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carl2009

Managing needle disease

carl2009
11 years ago

I posted a question about this issue earlier in the year and unfortunately do not recall any input from professional growers. Making a second attempt here. Needle disease can be problematic on some species of 2 needle pines (for me anyway). Because the infected needles are present as new needles form, transfer of the pathogen from one year to the next is common. I have had the best results in the past season with striping out the old needles as soon as enough new needles have emerged to reduce transfer of disease to the new needles, and trying to keep accumulation of fallen needles to a minimum. I did use some light duty fungicide, but I'm not sure it had as much success as striping old needles. Obviously for growers with hundreds or thousands of plants this manual approach would not be feasible. I would like to learn which are the preferred fungicides in conifer producing nurseries, timing of sprays, and any other management techniques. Thanks for any suggestions.

Comments (8)

  • kenptn
    11 years ago
    last modified: 9 years ago

    I have some Japanese black pines that have a needle disease. My fungicide of choice is a chain saw, applied once at ground level. I expect to make the application some time this winter, and I expect a complete cure!

  • fairfield8619
    11 years ago
    last modified: 9 years ago

    Good comment kenptn! While I'm not organic and not opposed to a spray or two, it really gets old after a while. I say plant it and see what happens and if it gets the funk, let it go. I try to grow things that I really should not from both ends of the spectrum but I have a limit to what I'm willing to do. Good basic care that's all. Do you really what to be spraying all the time? Time and money I guess, and you will be doing it forever.

  • gardener365
    11 years ago
    last modified: 9 years ago

    Try Xerotol.

    Dax

  • whaas_5a
    11 years ago
    last modified: 9 years ago

    Carl what are some of the reasons that you're getting these issues with your plants? To a point I think if you're getting those issues you're doing your customers a disservice by offering these plants, locally or even mail order.

    I could be completely off base though. Not sure if you are nursery owner for resale or a homeowner looking for ways to protect their specimens.

    This post was edited by whaas on Tue, Jan 1, 13 at 10:24

  • ken_adrian Adrian MI cold Z5
    11 years ago
    last modified: 9 years ago

    i am with ken on this one ...

    i watch them wither away ... until there comes the need to put them out of MY misery ...

    its akin to zone pushing.. if they arent happy.. why try to change that .. in this case chemically ... its simply signing up for a lifetime job ...

    its the same reason i do not really try to grow fruit .. who needs a spraying regimen??? .. and roses ... nor do i worry about powdery mildew on lilac.. etc ...

    ken

  • carl2009
    Original Author
    11 years ago
    last modified: 9 years ago

    When one attempts to collect conifers from sources other than your backyard, with each introduction you are inviting potential problems from somebody else's backyard. Scale, aphids, mites, root disease, etc. Believe it or not chemicals are used, and used commonly in the production of ornamental crops and conifers are no exception. Some nurseries are more attentive than others with efforts to limit the spread of fungal issues, and pest. Others do not seem to concern them selves much with shipping their problems to others. It can take some time and money to weed out the bad ones, and even companies with good reputations can still send out plants with problems. Whether they do this knowingly, I'm not sure. Some issues that may be only minor problems in a dry climate may pick up steam in a humid one. Issues also can be completely masked by chemical protection, and then when treatment stops suddenly with the new owner, then the problems begin to show. The issues are not necessarily insurmountable, in all cases, especially if it is more of an aesthetic issue which is what my problem is. I have my share of plants in the morgue pile from stuff I grew and killed as well as items others shipped me and died despite my best efforts. I have had growers ship me their scale problems, but with a dose or two of safari I finally figured out how to quickly and cheaply solve that problem. Needle disease may not be as simple to fix over a few weeks, but needle disease is only detrimental to the long term health if you stand by and do nothing, just as letting some insect destroy a plant. Yes, over time I might decide that certain pines are not resistant enough in my climate to continue growing. I tried to add up all the different companies I have purchased conifers and maples from and the count is at least 25. 25 chances that other peoples problems enter my growing area. Issues like this can be very risky. Sudden oak death being an example of how serious shipping plants around the country and the world can be. Am I going to stop collecting conifers and Japanese maples because of the potential risk? Not likely. I come from an organic vegetable growing background. I did not have the luxury of the simple chemical fix. You have to understand the life cycle of what you are dealing with and do your best to interrupt the lifecycle to reduce the severity of the problem. These pines are not at risk of dying, they just do not look as good as I would like them to look. Since they are ornamentals I would like them to look as good as they can. With time, attention to sanitation, optimizing irrigation techniques, and a few well timed chemical applications the severity and need for a constant battle scheme are not likely necessary. If it is I will probably retire the worst of the worst. In my area there is a well known perennial grower who claims to have to kill a plant species 3 times before he finally throws in the towel. I'm not even close to there yet. The pines are not dying they just look a little homely.

    The reason for my post was to get professional growers opinions, techniques and philosophies in dealing with such maters, but again no help from them. Thanks to Dax for a recommendation. I guess the only way to get input from the professional growers is to misspell the name of a cultivar.

  • coniferjoy
    11 years ago
    last modified: 9 years ago

    You guessed wrong about the only way to get input from the professional growers is to misspell the name of a cultivar.

    This is because most nurserymen will do their very best to sell only healthy plants.
    Which is for their own good reputation, nobody wants to have a bad name in selling bad or sick plants.

    Issues can arise in other climates/growing circumstances, this is true.
    But remember this, nurserymen only ship at requests so the person who's ordening is the one who must be careful and aware of eventualy problems.
    He or she is familiar with the differend living circumstances an is responsible for the new obtained specimens, not the nurseryman.

    In my case I also like to provide some help in misspelled conifer names...

  • gardener365
    11 years ago
    last modified: 9 years ago

    Hi Carl,

    I used to do tree and shrub care for an organic company company and in your case we would have sprayed with liquid copper when dormant. The next spray would be when the buds were unfurling needles. Then another spray 4-6 weeks later. If these initial three sprays didn't inhibit the needle cast, at the first sign of things beginning to go south again, we'd spray again and then continue as necessary every 2-4 weeks (if the label of the product said we could) or every 4-6 weeks.

    After I stopped that line of work, I got into grafting. I learned almost everything I know from a nurseryman and grafter and he uses Xerotol. It's no different in a closed structure when spraying ornamentals versus outdoor care. Xerotol has a fairly quick entrance time to get back into the closed structure. Of course one must follow the label to a tee, however it is one of the more relatively safe fungicides to use.

    Drench the tree(s) and the ground. Never spray when temps are above 70 F. Early mornings and evenings are good spray times.

    I hope this helps.

    Dax

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