scholarly journals Actigard Increases Fungicide Efficacy Against Tobacco Blue Mold

Plant Disease ◽  
2008 ◽  
Vol 92 (10) ◽  
pp. 1463-1467 ◽  
Author(s):  
J. A. LaMondia
Keyword(s):  
Nicotiana Tabacum ◽  
Blue Mold ◽  
Marketable Yield ◽  
Peronospora Tabacina ◽  
The Third ◽  
Combination Treatments ◽  
Fungicide Efficacy

Blue mold, caused by Peronospora tabacina, can be economically damaging to cigar wrapper tobacco (Nicotiana tabacum). We evaluated acibenzolar-S-methyl (ASM) as Actigard 50WG alone and in combination with a standard fungicide program for efficacy against blue mold on shade-grown cigar wrapper tobacco in Windsor, CT. The standard fungicide program consisted of dimethomorph (Acrobat MZ or Forum) plus mancozeb (Dithane), alternated with azoxystrobin (Quadris), and applied at label rates on six occasions at 14-day intervals. Treated and untreated 5-by-5-m plots were replicated four times in 2003, 2004, 2005, 2006, and 2007. ASM treatments were applied alone or in combination with fungicides at the third, fourth, and fifth spray dates at rates ranging from 1.1 to 17.5 g a.i./ha. Disease was greatest in nontreated plots and reduced in all fungicide, Actigard, or combination treatments. The combination of three ASM applications at rates of 17.5 g a.i./ha down to 4.4 g a.i./ha with the standard fungicide program was more efficacious than either fungicides or ASM alone (P < 0.001) in reducing the number of blue mold lesions per plot or number of diseased leaves harvested. The combination of fungicides and low rates of ASM (2.2 or 1.1 g a.i./ha) was similar to either fungicides or ASM (17.5 g a.i./ha) applied alone. Combining low rates of ASM with fungicide applications greatly increased efficacy and marketable yield.

scholarly journals Cocultures of Peronospora tabacina and Nicotiana Species to Study Host-Pathogen Interactions

2001 ◽  
Vol 91 (12) ◽  
pp. 1224-1230 ◽  
Author(s):  
E. P. Heist ◽  
W. C. Nesmith ◽  
C. L. Schardl
Keyword(s):  
Nicotiana Tabacum ◽  
Total Darkness ◽  
Blue Mold ◽  
Peronospora Tabacina ◽  
Genetic Studies ◽  
Free System ◽  
Light Regimes ◽  
Intact Plants ◽  
Reliable Source

Long-term cocultures of the tobacco blue mold pathogen, Peronospora tabacina, with Nicotiana tabacum and N. repanda callus were derived from infected host plant tissue. In this apparently contaminant-free system, sporulation occurred under similar conditions as in intact plants. Sporangia were collected from cocultures and used to complete Koch's postulates. The cocultures were grown under two light regimes. One consisted of 23 h of light followed by 1 h of darkness and the second comprised total darkness. Sporulation occurred frequently in the 23 h light-grown cocultures but resulted in production of abnormal sporangiophores and sporangia. Production of normal sporangiophores and sporangia was achieved by transferring light-grown cocultures to overnight darkness and resulted in necrosis of the callus. Cocultures of Peronospora tabacina with either host species, grown in total darkness, frequently sporulated with minimal necrosis over the course of 1 year. Thus, cocultures should prove useful as a source of Peronospora tabacina over extended periods of time at low risk of pathogen release, for studying the physiology of Peronospora tabacina- Nicotiana interactions, maintaining Peronospora tabacina lines for genetic studies, and providing a reliable source of axenic inoculum for research.

scholarly journals Population structure and migration of the Tobacco Blue Mold Pathogen,Peronospora tabacina,into North America and Europe

2018 ◽  
Vol 27 (3) ◽  
pp. 737-751 ◽  
Author(s):  
Monica Blanco-Meneses ◽  
Ignazio Carbone ◽  
Jean B. Ristaino
Keyword(s):  
Population Structure ◽  
North America ◽  
Blue Mold ◽  
Peronospora Tabacina ◽  
And Migration

The relationship between acquired resistance to Peronospora tabacina in Nicotiana tabacum and soil nitrogen levels

1962 ◽  
Vol 13 (1) ◽  
pp. 10 ◽  
Author(s):  
M Mandryk
Keyword(s):  
Nicotiana Tabacum ◽  
Protective Effect ◽  
Soil Nitrogen ◽  
Nitrogen Deficiency ◽  
Acquired Resistance ◽  
Nitrogen Level ◽  
Peronospora Tabacina ◽  
Plant Vigour ◽  
Stem Injection ◽  
Leaf Infection

When plants (Nicotiana tabacum L. cv. Virginia Gold) were supplied with suboptimal levels of nitrogen, the acquired resistance to blue mould (Peronospora tabacina Adam) evoked by injection of spore suspensions of the same pathogen into stems was associated with dwarfing, reduction in leaf areas, nitrogen deficiency-like symptoms, and premature senescence. However, when plants were supplied with adequate nitrogen, no morphological changes were associated with acquired resistance. The protective effect of stem injection against subsequent leaf infection was shown to be persistent and not affected by plant vigour, age, or soil nitrogen level. The protective effect of stem injection against subsequent leaf infection was shown to be persistent and not affected by plant vigour, age, or soil nitrogen level.

scholarly journals Organic fertilization and forms of application in Allium cepa growth, yield and bulb quality

2021 ◽  
Vol 25 (10) ◽  
pp. 670-676
Author(s):  
José M. F. de L. Cruz ◽  
Ademar P. de Oliveira ◽  
Otília R. de Farias ◽  
Francisco de A. F. D. da Silva ◽  
Valéria F. de O. Sousa ◽  
...  
Keyword(s):  
Experimental Design ◽  
Allium Cepa ◽  
Growth Yield ◽  
Cattle Manure ◽  
Organic Fertilization ◽  
Marketable Yield ◽  
The Third ◽  
High Doses

ABSTRACT Onion is the third most cultivated vegetable in Brazil, and organic fertilization can increase its productivity. The objective of this study was to evaluate the effect of doses of cattle manure and forms of applications on the growth, yield and bulb quality of onion cv. IPA-11 Vale Ouro. The experimental design used was randomized blocks, with four replicates, in a 6 × 2 factorial scheme, corresponding to six doses of cattle manure (0; 10; 20; 30; 40 and 50 t ha-1) and two forms of application (incorporated and topdressing). The onion growth increased with cattle manure doses. Using cattle manure fertilization is feasible for the production of onion, however high doses, regardless of the form of application are not recommended. Incorporated manure increases the leaf concentrations of primary macronutrients in onion and promotes 15 and 20% increment in total and marketable yield, respectively. The cattle manure incorporated into the soil increased the production of bulbs within the class of greater acceptance by consumers.

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