Please RSVP and join us for an Integrated Weed Management Field day with Extension Weed Specialists from around the region.
Featuring a Harrington Seed Destructor demonstration of Harvest Weed Seed Control!
Thursday, November 2, 2017 from 10:00 am to 2:00 pm. Free Lunch!
RSVP: flessner@vt.edu
Current situation in Virginia, 10/6/17
According to records of the Virginia Boxwood Blight Task Force, to date boxwood blight has been diagnosed in over 70 locations and approximately 30 counties in Virginia. There are likely additional undocumented incidences of the disease, for example, if no sample was submitted for diagnosis through Virginia Cooperative Extension or the Virginia Department of Agriculture and Consumer Services.
Although boxwood blight has been diagnosed in many counties in Virginia, there is no indication that it is widespread throughout any Virginia county. This is not unexpected, based on the current understanding of the biology of the boxwood blight pathogen. Boxwood blight is typically initially introduced into a new location on infected boxwood or other susceptible plants (e.g. pachysandra and sweet box). Holiday greenery containing infected boxwood can also introduce the disease into a new location. However, boxwood blight is not spread long-distance via wind currents. Therefore, one need not panic even if the disease has been found in one’s county. However, if the disease has been identified in one’s neighborhood, then there is a heightened risk of local spread of the disease.
After the initial introduction of boxwood blight-infected boxwood (or pachysandra or sweet box) into a location, neighborhood boxwood plantings are at risk for boxwood blight. There are a number of means by which the sticky spores of the fungal pathogen can move through a neighborhood. For example, they can be spread via contaminated pruning tools, spray hoses, equipment, vehicles, clothing, shoes, or infested leaves spread by leaf blowers. Wildlife (including birds), insects, domestic animals or humans that have been in contact with the spores may also move the infective spores through a neighborhood. Movement of the pathogen by many of these means has been documented in locations in Virginia.
To safeguard Virginia boxwood plantings and production, we call for community awareness and efforts to avoid accidental introduction of boxwood blight into new locations and prevent local spread of boxwood blight:
Specifically, we recommend and stress the following:
Additional Precautions for Landscape Professionals:
Resources: the Virginia Boxwood Blight Task Force website and Best Management Practices
Refer to the Virginia Boxwood Blight Task Force website for further information on boxwood blight. We recommend that you familiarize yourself with the appropriate Best Management Practice (BMP) for your situation. The BMPs are available on the website as PDFs.
Average nightly black light trap catches of corn earworm moths this week were: Southampton=0.3; Prince George (Templeton)=6; Prince George (Disputanta)=4; Hanover=2; Suffolk=26. Here is the data table: BLT_28_Sep_2017
Most traps are being stowed now. We greatly appreciate the reports this season from Watson Lawrence (Chesapeake); Mike Parrish and Angela Duncan (Dinwiddie); Laura Maxey-Nay (Hanover); Scott Reiter (Prince George); Mary Beahm (Warsaw); LIvvy Preisser (Southampton); and Sally Taylor and her entomology team (Suffolk). We also want to thank the growers who hosted the traps on their farms.
Average nightly captures of corn earworm moths in area black light traps were as follows: Suffolk=8; Southampton=1; Warsaw=20; Prince George (Templeton)=10; Prince George (Disputanta)=5. There were no reports of any brown marmorated stink bugs caught in the black light traps this week. Here is the corn earworm data table: BLT_21_Sep_2017
Charlie Cahoon, Extension Weed Specialist
Eastern Shore AREC-Virginia Tech
Italian ryegrass is one of the most common and troublesome weeds Virginia small grain producers face. The weed competes with wheat for essential nutrients, sunlight, and moisture and also interferes with harvest. In the past, growers have relied upon herbicides, such as Axial XL, Hoelon, PowerFlex, and Osprey, for control of Italian ryegrass. However, herbicide resistant Italian ryegrass biotypes have developed, limiting the herbicide options available to growers.
During the summer of 2016, the weed group at the Eastern Shore AREC traveled Eastern Virginia in search of resistant Italian ryegrass. To broaden the survey, we solicited samples from extension agents and members of the agriculture industry. In total, 82 samples were collected throughout Eastern Virginia (Image 1). The objective of this survey (and subsequent resistance screening) was to determine the distribution of resistant biotypes in Virginia; allowing growers to tailor management strategies specific to biotypes in their area.
Italian ryegrass heads collected during the summer were allowed to dry down and then threshed to separate the seed. Approximately 400 seed from each population were planted in a seed tray. Once Italian ryegrass reached 3.5 to 4 inches in height (1 to 2 leaf), plants were treated with a 1X rate of Axial XL (16.4 oz/A), Hoelon (43 oz/A), PowerFlex HL (2 oz/A), and Osprey (4.75 oz/A). A non-treated check from each sample location was included for comparison purposes. Visual injury was recorded at 28 days after treatment (DAT) for Italian ryegrass treated with Axial XL and Hoelon. PowerFlex HL and Osprey are both ALS-inhibiting herbicides and act much slower than the ACCase-inhibiting herbicides (Axial XL and Hoelon). Therefore, ryegrass treated with these products were evaluated 42 DAT. Also at 42 DAT, Italian ryegrass biomass (and subsequent % biomass reduction) was determined by cutting and weighing the above ground portion of ryegrass.
Image 1. Locations of 2016 Italian ryegrass samples collected.
Overall, approximately 23% of all samples collected were resistant to Axial XL (Image 2) compared to 30% that were resistant to Hoelon (data not shown). Most samples resistant to Hoelon were also resistant to Axial XL. However, for 6 samples, Axial XL remained effective despite poor Hoelon activity. Axial-resistant Italian ryegrass is widespread in two of Virginia’s major wheat producing regions (Eastern Shore and southern Chesapeake/Virginia Beach). Of the 14 samples collected in Northampton Co., 9 were found to be resistant to Axial XL (64%). In contrast, none of the 5 samples collected from Accomack Co. were Axial-resistant. In southern Virginia Beach and Chesapeake, 5 of 6 samples collected were resistant to Axial (83% of samples). Excluding the Eastern Shore and southern Chesapeake/Virginia Beach, only 9% of remaining samples were resistant to Axial XL; 1 samples east of Stony Creek in Sussex Co.; 1 sample south of Waterview in Middlesex Co.; 1 sample northeast of Newtown in King and Queen Co.; 1 sample northwest of Loretto in Essex Co.; and 1 sample south of Somers in Lancaster Co.
Image 2. Distribution of Axial-resistant Italian ryegrass in Virginia.
ALS-resistant Italian ryegrass is more widespread throughout eastern Virginia. Of the surveyed populations, 92 and 93% were resistant to Osprey and PowerFlex HL, respectively. Producers should keep in mind the presence of herbicide-resistant Italian ryegrass nearby does not automatically mean they have a resistant biotype on their farm. Fields with escaped Italian ryegrass were purposely chosen for this survey. It is best to rely on field history and performance of herbicides in the past when making management decisions. However, it is always a good idea to rotate modes of action to delay the development of resistant biotypes.
Unfortunately, if ryegrass is resistant to Axial XL and the ALS-inhibiting herbicides (Osprey and PowerFlex HL), there are no postemergence options left. In this situation, a residual product that includes pyroxasulfone (Anthem Flex and Zidua) is suggested delayed-preemergence or early postemergence. These products offer residual control of ryegrass only (they will NOT control emerged ryegrass). It is imperative that these products are applied and activated by a timely rainfall prior to ryegrass emergence. Rotating away from wheat also presents an opportunity to control Italian ryegrass (and prevent seed production) with glyphosate early burndown prior to planting corn or full-season soybean. Be aware that glyphosate-resistant Italian ryegrass is suspected in northeast North Carolina and eastern Virginia. In this situation, paraquat plus a residual herbicide like s-metolachlor applied to fallow ground during the fall would be in order.
Image 3. Axial XL-susceptible Italian ryegrass collected near Nassawadox, VA treated with no herbicide (left), Axial XL at 16.4 fl oz/acre (middle), and Hoelon at 43 fl oz/acre (right).
Image 4. Axial XL-resistant Italian ryegrass collected near Cheriton, VA treated with no herbicide (left), Axial XL at 16.4 fl oz/acre (middle), and Hoelon at 43 fl oz/acre (right).
This is the time of year when many are wondering what kind of yield potential is out there. You can estimate your yield using the steps outlined below. But I will warn you that such an estimate is not very accurate until soybean reach the late-R6 or R7 stage. In my experience, when trying to estimate yields during the late-R5 or early-R6 stages, cut the estimate in half – believe it or not, that usually works!
My point is to use extreme caution. Never make additional sales based on these “estimates”. But, such an estimate is useful if you’re thinking about entering a yield contest or just to help ease some worries (or maybe cause more).
To estimate soybean yield:
Use the numbers above to calculate yield using the equation below:
Bushels per Acre = [(plants/1,000th acre) x (pods/plant) x (seeds/pod)] ÷ (seeds/pound) ÷ (60 pounds/bushel)
The easiest mistake to make is in steps 3 and 4. I suggest using a range of seed per pod and seeds/pound. With experience, you’ll get pretty good with yield estimates.
Most reporting black light trap stations this week had decreased corn earworm moth captures (except for Chesapeake remaining constant). Nightly averages were Chesapeake = 11; Southampton = 1; Suffolk = 8; and Warsaw = 4 moths. Here is the data table: BLT_7_Sep_2017
No brown marmorated stink bugs were caught this week in the black light traps.
The Virginia Soybean Association in cooperation with Virginia Cooperative Extension would like to announce the 2017 Virginia Soybean Yield Contest. The purpose of the Virginia Soybean Yield Contest is to emphasize and demonstrate the practices necessary to produce maximum economic yields, to recognize those producers who grow high-yielding soybeans, and to gather data on the practices utilized by these outstanding producers. With the help of various seed companies, we reward and promote the achievements of Virginia’s most productive soybean farmers.
There are four Soybean Yield Contest categories: 1) Full-Season, Non-irrigated; 2) Double-Crop, Non-irrigated; and 3) Irrigated (encompasses Full-Season and Double-Crop); and 4) Most Efficient Yield (MEY). First, second, and third place winners of the full-season, double-crop, and irrigated contest will be recognized with appropriate trophies or plaques. In addition, cash awards of $200, $100, and $50 will be presented to the first, second, and third place winners in each of these categories. The winner of the MEY contest will receive a plaque declaring him or her the most efficient soybean producer in Virginia for that year.
In addition, the United Soybean Board is supporting a Soybean Quality Contest for the 2017 season. The Iowa State University Grain Quality Lab with evaluate these samples for protein, oil, and other quality measures. You can obtain a sample bag from me. If you do not have one at the time of harvest, just save a seed sample in a 1 gallon bag and send in to my office.
Printable entry forms and contest details can be obtained from your County Agent or on my website: (https://www.arec.vaes.vt.edu/arec/tidewater/extension/soybean.html). I look forward to seeing your entries.
According to the weather recordings (http://webipm.ento.vt.edu/cgi-bin/infonet1.cgi), the heat units received by peanuts grown in Virginia from May 1 through September 5 are in average 2370 °F. There are, of course, location variations. For example, in Suffolk total heat units from May 1 is 2566 °F, in Southampton 2314 °F, Greensville 2480 °F, and Waverly 2123 °F. The current Virginia type commercial cultivars predominantly grown in Virginia require in average 2650 °F to optimum maturity. With a daily average of 70 °F recorded in the past week, optimum maturity seems to happen in the next day and a half to 7.5 days. However, would it?
Probably not, and the pictures below prove it. Today, Sep 6, we determined the maturity of four cultivars, Bailey, Sullivan, Emery and Wynn, planted in Suffolk on May 3. Based on the mesocarp color, when laid on a color maturity chart, it seems that a minimum of 20 to 24 days are still needed to reach the optimum digging for this location and the current season. In average, cultivars only have 1% of black pods, 14% brown, 20% orange, 44% yellow and 22% white.
Pod blasting demonstrations will take place this week Friday, September 8, at the Southampton Fairgrounds from 8:00 AM to noon. It will be a repeat at Indika Farms in Windsor on September 14; times will have to be determined, but probably also in the morning. See you there with your peanut samples to be pod blasted!
Current maturity of Bailey peanut planted on May 3 In Suffolk, VA.
Current maturity of Sullivan peanut planted on May 3 in Suffolk, VA.
Current maturity of Emery peanut planted on May 3 in Suffolk, VA.
Current maturity of Wynne peanut planted on May 3 in Suffolk, VA.
