Posts Tagged ‘17:13’

WCU Volume 17, Issue 13 – June 12, 2009

Friday, June 12th, 2009

PDF Version of WCU 17:13 – June 12, 2009

In this issue:

Vegetable Crop Insects
Gummy Stem Blight Found on Watermelon and Cantaloupe Transplants
Potato Disease Advisory #9 – June 11, 2009
Cucurbit Downy Mildew Update
Mocap EC Receives a 24c Label for Nematode Control on Snap and Lima Beans in Delaware

Agronomic Crops
Agronomic Crop Insects
Wheat Disease Update
Hail Damage to Agronomic Crops
Soybean Rust Update
Postemergence Pokeweed Control
Postemergence Control of Glyphosate-Resistant Horseweed
Grain Marketing Highlights

Weed Science Field Day – June 24
On Farm Delaware Food Safety Training – Level I Certification – June 30


2009 Weed Science Field Day

Friday, June 12th, 2009

Wednesday, June 24, 2009     8:15 a.m.
Carvel Research and Education Center
16483 County Seat Hwy
Georgetown, DE

The 2009 Delaware Weed Day will begin with registration at 8:15 and opening remarks at 8:30 a.m. at the Pine Grove near the farm buildings and new office building on the north side of Route 9.

Coffee, juices, and donuts will be provided. We will also provide sandwiches for lunch.

Grain Marketing Highlights – June 12, 2009

Friday, June 12th, 2009

Carl German, Extension Crops Marketing Specialist;

June Supply and Demand Highlights
The seasonal rally is expected to resume based upon a favorable June supply and demand report. Bear in mind that the planted acreage estimates for this month’s report are based upon the earlier March 31 Prospective Plantings report. The next planted acreage estimates will not be released until June 30. These estimates should be viewed as very preliminary but headed in the right direction.

Corn Analysis
Due to late planting in the Eastern Corn Belt, USDA lowered the projected yield for ’09 U.S. corn production to 153.4 bushels per acre, a two bushel per acre decline from a month ago. Beginning stocks were unchanged, as were the projection for harvested acres, and imports resulting in a total supply projection of 11.935 billion bushels, 155 million bushels less than the May estimate.

On the demand side of the equation, USDA lowered the estimate for feed use 100 million bushels. All other demand items were left unchanged from last month, now projecting total demand at 12.460 billion bushels.

Ending stocks for U.S. corn for the ’09/’10 marketing year are now projected at 1.090 billion bushels, 50 million bushels less than last month. The season average farm price estimate was increased 20 cents per bushel on both ends of the price range, now estimated at $3.90 to $4.70 per bushel.

World corn ending stock estimates were lowered 3.75 MMT from the May estimate, due primarily to increased demand. World corn ending stocks for the ’09/’10 marketing year are now estimated at 125.46 MMT as compared to 138.54 MMT for the ’08/’09 marketing year and 130.7 MMT for ’07/’08.

Soybean Analysis
The U.S. soybean production estimate was left unchanged from a month ago at 3.195 billion bushels. At this point in time, there were no changes made in planted, harvested acreage, and/or projected yield. Those numbers will be updated in the July supply and demand report. The only change to the supply and demand projections for U.S. soybeans is attributed to the lowering of the beginning stocks number, reduced 20 million bushels from last month. This reduced the total supply projection by 20 million bushels, now placed at 3.317 billion bushels.

Ending stocks for U.S. soybeans for the ’09/’10 marketing year are now estimated at 210 million bushels, 20 million bushels less than last month. The season average farm price was increased on both ends of the price range, now estimated at $9.00 to $11.00 per bushel.

World ending soybean stocks were reduced from last month’s estimate of 51.88 MMT and are now projected at 51.02 MMT. World ending soybean stocks for the ’08/’09 marketing year were 41.85 MMT and 52.92 for the ’07/’08 marketing year.

Wheat Analysis
U.S. wheat production was decreased due to a drop of 2/10th per bushel in the per acre yield estimate for all wheat, placing production at 2.016 billion bushels, down 10 million bushels from a month ago. Imports and beginning stocks were left unchanged, bringing the estimate for total supply in at 2.8 billion bushels.

The demand for feed wheat was reduced 20 million bushels while all other demand items were left unchanged.

Ending stocks for all U.S. wheat are now estimated at 647 million bushels, a 10 million bushel increase from a month ago. The season average farm price is now estimated at $4.90 to $5.90 per bushel, an increase of 20 cents per bushel on both ends of the price range from last month.

World ending wheat stocks were increased slightly from last month, now estimated at 182.65 MMT. World ending wheat stocks are projected to be 14.25 MMT larger than last year and 62.68 MMT larger than the ’07/’08 marketing year.

Marketing Strategy
The summer commodities market will be marked by price volatility. Several factors will contribute to keeping commodity prices bouncing around. First, weather developments will play a major role in the direction that commodity prices take considering the lateness of planting in the Eastern Corn Belt. Commodity traders will be watching crop development throughout the season. Ideal weather would lead to lower prices, while weather problems would obviously lead to higher pricing opportunities. Second, outside market forces e.g., value of the dollar, price of oil, the stock market, and non-commercial fund trading will all have a significant impact on commodity prices as the summer progresses. With the SRW wheat harvest just around the corner and large stockpiles of wheat in the world, new crop SRW wheat could now be on a trek to making a harvest low before resuming more normal pricing patterns.

Technically speaking, resistance for new crop Dec corn futures is now at $4.72, support at $4.33; resistance for new crop Nov soybeans is at $11.77, support at $10.47; and new crop July SRW wheat resistance is at $6.76, support at $5.63. Currently, Dec ’09 corn futures are trading at $4.64; Nov ’09 soybean futures at $10.76; and July ’09 SRW wheat at $6.01 per bushel. For technical assistance on making grain marketing decisions contact Carl L. German, Extension Crops Marketing Specialist.

Postemergence Control of Glyphosate-Resistant Horseweed

Friday, June 12th, 2009

Mark VanGessel, Extension Weed Specialist;

Options for controlling horseweed resistant to glyphosate after the soybeans have emerged are very limited. FirstRate or Classic are only effective on small, newly emerged seedlings. However, neither FirstRate nor Classic, will consistently kill large horseweed plants nor plants that were “burned off” and are recovering. These herbicides may provide some suppression, but results have been quite erratic the past few years. Horseweed plants are generally not very tolerant of shade and most soybeans will begin to canopy over the horseweed and out-compete them. In most cases, I have recommended to not spray emerged horseweed plants with another herbicide. Rather, make postemergence applications of glyphosate based on need to control other weed species. Additional glyphosate applications will provide some suppression of horseweed and give the soybeans a chance to outcompete them.

Postemergence Pokeweed Control

Friday, June 12th, 2009

Mark VanGessel, Extension Weed Specialist;

Pokeweed has been on the increase the past few years and this looks like it may be the worst year yet. I have seen many fields with pokeweed seedlings emerging and I suspect there will be a number of fields needing a postemergence herbicide to control them. We have had limited experience with pokeweed, but we had a small test and found dicamba [Banvel, Clarity, Sterling]; Distinct; NorthStar, and Callisto were the best treatments for conventional corn hybrids. Glyphosate was also effective if Roundup Ready corn was planted. Our trial did not include Lightning, but a trial at Southern Illinois University reported good control with Lightning with Clearfield corn. For soybeans, glyphosate appears to be the best option; although it is not highly effective on this species. In non-Roundup Ready soybeans, Synchrony was fair in our results (but requires STS-soybeans) or FirstRate which was only fair in the SIU trial.

Soybean Rust Update – June 12, 2009

Friday, June 12th, 2009

Bob Mulrooney, Extension Plant Pathologist;

On June 9, soybean rust was detected on kudzu in Grady County, Georgia. On June 8, soybean rust was confirmed on samples collected in late May from a soybean sentinel plot in Washington County in Alabama. On June 4, soybean rust was found in a soybean sentinel plot in Iberia Parish in Louisiana. The reports of soybean rust on soybeans in Alabama and Louisiana are the earliest the disease has ever been detected on soybeans in either state.


Hail Damage to Agronomic Crops

Friday, June 12th, 2009

Gordon Johnson, Extension Ag Agent, Kent Co.;

There was heavy hail damage in the northwest area of Kent County on June 9. Of course, small grains will have large yield losses. Corn that is 10 leaf stage or younger may have limited yield losses.

 hailwheat1Hail damage to wheat

hailwheat2 Hail damage to wheat.

hailbarley1Hail damage to barley.

 hailbarley2Hail damage to barley.

hailcorn1 Hail damage to corn.

hailcorn2Hail damage to corn.

hailcorn3Hail damage to corn.

The following is information from the National Corn Handbook ( on assessing losses due to hail in corn.

1) Assess stand losses. Wait about a week and then go out into the field and check for plants that have died or where the growing point is dead. Split suspect plants open and check to see if the growing point is light in color (still alive) or dark in color (is dead or dying).

2) Assess the loss of leaf area.

The following tables from the National Corn Handbook are used to estimate yield losses to stand loss and leaf loss. (Click picture to see larger version.)



 The following information is from Iowa State University on hail damage in corn:

In contrast to soybean, corn has an advantage early season when hail damages the aboveground plant, because its growing point remains below ground until approximately the sixth-leaf stage. The sixth-leaf stage of the ISU leaf-collar system correlates to the seventh-leaf stage used by hail adjusters. Several fields that received hail damage are beyond this point, with the growing point at soil level or above.

Two different methods exist for assessing damaged fields based on the developmental stage of the crop when it incurred the damage:

In fields where the corn was at the fifth leaf or smaller, regrowth is expected and yield impacted negligibly. This is true regardless of the amount of defoliation.

In fields where corn was near or beyond the sixth leaf stage, evaluate injured plants to determine whether the growing point is viable. Make assessments of plant survival three to five days after the storm so that surviving plants have a chance to recover. If weather is not conducive for plant growth for a prolonged period after the storm, assessing the remaining stand may require waiting up to a week. It may take that long before it is clear which plants will survive and which will not.

Assessing a damaged field requires that the growing point is located and evaluated. Use a sharp knife and cut lengthwise down the stem in order to cross-section the stem. Assess the viability of the growing point; it should have a white to cream color. Plants with a healthy growing point should survive, especially if the growing point lies below the soil surface.

If most of the corn has not reached the V5-V6 growth stage yet this is good news because the growing point is still below ground and even if the leaves have been destroyed or the plant has been cut off, re-growth from the growing point below ground will occur. The loss of those early leaves will reduce growth rate following the damage but will not affect the overall yield significantly. Corn that had reached the V6 or more advanced growth stages may not be viable due to the growing point having moved above ground. At these growth stages, the plant will continue to grow if only the leaves have been knocked off or shredded and the stem has not snapped. When the stems have snapped at the base of the plant, the plant should not be considered viable. Leaves on the plant may have been shredded, but as long as they are connected to the stem they will continue to be an energy source for the plant and plant growth will therefore continue. Defoliation should not be considered a problem until later growth stages, approximately V7 or greater.

Unlike soybean, corn can do little to change its growth pattern to take advantage of increased space in reduced plant populations. A low plant population of corn will mean fewer ears on an area basis, resulting in a yield reduction. Therefore, stand loss is more of a problem in corn, making estimation of viable plants very important.

See the following for how insurance adjusters evaluate hail damage:

Soybeans were also damaged in the recent storms. The following is information from the Integrated Crop Management Newsletter from Iowa State University

Soybean differs from corn in that as soon as the plant emerges the growing point is above ground and is extremely sensitive to adverse weather events such as hail or frost. In the case of hail, the plant is considered dead if it is in the cotyledon stage and is cut off below the cotyledons, or if it is damaged by hail to such a degree that they have no green leaf tissue or re-growth. The reason is that nutrients and food reserves in the cotyledons supply the needs of the young plant during emergence and for about seven to 10 days after emergence, or until about the V1 stage (one fully-developed trifoliolate leaf). Cotyledons are the first photosynthetic organs of the soybean seedling and are also major contributors for seedling growth. Unlike corn, whose growing point is below ground until it reaches V5-V6, the growing point for soybean is between the cotyledons and moves above the soil surface at emergence. This makes soybean particularly susceptible to damage from hail, frost, insects like bean leaf beetles, or anything that cuts the plant off below the cotyledons early in its life. Stand reductions are likely to follow hailstorms. After V1, photosynthesis by the developing leaves is adequate for the plant to sustain itself. It is important to remember that defoliation during the vegetative stages will seldom have a large impact on yield. However, it is a whole other story during the reproductive stages.

Wheat Disease Update – June 12, 2009

Friday, June 12th, 2009

Bob Mulrooney, Extension Plant Pathologist;

Wheat is rapidly turning but scab is widespread in the state. We did not dodge the bullet unfortunately. Levels of scab really vary depending on the flowering time of the wheat and whether it corresponded with favorable weather for infection. We can expect lower yields and test weights were scab is heavy.

The first symptoms of Fusarium head blight include a tan or brown discoloration at the base of a floret within the spikelets of the head. As the infection progresses, the diseased spikelets become light tan or bleached in appearance. The infection may be limited to one spikelet, but if the fungus invades the rachis the entire head may develop symptoms of the disease. The base of the infected spikelets and portions of the rachis often develop a dark brown color. When weather conditions have been favorable for pathogen reproduction, the fungus may produce small orange clusters of spores or black reproductive structures called perithecia on the surface of the glumes. Infected kernels are often shriveled, white, and chalky in appearance. In some cases, the diseased kernels may develop a red or pink discoloration.


Grain produced in heads damaged by Fusarium head blight is often shriveled, white, and chalky in appearance.

Fusarium graminearum is known to produce two important mycotoxins, deoxynivalenol (DON) and zearalenone, which can contaminate the diseased grain. The mycotoxin DON can cause reduced feed intake and lower weight gain in animals at levels as low as 1-3 ppm, especially in swine. Vomiting and feed refusal can occur when levels of DON exceed 10 ppm. Humans are also sensitive to DON, and the FDA has recommended that DON levels not exceed 1 ppm in human food. Ruminant animals, including dairy cows and beef cattle, are less sensitive to the toxin. The fungal toxin zearalenone has estrogenic properties and produces many reproductive disorders in animals. Swine are the most sensitive to the toxin, but cattle and sheep may also be affected. Zearalenone concentrations of 1-5 ppm can result in negative effects in animals and humans. Producers concerned about these mycotoxins should have grain tested prior to feeding to animals. Contact the state or local extension office for more information about testing for mycotoxins.

When high levels of Fusarium head blight are present in fields, precautions can be taken to reduce mycotoxin contaminations of the grain. The mycotoxin contamination is often highest in the severely diseased kernels. Adjusting the combine to blow out the small, shriveled kernels can help reduce mycotoxin levels. Harvested grain should be dried to 13.5 percent moisture as soon as possible to limit continued fungal growth. Grain suspected to have been damaged by Fusarium head blight should be tested for DON and zearalenone at a private agricultural lab or grain elevator. Do not mix contaminated grain with good grain prior to a mycotoxin analysis. The mixing will result in more contaminated grain, which may be difficult to sell.

Edited from Penn State fact sheet on Head Blight authored by Eric DeWolf.

Leaf rust is present in varying amounts. In my estimation it has arrived too late to impact yield, but it can be seen on unsprayed wheat that is still green. Tan spot turned out to be the most prevalent foliage disease this year.

Agronomic Crop Insects – June 12, 2009

Friday, June 12th, 2009

 Joanne Whalen, Extension IPM Specialist;

Continue to sample for potato leafhoppers on a weekly basis. We are now finding adults and nymphs in fields. Although both life stages can damage alfalfa, the nymphs can cause damage very quickly. 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
Be sure to watch for armyworms moving out of small grains and into adjacent field corn. Remember, worms must be less than 1 inch long to achieve effective control. The treatment threshold for 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.


Be sure to sample seedling stage beans for bean leaf beetles, grasshoppers and thrips. We have seen an increase in both bean leaf beetle and grasshopper feeding damage. As barley is harvested and soybeans are planted, these fields will be especially susceptible to attack by grasshoppers which can often cause stand loss. If stand reductions are occurring from plant emergence to the second trifoliate, a treatment should be applied. Although no precise thresholds are available, a treatment maybe needed if you find one grasshopper per sweep and 30% defoliation from plant emergence through the pre-bloom stage. As a general guideline, a treatment may be needed for bean leaf beetle if you observe a 20 – 25% stand reduction and/or 2 beetles per plant from cotyledon to the second trifoliate stages. The Iowa State economic threshold for cotyledon stage is four beetles per plant. Once plants reach the V1 and V2 stages, their thresholds increase to 6.2 (V1 stage) and 9.8 (V2 stage) beetles/plant. These treatment thresholds should be reduced if virus is present or you suspected virus the previous season.


As far as thrips, information from North Carolina indicates that “soybean thrips and other thrips species can feed and reproduce on the leaves and buds of soybean seedlings. Their feeding creates bleached-out lesions along the leaf veins and gives a silvery/bronzed appearance to the leaf surface when damage is severe. These insects are very small (less than 1/10 inch) and are torpedo shaped. While thrips always occur on soybean seedlings, it is only during outbreak years that they cause concern. In particular, during dry weather and on earlier planted full-season soybeans, thrips populations can explode when plants are growing slowly. Under these circumstances thrips injury will occasionally kill seedlings. Other stressors, such as nutrient deficiencies and herbicide injury, can add to thrips damage and cause plant loss.” Yellowing can occur from thrips but there are also a number of other factors that can cause yellowing so it is important to scout fields to identify what is causing the yellowing. Although no precise thresholds are available, as a general guideline, treatment may be needed if you find 4-8 thrips per leaflet and plant damage is observed.

Mocap EC Receives a 24c Label for Nematode Control on Snap and Lima Beans in Delaware

Friday, June 12th, 2009

Bob Mulrooney, Extension Plant Pathologist;

Mocap EC received a 24c label for use in Delaware on snap beans and lima beans to control nematodes. Mocap 15G has been labeled for use on snaps and limas for a long time to control nematodes particularly root knot nematode (Meloidogyne incognita). Since nobody has insecticide boxes on their planters anymore if you needed to control root knot, especially in lima beans, nothing else is labeled except for fumigants. This 24c label will allow use of Mocap EC for either applying in a band over the row and incorporated or shanked into the soil two inches from the seed at planting. It is very important to keep Mocap from coming into direct contact with the seed since it can reduce germination. This is also a toxic product and all personal protection equipment (PPE) needs to be worn. Be sure to read the label for all the important information: The Delaware Dept of Agriculture granted this label in a timely manner for use this season after receiving the request from Bayer CropScience, the manufacturer of Mocap insecticide/nematicide.