This Week’s Fall Armyworm Numbers Up

This Week’s Fall Armyworm Numbers

                Dr. Pat Porter, District 2 Entomologist, wrote this in his September 22 release of Focus on Entomology:

Fall Armyworm Trap Captures Very High

As we start to wind down the season there has been a late surge of fall armyworm moths captured in the Lubbock traps. This puts late sorghum at risk of headworms. It also puts very late planted corn at risk of fall armyworm infestations in the ear.

 Thanks Pat!

                Jason Miller, CEA – Hale, is continuing to operate our Hale County FAW traps for us.  These were his numbers this week:

                Any late sorghum and late corn, particularly any pre-dent non-Bt or weaker Bt corn and soft dough sorghum, will be at serious risk of FAW damage this week.  This risk might even be higher on the latest of these fields due to the fact that most other crop and non-crop host plant options for FAW have finished the season out and are unattractive as hosts leaving some focused pest interests on these fields.  Early planted or recently planted wheat is also at serious risk from these FAW that could threaten stand establishment.

Blayne Reed

SCA Efficacy Trial 21 DAT Counts & SCA 2nd Treatment Decision Options

SCA Efficacy Trial 21 DAT Counts & SCA 2^nd Treatment Decision Options

                Before we started our counts today, we discussed the validity of these 21 DAT counts.  We knew that the untreated check would have fewer aphids due to the overall plant health and predation (although the predators are so far outpaced by the sugarcane aphids that this is not a control option alone).  We also suspected that most treatments would be losing control altogether this far out past treatment.  If both of those factors are true, these results would be skewed with heavier aphid numbers on treated plots.  We also knew that we did not get good control on the lower leaves in this trial.  To counter this potential affect, we are including a plant damage rating.  These were collected at 15 DAT and again today at 21 DAT.  This rating system is based on a 0-10 scale where 0 = no aphid damage and 10 = dead plants.  All graphs and statistics are shared below.  This rating system is new for the SCA and is only ready to evaluate damage and cannot be utilized as a threshold marker… yet.

                The take home message from the researchers involved in this trial today and gathering from our field experience these past few weeks is this: If you got good control with your first SCA treatment, you MIGHT be able to hold off on the next treatment until 17-21 DAT for the next (assuming aphids are still an issue; I have seen no field where they were not).  If you did not get good control, it is VERY LIKELY your next treatment needs to fall 10-14 DAT.  If and when a second, or even third treatments become necessary, remember we need to rotate chemistry between Tranform and Sivanto to prevent resistance from this aphid.

                I feel the majority of treatments in this trial fall into the second category.  If these plots were in a field situation, they would have required a second treatment 5 – 7 days ago.  Neither of these situations are what we want but that looks like what the situation is with even more aphids moving in to re-infest and / or populations recovering.  Both of these situations need to fall into considerations about how far out harvest is.  We would certainly prefer the next treatment, likely the third treatment if needed, would be the one that cleans the aphids for the combine in conjunction with a sorghum harvest aid.  We are so far out from a freeze at this point and these SCA still have a ballooning population that can stay in-field until and after harvest, I do not envision the possibility of being able to wait for a freeze to finish these aphids off so we can harvest.   

Blayne Reed

Sugarcane Aphid Update & 2015 Sugarcane Aphid Efficacy Trial – 14 DAT Counts

Sugarcane Aphid Update &

2015 Sugarcane Aphid Efficacy Trial – 14 DAT Counts

                The sugarcane aphid (SCA) is still having a heavy handed impact on the region.  In the field it does seem we are performing better in terms of knockdown and control with our treatments with several factors playing key roles.  The adjusted action threshold seems to me a better fit for the High Plains and hits these prolific aphids before they get their population built up too high.  Producers, consultants, and applicators seem to have a better understanding of the coverage needed via air or ground (air - 5 GPA minimum, 10 GPA preferred / ground – 15 GPA minimum, 20 GPA preferred) and the change of adjuvants to something heavier, such as an MSO or silicone based product, to better pull the treatment down lower into the canopy for control on the lower portion of the plant.

                On August 19, 2015 we gathered our 14 DAT counts from our SCA Efficacy Trial.  I have just now had the time to get the data analyzed and this information released. This trial is an RBD and has 4 replications.  Due to noted differences in control between the upper leaves and lower leaves, we have calculated differences in aphid numbers in terms of upper and lower leaves in addition to total aphids averaged per leaf.  Despite using 16.5 GPA, a standard rate of 0.25% NIS was utilized as an adjuvant, a standard practice for all treatments applied in this area and what was recommended for this research protocol.  We did not get good control on the lower leaves and no differences were found on those leaves.   This is one of the factors that lead us to recommend an adjuvant change with company agreement for all commercial applications.  For this trial, continuing to count the lower leaves was proving pointless and quite time consuming.  As a result we opted to only count the upper leaf for the 14 DAT counts.  This upper leaf is actually the second leaf below the flag leaf.

Questions about rainfastness

                Questions about the rainfastness of these two leading products Transform and Sivanto are common this season.  All I can speak of is this trial and what appears on the company label, which might not be mentioned specifically.  In addition, there are questions about Transform’s performance in this trial. 

                Applications for this trial were made on August 5, 2015.  Treatments began with the low rate of Sivanto at 9 am and continued down the treatment list until Lorsban was applied at 11 am.  We then gathered our pretreatment aphid counts in the untreated border rows from each plot.  Almost immediately following our leaving this trial location, a heavy 0.75 inch rain began at 4:15 pm. 

                Dr. Mike Lovelace, Dow, toured this trial with us as we made our 14 DAT counts.  Quoting from our discussion with Dr. Lovelace, “This is a good trial and I can see the differences it is showing…  This is the first instance with Transform I have seen that control that was not a premium and I feel we have a stronger product than this…  The rates are off due to the mistake in calibration, but all treatments are off the same… There must be some outside reason for Transform’s lackluster performance here…  The trial methodology is strong and there is no research bias here but right now I am looking at the rainfall that occurred after treatment on these plots as the culprit.”

Blayne Reed