In this issue:

FEATURED ARTICLE
- Basics of Insect Monitoring with sex pheromone traps

HORTICULTURE
- Strawberry Plasticulture Nutrition Research Update
- High Tunnel Small Fruit Research Update

ANNOUNCEMENTS
- Organic Tree Fruit Production for Commercial Orchard Growers – March 2, 2007

SUPPLEMENT
- Check for Flower Bud Survival and Crop Potential before Pruning Peach Trees

Basics of Insect Monitoring with Sex Pheromone Traps
Greg Krawczyk – PSU Extension Tree Fruit Entomologist

The presence (or absence) of insects pest species in the orchard can be detected and monitored by wide variety of traps and methods, but the utilization of traps with an insect sex pheromones is probably the simplest and at the same time, the most accurate way to monitor insect pests. Although there are multiple designs of traps that work best for various pests, the general principle of how the average trap works is almost always like this: each trap needs to have a source of pheromone (usually rubber or plastic based lure/septa with incorporated sex pheromone), means to capture visiting moths (usually floor or liner coated with non-drying glue) and some kind of plastic or paper dome to protect the lure and floor.

Although, multiple resources are available to help growers conduct their own monitoring of pests species on the farm, the general perception is that pest monitoring is either too difficult, too time consuming, or simply too confusing for an average person to do it right. Following are examples of some most common questions/ misconceptions related to insect pest monitoring using the sex pheromone traps:

Which insect pests can I monitor using pheromone traps?

The simplest answer is that the pheromone traps can be used to monitor insect species that are actually able to release pheromones. Most lepidopteran insects (moths and butterflies) produce pheromone to improve the ability of one gender individuals to find the other. And as long as the sex pheromone for the species is identified and can be manufactured, there is a possibility that pheromone traps can be used for monitoring of this species. But it is very important to remember that sex pheromone traps capture only individuals of one gender.

In Pennsylvania orchards, numerous pests can be responsible for injuries in fruit orchards. The importance of various pest species fluctuates from year to year, but almost always the most important pests will be part of leafroller complex with tufted apple bud moth (TABM), obliquebanded leafroller (OBLR), internal fruit feeders complex with Oriental fruit moth (OFM) and codling moth (CM) or borers such as dogwood borer or peach tree borer. Fortunately, with the current emphasis on practical implementation of Integrated Pest Management (IPM) methods, the sex pheromone traps for all of those species are available for a purchase.

Unfortunately, in our Mid-Atlantic fruit region, also a number of other common pest species such as apple maggot, plum curculio, European apple sawfly or various plant feeding bugs can create a serious threat to fruit. This group of pest does not have a good pheromone based monitoring system, however other trapping/monitoring methods utilizing other means such as visual or food odor related clues are also being utilized for pest detection. It is very important that growers monitor these pests as well.

Can I actually control insects by using pheromone traps?

No, the pheromone traps are a great tool for insect monitoring but will not control insect pests. Sex pheromones used to attract insect into the trap are the composition of chemicals that mimics the natural molecules actually released by one gender moths to attract the opposite sex individuals. Therefore, only one sex of moths (males or females) is attracted to the traps. In our specific orchard ecosystem, traps are competing with the female moths in attracting male moths, but since normally there are a lot of more wild moths than traps, there is a strong possibility that mating occurs anyway, and female moths will still be able to deposit viable eggs. Therefore traps are excellent tool for moths monitoring but not the control.

Since I spray my orchard with pesticides anyway then I do not need traps:

With a wide adoption of new generation of softer, more selective insecticides (i.e., methoxyfenozide, spinosad, novaluron, or neonicotinoid compounds) that are highly species specific in their action and requiring precise timing of application, it is very important that growers are fully aware of pest species present in their orchards. By utilizing the pest information provided by pheromone traps, the pest control effort (and expense) can be directed specifically against the species that really needs grower's attention and at the best possible timing.

Monitoring insect with pheromone traps is too time consuming:

A single trap should be used to monitor only a single insect species. In properly monitored orchard at least two traps per species should be used per block. In larger, over 20 acre blocks, at least one trap per every 10 acres should be employed. It is important that traps within each block will be placed in such locations that they would be able to provide accurate readings of moth pressure. Placing traps far away (or too close) from possible moth sources such as large bin piles, abandoned or neglected orchards may provide inaccurate image of possible pest pressure. In orchards, where only the absolute minimum trapping program is to be implemented, and traps will be used only to provide information about the best timing for insecticide applications, at least two traps per species have to be used per farm.

What is the best way to properly place trap in an orchard?

Pheromone traps should not be placed closer to the border of the blocks than on 2 nd -3 rd row/tree from outside of the orchard. All traps placed in the orchard should be easily accessible by person who will monitor them. The optional height for trap placement on the tree is at about 5-7 feet from above the ground although traps for some pest species, especially codling moth, should be placed in the upper fourth of the tree height. For this higher placement, traps can be attached to bamboo posts and elevated into the upper part of the tree. All traps should be placed within a tree canopy, not on the outside of the tree. To make it easier for the person who will monitor traps during the season, traps for different pest species can be located on adjacent trees. It also may be helpful if the trees and tree rows with the traps will be marked with contrasting flagging tape.

For how long a trap will provide accurate information?

The pheromone loaded septa attracts moths only for a set period of time, usually from 4 to 8 weeks depends on the kind of the lure. In order to maintain reliable pest monitoring, the lure needs to be replaced before lure's attractiveness starts to deteriorate. Usually, the manufacturer provides the information for how long a lure will be active in the orchard.

The glue coated floors or liners also need to be replaced regularly, especially if high numbers of moths are being collected regularly and the glue layer is no longer sufficient to capture moths. In contrast to lures, which can not be reused, the liners after cleaning and coating with new layer of glue can be reused in traps. It is very important that the reusable liners will be used only in the traps for the same species as they were used previously.

Insects in pheromone trap are too difficult to identify:

Insect pheromones are species specific, and each species use a different set of chemicals to attract individuals from the opposite sex. Therefore, unless the trap (or the lure) is contaminated with some other no pheromone specific chemicals, only the addressed species should be coming to the trap. Of course, various colors of the traps can also attract other insects by visual attraction, but the presence of other insect species in the trap most likely will be incidental and/or sporadic.

Pheromone traps are too expensive:

With the yearly estimated price of monitoring system for one species (two traps, 10 lures, 10 liners) circulating around $40-70 (without labor), the traps will pay for themselves in no time. Elimination of one, not needed insecticide application, will more than pay back all costs associated with the seasonal price of monitoring. But also, what is probably more important, a vigilant monitoring system should help growers to avoid problems with unexpected occurrence of pests in the orchard. Even, if as the result of pest monitoring, additional insecticide application will be necessary to manage detected problem, dealing with the infestation before actual fruit damage occurred, seems as a much better approach than dealing with injured fruit at harvest.

The names and contact information of various trap and pheromone suppliers are listed in the PA Tree Fruit Production Guide (2005-2006 edition) on page 75 and are also available at the web version of TFPG at http://tfpg.cas.psu.edu/42.htm

Although even the best designed and completed monitoring program will not eliminate the insect problems from the orchards, such activity will for sure help to better manage fruit pests.

If more detailed information about insect monitoring are necessary please contact the PSU Extension Tree Fruit Entomologist Dr. Greg Krawczyk at: gxk13@psu.edu .

Strawberry Plasticulture Nutrition Research Update:
From 2003 to 2005, research examining various aspects of plasticulture production was carried out on growers' farms in Pennsylvania and at the PSU Horticulture Research Farm at Rock Springs as part project funded by PDA. Below are some the questions we were trying to answer, and what we found.

1) How helpful are ion meters (aka petiole sap testers or Cardy meters) for monitoring nutrient status? These easy-to-use field-friendly devices can produce a nearly instant determination of plant sap nitrogen and potassium levels, but how reliable are these readings?

In the spring and early summer of 2003 and 2004, plant nutrient levels were tracked using both ion meters and a complete laboratory analysis for samples collected from six cooperating growers' fields. The bottom line was that the primary value for ion meters appears to be for confirming suspicions that an experienced grower might make based on visual observations of plant color and vigor (i.e, whether nitrogen levels are deficient, adequate, or excessive), or to make this determination for less experienced growers. However, to know the degree to which adjustments should be made to a nutrient program, a complete laboratory nutrient analysis is still needed. When using ion meters, take at least 3 separate readings from a sample consisting of a minimum of 12 petioles from any one field. Then average the readings, as individual readings can be quite variable.

2) Is a complete lab analysis of strawberry leaves in the spring useful, and is there a preferred time for taking samples then?

From monitoring the samples as described above, it was found that leaf nutrient levels change rapidly in the spring, but are especially unstable before bloom and after the fruit start to enlarge. The greatest period of stability occurred during the period from early bloom to full bloom. By taking samples then, you may be able to correct certain nutritional problems in time to minimize impact on the current year's harvest.

During the course of the project, it was found that leaf samples sent in for nutrient analysis typically still had the petioles attached, while the values established for interpretation, and instructions for sampling, are for the blades alone. Extra samples of separate petioles and blades were run to determine whether this discrepancy makes a significant difference in sample results. There was a significant difference in the nutrient concentrations in petioles and leaves. So, when sending in leaf samples to the nutrition lab for a complete analysis, be sure to remove the petioles. If the petiole is included as part of the sample, it would be possible for a misdiagnosis to occur.

3) How quickly does fertigation affect plant nutrient levels?

In a controlled experiment at Rock Springs in 2003, nitrogen levels in the leaves increased by 9.8% at 48 hours following fertigation, then fell gradually until nitrogen levels were 4.5% higher than in the control at 7 days. Fertilizer applications should be split into small but frequently applied (once per week) amounts. The quick uptake of nutrients means that growers can potentially correct nutrient problems through fertigation quickly.

Thanks to the following Extension Educators and grower cooperators without whom this project would not have been possible: Tim Elkner, Steve Bogash, George Perry, Scott Guiser, Tom Butzler, Harvey and Grace Sauder, Myron Kressman, Reuben Martin, Tim and Marcia Brown, Brad Eberly, and Seth Ulmer.

This research was supported in part by agricultural research funds administered by The Pennsylvania Department of Agriculture.

(K. Demchak, Dept. of Horticulture)

High Tunnel Small Fruit Research Update:
Research on small fruit crops in high tunnels was continued in 2006 at “ Tunnel Town ” at the Horticulture Research Farm at Rock Springs , PA. Most of the work this year was on strawberries, though there were a few interesting observations on other crops as well.

Strawberry plants were planted in the fall of 2005 and were harvested in the spring and early summer of 2006. Cultivars tested were the spring-bearers ‘ Chandler ', ‘Ventana', ‘Araza' (it was supposed to be ‘ Albion ', a day-neutral), and ‘Carmine', and day-neutrals ‘Seascape', NC 3-5 and NC 3-8. In a nutshell, we found that ‘ Chandler ' was still the best June-bearer under these conditions, producing about 0.8 lb/plant. This was a relatively low yield for ‘ Chandler ', but the plants got off to a bad start in the fall. I think the problem was due to high soluble salt levels at 3.85 mmhos/cm (not everyone's agreeing with me on this one). The good part was that we found that we could flush the salts to the area between the rows using about 10 days (2-3 days per week) of 8-hour per day trickle irrigation. The salt eventually appeared on the soil surface between the rows of plastic, and new leaves stopped having burned edges. From this point on, plants appeared to be very healthy, and yields were adjusted to a per-plant basis, since some plants had died or had been removed if very low in vigor. ‘Ventana' produced about half the yield of ‘ Chandler ', though berries were slightly larger. ‘Ventana's harvest season ran about 5 days earlier than for ‘ Chandler '. ‘Araza' and ‘Carmine' had very low yields at 1/3 pound per plant or less, and both also produced smaller berries than either ‘ Chandler ' or ‘Ventana'.

The day-neutrals were harvested only for the spring crop, since the hot temperatures in the high tunnels would have likely brought them to a halt for a couple of months, and we didn't want to occupy an entire commercial-sized tunnel for a dozen small plots. All performed very well. The most pleasant discovery of the year was the performance of the day-neutral selections NC 3-5 and NC 3-8, which are from Jim Ballington's breeding program at NC State. Both produced nearly 1.5 pounds of fruit per plant, which lasted about a month longer into the summer than for the June-bearers. Yield of ‘Seascape' was slightly lower, at 0.8 lb/plant. Fruit size on all of the day-neutrals was the same or slightly larger than for ‘ Chandler ' (given for comparison purposes), and color, size, and flavor were excellent for all three of them.

The worst discovery in the high tunnel work this year was that sowbugs and earwigs apparently like strawberry fruit very well. It's likely that the mild winter temperatures in high tunnels are allowing their populations to survive the winters more easily than in the field.

The ‘Autumn Britten' and ‘Heritage' raspberries and ‘Triple Crown' blackberries that were planted in 2000 are continuing to grow and produce, though we didn't collect yield data from them in 2006. We actually tried to dig out the blackberries in 2005. They had become infested with crown borers, and it seemed that the only way to get rid of the crown borers at that point was to dig out the crowns of the blackberry plants. So the crown borers are now gone, but the plants came back with a vengeance from the remaining root pieces, which now have formed a thick hedgerow. This is making me happy that ‘Triple Crown' is a USDA cultivar, since if it had been patented, I suppose I could have been illegally propagating them by digging them out. You just never know…

(K. Demchak, Dept. of Horticulture)

(You can still register for this if you are interested, call)
NOTE: Date rescheduled from Feb. 16th

Organic Tree Fruit Production for Commercial Orchard Growers
"What's science and what still needs research?"
STUDY CIRCLE

Date : March 2, 2007
Time : 9:00 a.m. – Registration 9:30 to 11:30 (Lunch follows)
Cost : $15.00
Place : Berks County Ag Center, Auditorium

Attendance is limited to 20 commercial orchardists. Registration due February 23 rd for Study Circle Meeting

Name_______________________________________________________________________________________

Address_____________________________________________________________________________________

Telephone ___________________________ E-mail ___________________________________

Any special dietary needs?________________________________________________________

#______ of reservations x $15.00/person = $________________ (Total enclosed)

Make check payable to: Berks Co. Ext. Special Account
Please mail to: Penn State Coop. Ext. – Berks County , 1238 County Welfare Road, Suite 110 , Leesport , PA 19533

Mena Hautau Extension Educator, Berks County

Penn State encourages persons with disabilities to participate in its programs and activities. If you anticipate needing any type of accommodation or have questions about the physical access provided, please contact Mena Hautau at (610) 378-1327 in advance of your participation or visit .

NOTE FROM THE FTN COORDINATOR . Based on the request from the county-based extension educators, during the 2007 season the Fruit Times Newsletter will be available only once per month (last Tuesday of each month except for special exceptions, see below). Ms. Karen Weaver will be compiling the FTN and distributing it to our electronic subscribers. Karen can be contacted by phone (717) 677-6116 ext. 0 or by e-mail: ksw5@psu.edu .

Listed below are the dates remaining for the year 2007 FTN schedule: March 27, 2007
April 24, 2007
May 30, 2007 (day later because of Memorial Day)
June 26, 2007
July 31, 2007
August 28, 2007
September 25, 2007
October 30, 2007
November 27, 2007

Please send all materials to be included in the newsletter to Karen no later than the day of publication at 10:00 AM. Your assistance in meeting this deadline is highly appreciated. If you have any questions or suggestions for the newsletter please feel free to contact me. Thank you.

Greg Krawczyk, Fruit Times Coordinator