On June 4th, Texas A&M AgriLife Extension Service and the Nueces County Crops Committee will host a Crop Tour highlighting area crop production and applied research demonstration being conducted by AgriLife Extension in cooperation with area growers. This will be an excellent opportunity for producers to obtain hands on information about several emerging issues affecting crop production in the Coastal Bend, as well as, obtain continuous education units (CEUs) for their pesticide licenses. Registration for the tour will begin at 8am at the Texas A&M AgriLife Research and Extension Center, 10345 Highway 44, Corpus Christi with buses departing promptly at 8:30.
Recent rainfall has sorghum and all other crops across the Coastal Bend Region in good condition and set up well for a good harvest. Therefore, tour participants will have a chance to see several on farm applied research demonstrations that have been established this year. Scheduled tour stops include a Grain Sorghum Hybrid Test, Cotton Variety Test, a test evaluating several Topguard application methods for cotton root rot control, and a herbicide demonstration on several cotton herbicides.
A major topic of discussion during the tour will be the emergence of the sugarcane aphid in sorghum production fields across Nueces County by AgriLife Research Entomologist, Dr. Mike Brewer. It was first observed in numerous fields around May 16th, but generally in low populations of 5 or so aphids on a leaf with 1 to 5% of the leaves infested. Although, some fields had 49% of leaves infested. On May 20th, we had our first grower report of heavy infestations in a field. The sample brought into the office had several 100s of aphids on it and the grower reported that it was representative of about 20% of the plants in the field.
An outbreak of this invasive aphid was discovered damaging grain sorghum in Texas,including Nueces County, and neighboring states in 2013. Infestations detected were very heavy, often with hundreds of sugarcane aphid per leaf. Leaves became sticky and shiny from honeydew and coated with sooty mold fungus (grows on honeydew) which hampered harvesting operations. The 2013 outbreak caused severe damage in fields affected by it. A repeat of what occurred in 2013 can already be observed in the Rio Grande Valley and Northern Mexico. The aphid may be a new variant of sugarcane aphid, Melanaphissacchari, which has a high preference for sorghum.
It should be emphasized that this aphid does not currently appear to vector any type of plant disease and plants do not show “warning signs” such as yellowing of lower leaves as they typically do for other aphid species. However, as the aphid load builds up on individual plants they eventually succumb and quickly defoliate.
An economic threshold for this pest still needs to be determined. Entomologist have emphasized that growers will not need to treat at the first sign of this pest, because it does not appear to vector any plant disease. Sorghum should be able to tolerate a fairly heavy population before treatment is necessary. However, when populations of sugarcane aphids are increasing rapidly, insecticides may be needed to prevent yield losses and honeydew buildup before harvest.
Dr. Joe Outlaw, Extension Economist, with the Agriculture and Food Policy Center is also scheduled to give growers updates on the 2014 Farm Bill. The 2014 Farm Bill contains significant changes to the farm safety net that include new options for producers. It will be important for growers and owners of agricultural real estate to educate themselves on all the facts in order to make informed risk management decisions that best suit their operation.
A final topic of discussion during the tour will be a Weather Outlook presented by John Metz with the National Weather Service. He will present information on the short and long term weather forecast and how that may impact future growing conditions. CEU’s (3 General and 1 IPM) will be given to those with Pesticide Applicator Licenses who attend the tour. Those who plan to attend are asked to RSVP to the Extension Office at 361.767.5223 by June 2nd so that arrangements can be made for the noon meal.