Texas Cooperative Extension
TEXAS PECAN PEST
MANAGEMENT NEWSLETTER

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This newsletter is being supported by the
TEXAS PECAN GROWERS ASSOCIATION

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June 16 , 2004
#04-4

Anyone wanting this newsletter by email please send me a note at w-ree@tamu.edu and I’ll put you on the list. If any one has had an address change from a rural route box number to a 911 address please let me know so I can make the change. I have had to drop several producers because of returned letters with incorrect/old addresses.

GENERAL
Much of the eastern two thirds of the state has received rain, anywhere from excessive to adequate. Crop loads seem to be variable with a moderate crop overall. Scab control in these wet areas is going to be very important, especially where scab susceptible varieties such as Wichita are grown.

DISEASES
Pecan Scab: A good portion of the eastern two thirds of the state has received adequate to excessive amounts of rain. The major threat to the crop in areas with all this moisture will be pecan scab. In addition to rain, humid conditions which allow for extended periods of heavy dew also provides ideal conditions for scab development. In fact heavy dew is probably worse than rain. Hard rains can help wash scab spores off of leaves while heavy dew allows scab spores on the leaf to germinate.Pecan scab.  Photo by Chip Lee

In many cases orchard floors might be to wet so aerial application might be an answer. Aerial application of a fungicide, although not as effective as a ground application is a lot better than not doing any thing. With aerial applications spreader stickers are not recommended and consider shorteningn treatment intervals.

Pecan Scab photo by Dr.Chip Lee

Several producers without pesticide licenses and homeowners have asked about available fungicides. I hate to say this but we are really hurting in this area with very few if any products available. For those without a license Topsin M might be your best or only choice.

For commercial producers the following fungicides are labeled for pecan:

Abound (azoxystrobin)
Flint (trifloxystrobin )
Enable (fenbuconazole)
Enable 75WSP/AgriTin
Orbit (propiconazole)
Orbit45WP/Supertin 80WP
Propimax (propiconazole)
Super Tin (triphenyltin hydroxide)
Stratego (trifloxystrobin)
Syllit 65W (dodine)

*** Grazing restrictions also apply to fungicides.

INSECTS
Aphids: Honey dew from blackmargined aphids is apparent on the foliage. My general recommendation for blackmargined aphid is to leave them alone. There are numerous beneficials such as lady beetle, lacewings and spiders that help maintain populations.

Cotton square borer: I’ve received several questions concerning pecan nutlets that have been observed with nice round holes and no frass, This damage is caused by larvae of the cotton square borer. This insect is occasionally found on pecan and does not represent any type of “economic” threat.

Fall webworm: Webs which are created by larvae of the fall webworm are very apparent at this time. I’ve received one report of very heavy FWW in Brazoria County.
Fall webworm.  Click to enlarge.

In this particular orchard it has been noted that where Confirm and SpinTor were applied for pecan nut casebearer there are significantly fewer FWW webs as compared to the Lorsban and untreated plots. This side benefit of using these products for PNC was also noted last year.

Grasshoppers: I have not heard any state wide report on grasshopper populations but I have noticed immatures and adults in many orchards in the Brazos county area.. I’m hoping that the wet conditions will help keep populations down. If the situation arises and you need to treat, treat the orchard floor, ditches and fence rows.

There are several products to choose from such as chlorpyrifos (Lorsban 4E), carbaryl (Sevin 80S, 50W, 4L, XLR), diflubenzuron (Dimilin 2L) esfenvalerate (Asana). Note - you will need to take into consideration grazing restrictions if livestock are present. Also, Dimilin 2L will only work on immature grasshoppers.

Pecan nut casebearer: Second generation PNC should be starting in the southern portion of the state. As a general rule the second generation is approximately 42 days or six weeks after the first. I recommend that new PNC pheromone traps be placed in the orchard to monitor for this generation. In most years insecticides are not required for the second generation but I still recommend monitoring and scouting for this second generation.

Stink bugs/ Leaffooted bugs: Although it is a little early for this group of insects it is not to early to start planning some type of management program - if you have been having problems. This complex of kernel feeding insects can feed on pecans up to the day of harvest. Feeding after shell hardening causes the black spots on pecan kernels at harvest.

Here are a few things to consider. Have you had problems in the past? If you are in an area with row crops - what crops have been planted?

Row crops such as soybeans and grain sorghum can produce a lot of stink bugs. As these crops mature and are harvested adult stink bugs can move into orchards. Also, with the spring rains, alternate weed hosts are very plentiful and might produce high numbers of leaffooted bugs and stink bugs.

There is one species of stink bug which can be very numerous in orchards and this is the rice stink bug. This insect is slender, straw colored with two forward pointing spines on the “shoulder area”. This stink bug is a grass feeder only and is not a threat to pecans.

TEXAS PECAN GROWERS CONFERENCE

I hope all of you will be able to make it to the annual TPGA Conference and Trade Show in San Antonio this year. Call the TPGA office 979-846-3285 or visit their web site at http://www.TPGA.org for more information. I will have an exhibit booth again this year and hope you will come by to visit.

Also this is a reminder that CEU credits will be given during the conference and you will have to sign up each day. Announcements concerning sign up location and CEU credits will be made each morning.

COUNTY REPORTS
Burnet county: Up to 2 inches of rain across county. Webworm activity is high. Crop is moderate and spotted but yard trees look good. Minimal first generation casebearer infestations

Comanche county: Good Wichita crop, Cheyenne is fair and Pawnee is poor. Natives havesome top crop. Even with lots of rain scab pressue id moderate overall. Pecan nut casebearer activity was light.

Eastland county: Fair crop overall. Pecan nut casebearer activity was light. The county has missed all of the big rains but did receive 2 ½ inches last week.

Guadalupe county: Rain, rain and more rain. 6 - 8 inches in two hours last week. Average crop and casebearer activity was very light.

MEETINGS:

June 16-18, 2004
Louisiana Pecan Growers Annual Conference
Baton Rouge, LA
Contact: Frances Knox 318-747-3003 or
francesknox@bell-south.net

July 11-14, 2004
83rd Annual Texas Pecan Growers Conference and Trade Show
San Antonio, TX
Contact: TPGA - 979-846-3285

For more information, contact:
Bill Ree
Extension Program Specialist
Texas A&M University-Riverside Campus
Bryan, TX 77806-2150
Phone: 979-845-6800
Email: w-ree@tamu.edu /

The information given herein is for educational
purposes only.  References to commercial products
or trade names are made with the
understanding that no endorsement by
Texas Cooperative Extension is implied.

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