Cotton ranges from 9 true leaves with 2 first position squares to 18.4 total nodes with 2.7 first position bolls and 5.2 nodes above white flower. Square set continues to be in the mid 90% range. Based on IPM Scouting Program fields there are 30% of fields at bloom/boll development stage. We have most acres which will see first bloom this weekend.
Cotton is going into bloom with 7.6 nodes above white flower (NAWF). Be reminded that the later a field begins to bloom the narrower the effective bloom period prior to our last effective bloom date (date in which we have high confidence that a bloom will result in a good quality harvestable boll) of August 12 for the Levelland vicinity.
A field which reached full bloom (100% of plants blooming) today, July 21, would have 22 days of effective bloom period. In 22 days, a producer could expect at least 7 first position bolls to be formed. Now this is irrigated cotton with available moisture such that no permanent effects of wilt/water stress have occurred.
Another point to this is that we normally hit 5 NAWF (physiological cut-out) on or about July 31. This give us time to literally be “blooming out the top” (hard cut-out), the cotton plant maximizing time so that bolls are mature, and not formed too late to be immature.
Bottom line is that blooming too late really shortens this prime window of opportunity to develop good bolls and relies too much on chance that late developing bolls will be of good quality and quantity.
Insect wise, these small buff white moths have generated a lot of concern. These moths are mostly one of two species. The first is the garden webworm, which is what we are seeing feeding on many pigweed plants. The other is a smartweed borer moth. Most likely these built to high numbers last year on Pennsylvania smartweed in playa lakes and are now spilling over into anything green.
Neither are considered pests of cotton, but always keep close watch for any damage to foliage, squares, and particularly bolls. We continue to see the Mozena plant bug in cotton, as well as a few stink bugs. Reports of bollworms and other larva pests in northern Lamb County warrant a mention.
Boot stage grain sorghum in Cochran County has small colonies of Banks grass mites developing. No sorghum aphids (aka sugarcane aphid) have been found in our vicinity yet. Stay tuned and scout, things could get interesting, and Pray for Rain!
Update on the Mozena leaf-footed bug in Texas High Plains cotton
Leaf-footed bug, Mozena obtusa is being spotted on a variety of plants across the Texas High Plains. We have gotten a few inquiries about how damaging this insect is to cotton and what insecticides would be most effective. In cotton, we spotted this insect in multiple counties across the South Plains region.
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The numbers remain very low in all the fields where we have seen it except one field in Hockley County where it was found to infest cotton in large numbers (15-20 immatures/plant). In this field, insects appeared to be moving from the adjacent fallow field with mesquite trees which are preferred host of Mozena bug. Even the immature stages of this insect are quite agile and can travel some distance in search of new hosts.
The graph below shows the results from an insecticide efficacy trial being conducted near Sundown, TX. Data collected at 3 and 7 days after treatment application indicate pyrethroids to be the most effective insecticides.
We are also collecting data on the impact of Mozena bug on square retention in cotton. Thus far, we have not observed any square loss that can be attributed to this insect. Overall, square retention across the trial area remains over 90%.
We are noticing a few egg masses and much smaller immatures on cotton plant indicating its suitability as a host for Mozena bug. With the absence and/or reduction in the availability of preferred hosts such as mesquite and other legumes, this leaf-footed bug can become an issue in cotton.
Leaf-footed bugs in general prefer to feed on fruits and seeds and therefore their populations need to be monitored closely as our crop enters the boll development phase. I would treat them more like stink bugs which feed in the similar manner with their piercing and sucking mouth parts and are mainly boll feeders in cotton.
When scouting fields monitor both insect population density and the extent of damage to the crop (fruit retention, external and internal boll injury) and base the treatment decisions accordingly.
Here is a link to our recently updated cotton insect management guide.
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