Efficacy of Peanut Seed Treatments for Organic Management in Georgia

2013 ◽  
Vol 40 (2) ◽  
pp. 149-155 ◽  
Author(s):  
R. S. Tubbs ◽  
E. G. Cantonwine ◽  
T. B. Brenneman

ABSTRACT One of the most critical and influential factors determining ultimate crop success is plant stand establishment. Because synthetic seed treatments are not allowed in organic production systems, alternatives are needed to assist in resistance of pathogens during germination and seedling growth. Several biological control materials were evaluated in laboratory assays and field trials to determine their potential for minimizing disease impact and maximizing yield in organic peanut production. These included Bacillus subtilis and several application methods of copper sulfate. Bacillus subtilis demonstrated excellent control of Aspergillus in the laboratory, but this was not confirmed in the field. Copper sulfate had no benefit against Aspergillus, but had some activity against Rhizopus in the laboratory. When applied dry to the seed, copper sulfate improved plant stands and reduced postemergence plant mortality (damping-off) compared to either B. subtilis or untreated seed. When applied in combination with cola as a sticking agent, copper sulfate did an excellent job of minimizing damping-off, but caused delayed emergence or a reduced plant stand compared to all other treatments. Because there was no evidence of direct toxicity against A. niger by the copper sulfate treatments in the lab assay, the field effect may be the result of enhanced host resistance to Aspergillus crown rot, or activity on another pathogen.

Plant Disease ◽  
2009 ◽  
Vol 93 (12) ◽  
pp. 1281-1292 ◽  
Author(s):  
Jaime A. Cummings ◽  
Carol A. Miles ◽  
Lindsey J. du Toit

The efficacy of 14 seed and drench treatments for control of soilborne damping-off pathogens in organic production of spinach was evaluated in a greenhouse study. The efficacy of each treatment was compared with nontreated seed and seed treated with a conventional fungicide for control of Fusarium oxysporum f. sp. spinaciae, Pythium ultimum, and Rhizoctonia solani. Two experimental seed treatments, GTG I and GTG II (each comprised of a proprietary organic disinfectant and the latter also containing Trichoderma harzianum T22), provided equivalent control to the conventional fungicide, mefenoxam, against P. ultimum in one trial and significant reduction of damping-off in the second trial. Natural II and Natural X (Streptomycete products), and Subtilex (Bacillus subtilis) seed treatments each suppressed damping-off significantly in one of the two trials. For R. solani, GTG I and Natural II seed treatments reduced damping-off as effectively as a drench with the fungicide Terraclor (pentachloronitrobenzene). A soil drench with Prestop (Gliocladium catenulatum) suppressed postemergence wilt caused by F. oxysporum in both trials; a compost tea drench and seed treatment with Yield Shield (Bacillus pumilis) each suppressed postemergence wilt in only one of two trials. GTG I and GTG II significantly increased seed germination compared to nontreated seed. No treatment was effective against all three pathogens, and some treatments exacerbated damping-off.


Plant Disease ◽  
2010 ◽  
Vol 94 (4) ◽  
pp. 445-454 ◽  
Author(s):  
S. J. Ruark ◽  
B. B. Shew

Diseases affecting stand establishment are a major obstacle to organic production of peanut (Arachis hypogaea). Stand losses of 50% or more are possible with untreated seed. Biological, botanical, and organic seed treatments or soil amendments were tested for efficacy against pre- and postemergence damping-off of peanut in greenhouse, microplot, and field plot trials. Seed of the lines Perry, GP-NC 343, and Bailey (tested as N03081T) were used in all trials. Commercial formulations of Bacillus subtilis (Kodiak), B. pumilus (Yield Shield), Trichoderma harzianum (T-22 PB and Plantshield HC), Muscodor albus, and Coniothyrium minitans (Contans); activated charcoal; two separate soil amendments of dried herbage of Monarda didyma cultivars; a commercial fungicide control (Vitavax PC); and an untreated control were tested in natural soil in the greenhouse. Vitavax PC and Kodiak were the only treatments that resulted in higher percent emergence and survival than in untreated seed. A separate greenhouse experiment was conducted in natural soil or natural soil infested with field isolates of Aspergillus niger. Seed were treated with Kodiak, copper hydroxide (Champion), Plantshield HC, Kodiak + Plantshield HC, Streptomyces griseoviridis (Mycostop), hot water, Vitavax PC, or were left untreated. Seedling emergence and survival was much lower in infested versus uninfested soil. Seed treatment with Kodiak increased percent emergence and survival compared to untreated seed, but was not as effective as Vitavax PC. Field microplot studies in 2007 and 2008 at Clayton, NC, evaluated four seed treatments on the peanut lines following small grain cover crops, soil amendment with M. albus, or no cover. Cover crops did not affect emergence or interact with seed treatments. In field studies in 2007 and 2008 at Lewiston, NC, the peanut lines were planted with M. albus infurrow, with Kodiak or T. harzianum seed treatments, or were untreated. In the 2007 trial, none of the treatments improved stands compared to the untreated check. In 2008, the highest stand counts were produced by seed treated with Kodiak. In both years, Bailey produced the greatest stand counts. A. niger was strongly associated with postemergence damping-off in the field. Regardless of peanut line, in many trials, Kodiak seed treatment increased emergence and survival over untreated seed.


1996 ◽  
Vol 42 (6) ◽  
pp. 533-538 ◽  
Author(s):  
A. R. Podile ◽  
A. P. Prakash

A biocontrol rhizobacterial strain of Bacillus subtilis AF 1 grown for 6 h was coinoculated with Aspergillus niger at different time intervals and microscopic observations revealed adherence of bacterial cells to the fungal mycelium. Bacterial cells multiplied in situ and colonized the mycelial surface. Growth of AF 1 resulted in damage to the cell wall, followed by lysis. AF 1 inoculation into media containing A. niger at 0, 6, and 12 h suppressed >90% fungal growth, while in 18- and 24-h cultures fungal growth inhibition was 70 and 56%, respectively, in terms of dry weight. In dual culture the fungal growth was not accompanied by formation of spores. The mycelial preparation of A. niger as principal carbon source supported the growth of B. subtilis, as much as chitin. Extracellular protein precipitate from B. subtilis culture filtrate had a significant growth-retarding effect on A. niger. Groundnut seeds bacterized with B. subtilis showed a reduced incidence of crown rot in A. niger infested soil, suggesting a possible role of B. subtilis in biological control of A. niger.Key words: mycolytic bacteria, Bacillus subtilis, Aspergillus niger, biological control.


Plant Disease ◽  
2002 ◽  
Vol 86 (2) ◽  
pp. 156-161 ◽  
Author(s):  
P. A. Abbasi ◽  
J. Al-Dahmani ◽  
F. Sahin ◽  
H. A. J. Hoitink ◽  
S. A. Miller

Field trials were conducted over 2 years to assess the effects of compost amendments on disease development in organic and conventional processing tomato (Lycopersicon esculentum L.) production systems. The incidence of anthracnose fruit rot was reduced in organic tomato plots amended with a high rate of composted cannery wastes compared with the incidence in nonamended control plots in 1998 when disease incidence was high. Marketable yield was increased by 33% in compost-amended organic plots. Plots amended with a high compost rate had more ripe fruit than the nonamended control. The incidence of anthracnose and of total disease on fruit was less on the cultivar OH 8245 than on Peto 696. Total fruit yield of OH 8245 but not Peto 696 in organic plots was increased by amendment with composted cannery wastes. In conventional tomato production, composted yard wastes increased disease severity on foliage both years but reduced bacterial spot incidence on fruit in 1997, when disease pressure was high. The incidence of anthracnose was not affected by composted yard wastes. Marketable and total fruit yields of Peto 696 were not increased in compost-amended conventional plots. The plant activator Actigard reduced foliar disease severity and the incidence of bacterial spot and anthracnose on fruit, while increasing yield of marketable fruit.


2009 ◽  
Vol 89 (4) ◽  
pp. 811-821 ◽  
Author(s):  
M R Fernandez ◽  
T K Turkington ◽  
W E May

Fusarium head blight (FHB) is well established in the eastern prairies, but for the most part it has been absent from western regions, especially under dryland conditions. This has been largely attributed to dry and hot conditions during some years, and the limited occurrence of F. graminearum in the western prairies. It is of importance to prevent the movement of F. graminearum, the most important FHB pathogen in North America, to areas where this pathogen is not commonly found. Three controlled-environment studies, using different Fusarium-infected common and durum wheat seed lots, were conducted to determine the effectiveness of currently registered fungicide seed treatments in improving seedling emergence and plant development, and preventing the growth of F. graminearum from infected seed to plant tissue. Fungicide treatments improved seedling emergence from the most infected seed over the untreated infected control, but most treatments did not improve emergence in the other experiments. Plant growth in the fungicide treatments was either similar to or slower than in the untreated controls. Fusarium graminearum was isolated from discoloured tissue in all treatments and was generally more common in crowns than in subcrown internodes. No fungicide treatment reduced discolouration of plant tissue or percentage isolation of F. graminearum or other Fusarium spp. consistently. We conclude that while currently registered seed treatments might be effective in improving seedling emergence in some infected wheat seed lots, they do not prevent the growth of F. graminearum from seeds to plant tissue. For the western prairies, the use of fungicide seed treatments as a strategy in the prevention of spread of FHB would require that they be effective primarily against F. graminearum. Performance of fungicide seed treatments against Fusarium-infected wheat seed should also be determined under typical growing conditions across the western prairies.Key words: Seed treatments, fungicides, wheat, root rot, crown rot, Fusarium graminearum, Fusarium avenaceum


2019 ◽  
Vol 98 (4) ◽  
pp. 1559-1567 ◽  
Author(s):  
D. Freihold ◽  
T. Bartels ◽  
S. Bergmann ◽  
J. Berk ◽  
F. Deerberg ◽  
...  

2009 ◽  
Vol 89 (13) ◽  
pp. 2275-2282 ◽  
Author(s):  
Anissa Riahi ◽  
Chafik Hdider ◽  
Mustapha Sanaa ◽  
Néji Tarchoun ◽  
Mohamed Ben Kheder ◽  
...  

2018 ◽  
Vol 24 (3-4) ◽  
Author(s):  
P. Dremák ◽  
Á. Csihon ◽  
I. Gonda

In our study, vegetative characteristics of 39 apple cultivars were evaluated in environmentally friendly production systems. Numbers of the branches of the central leader in different high zones were shown. According to our results, number of the branches of the axis was probably larger in the integrated production system, compared to the organic one, which is related to the conditional status of the trees. Based on our experiences training and maintaining canopies in integrated system was easier, as relative more extensive canopies were needed in organic farming.


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