followed by carbendazim (2.84%, 11.37%) at 35 and 65 DAS. Two years pooled data of Anthracnose disease indicated that the PDI of Anthracnose was significantly lower in dry seed treatment with carbendazim + mancozeb (0.81%, 6.71%).


2016 ◽  
Vol 7 (1) ◽  
pp. 1 ◽  
Author(s):  
Amran Muis ◽  
Arcadio J. Quimio

Rhizoctonia solani Kuhn. causing banded leaf and sheath blight diseases is one of the important fungi of corn world wide. The fungus is commonly controlled by using fungicide because no resistant variety available. The objective of the study was to develop a seed treatment formulation of the selected Bacillus subtilis to control R. solani in corn. The study was conducted in the Department of Plant Pathology, College of Agriculture, University of the Philippines Los Bañòs, College, Laguna from May 2004 to August 2005, using sweet corn var. IPB Supersweet as test plant. Corn seeds were surface sterilized for 10 minutes in 1% sodium hypochlorite solution and 5% ethanol, washed thrice with sterile distilled water and air-dried. The seeds were coated with formulated B. subtilis BR23 and used for several experiments, such as evaluation for their germination and growth in the laboratory, effectively on R. solani in the baked and nonbaked field soil under greenhouse condition, and in the microplots artificially infested with R. solani. The treatment was compared with other standard seed treatment of synthetic fungicides such as captan (10 g per kg seeds) and metalaxyl (10 g per kg seeds). The experiments were designed in a completely random design with three replications. Parameters observed were seed germination, plant height, disease scores, and plant yield. Laboratory formulated B. subtilis BR23 used as seed treatment had no detrimental effects on seed germination and seedling vigor. In microplots artificially infested with a selected highly virulent R. solani, seed treatment with the same formulation increased grain yield by 27% compared to that of the control captan seed treatment with 14.4%. The studies showed the potential of B. subtilis BR23 for commercialization as a seed treatment for the control of banded leaf and sheath blight disease (R. solani) in corn.


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