2015 Soil Temperatures and Planting, April 30, 2015

2015 Soil Temperatures and Planting

April 30, 2015

                It is that time of year again, time to get another season’s crop up and growing.  I know of several producers that were looking at getting an early planting of their sorghum in this year to hopefully avoid potential problems with the sugarcane aphid this year and others still planting corn.  The much needed rainfall that came earlier this week has delayed much of those plans.  With that much needed rainfall, came some cooler temperatures and the annual question of, “What is the soil temperature today?” applies not just to cotton as we come into the first week of May this year.

                With much of our plantings being delayed, it is still imperative that we get all of these crops off to a good start.  Often those crops planted later, but with a more suitable soil temperature can catch or even surpass earlier planted crops  planted into marginal or poor conditions.

                Cotton gets off to its best start when planted in a recommended 69°F consistent temperature soil (roughly 64°F bare minimum with a week’s worth of warm weather on the way).  Sorghum requires a 57°F recommended consistent temperature (roughly 55°F bare minimum with a warming trend to follow).  Corn needs a minimum of 50°F and no freezing temperatures and a general warming trend following planting.

                With those figures in mind, here are the four soil temperature readings I gathered early this morning from around the area.

Halfway Experiment Station, Halfway, Texas:  52°F in no-till old sorghum ground.

2 Miles southwest of Hale Center, Texas: 56°F in conventional tilled old cotton ground.

On the Hale Swisher County line north of Edmonson, Texas: 54°F in conventional tilled old corn ground.

4 Miles southwest of Kress, Texas: 55°F in no-till old cotton ground.

                The weathermen are calling for a general warming trend to continue that should help pull these soil temperatures up quickly.  They are also calling for a good chance of more rain early next week.  I find it very hard to complain about rainfall that might delay our plantings any farther and so you will not hear anything like that here.  As this next round hopefully comes our way, it should not come with any vastly cooler temperatures this time to cool that soil back down.  Once those temperatures get just right, likely in a just few days for corn and sorghum but up to a week or better for cotton, the only thing holding our plantings back should be muddy fields.  I bet we can live with a delay like that.

Good Luck!

Blayne Reed

Wheat Virus Early Detection Alert System Update- 15th April 2015

Wheat Virus Early Detection Alert System Update- 15^th April 2015

Jacob Price, Senior Research Associate Plant Pathology- Texas AgriLife Research, Amarillo TX, has released a wheat virus detection conformation / alert today.  The following came from the lab in Amarillo today:

  

Wheat Virus Early Detection Alert System Update- 15^th April 2015

Jacob Price, Senior Research Associate

Plant Pathology- Texas AgriLife Research, Amarillo TX

The following wheat viral pathogens have been identified from samples collected at the following dates and counties:

Beaver County, OK - Wheat streak mosaic virus 4-10-15

                                     Triticum mosaic virus 4-10-15

Sherman County, TX-  Wheat streak mosaic virus 4-10-15

Tom Green County, TX- Wheat streak mosaic virus 4-10-15

                                            Triticum mosaic virus 4-10-5

  

In many areas of the Texas High Plains, we have enjoyed a good start to the wheat season.   However, incidence of wheat viral pathogens are increasing within Potter County and other areas in Texas.  Many of these infections took place during the fall, but as temperatures continue to rise, symptoms of viral infection becomes more apparent.  To scout for these pathogens, look for a yellow splotchy pattern on the leaves, which progresses to streaks.  Symptoms usually begin on the edge of the field and decrease in occurrence with distance into the field.   To have plants tested for any pathogens, send whole plants to the diagnostics lab here at the Texas A&M AgriLife Research and Extension Center in Amarillo.  For further information on wheat virus disease management and identification, including diagnostic sampling and submission, please visit the Plant Pathology Wheat Virus Early Detection System website or contact Jacob Price.

Jacob Price

Senior Research Associate

Texas A&M AgriLife Research

Amarillo, TX

japrice@ag.tamu.edu

Thanks Jacob,

Blayne

Sugarcane Aphid Overwintering Study, Hale County, Results

Sugarcane Aphid Overwintering Site – Hale County, Texas

                Today, Dr. Pat Porter, District 2 Entomologist, and I concluded the Sugarcane Aphid Overwintering Site Trial near Hale Center in Hale County.   I am happy to report that we found no surviving sugarcane aphids in the overwintering site today.  The site had been successfully infested with sugarcane aphids from sorghum last fall with a thriving and established population of aphids confirmed to be healthy within the predator exclusion cage area before the local killing freeze date last November.  All green Johnson grass shoots, crowns, actively growing leaves and stalks, plus most rhizomes were methodically checked above ground and below for the aphid with no survivors found. 

                Near and alongside the predator exclusion cage containing the artificially infested Johnson grass utilized for the trial were placed two temperature sensors.  One sensor was placed in the soil surface near the cage and the other at a depth of 4.5 inches alongside neighboring Johnson grass rhizomes.  The temperature recordings for this winter are:

4.5 inch depth: hours below 32 degrees = 8 (all on Dec. 31). Lowest temperature = 31.7 degrees. 

Soil surface: hours below 32 degrees = 1151. Lowest recorded temperature = 8.5 degrees.   There were 109 days between Nov. 5th (tent deployment) and today that had at least one hour at 32.0 degrees or below. The last freeze was March 27th at 5:00 am. 

The longest continual period at 32 degrees or below was 65 hours (Feb 26 – March 1). The next longest was 64 hours (Dec 29 – Jan 1). 

This is not to say that we will not see the sugarcane aphid in this area this season.  They could very easily migrate in annually, much like the fall armyworm or the sorghum midge, and are very likely to do so.  For now, we can feel as reasonably certain as one site can that this aphid did not overwinter on the High Plains.

Thanks to Dr. Pat Porter and Dr. Ed Bynum for all their assistance and expertise.  Good Luck,

Blayne Reed 

Sugarcane Aphid Distrobution Map

Sugarcane Aphid Distribution Map

                The first official sugarcane aphid confirmed distribution map of 2015 has been released.  You can view it at our dedicated sugarcane aphid news blog at:

http://txscan.blogspot.com

Click the 2015 Distribution Map link to the right of that blog.  Please follow that blog for the latest sugarcane aphid news from across the state.  I will be utilizing this blog for local and area releases for all pests.

What I can say about this 2015 sugarcane aphid ‘starting point’ is that it is far to our south, but is also four tier counties closer than the 2014 sugarcane aphid ‘starting point.’  Due to this closer ‘starting point’ this aphid might be arriving here a few weeks earlier than last season.

This week we plan on concluding our sugarcane aphid overwintering study now that we are beginning to see spring growth on the Johnson grass patch where we placed the overwintering cage and temperature sensors.  I do not expect to find active aphids at this site, 2 miles south of Hale Center in Hale County.  If we do find active sugarcane aphids, sorghum IPM plans would need to intensify drastically.  As the situation stands today and based upon this current known sugarcane aphid distribution map and expected weather patterns, we should be seeing the aphid in Hale, Swisher, and Floyd possibly by the middle of August.

Even if this proves arrival date accurate or late I still do not feel this aphid will run roughshod over our sorghum or sorghum like hay crop production in the High Plains.  We have good IPM options to meet this foe with and we can put some of the basics into place today.

First, for this area I would suggest making use of an earlier planting date.  Sorghum only requires a 58°F soil temperature for planting.  For our sugarcane aphid IPM plan, this means we can plant our intended sorghum acres with an early-mid or maybe a mid-maturity sorghum variety earlier and add to the likelihood of avoiding the brunt of the economic impact of the aphid by being ready for harvest before the aphid can get a good foothold. 

Next, we need to evaluate the agronomic properties of the known tolerant or ‘resistant’ sorghum varieties and make use of those that look to be a good fit for your production needs.  These ‘resistant’ varieties will not be bullet proof to the sugarcane aphid.  We would still need to scout and check for the aphid if these varieties are grown.  Resistant varieties can reduce (not eliminate) the likelihood of developing an economic problem from an integrated approach. 

Our common seed treatments have also proven to give about 35 to 45 days of sugarcane aphid control starting from planting.  This could help slow or retard the establishment of the sugarcane aphid, particularly for a late planted or catch-crop sorghum or hay field. 

Finally we have our action thresholds and two products to choose from this season if chemical control is required.  Economic and action thresholds are and will be a work in progress for all new and invasive pests until the research can be done to determine the true economic impact.  While the ET (economic threshold) is still a subject of discussion, I am still encouraging the action threshold of 100 aphids per leaf average from 10 randomly selected from across the field plant’s top and lower leaves.  If at risk fields reach this threshold, treatment should be justified.  This season, Transform does have a section 18 label while Sivanto has a section 2 label. 

The highlights of the Transform Section 18 label are these:

• Use rate: 0.75 - 1.5 oz.
• Maximum number of applications: 2 (and not to exceed 3.0 oz of Transform per year).
• Minimum treatment interval: Do not make applications less than 14 days apart.
• Preharvest Interval: Do not apply within 14 days of grain or straw harvest or within 7 days of grazing.
• Restricted entry interval (REI): 24 hours. 

The highlights for the  Sivanto label are:

Sivanto 200SL (Flupyradifurone) insecticide has been issued a Section 2(ee) label for use on sorghum to control sugarcane aphid. The new sugarcane aphid use rate that became effective on 3/2/15 is 4.0 - 7.0 oz. (The full Section 3 label specifies 7.0 - 10.5 oz, but lower rates can now be used on sorghum to control sugarcane aphid.)

Other relevant information appears below.

Preharvest Interval (PHI): 7 days for forage, 21 days for grain, stover or straw.
Minimum interval between applications: 7 days.
Minimum application volumes: 10 GPA by ground, 2 GPA by air.
Maximum number of ounces that can be used per season: 28.

Thanks and good luck,

Blayne Reed