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Minzenmayer Extension Agent-IPM E-mail: r-minzenmayer@tamu.edu Website: http://entowww.tamu.edu Phone (915) 365-5212 Fax (915) 365-5337 |
June
27, 2002
Vol XV No. 8 P.O. Box 658 Ballinger, Tx 76821 Mobile: (915) 365-1292 |
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Hot and dry conditions prevail throughout the Concho Valley. We have a small chance of thunderstorms late this week so everyone wash their pickups and pray a lot. Think POSITIVE. Cotton ranges in growth from the cotyledon to approaching 1/3 grown square stage. Most of the grain sorghum is into bloom and most of the early Hybrids are in the soft dough stage. Headworm infestations remain low at this time. A few green stink bugs and some isolated infestations of grasshoppers were observed this week in sorghum fields in Runnels County. Dryland crops in southern Tom Green County are under severe moisture stress and needs rain now.
Grasshoppers are the pests which you should be on the look out for at this time. A few cotton fields have hot spots of aphids as well. |
As
I was discussing in the turnrow meetings this week, in some cases, we
have shot ourselves in the foot with some of the new technology. We have
transgenic cotton varieties, new precise cotton planters and with this
new technology comes a higher cost of production. Cost of planting seed
continues to go up and tech fees are high, so we reduce our seeding rates
to help offset these higher prices. Sometimes we forget that the seed
has an 80% germination rate and that a certain number of plants die due
to adverse weather conditions. There's also a lot of variation in seed
size which affects seeding rate. Sometimes we do not take all this into
consideration. In dryland cotton, a final plant stand around 39,000 to
44,000 plants per acre is ideal. That averages about three plants per
foot of row. In irrigated cotton, a final plant stand of 45,000 to 50,000
plants per acre is ideal. That averages around four plants per foot of
row. The cotton aphid infestations we are currently monitoring are in
cotton fields which have plant stands less than 30,000 plants per acre.
Cotton aphids prefer thin plant stands.
Grasshoppers and fleahoppers are of concern in some cotton fields and several have been treated this week. |
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Grasshoppers can devastate seedling cotton in a very short time. Pastures are burning up from the hot dry weather and the state is currently mowing the bar ditches and grasshoppers are moving to the plants that are small and succulent (cotton). Cotton fleahopper numbers are increasing and producers with squaring cotton should be monitoring their fields for fleahoppers and square retention. Cotton which is in the 3-4 true leaf stage will be squaring in 12 to 15 days so be ready. Remember: All over-the-top Roundup® applications must cease once cotton reaches the 5th true leaf stage. Directed sprays can be used after this growth stage as the label directs.
Grain sorghum is maturing rapidly and insect pressure remains light in most situations. Watch field borders for grasshoppers migrating into fields from adjacent pastures. Grasshoppers feeding on maturing grain heads reduce yields. A good two-inch rain would certainly help grain sorghum yields right now. Report on Grasshoppers in Texas compiled
by Grasshopper
infestations are generally on the increase across the state. Since our
last report on May 22, seventeen (17) Counties have been added to the
list of counties where moderate to severe grasshoppers infestations
are occurring. Entomologists are now reporting moderate to severe grasshopper
infestations in 107 counties in Texas. The infestation is still concentrated
in the Central Texas area. However, the Texas Panhandle and Far West
Texas are reporting increasing problems in pastures and crops.
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The eastern range for the current grasshopper infestation remains generally
along a line from Paris, Athens, Crockett to Houston. The western range
remains generally East of a line from Wichita Falls, Abilene to San Antonio.
The southern range is from San Antonio to Houston.
The situation in West Texas and the Panhandle has changed with moderate to heavy grasshopper infestations in just about all of the Texas Panhandle. Increased numbers and problems are being reported from some counties along the border with New Mexico. Outlook: There have been many field crops, pastures and hay meadows in Central Texas area treated since mid May for grasshoppers more are expected to be treated as summer progresses. Farmers and ranchers, who have had to deal with grasshoppers in the past few years, are once again having to invest more dollars in protecting their forage and crop assets. The conditions across the state are not in the emergency category at this time. Some areas have received rainfall that has been helpful in producing crops and forage in spite of the grasshopper infestation. Other areas are not so fortunate. The Texas Panhandle and Far West Texas situations are expected to become more severe with the passing of time.
written
by By now you probably heard that the first confirmed cases of West Nile Virus (in two birds) have been detected in Texas, in the Houston area. |
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In case you missed it, the recent (June 19) AgNews release can be read
at http://agnews.tamu.edu/dailynews/stories/ENTO/Jun1902a.htm West Nile Virus (WNV) is a new form of encephalitis caused by a virus transmitted by mosquitos. Encephalitid diseases are not new to Texas. From 1991 through 2000, an average of 62 cases of human encephalitis was reported yearly. Horse owners regularly vaccinate their animals for encephalitis diseases. As encephalitis diseases go, WNV is not one of the more pathogenic. In New York City, where the disease was first detected, an estimated 130 people contracted the virus for every one person who was hospitalized. Hospitalization rates are higher for people over the age of 65. Nevertheless, WNV has been incriminated in 10 human deaths and deaths of scores of horses in the eastern US since 1999. As far as we know, horses are the only domestic livestock likely to be harmed by WNV. As a result, horse owners east of the I-35 corridor in Texas are being urged by some veterinarians to get their horses vaccinated for WNV. Although the risk here is probably low, it is not safe to assume that it will be a long time until WNV reaches north Texas or other parts of the state. This virus has a history of jumping from one location to another fairly quickly. Although WNV is transmitted by mosquitos, it can be carried long distances by songbirds, including crows and grackles. Horse owners should check with their veterinarians to decide whether the vaccine is recommended in your county. You should
be alert to any unusual local die-offs of hawks, crows, grackles, or
bluejays. These bird species are apparently very susceptible to WNV
and are the ones TDH is most interested in surveying. Instructions for
sending in bird samples for analysis, as well as general information
on WNV impact on domestic livestock and humans, can be found at the
website maintained by the Texas Department of Health. |
IPM Decision-Making There is a six-step process to decision-making in IPM 1. Identify
the problem or pest
The "IPM Updates" have begun. The telephone number to call is 365-2642. This update will give producers a general insect and crop report for the different areas in Runnels, Tom Green and Concho Counties that is being monitored by the cotton scouts. I would encourage you to use this service. This allows you access to the information at your convenience. If it is not used this year, we will discontinue it next year. |
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County
Tom Green BUDWORM/BOLLWORM MOTH TRAPS
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Educational programs conducted by the Texas Agricultural Extension Service serve people of all ages regardless of socioeconomic level, race, color, sex, religion, handicap or national origin. The information given herein is for educational purposes only. References to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement by the Cooperative Extension Service is implied. The Texas A&M University
System, U.S. Department of Agriculture, and the Commissioners Courts
of Texas Cooperating
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