Texas Agricultural
Extension Service

 

 


Volume XXVII No. 5
March 30, 2001



GENERAL SITUATION: Very cool and damp, though not wet in the LRGV this week. More rain is need, fast. Rain amounts were less than ½ inch in most areas of the Valley this week. The cool to relatively cold temperatures kept the crops at a slow growth pace this week. However, even though some of the cotton plants did not appear to grow in stature, most continue to put on new leaves, but with extremely short internodes. Rainfall peaks in late April, May and early June in most years. Last year, the big rain event started on May 2 with a range of 2 to 8 inches. So, while the odds are in favor of some rain within the next three weeks or so, until it actually appears in the fields in effective amounts, most will just keep on wishing. Some insect activity observed in area fields, though none were reported to be economic to date.

Last Newsletter without Renewal

This will be the last newsletter we will be able to send to anyone who has not returned the newsletter request card or in some other way contacted us to ask to remain on the mailing list.

Cotton Growing Slow, but Maturing Anyway

Most cotton is up and alive this week. The cooler-than-desired temperatures have made some fields look puny due to the yellowed leaves and short statured plants. Some plant stand counts were not at desired levels with a few stand reports at 85 percent or less due to low soil moisture toward the middle of March and forward.

Growers should be taking a closer look at those fields of cotton which were planted as late as late February. Despite the cool weather and apparent slow growth, many of those fields have continued to put on new leaves and squares are not far behind. In fact, this week, several fields were observed that showed 5 and 6 true leaves and a square per plant buried in the terminal buds. Though the plants did not look like they could possibly be advanced enough because they were small in size, the plants were aging none-the-less.

Overwintered Boll Weevil Spray Timing

Cotton which is at the 5th and 6th true leaf stage need to be monitored very carefully in the next few days for squares. Once the oldest plants in the field have begun to square, and if the field(s) have a history of early boll weevil problems, then overwintered sprays should be applied. At least one application and preferably two, should be applied on a 5 to 7 day schedule to prevent as much overwintering boll weevil egg laying as possible. And remember, at this stage in the season, killing as many boll weevils as you can is the purpose of these treatments. There will not be any significant square or boll load you are trying to protect. Overwintered weevil sprays are intended to prevent boll weevil egg laying and the best way to do that is kill as many weevils as you can.

Educational programs conducted by the Texas Agricultural Extension Service serve people of all ages regardless of socioeconomic level, race, color, sex, religion, disability or national origin.
The Texas A&M University System, U.S. Department of Agriculture, and the County Commissioners Courts of Texas Cooperating.


PEST CAST continued

Weevil Trap Counts Lower

Speaking of boll weevils; trap counts were down this week, nearly everywhere (See attached graphs). Only a few high weevil trap counts appeared in various locations were observed this week. Some of the reduction may be from the cool weather conditions the Valley experienced since last week through most of this week. Some of the reduction is likely to be the presence of much cotton that is attracting the weevils more than even a few days ago. This is about the time of the year when cotton starts to become more available and more attractive to weevils. Thus, we expected to see the trap counts start to decline at this time. But, watch your areas carefully.

Worms, Aphids and Fleahoppers

Some terminal damage was noted in a few plants in the area this week. The damage was from some kind of worm, but the actual culprits were not found. Bollworm was the likely pest since that is the species we find very commonly at this time of the year. Other possibilities include barber pole worm and tobacco budworm. Terminal damage, whether it is from insects, wind damage or cultivator blight can lead to disfigured, "crazy" top cotton later in the season. Stalks which appear to be split and have more than one terminal or have extra long side branches could be the result from terminal damage at this stage of growth.

Aphids were observed in some fields of cotton this week. While the numbers were light this week, the possibility of an increase to economic levels exists. The Environmental Protection Agency (EPA) has granted a section 18 for the use of Furadan insecticide for use on cotton aphids. A complete copy of the section 18 document and amendment must be in the hands of the operator before Furadan insecticide can be applied to any cotton field for aphid control. For a complete copy of the section 18 document, contact the TDA office near you. The LRGV's local office is in San Juan and their phone number is 956-787-8866.

The following news release which was written by Roger Halenby of the Plains Cotton Coop in Lubbock provides the latest information about the "new" section 18 for Furadan on cotton aphids:

LUBBOCK, TX March 28, 2001 by Roger Haldenby

"As promised, the U.S. Environmental Protection Agency (EPA)
at last approved a FIFRA Section 18 Emergency Specific
Exemption request by the Texas Department of Agriculture
(TDA) on March 23, 2001 for the use of carbofuran (FURADAN
4F Insecticide/Miticide, EPA Reg. No. 279-2876) to control
cotton aphid on cotton in Texas.

The original approval contained an outdated provision that
would have required growers to first document treatment
failures of other previously approved but ineffective and
expensive pesticides before they could use Furadan.

Ag Commissioner Susan Combs and her staff have been
battling this unnecessary provision since last year, and
have finally been heard.

On March 28, 2001, EPA approved an amendment to the
specific exemption numbered 01-TX-05. The approval notice
and the amendment can be obtained from the TDA web site at:

http://www.agr.state.tx.us/pesticide/18crops.htm
(not up as of 3:30 CST 3/28/01 but should be very soon)

THE INFORMATION GIVEN HEREIN IS FOR EDUCATIONAL PURPOSES ONLY. REFERENCES TO COMMERCIAL PRODUCTS OR TRADE NAMES ARE MADE WITH THE UNDERSTANDING THAT NO DISCRIMINATION IS INTENDED AND NO ENDORSEMENT BY THE COOPERATIVE EXTENSION SERVICE IS IMPLIED.

In a press release Wednesday, TDA commented that the
amendment REMOVES item number 4 on the approval notice
requiring the use of flowable carbofuran to "only those
acres that can provide documentation of treatment failures
attributable to resistance or in the absence of such
documentation, growers are allowed to use flowable
carbofuran only if application of a recommended aphicide
has failed (less than 80 percent control) and aphid
populations have again reached the treatment threshold."

This change, made possible by Commissioner Combs'
persistence means we must no longer document failures of
registered alternative aphicides before FURADAN can be
used. If and/or when populations build to threshold
levels, carbofuran may be used as the product of choice.
TDA does not need to approve the use of FURADAN by
Extension District as has been the requirement in the past.

All other provisions of the EPA approval notice must be
followed and of course, always read and follow label
directions."

Cotton fleahopper is another possible pest of concern as cotton begins to square. Reports of fleahoppers have not been received so far, but conditions still could be favorable for them this year.

Sorghum On the Move

Grain sorghum growth did not appear to suffer as much as cotton from the cool temperatures this week. Most fields with adequate moisture appeared to be making good progress. Some reports of sorghum showing twisted leaves due to drought conditions were received this week in the dryland areas of Willacy county. Obviously, this is a major concern since the report came in March and we have until about June before sorghum harvest begins. Without rain and soon, many fields of sorghum will have little to no chance for a normal yield.

Aphids and the "Fungus"

Cornleaf aphids have been observed in sorghum. No serious numbers have been observed. In fact, in at least one situation, a fungus was attacking the aphids like we often see in cotton in May here in the LRGV. The aphids had the usual grey colored fungal mats spread out over the leaves where the aphids had been present. The presence of the fungus as this time of the year could bode well for possible aphid control in cotton and other crops as well.

Cotton Heat Unit Accumulation Table
Planting
Dates
Accum.
H.U.
Planting
Dates
Accum.
H.U.
2/15
368.5
3/15
112
3/01
223.5
4/01
0000



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