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sharppa

Any treatment suggestions for my asian pear?

sharppa
11 years ago

My Asian pear tree is getting hit hard by some sort of fungus or disease this year after several years of no spraying and trouble free growth. Is there anything I could or should spray now to help it? For fungicides, I have immunox (not rated for Asian pears?), sulfur and copper. The leaves are covered with black spots (pear spot?) and are yellowing and falling off.

This tree has 4 varieties grafted on one tree and the early variety has aborted a lot of fruit and a lot of them have been lumpy/misshapen. The later variety (brown, russetted) seems somewhat more resistent to the black spotting as well as the fruit being lumpy.

I have used baggies on all the fruit in past years and gotten perfect fruit. This year I only bagged maybe 10% of the fruit and still see very little pest pressure. Maybe 10% of the fruit get a bug but about 50% of the early yellow fruit are misshapen...either failed bug bites or a fungus?

Thanks for any advice.

Comments (19)

  • jean001a
    11 years ago

    How long ago was it planted?

    Perhaps ran short of water this summer? Would account for dropped fruit as well as leaf yellowing and loss.

  • sharppa
    Original Author
    11 years ago

    This is a 5 year old tree that has never had these symptoms until this year. I'm in the Lehigh Valley and we've had a regular amount of rain the past 6 weeks or so after a dry June. I don't think it's just lack of water.

    The later variety (see new pic) is still quite healthy.

  • Scott F Smith
    11 years ago

    Sharp, leaves can start looking like that when the tree is not being fed properly from the roots. There are many reasons why a tree is not getting proper nutrients. There could be a fireblight strike by the tree base. The graft could be experiencing delayed incompatibility. There could be a nutrient imbalance. The tree could have gotten girdled and you did not notice. There could be borers at the base. The roots could be drowning from too much water, or suffering from too little. There could be a root disease or nematodes.

    Many of these problems manifest at the base of the tree so have a good long look there to see if there is anything odd-looking. If you don't see anything there, there is not much I can think of to do other than perhaps give it some fertilizer if you did not fertilize this year.

    Scott

  • sharppa
    Original Author
    11 years ago

    Thanks for the info. I don't see any fireblight, borers or any damage to the tree trunk itself. The unhealthy part is the biggest of the grafts. I'm surprised that just one variety is so unhealthy compared to the rest.

    I may not have fertilized is this year so can try that.

    Do Asian Pears get Leaf Spot? See link below that matches up with the symptoms fairly well.

    Here is a link that might be useful: Leaf Spot link

  • Scott F Smith
    11 years ago

    Ah, I didn't realize the second picture was on the same rootstock. I would say the greatest chance is that variety is experiencing a delayed graft incompatibility issue. It could also be leaf spot or pear scab or some other disease, but it doesn't look a whole lot like either to me -- those diseases grow out a damaged spot from a single point of infection so there is a consistent circular shape to the spots. Necrotic spotting can be produced only by poor nutritition.

    The misshapen fruit could be from stinkbugs, even if you don't see them now they could have been busy on your pears a month ago. They sure were busy on mine.

    Scott

  • Scott F Smith
    10 years ago

    Thats definitely pear leaf blister mite. Its extremely common; it was also your problem the previous year but the pix are after the mites had died and I couldn't figure it out. Next year spray lime/sulphur and oil just as the buds start swelling and you will nail it. For this year hit with sulphur or lime/sulphur (watch the rate on l/s when not dormant). It may take multiple sprays.

    I had a fair amount of damage the last two years. This spring I completely nailed it with l/s and oil, except for one tree I think I forgot to spray, and its getting the sulphur treatment now.

    Scott

  • sharppa
    Original Author
    10 years ago

    Thanks very much Scott!

    I just got back from the PA extension office and the woman there also said it was pear leaf blister mite.

  • mamuang_gw
    10 years ago

    Thank you very much, Scott.

    I saw it last year on Hosui. I thought it was some mineral deficiency since the soil in where it's planted is not that good.

    Now I see it again this year on young leaves. Hosui is most affected, some on 20th century, nothing noticable on Shinko and Olympic.

    It's time to look for sulfur. I have not seen lime-sulfur in any store around here anymore these days. The last one I bought was 5 yrs ago.

  • sharppa
    Original Author
    10 years ago

    There is conflicting evidence about lime-sulfur being phased out that I have read online. I just bought a bottle off Amazon and will definitely use it next winter.

    I did a sulfur spray last night and will follow up with a 2nd in a week or two. The apples are just about at petal fall and ready for some spray too.

    This pear has four varieties grafted and the mites are definitely attacking one variety more than the others. I don't know which variety it is though.

  • sharppa
    Original Author
    10 years ago

    I thinned my Asian pear today and a majority of the fruit have some damage like the picture below. Is this blister mite damage? Or maybe PC or OFM? This tree has had two sulfur sprays in the past four weeks and the mite infestation is less than it was.

    My other trees (a 4-1 peach, several apples) have had two sprays of triacizide + immunox and have very little PC activity from what I can see during thinning. I thinned hundreds of peaches today and only a few had a bug bite.

  • sharppa
    Original Author
    10 years ago

    Anyone recognize this damage? None of the holes are crescent shape like PC scars. The top one in the picture is round but just looks curved because of the angle.

  • JIMMY_SAYAVONG
    10 years ago

    Two of my asian pear trees at my backyard having of some sort leaf fungus problem this summer , see photo attached . I live in Dallas Texas area. I picked up a bottle of fruit spray fungicide from LOWS and sprayed on the trees last weekend, and i just wait and see how things changed if any.
    Any idea from anybody? What should i do? The trees are about 6 yrs old.

  • Scott F Smith
    10 years ago

    Sharp, I didn't see your last message. I get damage like that and I believe it is curculio of some sort. I found out that cherry curculio makes scars that are not crescent. I use Surround on early pears to prevent curculio problems. As an added bonus it slows down the stinkers.

    Jimmy, I have not seen damage just like that but any time you get blackened leaves on pears you have to be concerned about fireblight. Fireblight can strike in many forms; the most common is shoot tip strikes which bend the shoot over, but you can also get random strikes on leaves. So my guess is some particular weather conditions produced fireblight. Sun scald can also look like that but it doesn't seem to match the sun exposure.

    Scott

  • JIMMY_SAYAVONG
    10 years ago

    Thanks Scott,
    Yes, I have been fighting fire-blight all along. In fact, this year I have lost about 80% of the crop due to fire-blight during and shortly right after bloom time (mainly shoot tip strikes). I did some research and somebody suggested to use copper spray during dormant -- I did that and still did not appear to make any improvement. Do you or anybody in this forum have found a "silver bullet" to effectively solve or at least relieve this problem? I am quite frustrated and really ran out of idea what to try next !! Any advise will be very appreciated ...

    JIMMY

  • sharppa
    Original Author
    10 years ago

    Hi Scott and others,

    My pear tree is having the same symptoms as the original post. Leaf spots are developing and the fruit are ripening but mealy and not sweet. Weird too, the majority of leaf spotting is on the opposite side of the tree from the blister mite infections and a different grafter variety. I did two sulfur sprays a week or two apart around the end of May but nothing since. I guess I will try another.

    Do people have a spray program for Asian pears? I'm frustrated with this tree and not getting any good fruit off of it.

    It is next to a peach tree that has leaf curl, brown rot and bacterial leaf spot. I have sprayed that one with triacizide and immunox 2x this year but still have problems with the fruit. Peaches seem to be the hardest things to grow.

    Got my first William's Pride apples this week and they were excellent.

  • mamuang_gw
    10 years ago

    Sharppa,

    From what I've gathered from several experts here, for peach, each problem is treated with different chemicals at different time.

    Peach leaf Curl and backterial leaf spot, I use copper during dormant season. I use copper hydroxide (Kocide 3000) in late fall and early spring.

    For brown rot, some use Monterey Fungi Fighter about a month before harvest. Otheres use Captan (which also helps with peach scab). I have not used any. So far, brown rot is not too severe for me (yet).

    Peach scab, some use Captan, I use wettable sulfur (not as effective but, to me, it's less harmful than Captan).

    You should add sticker such as Bonide Turbo or NuFilm 17 so the chemicals stay on trees longer.

    As for insects, I also use Triazicide but some here don't think it works for them. I work for me.

    I don't use immunox on peach. It does not help. Immunox is famous for preventing Cedar Apple Rust on apples in the spring.

    I'll see if I could answer your Asian pears on another post. I have 4 Asian pear varieties and more than 4 pear problems!!!

    By the way, what part of the country you live. It can make a difference.

  • sharppa
    Original Author
    10 years ago

    Thanks for the peach suggestions. I sprayed the peach with triacizide and immunox this year hoping that they would work as well as they work on the apples. I will try monterey fungus fighter next year. The one hard this is the peach has three varieties grafted, all with different ripening times so PHI is an issue.

    I'm in eastern PA, the Lehigh valley. It is hard to find much literature about Asian pear spraying and a lot of the comments you read is that it can be a no-spray tree. It was for the first three years or so.

  • sharppa
    Original Author
    10 years ago

    Hey Scott,

    Have you done your early spring oil + lime-sulfur spray this year yet? I have not yet and I'm wondering if it's too late. It's been a cold winter though and not much activity yet on the trees.

    Can I spray the Asian pear, apple and peach trees all with the same concentration of oil + lime sulfur?

    For during the growing season, an Asian pear can have sulfur but there aren't a lot of pesticides listed. I'm going to try Surround this year to hopefully stop the insect bites shown above. The fruit still grew fine just with some damage.