Fruit Pest News
Volume 8, No. 14 June 12, 2007
A weekly, online newsletter whose goal is to provide all interested persons with timely information on diseases and insects of commercial fruit and vegetable crops in Tennessee.
Text appearing in blue or red can be clicked to link to other web sites. Be aware that much of the linked information is produced in other states and may not be applicable to Tennessee.
In This Issue:
1. First Reports for the Year in TN
2. Tomato Spotted Wilt Virus Reports Since Last Week
3. Wine Grapes: Time for Botrytis Spray
4. Apple: Fire Blight and Powdery Mildew
5. Tree Fruit: Possible Effects of Freeze on Insects
6. Pheromone Trap Catch Reports
1. First Reports for the Year in TN
Southern blight of tomato, Humphreys County - June 5. Pecan phylloxera, Fayette County - June 8.
2. Tomato Spotted Wilt Virus Reports Since Last Week
Crockett County - June 4. Chester County - June 4. Hardeman County - June 7. Cannon County - June 11. Cannon County is the easternmost report we have received in Tennessee this year. To this point, all reports have been from home gardens and a small "truck" patch.
Additional information on tomato spotted wilt can be found at http://westtennessee.tennessee.edu/research/Canaday/TSWV.pdf (a PowerPoint presentation) and http://westtennessee.tennessee.edu/research/Canaday/EPP159TSWV.pdf (a fact sheet). (SB)
3. Time for Botrytis Spray on Wine Grapes
Bunch closing, the time when
the berries start to touch, is coming soon for most varieties. A Botrytis fungicide
should be applied before bunch closing on tight-clustered French hybrids such as Vignoles
and Seyval, and most vinifera varieties, especially Pinot Noir, Riesling, and Chardonnay.
Also, removal of leaves around clusters before bunch closing has
been shown to reduce losses to Botrytis, by improving the drying conditions in the
cluster.
The lineup of bunch rot fungicides has become impressive. It
includes Rovral, Vangard, Elevate, Endura, and Scala. Endura has powdery mildew
activity, but the others are effective only against
Botrytis. You need to apply other appropriate fungicides for control of black rot,
bitter rot, the mildews, etc., all of which will continue to be active throughout
the summer. It is also important to remember that these Botrytis fungicides are prone
to resistance development in the pathogen population. It is therefore recommended
that none of these materials be used more than 3 times per year. The Vangard label limits its use to
2 applications per year, at the 10 oz/A rate). Try to use 3 products for Botrytis
control, and alternate them. (SB)
4. Fire Blight and Powdery Mildew in Apples
Fire blight and
powdery mildew spread will end as shoot growth slows down and hardens off.
With the persistent dry weather, this time appears to be now, in most places.
You can let your guard down safely against these two diseases when this time
occurs. You may have been trying copper this year for fire blight management,
especially in blocks lacking fruit. And apple growers are always on the alert
for "trauma blight," which is fire blight that results from infections
associated with injuries due to late frosts, hail, or high winds. After such
an event, streptomycin may be applied within
24 hours, if fire blight symptoms are present in the orchard. Hardened-off tissue
should reduce the chances of trauma blight.
By the same token, powdery mildew spread ends as the leaf and stem tissues mature. Until then, a powdery mildew material such as sulfur should applied every 10 to 14 days. Cedar-apple rust season is finished and sprays are no longer needed. And there is nothing you can do about those yellow-orange leaf spots! (SB
5. Possible Effects of Freeze on Insect Pests of Tree Fruits
I checked with Dr. Jim Walgenbach (NCSU entomologist) at Fletcher, NC about what the loss of tree fruit from the freeze could possibly mean for the tree fruit pest situation next year. Populations of direct fruit pests such as codling moth, oriental fruit moth and plum curculio probably will be affected by the lack of fruit on most of the cultivated trees and wild host plants (crab apple, hawthorn, wild plums etc.). Dr. Walgenbach plans to do a survey at the end of the month to determine the number of infested fruit in various orchards and try to compare this to a so called "normal" year.
Where there are very few or no apples, populations of plum curculio and codling
moth should be very low next year. The oriental fruit moth can complete development
on vegetative shoots so populations of this pest next year will probably not be that
much different than for a typical year. I asked Dr. Walgenbach about the use of mating
disruption pheromone materials next year for codling moth and oriental fruit moth.
Given the possibility of low codling moth and plum curculio populations, next year
could be an ideal time to try mating disruption for codling moth. When pest populations
are high, there tends to be more problems with consistency of control using mating
disruption for codling moth than for oriental fruit moth. (FH)
6. Pheromone Trap Catches for 2007
Nashville
(Davidson County)
Oriental fruit moth (OFM), redbanded
leafroller (RBLR), obliquebanded leafroller (OBLR), codling moth (CM), grape berry
moth (GBM), variegated leafroller (VLR), black cutworm (BCW), diamondback moth (DBM),
armyworm (AW), cabbage looper (CL)
| OFM | RBLR | OBLR | CM | GBM | VLR | BCW | DBM | AW | CL | |
| 2-22 (caught one RBLR in last year's trap) put out new trap | -- | 1 | -- | -- | -- | -- | -- | -- | -- | -- |
| 2-26 | -- | 0 | -- | -- | -- | -- | -- | -- | -- | -- |
| 2-28 | -- | 1* | -- | -- | -- | 1 | -- | -- | -- | -- |
| 3-2 | -- | 3 | -- | -- | -- | 0 | -- | -- | -- | -- |
| 3-12 | -- | 50 | 0 | -- | -- | 0 | -- | -- | -- | -- |
| 3-14 (Put out OFM, CM, OBLR, BCW) | -- | 26 | -- | -- | -- | 0 | -- | -- | -- | -- |
| 3-20 | 0 | 33 | 0 | 0 | -- | 0 | 0 | -- | -- | -- |
| 3-21 | 1 | 7 | 0 | -- | -- | 0 | 0 | -- | -- | -- |
| 3-26 | 20** | 34 | 0 | -- | -- | 0 | 0 | -- | -- | -- |
| 3-27 (put out AW trap) | 8 | 4 | 0 | 0 | -- | 0 | 0 | -- | -- | -- |
| 3-30 | 12 | 16 | 0 | 0 | -- | 0 | 0 | -- | 0 | -- |
| 4-2 | 18 | 18 | 0 | 0 | -- | 0 | 0 | -- | 1 | -- |
| 4-3 (put out DBM, GBM, CL) | 10 | 1 | 0 | 0 | -- | 0 | 0 | -- | 0 | -- |
| 4-5 | 11 | 0 | 0 | 0 | 4*** | 0 | 0 | 0 | 0 | 0 |
| 4-10 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| 4-17 | 2 | 1 | 0 | 0 | 2 | 0 | 0 | 0 | 0 | 0 |
| 4-23 | 28 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| 4-25 | 8 | 0 | 2**** | 0 | 0 | 0 | 0 | 4^ | 0 | 0 |
| 4-30 | 5 | 0 | 6 | 0 | 0 | 0 | 0 | 1 | 0 | 0 |
| 5-21 | 3 | 2 | 6 | 0 | 0 | 0 | 0 | 4 | 5 | 5 |
| 5-29 | 6 | 9 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| 6-4 | 7 | 1 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 0 |
| 6-11 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 0 |
* Biofix for RBLR in Davidson County was February 28.
** Biofix for OFM in
Davidson County was March 26.
*** Biofix for GBM in Davidson County was April
10.
**** Biofix for OBLR in Davidson County was April 25.
^ Biofix for DBM
in Davidson County was April 25.
Bradley County
| OFM | CM | |
| 3-26 | 1 | 0 |
Putnam County
| OFM | RBLR | OBLR | CM | VLR | |
| 3-19 | 1 | 9* | 0 | 4*** | 0 |
| 3-21 | 1** | 3 | 0 | 2 | 0 |
| 3-23 | 2 | 6 | 0 | 1 | 0 |
| 3-26 | 2 | 15 | 0 | 2 | 0 |
| 3-28 | 4 | 7 | 0 | 1 | 0 |
| 3-30 | 2 | 14 | 0 | 0 | 1 |
| 4-2 | 6 | 32 | 0 | 0 | 0 |
| 4-6 | 2 | 28 | 1 | 1 | 0 |
| 4-13 | 0 | 2 | 1 | 0 | 0 |
| 4-20 | 0 | 7 | 0 | 0 | 0 |
| 4-23 | 0 | 1 | 1 | 2 | 1 |
| 4-25 | 0 | 0 | 1**** | 0 | 0 |
| 4-27 | 0 | 1 | 3 | 0 | 0 |
| 5-4 | 0 | 1 | 5 | 6 | 2 |
| 5-11 | 0 | 15 | 0 | 0 | 1 |
| 5-25 | 0 | 24 | 0 | 0 | 0 |
| 5-28 | 0 | 15 | 0 | 2 | 0 |
| 6-2 | 0 | 26 | 0 | 0 | 0 |
| 6-4 | 0 | 8 | 0 | 0 | 0 |
| 6-8 | 0 | 0 | 0 | 0 | 0 |
*Biofix for RBLR in Putnam County estimated as March 2 (trap not out early enough).
**Biofix
for OFM in Putnam County March 21.
***Waiting to verify biofix for CM, many unknown
moths being caught in these traps that can easily be mistaken for CM.
**** Biofix
for OBLR in Putnam County for OBLR was April 25.
Obion County
| OFM | RBLR | OBLR | CM | VLR | |
| 3-19 | 0 | 17* | 0 | 0 | 0 |
| 3-26 | 5** | 89 | 0 | 1 | 0 |
| 4-11 | 0 | 0 | 0 | 0 | 0 |
| 4-16 | 2 | 0 | 0 | 0 | 0 |
| 4-23 | 0 | 0 | 0 | 0 | 1 |
| 4-30 | 7 | 0 | 10*** | 0 | 17**** |
| 5-7 | 10 | 0 | 3 | 0 | 2 |
| 5-17 | 11 | 3 | 7 | 1 | 14 |
| 5-21 | 0 | 7 | 1 | 0 | 5 |
| 5-29 | 0 | 5 | 0 | 0 | 0 |
| 6-4 | 2 | 7 | 1 | 0 | 2 |
| 6-11 | 10 | 2 | 0 | 0 | 0 |
* Biofix for RBLR in Obion County estimated to be on March 2 (trap not out early
enough).
** Biofix for OFM in Obion County on March 26.
*** Biofix for OBLR
in Obion County on April 30.
**** Biofix for VLR in Obion County on April 30.
(FH)
The Fruit Pest News URL is: http://web.utk.edu/~extepp/fpn/fpn.htm
Contacts:
Steve Bost, Professor and Extension Plant Pathologist
Frank Hale, Professor and Extension Entomologist
Both authors available at:
615-832-6802
fax 615-781-2568
Plant and Pest Diagnostic Center
5201 Marchant Drive
Nashville, TN 37211
Copyright 2007 The University of Tennessee. All rights reserved. This document may be reproduced and distributed for nonprofit educational purposes provided that credit is given to University of Tennessee Extension.
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