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This newsletter is being supported
by the
TEXAS PECAN GROWERS ASSOCIATION
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May 12, 2004
#04-3 |
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
Rains across the state have caused some concern and problems
with timing pecan nut casebearer applications and fungicides
for pecan scab. From what I have observed the crop is quit
variable with some varieties having good to heavy crop loads
and some bing light. Overall I would have to say the crop
is moderate. PNC seem to be later than normal and egg lay
has ranged from 0 to 10%. Egg development also appears to
be a little slower, at least here in the College Station
area.
INSECTS
Phylloxera
Galls produced by the different species of phylloxera are
very apparent at this time. Galls that develop on the
new woody tissue such as stems, nutlets, leaf petioles and
mid veins of leaf lets are cause by the pecan stem phylloxera.
These galls will be opening later this month and during June.
Phylloxera infestations will cause some defoliation during
June. There is no need to treat for these emerging phylloxera
for no more galls will be formed this year. Trees with severe
phylloxera infestations should be noted for treatment next spring.
Treatment timing is when shoots have around 2 inches of new growth.
Spittle bug
Spittle masses caused by immature spittle bugs will be showing
up soon. Here in Texas we do not see any economic benefit
in a routine treatment for spittlebugs. However, I never
like to say never. The nymphs which feed within the spittle
masses on nutlets can cause nutlets to drop. Under high infestations
rates (greater than 50 % of clusters infested on light crop)
a treatment might be justified - in my opinion. Currently
we do not have any data regarding the relationship of high
percent infestations of nut clusters and crop impact.
Pecan Catocala
I have received one report of this insect defoliating trees
in Gonzales county. Pecan catocala larvae can reach lengths
of 2 1/2 to 3 inches and are solitary feeders and there is
only one generation per year. The larvae are dark gray and
will resemble tree bark so they can be difficult to spot.
When handled, the larvae whip their bodies from side to side.
Treatments are generally not needed for this pest but if
an infestation is out of control, they are easily controlled
with most any insecticide.
Pecan nut casebearer
Pecan nut casebearer activity has been slow to develop in some
areas. Trap catches have been later than in past years and
some producers have commented that trap catches have been
very light. Egg lay also seems to be slow. In our PNC publication
we state that egg starts around 7 to 10 days after initial
trap catch. From what I have seen to date it is more toward
the 10 day time period. I have also seen some eggs that are
slow in maturing.
White eggs that were flagged near College Station on Friday
were just showing some spots on Monday so development will
take longer than the 4 to 5 day time period. This is an example
of why I like to flag infested clusters.
In orchards that I have scouted, egg lay has ranged from 0
to 10%. Orchards with very light egg lay may get by with out
an insecticide application this year. With rain predicted across
part of the state for the next several days the egg laying
period could be extended. My best advice is to continue to
scout even after treatments have been made. Egg development
usually takes 4 to 5 days so if new eggs are laid 6 days after
an insecticide application there will be active larvae 10+
days after your application and this might be pushing the residual
effectiveness of your insecticide. Depending on crop load and
percent egg a second application might be needed.
WEB SITE
Well, I have finally received some much needed help in
updating my website. The pecankernel.tamu.edu site has been redone.
There are still a few sections that are undergoing construction
and hopefully finished in the next week. I will try and keep
current information available at this site. You will also
be able to access past newsletters, Pecan South articles
and publications. If you have any comment about the site
or there are is something you would like to have posted,
please let me know. The information on this site is for you
the producer.
GRAZING RESTRICTIONS
So
far this season I have received several inquiries on grazing
restrictions associated with insecticides. A pesticide label,
whether it is an insecticide, fungicide or any other pesticide
is a legal document. On the label under directions for use
it will state “It is a violation of Federal Law to use this
product in a manner inconsistant with its labeling”.If
the label states “No livestock grazing - period” this
means that after an application it is not legal to graze livestock
until next spring. That’s the law.
Current insecticides which allow grazing include:
malathion, carbaryl (Sevin), Bacillus thuringiensis (B.t. insecticides
such as Dipel, Javelin), meth (Intrepid 2F), spinosad (SpinTor,
Entrust) diflubenzuron (Dimilin 2L)
LEAF CONDITION
Over the past several years I have received several questions
concerning the leaf condition depicted in the picture. The
small necrotic lesions, irregular shaped holes or tears can
make some leafs look very ragged. Honestly I do not know
what causes this. One explanation I have heard is it is caused
by thrips feeding while leaves are in the bud or just unfolding,
but I have no data or information to back this up. Although
terminals might look very ragged, I don’t feel that
the overall impact is significant. There is no need for any
insecticide or fungicide application to correct this problem.
MEETINGS:
June 11-13, 2004
Oklahoma Pecan Growers Annual Conference
Idabel, OK
Contact: OPGAShelton @aol.com
June 14-15, 2004
Pecan Producers of Louisiana Annual Conference, Best Western
St. Francis on the Lake, St. Francisville, LA
Contact: 318-448-3139
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
Texas County Meetings:
May 13, 2004
Gaines County Pecan Field Day
Contact - 432-758-4006
May 19, 2004
El Paso County Pecan Field Day
Contact: Sarah Downing 915-859-7725
Note the Wichita/Clay county meeting has been moved from May
20. At this time the date has not been set.
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