%0 Journal Article
%T The Sprout Regulating Compound 1,4-dimethylnaphthalene Exhibits Fungistatic Activity - The Sprout Regulating Compound 1,4-dimethylnaphthalene Exhibits Fungistatic Activity - Open Access Pub
%A Emily Dobry
%A Jessica Till
%A Kara Dobson
%A Michael Campbell
%A Rachael Adams
%A Veronica Stefanick
%J OAP | Home | Journal of Agronomy Research | Open Access Pub
%D 2018
%X The compound 1,4-dimethylnaphthalene, originally isolated from dormant potatoes, is currently in use as a commercial sprout inhibitor. Growers and processors report a reduction in fungal infections in potatoes treated with DMN resulting in increased yields. To assess the effects of DMN on fungal growth a culture of Fusarium oxysporum was isolated from potato tubers and identified via DNA fingerprinting using the 18ITS ribosomal region. Growth of F. oxysporum was inhibited by 31% after four days of exposure to DMN but overall rate of spore germination was not affected by DMN treatment. The growth of additional fungi, including Alternaria alternata, Aspergillus niger, Epicoccum nigrum, Gnomoniopsis smithogilvyi, Phoma medicaginis, and Pythium ultimum was inhibited by DMN as was suppression of sporulation in A. niger. These results suggest that DMN is fungistatic at the application levels examined. DOI10.14302/issn.2639-3166.jar-18-2502 Harvested potatoes are often treated with sprout regulators to prolong storage. The synthetic compound isopropyl-(N-3-chloro-phenyl)-carbamate (Chlorpropham) is widely used to prevent sprouting on stored potatoes. However, the inability to use Chlorpropham on potato tubers used as seed, and concerns about residue levels on tubers used for food, has created an interest in finding alternative compounds11. The naturally occurring volatile carbon compound, 1,4 dimethyl naphthalene (DMN), is an effective sprout control agent when applied to harvested potato tubers 1, 7, 16. Growers who utilize DMN demonstrate reduction of potato sprout growth, prolonged storage, and often see a reduction in product loss due to decrease in fungal pathogens. It is unclear if the reduction of disease in storage is a function of DMN directly on pathogens or if DMN induces a response in tubers that increases pathogen resistance. Gene expression analysis on potato tubers treated with DMN did reveal an increase in genes associated with pathogen response 3 but the interaction of DMN directly with fungal pathogens has been poorly assessed. Essential oils derived from plant material, in many instances containing a complex mixture of hydrophobic molecules, have been shown to have antimicrobial and antifungal activity 2, 5, 12, 18. DMN is a polycyclic aromatic hydrocarbon (PAH) and hydrophobic molecule that is found in some essential oil extracts. Given that growers see a reduction in loss due to disease following treatment with DMN, and that essential oils have been shown to have antimicrobial activity, we undertook an evaluation of fungal growth in
%U https://www.openaccesspub.org/jar/article/961