Insect problems continue to march across the High Plains with persistent beet armyworm and bollworm infestations, increasing aphid infestations, and exploding boll weevil numbers outside of active eradication zones. We have finally determined that EPA will not be granting our section 18 request for Pirate. And EPA has also formally denied American Cyanimid’s section 3 request as well. This pretty much kills Pirate for cotton for all time. There have been some spot shortages of insecticides for beet armyworm control but for the most part, supplies of most products have kept up with demand. The key insecticide players are Confirm, Lorsban, Steward and Tracer. Steward supply is limited as may be Confirm’s. Typical treatment costs have escalated to $19-$32 per acre, especially where multiple pest problems exist. Producers have done a good job at protecting yield but at a horrific expense.

Boll weevils have gotten out of hand in some fields outside of active eradication zones. In some of these instances, it is no longer economically possible to continue to control these infestations. Commercial applicators have just not been able to maintain a tight enough spray schedule. The eradication program in three High Plains zones continues on track, avoiding flaring secondary pests and reducing boll weevil numbers, based on trap counts, by over 92%.

Aphid infestations are variable in cotton with some fields taken care of by natural enemies while other fields needing help through insecticide applications. Bidrin and even Furadan are not providing consistent control in some areas. Let us hope that aphids are not becoming resistant to these materials at our legal use rates.

Some corn fields have the potential for later spider mite problems, mostly the late planted fields. The corn borer problem is almost over. Southwestern corn borer activity was heavy in some areas.

Sorghum fields are beginning to see their share of caterpillar pests. Worms infesting heads are called collectively, headworms. Late greenbug infestations are developing but for the most part remain below economically damaging levels.

Peanuts are also seeing their share of the area’s beet armyworm problem and will need to be monitored to avoid problems with this pest.

Various kinds of peppers are also under attack from beet armyworms, mostly feeding on leaves and flower buds. They can enter the pepper as well.

When Will The Beet Armyworm Problem End?

There appears to be no end in sight for beet armyworm (BAW) problems for many producers. Egg laying pressure continues across the area with several fields cycling 25,000 to 60,000 larvae through each week. We have the really high counts of 100,000, 200,000, 300,000 and above of caterpillars per acre but these are not typical of much of the cotton. And while I have been unfolding what appears to be a virtual horror story for this area, there has not been wholesale crop devastation up to this point. To be sure there are some dryland fields where producers have turned their backs and walked away (how can you justify $30-$60 dollar spray bill on 125 pound cotton?). Also, there are certainly fields that have actually escaped the ravages of the recent beet armyworm attack. The real story is not how much yield has been lost to this point but rather how much money has been spent targeting BAWs alone or in combination with the other pests?

Judging from the number of phone calls I am receiving (over 50 per day), there is certainly concern for the cost of control, insecticide availability and performance of the various treatments. The first insecticide issue to put to rest is Pirate. I have been in close contact with representatives of American Cyanamid/BASF, Plains Cotton Growers, Inc., Congressman Combest’s aide, Jimmy Clark, the Environmental Protection Agency (EPA) and the Texas Department of Agriculture (TDA). We have gone around and around the issue of a section 18 for Pirate. Bottom line? It is a dead issue! EPA will not give us a section 18 for Pirate---this is not an option and will not be considered by them. In fact, EPA has formally turned down in writing, American Cyanamid’s section 3 request citing serious environmental impact concerns (=bird kill). There is nothing more that can be done. We must forget about Pirate and move on to the business at hand, which is how can we best address the pest problems we are facing today with currently available materials?

Without the chance of obtaining Pirate, what are your options? First, you must scout frequently enough to target applications against small caterpillars. None of these materials can guarantee adequate control of worms larger than one-quarter inch long. Sure, you’ll sometimes get some of these snakes, but not consistently. So, what are the chemicals we have for beet armyworm control. These would include: Confirm, Lorsban, Steward, and Tracer. The list does not include Intrepid or Denim since supplies of these are virtually nonexistent. I also will not include Curacron, Lannate Larvin or any of the pyrethroids. Any control these materials provide is not sufficient to warrant their expense. I also don’t advocate mixtures unless going for multiple pest situations. I base the above and below statements on tests conducted by us this year and earlier years, as well as tests conducted by others in Texas and across the cotton belt.

Let’s look at Confirm. This is a good BAW material and should be used at the 8.0 ounce per acre rate. A spreader-sticker such as Latron CS-7 should be used with this product. I understand that both Confirm and Latron are getting harder to find. Confirm will not control bollworms, weevils or aphids. It is slow to kill BAWs but will stop their feeding and subsequent damage in under 24 hours. Residual activity will be in the 14 day range. This product should target small, 1-3 day old worms. Larger worms will not generally be controlled adequately. Applications should be made with 5 gallons by air or 15 gallons by ground rig. Control problems will be more of a problem in bigger cotton. Don’t evaluate this product’s performance for 7 days. Cost will range from $10-$13 per acre, depending upon who you buy it from.

Now what about Steward? This product has performed well this year but became unavailable for a while when DuPont’s plant was shut down. As I write this, 9,000 gallons should be arriving in Lubbock. This is enough to treat 126,000 acres at the low rate of 9.2 ounces per acre. DuPont promises 1,000 gallons a week delivered to our area until the BAW problem is finished. This would add another 14,000 acre treatments weekly. This product does have some bollworm activity and has looked good targeting mixed bollworm/beet armyworm field infestations. While soft on most beneficial insects, it will be harsh on lady beetles, and as a consequence, could flare aphid numbers. Residual activity would be in the 5-7 day range. I would also use the higher spray volumes suggested for Confirm, for Steward or any of the other BAW materials. While larger worms have been killed by this product, the correct target size is still one-quarter inch or smaller. Cost will range from $13-$17 or more per acre depending upon the dealer and rate used. The maximum rate is 11.3 ounces per acre.

Tracer is both a BAW and bollworm material. The lowest consistent performing rate has been 2.4 ounces per acre. The 2.9 ounce maximum rate will increase residual activity to the max but this is still no more than 7 days. There is plenty of Tracer available. Dow AgroSciences indicates that 10% of all acre-applications for BAWs to date have been made with Tracer. Cost will range from $14 to $17 per acre, starting at the suggested 2.4 ounce rate. The labeled low rate is 2.14 ounces per acre.

Lorsban has been used on 50% of the treated acreage so far according to Dow. This product really should go out at the 32 ounce rate per acre and not lower as some have done. It will give you 80% control on average while the other products should be more in the range of 90% or more control if properly applied and targeting the right size worms. Lorsban has some bollworm activity and aphid control performance averages 65%. Lorsban at the above rate will cost around $12 per acre.

Because of the continuous egg lay, the huge number of worms and delays in getting a commercial applicator to treat a field, even the good BAW insecticides can leave too many worms. Table 1 provides information that shows the relationship between initial infestation, percent control and final infestation. Obviously, once infestations get above 80,000 per acre, even excellent control is often not good enough.

Table 1. The relationship between initial beet armyworm infestation level, percent control and final infestation levels following treatment.

Percent Control	Initial beet armyworm infestation level per acre
	20,000	40,000	80,000	160,000	320,000
95	1,000	2,000	4,000	8,000	16,000
90	2,000	4,000	8,000	16,000	32,000
85	3,000	6,000	12,000	24,000	48,000
80	4,000	8,000	16,000	32,000	64,000

What does this all mean? Don’t expect miracles as BAW numbers reach astronomical levels. Don’t expect to kill larger worms. Coverage is especially critical on larger plants. Request 5 gallons by air or 15 gallons by ground. Some commercial applicators are doing this. Others are saying they are spraying at these higher volumes but are not! If these treatments fail, it is either a coverage problem, rate problem or target size problem. You might have to spray twice on a close interval to bring very high BAW numbers down to acceptable levels.

Bollgard varieties have continued to perform well in the face of persistent caterpillar problems. But nothing is magic out there and so even the Bollgard fields have required treatment for caterpillar pests such as beet armyworms. Even so, fewer treatments and less yield loss should be the result of using these varieties. This was the year to plant Bollgard varieties. This was the year to test them.

With the continued pressure from beet armyworms, Cotesia cocoons have been very common on the undersides of leaves in many fields, even within active eradication zones. This white cocoon is about one-quarter inch long and looks like the end of a thin Q-tip. The wasp that emerges from this cocoon is a very important parasite of BAWs. Its presence is an indication that all of our sprays and all of the Eradication Foundation sprays have not wiped out this important natural enemy. I think this bodes well for our area.

When will it be over? Once again, that depends upon when your crop is safe. I think BAWs could be around well into September. Once cutout occurs, another 450 HUs is required to make a relatively safe boll of a bloom on that magic day. Overhead sprinkler irrigation may delay this somewhat. See Randy Boman’s COTMAN discussion under COTTON AGRONOMY for more detail. He and I worked on this quite a bit and believe it is important information needed by producers wanting to know when to quit spraying.

Bollworm Problems Eclipsed by Beet Armyworms

We have continued to have problems with bollworms mixed in with our beet armyworms. High egg counts have usually not resulted in high caterpillar counts. Are the beet armyworms eating the bollworms? (Just kidding, or am I?). With bollworms in the mix with BAWs, producers may need to mix something in with their BAW material. For most infestation levels of bollworms, Steward and Tracer should be adequate alone. Lorsban or Confirm will need some help from a pyrethroid. A pyrethroid may also be necessary with the first two BAW materials if extended residual is needed or boll weevils are in the mix.

Loopers Beginning to Concern Growers

There are beginning to be lots of loopers out there in many fields. This is exactly what we saw in 1980 too. Bollworms, beet armyworms and loopers covered up lots of fields. I have never seen a field infestation of loopers that I would treat. This includes infestations in 1980 that exceeded 500,000 per acre. Loopers are leaf feeders. Their defoliation makes cotton look bad but is not sufficient to affect yield. Besides, we all grossly overestimate percent defoliation anyway. Ignore the loopers. Concentrate on beet armyworms, bollworms, boll weevils and aphids.

An Aphid Problem Boosts Concerns for Control

The aphid situation is quite variable. Some fields have had their aphids taken care of by numerous lady beetle larvae, much like we saw last year. Other fields have infestations that have naturally reached damaging levels of 50 or more per leaf. Still other fields have received an earlier pyrethroid application and are now seeing increased aphid numbers. As long as boll filling is taking place, yield is at risk from aphid infestations. Fifty aphids per leaf for a short time is not sufficient to cause a problem but hundreds of aphids per leaf will. Unless natural enemies or other mortality agents keep aphids in check, once the level of 50 aphids per leaf approaches, most fields will end up with yield damaging levels of aphids. And this happens in short order. So frequent scouting is necessary.

What insecticides are working? You may have to tell me! At least in the Lubbock-Idalou-Slaton area, Bidrin has not been very effective. Furadan may not be as good as it used to be either. Brant Baugh, Lubbock County Extension IPM Agent and I have an aphid control test going north of Idalou. No registered product looked that good. See five day results below in Table 2.

Table 2. Control of cotton aphids with various insecticides. Idalou, TX. 2000.*

Treatment	lbs. ai/AC	Average 5 day post treatment aphid counts per leaf	Adjusted percent control**
Actara	0.047	23	93
Assail	0.1	4	99
Assail	0.05	2	99
Bidrin	0.33	143	72
Bidrin	0.5	69	87
Capture	0.0625	281	33
Centric	0.047	29	91
Fulfill	0.085	139	71
Furadan	0.25	66	78
Provado	0.047	81	62
Untreated	----	402	----

*Counted and treated on August 2. Post treatment counts on August 7. Treated with a small plot sprayer, 12.5 GPA, three nozzles per row with two on 18" drops. Assail is an Aventis product not yet labeled. Centric and Actara are Novartis products with the same active ingredient, not yet labeled. Fulfill is also an unregistered Novartis product. Provado is a registered Bayer product, Bidrin is a registered AmVac product and Furadan is a section 18 FMC product.

**Henderson’s Formula used to adjust for natural mortality and unequal pretreatment counts.

What does this test tell me? None of the legal materials worked well enough. Not Bidrin or Furadan. Now 87% control at the 8.0 ounce rate of Bidrin doesn’t sound all that bad but leaving 69 aphids per leaf is. This is above my 50 per leaf threshold and could result in even higher numbers real soon. Provado again performed much as it has in the past. This product may work in other areas of the cotton belt, but not here. I have never been impressed with Fulfill although in all fairness, it needs more time before a realistic evaluation can take place. After all, it is an anti feeding material. Centric and Actara are different formulations of the same material and looked promising. Capture, as expected, provided poor control and left lots of aphids. But what Capture will also do is keep aphids at higher levels longer than if we had done nothing at all. Obviously Assail looked the best, like what Furadan used to look like in our tests. We are going to do a large plot, commercial application with this product next week and expect to see more of it next year.

I’m going to assume that our control problems in the Lubbock area are not widespread. If that is the case then Furadan or Bidrin would still be my choices for aphid control. Where control problems exist, consider adding Ovasyn or Curacron to the Bidrin to spike its effectiveness. If you cut the Bidrin rate to compensate for the cost of the other insecticide, you will reduce its residual activity. Don’t put Furadan or Bidrin out with an additive that would impede the movement of these products into the leaves. This will really hurt their performance.

Boll Weevils Becoming A Real Issue

Boll weevils are becoming a real issue in some areas outside of active eradication zones. Punctured boll counts exceeding 50% have been reported. And we haven’t seen the worst yet. Even so, GRID traps caught fewer weevils on average this week than last, when numbers increased dramatically (Tables 3, 4, & 5). There still were more weevils caught than two weeks ago though. I think these adult weevils are now busy laying eggs rather than flying around looking for cotton and getting fooled by traps.

The big losers (big reductions in weevil numbers over last year) remain Andrews, Dawson, Deaf Smith, Gaines, Howard, Martin, Midland, Terry and Yoakum counties. The big gainers (increases compared to last year) are Crosby, Floyd, Lubbock and Hale counties.

Table 3. Total boll weevils caught per week and percent of traps catching boll weevils since April 24, 2000 in the GRID trapping program.*

Week beginning	Total weevils caught	% of traps catching weevils
April 24	948	30
May 1	887	34
May 8	5243	67
May 15	1112	34
May 22	2106	45
May 29	1651	46
June 5	4163	56
June 12	3391	47
June 19	5684	49
June 26	3346	53
July 3	3318	48
July 10	2057	32
July 17	1522	42
July 24	1772	41
July 31	4534	50
August 7	2960	45

*Includes three counties in the Rolling Plains

Table 4. Comparison of average weekly boll weevil trap catch in the Southern High Plains/Caprock Zone between 1999 and 2000.*

Week beginning	1999	2000
June 5	12.2	6.8
June 12	7.8	6.1
June 19	9.9	4.1
June 26	9.5	6.0
July 3	3.3	4.6
July 10	2.0	1.8
July 17	2.1	5.1
July 24	2.0	6.0
July 31	5.8	18.8
August 7	5.5	10.0
August 14	13.7

*This data represents the average number of weevils caught per trap catching weevils. Zeros are not counted.

Table 5. Week 32 (week beginning August 7)— Accumulative average number of boll weevils caught per trap in the GRID trapping program starting with week 18.

Location	1999	2000
Northwest High Plains	43.8	23.3
Northern High Plains	73.4	76.0
Southern High Plains	106.6	98.7
Western High Plains	204.6	33.4
Permian Basin	109.1	37.4
Andrews	182.6	37.8
Bailey	46.7	24.8
Borden	80.4	50.2
Briscoe	84.3	77.1
Castro	14.9	9.7
Cochran	80.1	70.2
Crosby	137.2	163.4
Dawson	151.4	52.1
Deaf Smith	10.0	2.0
Floyd	56.3	108.5
Gaines	255.2	28.3
Garza	183.9	153.5
Hale	64.3	72.1
Hockley	65.4	54.8
Howard	107.0	27.0
Lamb	49.5	20.9
Lubbock	87.8	98.8
Lynn*	88.8	53.8
Martin	51.9	18.2
Midland	43.9	19.7
Parmer	9.9	5.0
Swisher	64.6	59.1
Terry	133.6	25.8
Yoakum	176.7	26.7

This data represents the average number of weevils caught per trap catching weevils. Zeros are not counted. Refer to the Plains Cotton Growers, Inc. web page for actual total numbers caught and percent of traps catching weevils each week.

*Includes traps both inside and outside active eradication zones.

There are now fields that have reached the point where we can no longer maintain the upper hand on boll weevil damage. This is partly due to the sheer numbers of boll weevils entering fields and damaging squares and bolls, but it is also partially due to the problem of maintaining a tight enough application schedule, 3-4 days. With commercial applicators falling behind treating for the "big four", 2-3 day delays are not uncommon and are totally unacceptable where weevils are concerned. Once cutout occurs, it is only a matter of accumulating with 350 HUs or more past this date to achieve relative safety for this last cohort of bolls (flowers at cutout). See COTMAN discussion under COTTON AGRONOMY.

A reminder: if a field is past peak bloom but before cutout, move the punctured square threshold up to 25-30%. Once cutout approaches, switch to looking at 100 quarter sized bolls for punctures. A threshold of 15% punctured bolls is the starting point in control decisions. We will discuss seasonal cutout pest decision making in future issues of FOCUS. These present discussions have targeted fields at or past physiological cutout.

Eradication Update

What a year for full season eradication to begin. The Foundation is getting an acid test at how good they are at keeping boll weevils at bay while avoiding flaring secondary pests. So far they pass with flying colors. Manipulating treatment trap triggers has resulted in maintaining the percent of acres treated in a given work unit in a given week below 10%. This is better than producers are doing in their efforts to maintain control of caterpillar pests, aphids and boll weevils, in the case of fields outside active eradication zones. Table 6 summarizes Foundation trap and treatment information for last week.

 Table 6. Weekly summary of the Texas Boll Weevil Eradication Foundation program activities: treated acreage, boll weevil trap catches and beet armyworm trap catches for 2000.

Zone	Accumulative acre applications	Avg. # boll weevils per trap	Avg. # beet armyworms per trap
Northwest	624,683	0.15 (2.23)*	500
Western	1,027,950	0.13 (3.00)	220
Permian Basin	552,367	0.17 (1.00)	68

* (#) = 1999 number

Beet armyworm trap catches continue to be at elevated levels in each of the zones although the most activity is to the north. We are also trapping very large numbers of BAWs in the inactive Northern High Plains Zone. The pattern of caterpillar activity observed so far this year is very similar to that observed in 1980 when there were no boll weevils in the area and hence no spraying for weevils. The Foundation’s trap numbers would indicate that boll weevils trapped this past week were 92.8% lower than those trapped last year at this time. JFL

Fields should be scouted at 5 day intervals. The best (and fastest) way to accurately count headworm numbers is to use a "beat bucket". This method is especially good for finding small larvae that often go undetected by simply examining heads. Select 30 plants from a field and thrash the head of each into the bucket.

Economic thresholds are straightforward. Determine the market value of the expected crop and estimate the control cost per acre. Use Table 8 below to find the threshold. For example, if a field had a market value of $120 per acre and it cost $9 to control headworms, the threshold would be 1.9 headworms per head. RPP

Table 7. Economic injury level for corn earworm in sorghum based on number of larvae per head.

Control cost ($) per acre		Market value ($) per acre
	100		120	140		160		180		200		220		240 1/
2	0.5		0.4	0.3		0.3		0.3		0.2		0.2		0.2
3	0.8		0.6	0.5		0.5		0.4		0.4		0.3		0.3
4	1.0		0.8	0.7		0.6		0.6		0.5		0.4		0.4
5	1.2		1.0	0.9		0.8		0.7		0.6		0.6		0.5
6	1.5		1.2	1.1		0.9		0.8		0.8		0.7		0.6
7	1.7		1.4	1.2		1.1		1.0		0.9		0.8		0.7
8	2.0		1.7	1.4		1.2		1.1		1.0		0.9		0.8
9	2.2		1.9	1.6		1.4		1.2		1.1		1.0		0.9
10	2.5		2.1	1.8		1.6		1.4		1.2		1.1		1.0

1/ Economic injury level remains the same for higher crop values.

Crop progress continues on track due to "normal" temperatures. As with last week, this is contingent upon good soil moisture conditions. Many dryland fields across the region are beginning to "crash" due to lack of rainfall. Some spotty rainfall has been obtained across the area during the week, with Littlefield reporting about 1 inch, Muleshoe at 0.5 inch, and Post at 0.8 inch. Heat unit accumulation has been averaging about 20 per day at Lubbock for the past several days. The daily PET has ranged from about 0.20 to 0.25 inches per day at Lubbock, and 0.25 to 0.30 at Lamesa. Insect problems and lack of moisture in dryland fields continue to be major concerns for most producers across the region.

Fruit shed is underway in some fields that can’t keep up with crop moisture demands. Normally a boll will be retained once it reaches 10-14 days after bloom. Even though the boll may still be retained by the plant, it will likely be smaller and have shorter fiber length due to moisture stress.

Many deficit irrigated pivot fields have soil profiles that are getting depleted of moisture. We would like to target the soil profile to be nearly depleted as we enter harvest aid season. One should keep the field with reduced stress at least until the final bloom to be taken to the gin becomes about a 10-14 day old boll. This will reduce the likelihood of small bolls shedding due to water stress.

Fiber length is generally determined during the first 25 days or so in the life of the boll. This indicates that small amounts of irrigation should be applied to carry the boll through the important fiber length development phase. After that, late bolls can handle considerable stress. For a boll set on August 10th, it is apparent that the field should have reduced amounts of water stress probably at least through the end of the month, unless rainfall is obtained to offset irrigation needs. Otherwise moisture stress could limit quality of the uppermost bolls. A rod probe or other tool may be useful in determining the amount of moisture remaining in profiles in fields.

Early Cutout May Be Beneficial?

We have worked some with the COTMAN cotton management program developed by personnel at the University of Arkansas with funding from Cotton Incorporated. One of the key components of COTMAN for determining when to stop spraying for insects and when to apply harvest aids is identifying cutout. We have a lot of fields this year which exhibited physiological cutout fairly, especially dryland fields. Physiological cutout is defined as the point at which the plant reaches 5 nodes above white flower (NAWF) after an extended bloom period. We have discussed this and generally agree that 4 NAWF may better fit the High Plains region, due to our "living on the edge" with many fields lingering at 5 NAWF for several days at a time. When cotton "blooms out the top" and quits, this is an example of physiological cutout IF there is adequate time to mature the bloom on that date. Seasonal cutout is defined as the point in the season at which there is no longer enough anticipated heat units (based on long-term temperature data sets) available for a bloom to produce a high quality boll. COTMAN uses 850 heat units past bloom as a point at which a bloom can make a "normal" boll. In the High Plains, heat unit accumulations of 750 past bloom will probably make an "acceptable boll" that may not have "normal" lint production or may be of lower quality (low micronaire).

We stated last week that the physiological cutout we are seeing across the area may be beneficial in terms of managing this crop in this insect-infested year. Some fields are as much as 2 weeks ahead of "normal" in terms of development. Data accumulated from across the Cotton Belt to establish COTMAN guidelines for crop termination have generally indicated that once a boll reaches 350 heat units past bloom, it is relatively safe from boll weevil damage. To be safe from a bollworm egg lay, at least 450 heat units past bloom are required. Data collected over multiple site-years by Dr. John Benedict (formally TAES entomologist at Corpus Christi) support this concept (boll penetration picture). Of course you cannot walk away from a field once the magic number of heat units is obtained, as it is only a guideline. Since we have had many fields reach 4 NAWF over the last several days, the clock is ticking for termination of some insect management decisions. We believe that beet armyworms would fit the guidelines for bolls safe from bollworms.

We have developed a table that indicates where we are as of August 9 (Table 8). It is based on actual Lubbock heat units from August 1 through 8, and from that point forward, it uses the 30-year long-term average for each day. For example, the table shows that for a field that reached cutout on August 1, we should obtain 350 heat units by about August 19 IF we have "normal" temperatures. The 450 total should be reached around August 24. For cutout on August 10, we should obtain 350 heat units by August 29, and 450 heat units by September 5. This table also indicates the likelihood of obtaining maturity of late season bolls.

Table 8. Heat unit events based on date of cutout (4 NAWF) and actual Lubbock August 1-8 temperatures with subsequent long-term average values for the remainder of the season.

A lot of discussion has centered around the yields obtained in the previous three years and the warm fall temperatures encountered in those years. If we take the mean daily high and low temperatures for the 1997, 1998, and 1999 crop years and generate DD60 accumulation based on the 3-year mean temperature, then the numbers in Table 9 show how insect management could be affected and also why late-set fruit matured in those years. Is this series of years simply a "shift in weather patterns" or only anomalous outliers? Can we count on this every year?

Table 9. Heat unit events based on date of cutout (4 NAWF) and 3-year mean daily high and low temperatures at Lubbock (1997, 1998, and 1999).

Table 10 provides the deviations from the 30-year mean DD60 accumulations for the 1997, 1998, and 1999 crop years. It provides an interesting perspective of what has occurred.

Table 10. Heat unit accumulation at Lubbock as a percentage of the 30-year long-term average.

We are also working on crop termination using COTMAN defoliation guidelines. Several IPM agents across District 2 had harvest aid timing trials in fields last year. We will be reporting those results before we get into our "harvest aid run". RB

Table 11. Data from the South Plains PET Network, July 27 — August 2, 2000:

*	Reference	*	Estimated Crop ET in inches [a]
	PET (inches)	Rain (inches)	Cotton		Sorghum		Corn
			1st square	max bloom - 1st open	boot — head	soft dough	Dough	dent	black layer
Lubbock	1.59	0.04	0.70	1.75	1.75	1.51	1.91	1.59	1.35
Lamesa	1.75	0.04	0.77	1.93	1.93	1.66	2.10	1.75	1.49
Halfway	1.53	0.07	0.67	1.68	1.68	1.45	1.84	1.53	1.30
Ropesville	1.65	0.09	0.73	1.82	1.82	1.57	1.98	1.65	1.40

[a] Potential Evapotranspiration, often referred to as "PET" or "ET", is an estimate of maximum crop water demand based upon weather data. Actual water use by a crop will vary with soil and crop conditions.

Table 12. Data from the South Plains PET Network, August 3 — August 9, 2000:

*	Reference	*	Estimated Crop ET in inches [a]
	PET (inches)	Rain (inches)	Cotton		Sorghum		Corn
			1st bloom	max bloom - 1st open	boot — head	soft dough	dough	dent	black layer
Lubbock	1.67	0.04	0.73	1.84	1.84	1.59	2.00	1.67	1.42
Lamesa	1.90	0.03	0.84	2.09	2.09	1.81	2.28	1.90	1.62
Halfway	1.74	0.26	0.77	1.91	1.91	1.65	2.09	1.74	1.48
Ropesville	1.73	0.15	0.76	1.90	1.90	1.64	2.08	1.73	1.47

[a] Potential Evapotranspiration, often referred to as "PET" or "ET", is an estimate of maximum crop water demand based upon weather data. Actual water use by a crop will vary with soil and crop conditions.

Crop water demand varies with growth stage (planting date and accumulation of heat units) and crop. You are encouraged to customize your crop water use estimate by multiplying the reference PET value by the appropriate crop coefficient. Crop coefficients for additional crops and growth stages are available from the Texas PET Website at the following:

High Plains Corn - http://texaset.tamu.edu/include/crop/corn.html

High Plains Cotton - http://texaset.tamu.edu/include/crop/cotton.html

High Plains Sorghum - http://texaset.tamu.edu/include/crop/sorghum.html

Other Crops - http://texaset.tamu.edu/include/crop/cropcoe.html

Turf – http://texaset.tamu.edu/turf.asp

PET data and weather data for Halfway, Lamesa, Lubbock, Seminole and Ropesville are available at: [http://achilleus.tamu.edu/data/data.html].

The Northern High Plains PET Network provides detailed PET estimates by crop and by planting date for Bushland, Dalhart, Dimmitt, Earth, Etter, Farwell, Morse, Perryton, Wellington, and White Deer. Current data are available at http://amarillo2.tamu.edu/nppet/station.htm. DP

The primary method of controlling bacterial blight is by planting resistant varieties. Unfortunately, most of the varieties planted in the High Plains of Texas (> 80 % of the acreage) are susceptible to bacterial blight. To address this need, the Plains Cotton Improvement Program and area seed companies (All-Tex, Aventis, DeltaPine, Novartis, Phytogen, and Stoneville) provided funding to start a bacterial blight screening program. An 18-acre field site with an overhead sprinkler system was provided by the Farmer-Stockman Show (East of 50th St., Lubbock) to allow establishment of disease, after inoculation with the bacteria. A number of varieties have now been rated for bacterial blight, and all the seed companies which participated did have at least one variety with partial or full resistance. It is recommended that producers contact their seed companies to obtain more information about bacterial blight resistant varieties. TW & JG