Fruit Pest News. Volume 4, No. 22 September 30, 2003

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Roberta Miles
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1 Volume 4, No. 22 September 30, 2003 An online newsletter whose goal is to update Extension agents and growers of commercial tree fruit and small fruit crops on diseases and insects in Tennessee. This is the last issue of for The next issue will be posted at this web site in early March, The focus of this issue of is a subject index for all issues to date for this year. This index will allow you to review a topic, and there should be new readers (hopefully) who might wish to read certain topics that they missed. The opening page of the web site contains a list of all of the issues. You can connect to the issue of interest there. We want to take this opportunity to thank you for your readership. Please help us spread the word to other interested readers. This newsletter is for you, so please let us know how we can improve it to serve you better. Suggestions for topics to address are very welcome. The greatest need I see is for more scouting reports from across the state. We're grateful for the insect trap counts that some of you have been sending us. We would like to hear when you see a disease or insect for the first time for the year, or if you are experiencing a severe outbreak. The weekly format of this newsletter is designed for reporting such time-sensitive news. Try to phone or us your news. Of course, all reports are kept anonymous (unless you want us to use your name!). (SB) In This Issue: 1. Subject Index for Strawberry Anthracnose Update: Should You Spray? 3. Peach: Items from S.E. Regional Newsletter (Plum Pox Virus, Halford Seed Purity) 1. Subject Index for, 3/10/03 through 9/29/03 Crop Subject Issue Date Apple Alternaria leaf blotch, description and control 6/17 Apogee growth regulator, changes to label 4/28 bitter rot, description and control 7/21 codling moth 7/21, 9/2 decays, storage, description and control 9/2 disease control during bloom through petal fall 4/14 disease control, "soft" products 4/28 (1 of 7)12/6/2012 3:28:43 AM

2 dogwood borer 5/27, 8/4 diseases, summer, control program 5/19, 6/9 dormant oil spray 3/10 fire blight, tips for control during bloom 3/31 fire blight, first report of year 4/29 fire blight, MaryBlyt, description and update 3/24, 4/7 fire blight, secondary blooms, importance of 5/5 fire blight, summertime control strategies 5/19, 6/3 fire blight, trauma blight 5/12, 6/3 fruit rot diseases, identifying 8/18 fungicide selection, late season 8/4 fungicide spray program, early-season 3/31 Glomerella leaf blotch, description and control 6/17 insects, how to use pheromone traps and how to monitor 3/24 insects, pheromone traps, count updates 4/7, 4/21, 4/28, 5/5, 5/19, 5/27, 6/3, 6/17, 6/24, 7/21, 8/4, 9/2, 9/15 necrotic leaf blotch of Golden Delicious, description and control 6/9, 6/17 nectria twig blight, description and control 8/4 oriental fruit moth 7/21, 9/2 Phytophthora crown and root rot, description and control 8/18 phytotoxicity reminder for Quadris/Abound 5/12 (2 of 7)12/6/2012 3:28:43 AM

3 powdery mildew, control 6/9 plant bugs, description 6/10 redbanded leafroller moth activity 3/24, 6/3 scab, infection periods 5/27 scab, threat is real 6/3 sooty blotch/flyspeck, first appearance & control 6/17 sooty blotch/flyspeck, infection periods 5/27 sterol inhibitors, don't use low rates 5/19 wasps, yellowjackets, hornets 9/15 Blackberry and Raspberry double blossom - see "rosette" anthracnose, description and control 5/5 captan, new registration 4/21 orange rust, description and control 5/5 rosette, description and control 4/7, 6/9 production without Benlate 3/10, 5/5 Septoria leaf spot of raspberry, description & control 6/24 Switch, new registration 4/28 virus-indexed plants, nurseries 8/18 Blueberry Cabrio, new registration 3/10 leaf rust, description and control 9/15 Switch, new registration 4/28 (3 of 7)12/6/2012 3:28:43 AM

4 twig blight, description and control 4/7 Cherry leaf spot, description and control 6/24 black knot, description and control 8/4 Cucurbit crops spray program for disease control 6/24 powdery mildew control program 7/21 Grape black rot, infection periods 5/27 black rot, spray program strategies 5/19 berry moth 5/19, 8/4, 9/2, 9/15 bitter rot, description and control 7/21 Botrytis bunch rot, infection periods 5/27 Botrytis bunch rot, time for spray 5/12 downy mildew, description and control 8/18 downy mildew, infection periods 5/27 fungicide spray program, early-season 4/7, 4/21 Intrepid insecticide, new registration 5/5 Pierce's disease, description and control 8/4 powdery mildew, infection periods 5/27 Peach and other stone fruits bacterial spot, description and control 5/12 black knot, description and control 8/4 brown rot, description and control 6/17 Flint, new registration 4/21 green fruit rot, description and control 5/12 (4 of 7)12/6/2012 3:28:43 AM

5 Halford seed purity 9/30 insects, pheromone traps, count updates 4/7, 4/14, 4/21, 4/28, 5/5, 5/19, 6/3, 6/17, 6/24 Mycoshield shortage 3/31, 4/14 Oriental fruit moth 4/21, 5/19, 6/24 plum curculio 4/14 plum pox virus, found in nursery 9/30 Rhizopus rot, description and control 7/21 Scholar fungicide, new registration 7/21 scab, description and control 5/12, 5/27 split pits 6/24 Pumpkin fruit rots, description and control 7/21 Strawberry anthracnose, scouting and control, field 4/21 anthracnose, alert and control for Fall 9/2, 9/15, 9/30 Botrytis - see "gray mold" Cabrio, new registration 3/10 disease control after harvest, matted row 6/3 disease update 5/5 fungicides, designing a spray program 3/24 gray mold, leaf sanitation for control 3/10, 3/24 Phytophthora crown rot, in plugs 9/15 Phytophthora crown rot, scouting and control 3/31, 4/14 (5 of 7)12/6/2012 3:28:43 AM

6 Procure, new registration 3/10 Rhizoctonia root rot, description and control 5/12 virus-indexed plants, nurseries 8/18 Tomato southern blight, description and control 8/4 tomato spotted wilt virus, description and control 8/4 Miscellaneous Captan label changes 4/21 current conditions and crop development stages 3/10, 3/24, 3/31, 4/14, 4/21, 4/28, 5/5, 5/12, 6/3 diagnostic assistance: how to obtain in Tennessee 3/31 Endura fungicide, new registration 9/2 fungicides, small-batch preparation 5/12 fungicides, effect of rain on wash-off 6/3 methyl bromide exemptions 3/10, 6/24 Pristine fungicide, new registration 9/2 Sandea herbicide registered for some vegetable crops 4/28 spray guides (commercial), how to obtain 3/24 2. Strawberry Anthracnose Update: Should You Spray? As discussed in the two previous issues of, several growers received anthracnose-infected tips from a nursery. The disease appeared in the plug beds in which these tips were used. Remedial options are limited, since there are no clean tips available, and the use of bare root plants is not feasible for most Tennessee growers. Roguing of infected plants is not practical because anthracnose levels in the affected beds are too high. Most growers in this predicament have elected to proceed with field planting, using contaminated plants, even those showing symptoms. How should these anthracnose-infected plants be treated, to optimize chances for a successful crop? The first reaction would be to spray. A research trial conducted last year in North Carolina by Dr. Frank Louws indicated that a fungicide application on infected plants in the plug bed did not reduce damage in the field. Plant mortality and stunting was as great in the sprayed as in the unsprayed. It is not known whether a fungicide spray schedule during the fall would have been beneficial. I think it is rather unlikely, based on the experience I have had with attempts to control anthracnose during the summer in matted row (6 of 7)12/6/2012 3:28:43 AM

7 plantings. Fall applications of fungicides are not recommended because they may not provide any benefit and they should be reserved for use during the spring, when we know they will be effective. All fungicides have a labeled limit on the number of times they can be applied; these limits would be exceeded if the materials were used both in the fall and spring. The manufacturers limit the number of applications to avoid residues on the harvested product that exceed the tolerance level, and to avoid encouraging the development of resistance in the fungal population. Furthermore, a fall fungicide program would do little to protect the berries next spring, even if it prevented spread of the disease. With favorable weather during harvest, a severe outbreak of berry rot can result from a small amount of inoculum. Abide by the label, spend less money on fungicides, and spray next spring, when we know the fungicides will be effective. (SB) 3. Peach: Items from Southeastern Regional Peach Newsletter In the survey and eradication program in Pennsylvania this year, plum pox virus (PPV) was found in 6 homeowner sites, 2 commercial orchards, and one fruit tree nursery. The nursery is the most troubling site, since the implications are obvious. Investigations are underway to determine whether budwood or rootstocks played a role in this case. Our nurseries must be protected. The Southeastern Budwood Testing Program is reportedly going well, and budwood stocks for southeastern peaches should be relatively clean of viruses. However, some viruses can enter a nursery through seed stocks as well. There appears to be a need for a controlled seed stock. This is illustrated by the PPV case and by the recent discovery by Dr. Simon Scott, Clemson University, that 'Halford' seed stocks are of mixed genotype and prone to infection with prunus necrotic ringspot virus (PNRV). More news will be reported as it becomes available. (SB) The URL is: Contacts: Steve Bost, Professor and Extension Plant Pathologist scbost@utk.edu Frank Hale, Associate Professor and Extension Entomologist fahale@ext1.ag.utk.edu Both authors available at: fax Plant and Pest Diagnostic Center 5201 Marchant Drive Nashville, TN (7 of 7)12/6/2012 3:28:43 AM

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