Friday, March 27, 2015

Excellent Mississippi Pre-season Publication

Angus Catchot and the other entomologists at Mississippi State University have written an excellent pre-season guide for dealing with sugarcane aphid this season, and they have incorporated most of the "lessons learned" in 2014. The publication is here: http://www.mississippi-crops.com/2015/02/24/management-guidelines-for-sugarcane-aphids-in-ms-grain-sorghum-2015/ .

There are two places where the Mississippi suggestions differ from what might be applicable in Texas. The first is that Mississippi suggests that, based on anecdotal information (but not research), narrower rows and/or higher plant populations may result in lower sugarcane aphid populations. The closest information we have on this topic is that Roy Parker demonstrated fewer greenbugs on narrow row sorghum on the Gulf Coast in the early 2000s. Whether or not narrow rows and/or higher plant populations affect sugarcane aphid, we do know that in many parts of Texas with limited rainfall or irrigation capacity it is not wise to increase plant populations beyond the available water.

Secondly, the Mississippi entomologists use a threshold based on percentage of plants infested and established aphid colonies present. This method allows for rapid scouting and we have no doubt that the action thresholds based on this method are valid in Mississippi. However, the Texas threshold is based on aphid counts or estimation of the numbers of aphids in colonies. We have not investigated the Mississippi method in Texas production.  Additionally, the Mississippi article provides different thresholds depending on growth stage and warns that pre-boot infestations can result in 81 - 100% yield loss, and projected yield loss ranges are provided for later growth stages.

Tuesday, March 24, 2015

SCA Update in the LRGV : March 22, 2015


Grain sorghum that was planted prior to these recent rains has average stands at V2 and V3 growth stage.  There is still much grain sorghum acreage to be planted.  The sugarcane aphid is currently present in all 3 counties as we have found it on haygrazer, Johnsongrass mainly, with some being seen on volunteer grain sorghum.  For the most part it has been very hard finding volunteer grain sorghum this year… which is good.  However it has been easier finding the sugarcane aphid present on other hosts. Our conclusion from these observations is sugarcane aphids are more thoroughly established this year in their winter populations. Current products that are effective at controlling the sugarcane aphid and are available for use are sulfloxafor (Transform) and flupyradifurone (Sivanto).  Sulfloxafor received approval for use in Texas (Section 18) and has an updated label for this year that you can find at https://texasagriculture.gov. Flupyradifurone is also effective and has received approval for reduced rate use.  Please contact your local chemical dealer for further information on these products.



Preventative Sugarcane Aphid Conference for the Lower Rio Grande Valley Growers- 2015

 

Join us on Tuesday April 14th 2015 from 9am to 11am at the Texas A&M AgriLife Research and Extension Center for information about the sugarcane aphid from two guest speakers Dr. JP Michaud of KSU and Dr. Scott Armstrong, researcher for USDA-ARS Oklahoma as well as Dr.Villanueva and myself as we discuss the current state of the sugarcane aphid and expectations for this year. One TDA CEU will be available as well as breakfast during registration.

To view the complete Pest Cast for the Lower Rio Grande Valley Producers you can go to:

Sunday, March 8, 2015

Sivanto (Flupyradifurone) Now Labeled at Lower Rates for Sugarcane Aphid

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.

The full Section 2(ee) label is here: http://www.cdms.net/LDat/ldC4K006.pdf