Fruit Pest News

Volume 3, No. 2    March 18, 2002

A weekly, 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.

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.

1. CURRENT CONDITIONS - WET!

Tennessee received 5+ inches of rain over the weekend, causing flooding problems.  We have not seen the sun since Thursday.  This is setting us up for problems with Botrytis in strawberries, which were in early bloom when the recent freezes occurred.  With so much dead plant tissue and now the soggy conditions, Botrytis has everything it needs to build up.  Redhaven peaches are at pink tip and apples buds are beginning to show green. (SB)

2. FRUIT SPRAY GUIDES: AVAILABILITY

All of the commercial fruit and vegetable spray guides that we commonly use in Tennessee have been revised and are now available.

• Commercial Vegetable Disease, Insect and Weed Control (University of Tennessee PB 1282). Printed, bound copies are available at county Extension offices. It is also available for downloading from our web site at http://web.utk.edu/~extepp/pubs/PB1282-2002.pdf

• 2002 Commercial Small Fruit Spray Schedules (University of Tennessee PB1197). Printed, bound copies are available at county Extension offices. It is also available for downloading from our web site at http://web.utk.edu/~extepp/pubs/PB1197-2002.pdf

• 2002 Integrated Orchard Management Guide for Commercial Apples in the Southeast (regional publication). Printed, bound copies are available at county Extension offices.  

• 2002 Southeastern Peach, Nectarine, and Plum Pest Management and Culture Guide (regional publication). Printed, bound copies are available at county Extension offices. (SB)

3. MaryBlyt Program for Fire Blight Management: Plans for the Year and What to Do Now

One of the priorities for this newsletter is to provide training and updates for the Mary Blyt program. Fire blight will require increasing attention as time goes by, with the changes that are taking place in apple production. Many areas of Tennessee experienced significant fire blight damage last year. There is plenty of inoculum for this year.

I have a limited number of MaryBlyt programs (software and manual) available for free. Please let me know if you would like one. I only ask that the cooperator use it diligently and report to me when the program indicates that an infection period has occurred and when you see your first fire blight symptoms. The program is not difficult to operate, and can help tremendously in managing fire blight.

What it does: The program use temperature and rainfall amounts to tell you when you need to spray with streptomycin and to tell you when to expect fire blight symptoms to appear. The program will improve control efficiency, resulting in better control with fewer sprays than would be obtained by spraying on a fixed schedule. Fewer sprays mean less chance of resistance to streptomycin developing.

For those of you who have begun to use MaryBlyt, here are some points to keep in mind:

• Begin monitoring temperature and rainfall when 50% of the buds show green tissue. This is the "biofix," when the program begins calculating pathogen and plant development. In judging when to begin measurements, consider only blossom buds (those at terminals and spurs). Don't consider the leaf buds (those at the nodes).

• You don't need to enter the data into the computer until the blooms begin to open, but you do need to record the measurements every day, and reset the max-min thermometer and empty the rain gauge after the reading. When the first blossom bud opens, the data must be entered into the computer each day.

• The thermometer should be located in the shade, away from the ground. The rain gauge should be located in the open.

• Time of day to take measurements: Can be taken any time, but you should choose a time and be consistent with it each day. I think the most desirable time is late afternoon, because it would allow all of the measurements for that day to be kept together . . . and a spray decision based on that day's data to be made that night (streptomycin applications work well under the slow drying conditions of night). Remember to take note of whether a dew occurred in the morning, since dewfalls are also recorded. (SB)

4. PEACH: NEW SOUTHEASTERN VIRUS TESTING PROGRAM

A program designed to prevent the introduction of viruses into peach orchards has been put into place.  Supported by commercial growers and the nursery industry, trees produced from virus-tested budwood will now be available. An assessment of 5 cents per tree will be charged on all commercial purchases of peach trees. Cooperating nurseries (Hollydale, Vaughn, and Cumberland Valley Nurseries) have agreed to contribute 1% of their gross sales to this program. The proceeds will go toward the cost of testing the budwood used to produce these trees. Testing will take place at Clemson University.

Please support this program by purchasing virus-tested trees. The 5 cent surcharge will be assessed on all trees, whether virus-tested or not.  Check with the nursery for variety availability. (SB)

The Fruit Pest News URL is: http://web.utk.edu/~extepp/fpn/fpn.htm

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:

615-832-6802

fax 615-781-2568

Plant and Pest Diagnostic Center

5201 Marchant Drive

Nashville, TN 37211