Posts Tagged ‘20:10’

WCU Volume 20, Issue 10 – May 25, 2012

Thursday, May 24th, 2012

PDF Version of WCU 20:10 – May 25, 2012

In this issue:

Vegetable Crops
Vegetable Crop Insects
Early Planted Lima Beans
Poor Stands or Stand Loss Due to Poor Seed or Plant Quality
Spinach Foliar Diseases
Apply Preventative Fungicides for Late Blight on Potato and Tomato
Cucurbit Downy Mildew Present Early in North Carolina
Potato Disease Advisory #6 – May 24, 2012

Agronomic Crops
Agronomic Crop Insects
Control of Palmer Amaranth
Texas Panicum Control
Marestail Causing Headaches this Spring
Grain Marketing Highlights

University of Delaware Pea Twilight – June 6



University of Delaware Pea Twilight

Thursday, May 24th, 2012

Wednesday June 6, 2012     6:00-8:00 p.m.
Carvel Research and Education Center
16483 County Seat Highway
Georgetown, DE 19947

Tour the late pea variety trial and discuss preliminary results from the early pea trial.

Preliminary results from tillage and cover crop studies on peas will be presented.

UD Extension personnel will be on hand to answer questions.

There will be refreshments following the tour.

To register, contact Karen Adams at (302) 856-2585 ext. 540 or by Monday, June 4.

For additional program information, contact Emmalea Ernest at (302) 856-2585 ext. 587 or

Grain Marketing Highlights – May 25, 2012

Thursday, May 24th, 2012

Carl German, Extension Crops Marketing Specialist;

Will Greece Stay or Go?
Uncertainty in world equity markets, dry conditions in portions of the U.S Corn Belt, needed rain in the Russian wheat region, strengthening of the dollar, a commodity sell-off driven by non-commercial fund trading, and tight old crop corn and soybean supplies have kept market participants hopping this past week. Most notable is the commodity sell-off that occurred on Tuesday due to the EU situation that has seen the Euro decline in value and the U.S. dollar strengthen. The matter of whether Greece stays a part of the Euro or goes on its own is still pending? Either way the economic problems of the EU will not be going away anytime soon.

Crop Progress
U.S. corn planting was reported to be 96 percent complete, 76 percent emerged, with the crop condition rated at 77 percent good to excellent. U.S. soybeans were 76 percent planted and 35 percent emerged. The U.S. winter wheat crop was reported as 79 percent headed, with 58 percent in the good to excellent category, and 3 percent harvested. Spring wheat was reported to be 99 percent planted, 86 percent emerged, with 74 percent in the good to excellent category.

Overall, crop progress and condition ratings are well ahead of the five year average(s). However, the ink was no sooner dry on this week’s report when market analysts began expressing concerns about portions of the Corn Belt needing rain in order to maintain the current lofty 2012 crop ratings. We have officially entered into a weather market. Decent rains occurring over the weekend would send new crop prices tumbling while insufficient rains would send prices soaring.

USDA Export Sales Report 05/24
Pre-report estimates called for weekly corn export sales at 35.4 to 78.7 million bushels. Total export sales of only 19 million bushels were reported with 6.1 million bushels scheduled for ‘11/‘12. This was below the 13.1 million bushels needed this week to stay on pace with USDA’S demand projection of 1.7 billion bushels. Weekly shipments of 27.1 million bushels were below the 36.1 million bushels needed this week. This report should be viewed as bearish.

Pre-report estimates for weekly export sales of soybeans ranged from 25.7 to 40.4 million bushels. Total export sales were reported at 35 million bushels with 29.4 million bushels scheduled for ‘11/‘12. This was well above the 1.6 million bushels needed this week to stay on pace with USDA’s export demand projection of 1.315 billion bushels. Shipments of 14.7 million bushels were above the 13.3 million bushels needed this week. This report should be viewed as bullish.

Pre-report estimates for weekly wheat export sales ranged from 14.7 to 29.4 million bushels. Total export sales were reported at 30.4 million bushels with 2.7 million bushels slated for ‘11/‘12. This was above the 0.9 million bushels needed this week to stay on pace with USDA’s demand projection of 1.025 billion bushels. Weekly shipments of 20.9 million bushels were below the 36.9 million bushels needed this week. This report should be viewed as bearish.

Market Strategy
Commodity prices are bidding higher in e-trade with soybeans showing double digit gains. It could be that the markets were becoming oversold or that the advancing dollar stabilized, if only briefly. The Dow is currently higher on the day at 12,523. Nearby crude is down about $20 per barrel since the first of March, now at $90 per barrel for nearby crude.

Commodity prices can be expected to remain extremely volatile over the near term. The weather and crop development are likely to take precedence over outside forces in determining whether opportunities for advancing sales are presented in the near term. Rain was reported earlier in the week to have occurred in the Russian wheat region. Traders will be paying close attention to rain events now occurring across the U.S. Corn Belt. Position squaring can be expected ahead of the three day Memorial Day holiday weekend. Currently, Dec ‘12 corn futures are trading at $5.21; Nov ‘12 soybeans at $12.71; and July ‘12 SRW wheat at $6.71m per bushel.

For technical assistance on making grain marketing decisions contact Carl L. German, Extension Crops Marketing Specialist.

Marestail Causing Headaches this Spring

Thursday, May 24th, 2012

Mark VanGessel, Extension Weed Specialist;

This spring has been very challenging for marestail control. A number of fields were sprayed early, when horseweed plants well under 6 inches tall, and got excellent control of emerged plants. But this spring we have seen fields with lots of plants that emerged after the initial burndown treatment. In many cases horseweed plants that emerged in April were controlled with a second burndown application that included Liberty or Gramoxone. More frustrating are those plants that were not killed with the initial burndown treatment. Most of these plants were treated when they were over 6 inches tall, or not treated with a full rate of the burndown mixtures. At this time, options are very limited for these fields and often decisions need to be made on a field by field basis.

Texas Panicum Control

Thursday, May 24th, 2012

Mark VanGessel, Extension Weed Specialist;

In 2011, there were a number of fields with severe infestations of Texas panicum in corn and soybeans. Texas panicum is a grass species that needs to be controlled with postemergence herbicides. UD Weed Research program currently has trials for control in both corn and soybeans, so local data is limited. Based on research in the southern US, options in corn include Accent, Laudis or Impact. These products will provide some residual control, which appears to be adequate for full-season control. Glyphosate or Liberty, which provide no residual control, often require two applications for full-season control. Options for soybeans include glyphosate or Liberty (possibly requiring two applications) or postemergence grass herbicide such as Select, Assure II, Poast, or Fusilade.

Control of Palmer Amaranth

Thursday, May 24th, 2012

Mark VanGessel, Extension Weed Specialist;

Palmer amaranth was seen in a number of locations in DE and MD eastern shore last summer. We found fields near Dover and throughout Sussex County with Palmer amaranth infestations. We talked about this plant at most of our winter meetings. It looks much like smooth or redroot pigweed early in its growth. The link below will show you some bulletins on how best to identify Palmer amaranth, but the watermark is very diagnostic. However, many plants never develop these “V” markings on the leaves.

This species needs to be taken very seriously; it can overwhelm a field in a few years. It is a species that has developed resistance to glyphosate very quickly and once that happens, it will make control very difficult. (If you think glyphosate-resistant marestail has been a headache; Palmer amaranth is much worse.)

Palmer amaranth grows very rapidly, which means you have only a few days to make postemergence herbicide decisions and get the field treated. Without effective control, Palmer amaranth will grow 5 to 6 feet tall. If you know you have Palmer amaranth, or you suspect you might have it, do not rely on glyphosate alone for postemergence control. Options for corn include HPPD-inhibiting herbicides (Group 27, Callisto, Impact, or Laudis); ALS-inhibiting herbicides (Group 2, Resolve, Steadfast, Permit Plus, Capreno, plus many others); and plant growth regulators (Group 4, such as Status).

Postemergence options in soybeans include PPO-inhibiting herbicide (Group 14, Reflex) and ALS-inhibiting herbicides (Group 2, FirstRate, Pursuit, Classic, etc).

We had a number of reports of poor performance with glyphosate last year for Palmer amaranth control, and so tankmixes will be essential for resistance management. Most of these postemergence options need to be applied to Palmer amaranth before Palmer amaranth plants are 4 inches tall.

Agronomic Crop Insects – May 25, 2012

Thursday, May 24th, 2012

Joanne Whalen, Extension IPM Specialist;

Potato leafhoppers are now present in fields so be sure to sample on a weekly basis. Once plants are yellow, yield loss has already occurred. The treatment thresholds are 20 per 100 sweeps on alfalfa 3 inches or less in height, 50 per 100 sweeps in 4-6 inch tall alfalfa and 100 per 100 sweeps in 7-11 inch tall alfalfa.

Field Corn
True armyworms can now be found in corn fields. There have also been reports of yellow striped armyworm in fields which I have not seen before. As small grain dries down, be sure to watch for true armyworms moving out of small grain and into adjacent corn fields. You should also scout corn for true armyworms in fields that were planted into a small grain cover. Remember, worms must be less than 1 inch long to achieve effective control. The treatment threshold for true armyworms in corn is 25% infested plants with larvae less than one-inch long. Large larvae feeding deep in the whorls will be difficult to control.

This past week we saw a significant increase in slug damage in no-till soybeans, especially in fields planted into heavy corn stalk or double crop soybean stubble. Slugs are extremely difficult to manage in soybeans because the damage can occur below the ground before plants emerge. Damage to soybean can be more severe than damage to corn because the plant’s growing point is within the emerging cotyledons. If soybean plants are able to emerge, the plant may be able to send out the unifoliate leaves where slug feeding will be noticeable. However, slugs often feed on the cotyledons below ground and/or just as the beans are cracking through the surface feeding on the growing point. This type of feeding results in the death of the plant and significant stand loss. In 2010, we saw significant stand losses from slugs feeding below ground before plants emerged. With the continued cool, wet weather in 2010, the only effective control option was to till fields , then wait until fields dried out and the weather was warmer to encourage quick germination before re-planting. In 2010, it was also extremely difficult to time a bait application. This year, a bait application could be an option if you are scouting fields routinely, plants are just emerging and before there is significant feeding on the growing point. We have had very limited experience with bait applications in soybeans, especially with applications ahead of plant emergence. We will be evaluating fields treated recently to determine the effectiveness and timing of the bait applications.

Potato Disease Advisory #6 – May 24, 2012

Thursday, May 24th, 2012

Phillip Sylvester, Kent Co., Ag Agent; and Nancy Gregory, Plant Diagnostician;

From Andy Wyenandt, Extension Vegetable Pathologist, Rutgers University: Late blight was confirmed on actively sporulating leaf lesions from an 8 acre potato field in Burlington County, New Jersey. The few infected plants were found at the end of a row where the boom sprayer was most likely turned off. The grower had preventative applications of manzate followed by chlorothalonil prior. Seed pieces were sourced from Maine. This is the first report of Late blight in New Jersey on potato or tomato this year.

Continue to scout for Late blight symptoms in local potato fields. Please notify and submit samples with symptoms to your local county extension office (Kent: 302-730-4000 Sussex: 302-856-7303) or contact the UD Plant Diagnostic clinic (302-831-1390) to have the sample confirmed. You may also email Nancy Gregory at or Phillip Sylvester at if you have a sample to submit.

Good coverage with preventative fungicides application is very important for Late blight control. Commercial fungicide recommendations can be found in the 2012 Delaware Commercial Vegetable Recommendations Guide at

Late blight Advisory
Location: Art and Keith Wicks Farm, Rt 9, Leipsic, Kent County
Greenrow: April 20



Total DSV

Accumulated P-Days

Spray Interval Recommendations

4/20 – 4/30




4/30 – 5/1




5/1 – 5-8




5/8 – 5/10




5/10 – 5/13





5/13 – 5/16




















The threshold of 18 DSVs has been exceeded. Fifty-seven (57) DSVs have accumulated as of Wednesday, May 23. This includes any potatoes that established green row (approximately 50% emergence) prior to and on April 20. An additional thirteen (13) DSVs accumulated from Sunday, May 20 to Wednesday, May 23. Recent weather conditions have been favorable for late blight development since the last report. The predicted hot weather would make conditions less favorable for Late blight. The spray interval recommendation has been lowered to 5 days.

Early Blight
We are using the predictive model WISDOM to determine the first fungicide application for prevention of early blight. The model predicts the first seasonal rise in the number of spores of the early blight fungus based on the accumulation of 300 physiological days (a type of degree-day unit, referred to as P-days) from green row. A total of 238 P-days have accumulated at this site as of Wednesday, May 23. Once 300 P-days have accumulated, the first fungicide for early blight control should be applied. This usually occurs when rows are touching.

Cucurbit Downy Mildew Present Early in North Carolina

Thursday, May 24th, 2012

Kate Everts, Vegetable Pathologist, University of Delaware and University of Maryland;

Cucumber growers should monitor their crops for downy mildew. Symptoms of downy mildew on cucumber are angular yellow to tan lesions on the upper surface of the leaf and brown to black sporulation on the lower surface.

Downy mildew was found a second time last week in North Carolina on greenhouse grown cucumbers. This outbreak may have started two months ago. Although there are no reports north of the Carolinas, it is extremely troubling that downy mildew is present there so early in the season. Growers should scout their fields and monitor the Cucurbit Downy Mildew ipmPIPE site for the progress of the disease. Preventative fungicide applications should begin when disease occurrence is predicted in our region.

Downy mildew on cucumber leaf. Angular necrosis on upper leaf surface and dark sporulation on lower leaf surface.

Spray to Prevent Late Blight on Potato and Tomato

Thursday, May 24th, 2012

Kate Everts, Vegetable Pathologist, University of Delaware and University of Maryland;

Late blight has been found on potato in central New Jersey. The grower was applying preventative fungicides, however lesions occurred in a part of the field that the sprayer missed. All potato and tomato crops are susceptible to this disease. Growers should scout and apply preventative fungicides to protect their crops. Chlorothalonil, mancozeb or Polyram can be applied to potato and chlorothalonil, Gavel, or mancozeb can be applied to tomato. Complete coverage of the field is extremely important. Once late blight has been found close to a grower’s field, switch to a fungicide that is late blight specific. More information on available fungicides for this disease can be found at

Controlling late blight in organic systems is extremely difficult. Organic growers should apply a protectant such as copper to their crop. Serenade, Sonata and Sporatec are OMRI listed, and labeled for late blight. (However, there are very few research trials on efficacy of these products). It is critical to apply these materials with adequate coverage and at short spray intervals.