So what is the most effective fungicide to use on soil wherein the grower suspects fusarium pathogens and is available to gardeners in the USA. Same question with regard regarding insecticides for bulb fly prevention and eradication? I have been using lawn grub control over the beds the last few years.
All Categories
A discussion forum for daffodil enthusiasts around the world.
I don’t have any answers on bulb fly that meet my need for an organic solution.
My personal suspicion is that it is the use of fungicides that encourages fusarium growth through suppression of the beneficial soil fungi such as trichoderma that would otherwise keep fusarium in check. I find the situation analogous to that of the human gut, where antibiotic use upsets the normal flora, and secondary diseases result unless the beneficial bacteria are replenished through use of probiotic supplements. One can purchase soil inoculants that contain trichoderma and other beneficial species. The growers in New Zealand affirm that they find benefit of such inoculation. I am doing a small controlled trial myself to see whether I can measure an effect. All the blooms John and I exhibited at Murphys were treated with DieHard Transplant inoculant, which can be obtained from http://www.horticulturalalliance.com among other vendors.
The basic idea is that Trichoderma’s favored food source is fusarium. The Trichoderma wraps its hyphae around the roots of the narcissus and prevents fusarium infection by eating any fusarium that happens past.
What I would dearly love to find a source of would be Minimedusa polyspora, which has been shown to be specifically beneficial for prevention of fusarium in narcissus. One article states that thiabendazole used in combination with Minimedusa polyspora, Trichoderma viride and Streptomyces gave fewer infections and greater numbers of flowers than either treatment alone. http://www3.interscience.wiley.com/cgi-bin/fulltext/119370574/PDFSTART
Another article which discusses mycorrhizal association mechanisms is Microbial Interactions and Biocontrol in the Rhizosphere http://jxb.oxfordjournals.org/cgi/reprint/52/suppl_1/487
The two pdfs are too long to go through the usual daffnet size filter, but are freely available. If you have trouble downloading them, let me know and I’ll happily send them to you.
Happy Reading!
m
pun intended, or at least noticed…
Melissa, thanks for posting the link for the source for the DieHard Transplant inoculant. There’s an article in GreenHouse Grower at http://www.greeenhousegrower.com/magazine/?storyid=3078 by Juergen Steininger, the horticulturist at Longwood Gardens, and he talks about adding RootShield to his potting media. He thinks that by using RootShield, it eliminates a lot of fungicide drenching of pots. Since I have trouble with some things in pots–bulbocodiums, for example–I’ll be getting something to add to the potting soil.
(If you can’t get to his article from the above, there’s a link to it on the ADS website, under Links.)
Mary Lou