Texas West Plains IPM: Sugarcane Aphids Confirmed; Keep Scouting Cotton Fields

    Late planted sorghum leaves covered by honeydew from feeding sugarcane aphid. Photo: Texas Sugarcane Aphid News, Texas AgriLife Extension

    The presence of Sugarcane Aphid (SCA) has been confirmed in grain sorghum in Hockley County as of Wednesday, August 4th. The field confirmed with SCA was planted first week of June. The confirmed field has been sprayed. I would highly suggest that you begin weekly inspections of all grain sorghum fields. Scout! Here is the link to the management guide.

    If you have any questions, please do not hesitate to give me a call.

    Cotton ranges from just beginning to bloom with more than 6 nodes above white flower (NAWF) to past physiological cutout with 3.5 NAWF. Using our IPM scouting fields as a representation of the area cotton crop, we see that 20% of fields have reached physiological cutout (<5 NAWF) this week.

    For those fields we need approximately 400 more heat units (HU) to accumulate to be safe from bollworms. With the current weather trend of +17.5 heat units per day, those fields which have reached cutout should be safe from bollworms around August 29.

    The remaining 80% of the cotton acreage has such a wide range of maturity levels that it would be difficult to be as certain of when it will be safe from worms. I would approach these later maturing fields from this angle.

    We historically say our last effective bloom date is August 20th. This is a date in which a boll can be formed, have time to mature, and contribute to yield. Therefore, if we continue with this weather pattern into September, and we are accumulating 17.5 HU/day, we can add 23 days to this date. Thus, would give us a target of September 12 for those late fields needing to be scouted and protected from worm issues.

    The point being is that NAWF is an important gauge of maturity and can help project time needed to be safe from worms and even manage irrigation.

    Currently, bollworms are just beginning to be found infesting area fields and need to be scouted, particularly those varieties with lesser than Bollgard II or no Bt technology. Lygus, stinkbug, and cotton aphids should be included in those scouting procedures.

    Cotton aphids have been the most prevalent insect in many acres. To-date beneficial insects as lady beetles and lacewing have keep up and cleaned up most of the infestations. Remember, cotton aphids thrive in skippy cotton, and excessive/late nitrogen.

    Late nitrogen can also delay cotton maturity. For more information on managing cotton insect in Texas go here.

    My priority list for cotton in August:

    1. Keep close watch on cotton bollworms, larva pests in general, cotton aphids and Lygus. Scout, apply economic threshold, act on good information.
      Continue with late season weed control: residual herbicide, cultivate, hoe, whatever it takes to keep the pigweed from going to seed. It is a numbers game.
      Be careful when irrigating not to cause additional vegetative growth resulting in delay of plant maturity. The goal is to be done blooming before end of August.

    Peanuts are doing very well at this point with mostly excellent health of pods and foliage. Most everyone is doing a great job of staying on top of weeds and irrigating around rains. As we move into mid and late August be mindful of weather changes to cooler temps and more moisture such as from morning dews. These conditions are conducive to disease development.

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