The cotton crop is finally taking off in response to a higher than normal heat unit accumulation rate. Fields that are slow to respond to improved conditions probably have rhizoctoria thrips damage, and or maybe under moisture stress. The thrips problem is winding down, although many fields are not out of the woods yet. Beet armyworm infestations are still present although heat mortality and predators are keeping their numbers and damage in check.

With many earlier planted fields in the square mode, producers need to watch square set. Fleahoppers are beginning to move out of weeds and into cotton. Some areas have had insufficient rainfall and cotton is beginning to show signs of stress. Watch out for premature cutout. The window of opportunity for weed control in cotton is upon us. Producers are cautioned to read the Roundup and Buctril labels and information in FOCUS for safe, effective weed control.

Boll weevil numbers remain low, but still some squaring fields are receiving needed overwintered boll weevil applications. Also good news is the abundance of crab spiders, big-eyed bugs and minute pirate bugs being found in cotton.

Southwestern corn borers are heavier this year with egg laying yet to peak.

Many sunflower fields are approaching bloom and need to be monitored for sunflower moth activity.

Peanuts are being attacked by lesser corn stalk borers in fields southwest of Lubbock.

False chinch bug problems continue mostly as a nuisance, but could pose a threat to our crops as well.

Thrips infestation levels appear to be higher north of Lubbock than from Lubbock south. This may be due to the effect of blowing sands we have experienced more in the southern, sandier areas.

Our thrips control test north of Earth is still intact although weather damage has kept plant growth down to a crawl with reduced leaf area. Thrips numbers have generally dropped off for most treatments with the possible exception of the Orthene planterbox treatment, which averaged almost 7 thrips per plant (Table 1). Thrips numbers in all treatments except the Orthene planterbox treatment and the Roundup application window treatment were below the treatment threshold of 4 thrips per plant. The Roundup application window treatment was sprayed for the 1^st time on June 12, following thrips counts. The Orthene foliar - ET plots did not require a 3^rd treatment and actually looked pretty good this week. As evidenced by the presence of immatures and lack of differences between untreated plots and treated plots it was clear that the seed treatments and Temik were no longer effective after 25 days.

Table 1. Thrips Control Test - North of Earth, Texas. 2001. 1/

The Amherst thrips test was planted on May 28 and has not suffered through any adverse weather. Therefore plants have huge cotyledons and larger true leaves than the plants in the Earth test. Thrips pressure is also lower than the Earth test with an adjacent CRP field the apparent source of these thrips (Table 2). We did not treat the foliar Orthene plots based on Extension’s thresholds on June 8 since thrips numbers did not reach the 1 per plant level required. All treatments were effectively holding thrips levels down compared to the untreated check. By the June 12 test monitoring date, thrips numbers had increased due to reproductive recruitment. But the Adage seed treatment, Orthene planterbox treatment, and Temik plots were all holding thrips numbers below the treatment level of two thrips per plant. The Gaucho seed treatment was again not controlling the western flower thrips. The foliar ET treatment was sprayed following the counts.

Table 2. Thrips Control Test -- West of Amherst, Texas. Randy Bales. 2001 1/

The thrips problem is not over for everyone yet. Even though migration pressure has lessened considerably there will be areas where sufficient winged adult thrips can get some of these later-planted fields in trouble. Just follow Extension's treatment guidelines and you should be OK. Where Temik was used prior to a replant decision, you will need to be ready to protect newly emerged seedlings. I doubt that there is sufficient Temik residual left by the time plant roots tap into the treated zone to afford protection.

The hot weather we are experiencing should begin to push plant development and growth rapidly out of the thrips vulnerability period. Plants may still receive wind or sand damage after this but thrips impact on yield potential is pretty much over once squares appear. Don't waste money here.

The real danger comes when plants begin to square and survival increases. During the first 5 weeks of squaring would be where I would put most of my investment if needed for beet armyworm management. Thresholds will vary between 10,000 to 20,000 per acre, depending upon the level of leaf feeding versus square feeding. While waiting for caterpillars to gain any size puts you at a control disadvantage, it will allow a truer picture of actual survival and the number of "beets" that need to be addressed. Often times this wait will save you a spray job.

There are several effective insecticides out there including: Dow AgroSciences' Tracer and Intrepid, Dupont's Steward, and Syngenta's Denim (Section 18). Dow's Lorsban may also be a good choice, especially on this smaller cotton. Coverage is critical for good beet armyworm control. This should not be a problem at this time unless you cheat on spray volume. Banded ground applications can be reasonably economical. None of the pyrethroids are effective "beet" materials.

I would expect boll weevil trap catches to run a little higher over the next couple of weeks but with more cotton squaring, the attractiveness of the trap will be compromised by the greater attractiveness of nearby squaring cotton fields. Most of our traps catching weevils have no more than 1-2 weevils after a week. A few catches are higher but these are few and far between.

There is a potential downside to less weevil spraying. Cotton fleahoppers and even western tarnished plant bugs were often incidentally suppressed and even controlled by the overwintered boll weevil sprays. Producers will have to be more diligent in their scouting so that these square thieves don't set you back.

Fleahoppers are moving into squaring cotton fields. As fields begin to square the threat of fleahopper movement (and yes western tarnished plant bug too) to these fields becomes real. We are beginning to observe this although it is still too early to get a fix on their effect on squaring. Fleahoppers generally attack pinhead-sized squares and leave the larger squares for plant bugs, weevils, and caterpillar pests (pictures).

Extension guidelines would have you manage these bugs more aggressively during the first week of squaring than during the 2^nd or 3^rd week of squaring. I am involved in a Cotton Incorporated COTMAN study investigating the correctness of this approach. According to doctoral research conducted by Dr. Holman in Arkansas, the best approach turned out to be one where square protection became more aggressive as you closed in on first flower. This is the opposite of our current management strategy. Our thresholds would have you treat during the first week of squaring if fleahopper numbers reached 25 per 100 plants and square set dropped below 90%. The 2^nd week threshold would be 85% square set and the 3^rd week accumulative square set threshold would be 75%. Both approaches would target a three week accumulative square retention of about 75%. This level would result in no significant loss in yield or earliness.

With the hot, dry, windy conditions we have experienced, some fields have become very dry and plants are under considerable stress. This coupled with blowing sand has caused some plants to begin shedding squares. Do not automatically assume that this square shed is due to the activities of insects. I know that most agronomists and plant physiologists will tell you that cotton plants rarely shed squares without insect damage. This may be a good beltwide generalization but it does not always hold true in our area of environmentally challenging growing conditions.

With the Roundup application window rapidly passing by, if you are spraying weedy fields, you might consider adding an insecticide for fleahoppers. If they are on the weeds, they will be forced into the cotton as the weeds die. Of course I would hope that you would survey the weeds to confirm that there are fleahoppers present.

Several insecticides will be effective against cotton fleahoppers. Higher rates will need to be used if plant bugs are in the mix. These include: Orthene, Address, Bidrin, dimethoate, Provado, Steward, Vydate and Metasystox-R.

Probably the most effective time to address fleahoppers in squaring cotton in our area is in the 2^nd to 4^th week of squaring, depending upon their numbers. It usually takes a generation to get damaging numbers.

False chinch bugs are on the move this year. We have received many calls from homeowners and some producers. For the most part, these tiny pests have been more of a nuisance than a real problem. They can however cause stand reductions if sufficient numbers move into adjacent cotton rows and suck sufficient sap from plants to cause their demise. I have seen this in limited cases in previous years. But we are talking about hundreds per plant (picture), not 5-20 per plant. We have not been able to document square loss due to the presence of false chinch bugs in smaller numbers. I would watch fields with false chinch bugs present but would be real slow to pull the trigger. JFL

Third instar southwestern corn borer (SWCB) larvae are being found (picture) in older corn in Lubbock County, and there is still some egg-laying yet to go in the southern area. Extension IPM Agent Greg Cronholm (Hale/Swisher counties) reports higher than normal SWCB captures in pheromone traps, and egg laying has yet to peak in the northern areas. SWCB trap captures are averaging 117 moths per week per trap in the Edmonson and Kress areas, but one trap caught 308. The good news is that European corn borer numbers are lower than usual in the area. Corn earworm and fall armyworm caterpillars continue to feed in whorls. PP

Plants nearing bloom should be monitored for sunflower moth (pictures). Here, "bloom" is defined as any head with any part of the flower exposed. Our publication, Managing Insect Pests of Texas Sunflower http://lubbock.tamu.edu/ipm/AgWeb/sunflower/docs/b1488.pdf] (1998) states to start applying insecticides at 20 - 25 percent bloom when ANY moths are found in the field. Here is the rub: some hybrids go from 5 to 50% bloom in as little as two days, so it is very difficult to achieve a perfectly timed application. Practicality may dictate that the first insecticide application be applied at 5 percent bloom, which is when the yellow ray flower petals are visible. Don't get caught with a late application, and be prepared to make a second (and possibly a third) application at 5 day intervals for moderate to severe pressure. Remember that newly-hatched larvae are relatively exposed on the head for the first 5 - 6 days, but bore into seed thereafter and are harder to kill with insecticides.

Old habits die hard, especially when the new labels are printed in microscript. Karate is no longer labeled for use on sunflowers, but Warrior (same active ingredient) is. This will only matter if an applicator is audited by TDA. PP

Extension IPM Agent Scott Russell (Terry and Yoakum counties) reports that Clyde Crumley, former IPM Agent in Gaines County, and now with the Llano Estacado Water District, is finding lesser cornstalk borer (LCSB) (picture) infestations as high as 10% in some Gaines County fields. The LCSB feeds primarily underground in a silken tube and is usually more harmful to peanuts grown under drought-stressed conditions. Rainfall and irrigation contribute to larval mortality.

Economic thresholds differ for dryland vs. irrigated peanuts. In irrigated peanuts the threshold is 10 percent of plants infested before initial pegging, and 15 percent infested after initial pegging. Lorsban 15G is suggested as an insecticide. Please refer to the new version of the Texas Peanut Production Guide : http://lubbock.tamu.edu/ipm/AgWeb/peanut/docs/PeanutProdGuide2001.pdf for complete information on scouting and control. PP

Everyone knows they are here. False chinch bugs have been leaving wheat fields, CRP fields, rangeland and playa lake bottoms by the millions and moving to nearby fields (and houses, nursing homes, restaurants and greenhouses according to our telephone calls the last three days). The bugs are looking for succulent plants on which to feed. They use their straw-like mouthparts to suck juices. To quote the latest version of The Kansas Insect Newsletter [LINK http://www.oznet.ksu.edu/entomology/extension/KIN/kin01_3.pdf], "these bugs suck, they don't chew (if you are seeing chewed plants, look further)."

Crops at risk include small sorghum, soybean, sunflower, and possibly corn. Fortunately, the risk is low except in borders near the fields the insects are leaving. Heavy infestations can kill young plants simply through removal of water and associated worsening of drought stress. There are no established false chinch bug thresholds, but for very young sorghum or corn, 20 per plant would be the level to contemplate control in the 20 -30 rows nearest the source fields. Chinch bug insecticides should work on false chinch bugs, but think twice before using pyrethroids in situations where mite problems may occur later. The false chinch bugs will dissipate in a week or two. PP

Over the last week, many cotton fields have really taken off. The recent oppressive heat however, is not necessarily what we need to get things up to speed. When looking at June temperatures thus far, we can conclude that we are way above average for both the highs and lows (June temp slide here). The PET Network has indicated that we have been averaging 0.425 to 0.554 inches per day potential evapotranspiration across the region (Halfway, Lubbock, Lamesa, and Slaton) over the last few hot, windy days. Heat unit accumulation has recently ranged from 25 to 30 per day. The seasonal totals since May 1 indicate that Halfway is at 481, Lubbock is at 604, and Lamesa is at 698. The percentages of the long-term average for those locations is 105, 125, and 124% for Halfway, Lubbock and Lamesa, respectively. This indicates that on a relative basis, we have experienced cooler conditions for the area north of Lubbock. We have some cotton squaring now, and we have some that has just been recently planted or replanted. It appears that we will have a crop that is "all over the board" with respect to maturity. This will likely pose some unique challenges down the road, particularly when it comes to the end of the season. Don=t forget that we have been averaging about 40% above normal for heat unit accumulation in September for the last 4 years. Are we due a correction?

Some cotton fields are still exhibiting poor growth. This is most likely due to seedling disease problems. I recommend that plants in these types of fields be inspected by using a shovel to carefully dig up the plants, and check for root discoloration. Rhizoctonia or other seedling diseases may be present (rhizoc slide here). The key for recovery is whether or not a lesion has girdled the stem. Those plants that have severe lesions will not be thrifty for a period of time, but may still recover if the weather conditions get more normal for this time of year. There is really nothing we can do to help these plants at this time, and hopefully they will recover.

Small square shed has also been noted in some fields. Blowing sand may be the culprit here. Mechanical injury to small squares is likely causing the problems. We need to make sure that sand fighting and rotary hoeing is timely to prevent these problems. Cotton certainly has a tremendous capacity to recover from early season fruit loss. However, in order to maintain earliness, retention of early season squares is very important, particularly if the goal is to make an early crop.

Fields without environmental damage normally begin squaring about 35 days after planting, or about 525 heat units after planting (Table 3). First fruiting branches should begin appearing at mainstem nodes 5-6. Some very vigorous fields may actually initiate the first fruiting branch on node 4. Watch fields carefully in order to determine the status of fruiting and for timing overwintered boll weevil insecticide applications. Check in the terminal to find pinhead squares - squares will be small, fuzzy, and pyramid shaped. When in doubt, pry bracts open on squares and look for a dome shaped structure. This is the flower bud.

Table 3. Cotton development by heat units and calendar days.

Based on published data and historical weather patterns, the last effective bloom date for the Lubbock area is about August 15^th; for Halfway it would be about a week earlier, and for Lamesa, about a week later. If we assume we need at least 4 weeks of blooming for a "normal" crop, then we should be blooming in the Halfway area at least by July 9^th. Based on normal developmental rates, we should be at pinhead square about 3 weeks earlier. For this year's crop to be close to "normal", then we should be at pinhead square at about June 20^th. White blooms require about 800-850 heat units to make a productive boll.

For those interested, the 30/90 day weather outlooks for the South Plains for June through August (last updated 05/25/01) can be found at: http://www.srh.noaa.gov/lub/SPLRF/outlook.html

Research conducted by TAES weed scientists Dr. Wayne Keeling and Dr. Pete Dotray
indicates that the addition of a half-rate (0.6 oz/acre) of Staple herbicide to the first OT application of Roundup UltraMAX may enhance control of several weed species and also provide some residual control. The DuPont Staple label should be consulted for specifics. Improved control of some morning glory species and palmer amaranth is stated. Rainfall or sprinkler irrigation (0.5 to 1") after application is required for residual control.

Ammonium sulfate is generally necessary when preparing Roundup UltraMAX spray mixtures in West Texas due to "hard" water. The general recommendation for Roundup UltraMAX spray mixtures is to add 17 lb of spray grade ammonium sulfate/100 gallons of spray.

Table 4. Use rate conversion of Roundup Ultra to Roundup UltraMAX.

In some environmentally sensitive areas such as near conventional cotton, or differing transgenic varieties or crops, towns, farmsteads, etc., drift control becomes important. Proper selection of spray tips can help reduce drift. Tips such as TeeJet wide angle flat spray tips generate larger droplets which results in less drift potential. Tips with wider spray angles, such as 110 degree, vs. 80 degree fans allow the spray boom to be placed somewhat closer to the target and can also be beneficial. There are several drift minimization agents available. The merits of such products may be debated and although pricey, these materials may warrant investigation where drift is a concern. Materials such as Strike Zone and Drive have ammonium sulfate included.

Buctril 4EC on BXN cotton. Buctril 4EC is a herbicide that offers good control of many broadleaf weeds, as long a size is not an issue. Targeting small weeds is critical. With the BXN weed control system, one needs to remember to stage the weeds and not the crop. When the 3/4 pint/acre rate is used, most weeds should be 1-3 inch tall. If the rate is increased to 1 pint/acre, then weed size can be up to 4 inches tall. Consult the label for specific weeds and sizes. In general, morning glories should be not larger than 3-4 inches at application. Pigweeds should not exceed 1-2 inches in height. Sequential applications may be required for control of some weeds species. When high densities of weeds are encountered, make sure excellent coverage is obtained. For best results, broadcast applications using 15-20 gallons per acre total volume are recommended by local Aventis personnel. Use nozzles that provide good coverage such as flat fans. Including a refined crop oil at 0.5% to 1.5% of the total spray solution (2-6 quarts/100 gallons) should increase weed control.

When fields require a graminicide for grass control, the Buctril 4EC label states that if Buctril is applied first, then wait 7 days before applying Assure II, Fusilade 2000, Poast or Select. When the grass herbicide is applied first, wait a minimum of 3 days before applying Buctril 4EC. Due to herbicide antagonism problems, grass control may be reduced if Assure II, Fusilade 2000, Poast or Select are tank mixed with Buctril 4EC.

According to the DuPont Staple label, Staple can be tank mixed with Buctril 4EC for use on BXN cotton. The Staple rate should be 0.8 oz/acre plus 1 pint/acre of Buctril 4EC. Improved control of various pigweed species can be obtained. Rainfall or sprinkler irrigation amounts of 0.5 to 1 inch is required to obtain residual control.

Touchdown Herbicide Use on Roundup Ready Cotton

There has been some confusion concerning the use of Touchdown herbicide on Roundup Ready cotton. Perhaps the following comments will help. Glyphosate (Roundup Ultra) is an isopropylamine salt of N-phosphonomethyl) glycine. The Touchdown IQ (3 lb glyphosate acid per gallon) material which has been labeled for Roundup Ready cotton is a diammonium salt of N-(phosphonomethyl) glycine. See the Touchdown label available at, www.greenbook.net enter Touchdown and see page 6. or go to: www.cdms.net/ldat/ld4BG002.pdf - page 7

Both herbicides contain the same active ingredient, only the salt formulation and surfactants are different. The differences in the efficacy of these materials for weed control are generally very minimal according to various weed scientists. For very good comments concerning this from Dr. Bob Hartzler (Iowa State University) go to:
www.weeds.iastate.edu/mgmt/2001/glyphosateformulations.htm

Of course, when you do not use an approved Monsanto brand Roundup formulation for burndown or in-crop applications, the Roundup Rewards Value Package is voided. However, Syngenta has established the Touchdown Assurance Program for eligible stripper cotton varieties (including Paymaster 2145RR, Paymaster 2156RR, Paymaster 2200RR, Paymaster 2326RR, and Paymaster 2379RR). This program enables producers to apply Touchdown IQ to Roundup Ready cotton and Syngenta will provide a replant program and a crop destruct program. There are lots of qualifications for this program and producers should make inquiry with local Syngenta representatives and read the fine print. Some of the disqualifications include: certain Texas counties are excluded, stand failure must be verified, claims must be filed with Syngenta representatives no later than July 13, 2001 or 60 days following planting - whichever occurs first, an offer does not apply to ultra-narrow row cotton. RB

Table 5. Comparison of Roundup Ultra and other glyphosate formulations. 1/

Seedling disease has been a problem this year. Some early-planted cotton that was rained on had poor emergence. This seed rot was caused by a combination of the fungi Rhizoctonia solani and Pythium spp. However, some plants that emerged have also had lesions forming on the hypocotyl area of the root. Rhizoctonia solani has been the culprit causing these sunken lesions. If we continue with hot, dry weather, the plants should grow out of the damage. If the weather turns wet, the lesions could continue to expand. TW

We are having some problems with calibration of instruments at our South Plains Evapotranspiration Network weather stations. We apologize for the inconvenience, and we are working to correct the problems. In the mean time, we will continue to provide estimated ET crop water use values to assist in irrigation scheduling, as we believe the data errors are relatively small.

For the week of June 6-13, reference crop ET was fairly high, resulting from high temperatures and wind. DP

Reprinted from the Kansas Pesticide Newsletter: "Former EPA Head Destroyed Records on Last Day in Office - (Herndon, Virginia) - Former EPA Administrator Carol Browner ordered the destruction of her computer records on the last full day of the Clinton Administration. The admission was made in a hearing today before Federal District Judge Royce Lamberth in a lawsuit brought by the Landmark Legal Foundation. On September 29, 2000, Landmark sued the EPA to force the disclosure of the identities of special interest groups that may have worked with the Agency in producing environmental regulations in the final days of the former administration." Read the full report [http://www.oznet.ksu.edu/entomology/extension/newslet.htm