Tuesday, June 16, 2015

Weed Science Training on Resistant Weeds & New Herbicide Traits

The UK Extension Weed Science Group is conducting a Weed Science Training from 9 am – 3 pm. Two locations will be offered - June 23, 2015 - UK Research and Education Center (Princeton, KY) and June 25, 2015 - UK Spindletop Farm (Lexington, KY).
Please RSVP for lunch count at one of the following locations. UKREC Princeton - (270) 365-7541 ext 264 or email claurent@uky.edu 
UK Spindletop Farm – (859) 257-4898 or email jdgreen@uky.edu  

The Weed Training will cover the following topics: Herbicide Resistant Weeds, New Herbicide Tolerant Crop Traits, Application Stewardship, Herbicide Symptomology, Weed Identification and Cover Crops in Weed Management.
This program will be offered to UK Agriculture and Natural Resource Agents, other UK Agronomists, pesticide applicators, crop consultants, crop producers and agribusiness personnel. Commercial Pesticide Applicator Credits offered 2 general hrs and 2 specific (1A,10 and 12). CCA credits  have also been requested.
For more information, email J.D. Green or James Martin or call (270) 365-7541 ext. 203

Sugarcane Aphid Active in Mississippi…..Not close to Kentucky Yet

Doug Johnson, Extension Entomologist

Several locations in Mississippi (MS) have been identified as having grain sorghum infested with sugarcane aphid. Though it is important to keep up with what is happening, it is also quite important

Tuesday, June 9, 2015

Kentucky Extension Wheat Contest Forms

Chad Lee, Extension Professor and Agronomist, University of Kentucky

The 2015 Kentucky Extension Wheat Contest forms are available. Entries must be postmarked by July 24, 2015 for eligible entries.

In both 2013 and 2014, Jeff Coke of Daviess County won the tilled division with yields over 120 bushels per acre. In both 2013 and 2014, Duncan Gillum of  Todd County won the no-till division with yields over 115 bushels per acre. The contest also has four area winners:

Friday, June 5, 2015

Corn Nutrient Deficiency from Sidewall Compaction

Chad Lee, Extension Professor and Agronomist, University of Kentucky

This corn field had numerous plants that were stunted with striped leaves. This field was adequate to high in soil test values and had proper pH. When we dug up some plants, we found that the majority of stunted plants suffered from sidewall compaction. Images of the field, the leaf symptoms and the compacted roots follow.

Field where most of the corn appeared yellow with striped leaves.

Thursday, June 4, 2015

Cloudy Skies and Striped Corn

Chad Lee, Extension Agronomist, University of Kentucky

Cloudy skies and cool weather can make corn appear deficient.
Leaf striping on corn is being reported across the state. The recent cooler, cloudy weather is probably a big factor in many fields. In these cases, the symptoms are temporary or transient. They are cured by ample sunshine and warmer weather.
Other fields have a legitimate deficiency. Soil testing will identify those deficiencies. A tissue test will likely show a deficiency, but won't explain why it is occurring. A soil test will explain why. If the soil is deficient, then apply the appropriate fertilizer if at all possible. If the soil is test is adequate or above, then wait for the sunshine.
While pulling the soil test, dig up a few roots. Sidewall compaction can lead to these symptoms as well. I'm sure no one reading this post "mudded-in" corn. But your neighbors may have! Feel free to pass this along to them to check for sidewall compaction. If they have sidewall compaction, there is not much they can do. Sidewall compaction is a field where they should cut their losses and move on.
Here are some previous articles on corn leaf striping.

Wednesday, May 27, 2015

Head Scab Minimal Thus Far, But Stripe Rust is Widespread

Wheat that flowered May10 or earlier has mostly escaped Fusarium head blight (A.K.A head scab). Infections take about 21 days to be fully expressed following infection, so it is still a tad early to know the fate of later flowering wheat fields. I am optimistic, however, that this will not be a big head scab year.

On another front, I am seeing a considerable amount of stripe rust in fields that have not been treated with a fungicide. Neighboring states are seeing the same. Symptoms are very striking and are evident as long, thin lesions filled with masses of very bright yellow-orange spores (see photo). Modern fungicides like Caramba, Headline, Prosaro and the like are highly effective against all rust diseases. As a result, I would not anticipate seeing significant damage from stripe rust in fields treated for head scab (at early flowering, for example). In any event, you might want to go out to your fields at this time and take a peek.

Tuesday, May 26, 2015

New Aphid Pest on Grain Sorghum – Sugarcane Aphid

Doug Johnson, Extension Entomologist, University of Kentucky

Figure 1. Sugarcane aphid on
sweet sorghum; Shelby Co. TN
2014. Univ. TN.
Over the past two growing seasons a difficult new insect pest of grain sorghum has been found across the mid-south. This new pest is an aphid called the sugarcane aphid, Melanaphis sacchari. Be sure not to confuse this with the yellow sugarcane aphid, Sipha flava, which has been around the lower Mississippi river valley for several years. These are two completely different insects. Before we go any further, it is important that you understand that at present, NEITHER of these aphids have been found in Kentucky. My concern is one of preparation, as both of these aphids are found in western Tennessee and southeastern Missouri.