Volume 14, Issue 21                                                                             August 18, 2006

Soybean Rust Update



Soybean Rust Update from the National Soybean website www.sbrusa.net:

“Soybean rust was reported on soybeans in sentinel sites for the first time in Avoyelles and Natchitoches Parishes (8-15), and Tensas Parish (8-11) in Louisiana. Currently rust has been found infecting this year's soybeans in 12 different counties in AL, FL, GA, LA, and MS. Including reports on kudzu, there are a total of 32 counties with rust this year including five in Alabama, 13 in Florida, six in Georgia, six in Louisiana, one in Mississippi, and one in Texas. Spore trapping continues throughout the U.S. using both active and passive traps.”

Weather has been more favorable for infection in some areas of the South but the high temperatures and drought in others has limited infection as well as severity of the disease.


Weekly scouting continues in Delaware with Septoria brown spot being the most common disease found in the sentinel plots as well as the Soybean Board sponsored plots. Most of the infection is mid-canopy and lower. Downy mildew is increasing but not economical. Group III sentinel plot soybeans are at R4 and the Group V are at R3 at the present time. Most of the non-irrigated soybeans are in need of a timely rain.

Bob Mulrooney





Vegetable Crop Insects - Joanne Whalen, Extension IPM Specialist; jwhalen@udel.edu



We continue to find economic levels of beet armyworm, diamondback and cabbage looper larvae. Be sure to apply treatments before larvae move deep into the hearts of plants.


Lima Beans

Continue to scout all fields for lygus bugs, stinkbugs and corn earworm. All three can be found in fields at this time. The higher labeled rates of insecticides will be needed for stinkbug control. For corn earworm, higher rates will also be needed if population levels are high and worms are large at the time of treatment. As you approach harvest, be sure to check all labels for days from last application to harvest as well as other restrictions.



Continue to scout for both aphids and cucumber beetles. We continue to receive reports of an increase in aphid and cucumber beetle populations, especially in later planted fields.



In areas where corn borers are being caught in local traps, fields should be sprayed on a 7-day schedule for corn borer control. As soon as corn borer trap catches increase to above 10 per night, a 5 to 7-day schedule may be needed. Since trap catches can increase quickly at this time of year, be sure to check local moth catches in your area at http://ag.udel.edu/extension/IPM/traps/latestblt.html. We continue to find beet armyworms (BAW) so be sure to watch for feeding signs and apply treatments before significant webbing occurs. We are also starting to see an increase in aphid populations. Treatments should be applied before populations explode.


Snap Beans

As corn borer and corn earworm populations continue to increase, you will need to consider treatments for both insect pests. Sprays are needed at the bud and pin stages on processing beans for corn borer control. Since earworm trap catches have significantly increased, an earworm spray will also be needed at the pin stage. You will need to check our website for the most recent trap catches to help decide on the spray interval between the pin stage and harvest for processing snap beans (http://ag.udel.edu/extension/IPM/traps/latestblt.html and http://ag.udel.edu/extension/IPM/thresh/snapbeanecbthresh.html). Once pins are present on fresh market snap beans, a 7-day schedule should be considered for corn borer and corn earworm control.



Since webworm and beet armyworm moths are both active, be sure to watch for both worm pests as soon as plants emerge. Controls should be applied when worms are small and before they have moved deep into the hearts of the plants. Also, remember that both insects can produce webbing on the plants.


Sweet Corn

Fresh market silking sweet corn should be sprayed on a 2-day schedule in the Harrington, Killens Pond, Little Creek, Milford, Bridgeville, Greenwood, Laurel and Seaford areas. In all other areas, sprays are needed on a 2 to 3-day schedule. Be sure to check trap catches for the current spray schedule since trap catches quickly change. Trap catches are generally updated on Tuesday and Friday mornings. (http://ag.udel.edu/extension/IPM/traps/latestblt.html and http://ag.udel.edu/extension/IPM/thresh/silkspraythresh.html). You can also call the Crop Pest Hotline for current trap catches (in state: (800) 345-7544; out of state: (302) 831-8851). Continue to watch for fall armyworm feeding in whorl stage corn. We continue to find economic levels in all late planted fields. A treatment is needed if you find 12-15% of the plants infested. Multiple whorl applications are generally needed for fall armyworm control. In addition, you may need to combine a fall armyworm material with a pyrethroid for the first 2-3 silk sprays for fall armyworm control.



Agronomic Crops


Agronomic Crop Insects - Joanne Whalen, Extension IPM Specialist; jwhalen@udel.edu



Continue to sample fields on a weekly basis for leafhopper adults and nymphs. Remember, once plants are yellow damage has already occurred. A treatment is needed if you find 20 per 100 sweeps in alfalfa 3 inches or less in height; 50 per 100 sweeps in 4-6 inch tall alfalfa; 100 per 100 sweeps in 7-11 inch tall alfalfa and 150 per 100 sweeps in alfalfa 12 inches or taller in height. You will also need to watch for defoliators, especially webworms which can now be found in fields. Webworms may be destructive in last cuttings during drought conditions. When this pest is present, early harvest will often eliminate the problem. However, if the crop is more than 2 weeks from cutting and 25 to 30 percent of the terminals are damaged, treatment is suggested. Labeled pyrethroids should provide control; however, controls should be applied before significant webbing occurs.



As we enter August and the potential for insect control increases, be sure to check all labels for the days from last application to harvest as well as other restrictions.


Continue to scout full season and double crop soybeans for defoliators including grasshoppers, bean leaf beetles and green cloverworm. The prebloom threshold is 30% defoliation and once fields reach the bloom to pod-fill stage the threshold drops to 15% defoliation.


You should also continue sampling fields for soybean aphids. Remember that this aphid is favored by cooler temperatures. Since low levels have been present in the state since late June, cooler weather could trigger an increase in populations. The action threshold – developed in the Midwest - is an average of 250 aphids per plant, on plants sampled throughout the field. In the Midwest, spraying at or beyond R6 has not been documented to increase yield.


Be sure to continue to sample all fields that are in the pod development and pod fill stages for stinkbugs. You will need to sample for both adults and nymphs when making a treatment decision. As indicated in past newsletters, available thresholds are based on beans that are in the pod development and fill stages. We are currently following the same guidelines that are being used in Virginia: 1 large nymph/adult (either brown or green stink bug) per row foot if using a beat sheet, or, 2.5 per 15 sweeps in narrow-row beans, or 3.5 per 15 sweeps in wide-row beans.


You should also begin sampling for corn earworm. In most cases, full season fields should escape damage; however, it will be important to check those fields at least 1-2 times to be sure that you do not miss an infestation. With the recent increase in corn earworm trap catches, open canopy blooming fields will be attractive to egg laying moths. A treatment should be considered if you find 3 corn earworm larvae per 25 sweeps in narrow fields or 5 per 25 sweeps in wide row fields (20 inches or greater).



August Report Recap - Carl German, Extension Crops Marketing Specialist; clgerman@udel.edu


Corn Analysis

US. Corn production was forecast at 10.976 billion bushels for the '06 crop. Total corn use for the '06/'07 marketing year is projected at 11.815 billion bushels. USDA is said to have done what commodity traders thought they would not do, reported a record U.S. corn yield in the August report at 152.2 bushels per acre. This is said to take some of the pressure off of the corn market to bid for '07 corn acres, but not much. From a production point of view the August estimate has been below the final production estimate 15 out of the past 25 growing seasons and above it 10 years. A ball park figure for the '07/'08 marketing year carry out is estimated to be about 1 billion bushels. For the current marketing year ('06/07) we are looking at a carry over of 1.232 billion bushels. Production is important in that the U.S. is now producing less corn than we are using within a given marketing year. The same was true for the '05/'06 marketing year.


Soybean Analysis

U.S. soybean production is now pegged at 2.928 billion bushels for the '06/'07 marketing year. U.S. soybean use is also outpacing production for the current marketing year by 68 million bushels. U.S. soybean yields are estimated at 39.6 bushels per acre (compared to 40.7 last year and 43.3 in the '05/'06 marketing year). Ending stocks for U.S. soybeans are now estimated at 450 million bushels, 110 million bushels less than last month. Ending stocks for the '05/'06 marketing year have been adjusted to 515 million bushels and the average farm price was $5.70 per bushel. The season average farm price for the current marketing year is estimated at $5.00 to $6.00 per bushel.


Southern Hemisphere production for Brazil and Argentina combined remains at 97.3 million metric tons (mmt), as compared to 107.51 mmt last year. Bear in mind that the Southern Hemisphere is projecting a 6 or 7 percent acreage reduction for the '07 growing season.


Wheat Analysis

U.S. wheat production for all wheat was reduced by 5 million bushels in the August report and is now placed at 1.801 billion bushels. Wheat area harvested in the U.S. totaled 47.1 million acres at 38.3 bushels per acre. Beginning stocks for the '06/07 marketing year were 568 million bushels, imports at 105 million bushels for a total supply of 2.474 billion bushels. Domestic total use is estimated at 1.140 billion bushels, exports at 900 million bushels for a total use of 2.040 billion bushels. Ending stocks for the current marketing year are now placed at 434 million bushels.


Understanding the Falling Number Wheat Quality Test

The new wheat quality test that farmers and grain dealers on the Eastern Shore are being confronted with is called falling number (not falling quality). Falling number is a test recently introduced into country elevators and mills. It gives an indication of the amount of sprout damage that has occurred within a wheat sample. Generally, a falling number value of 350 seconds or longer indicates low enzyme activity and very sound wheat. As the amount of enzyme activity increases, the falling number decreases. Values below 200 seconds indicate high levels of enzyme activity. Sprouting is said to affect food made from wheat in many ways. It can reduce mixing strength, cause sticky dough, affect loaf volume, and shelf life. In pasta, sprouting can reduce shelf life, increase cooking loss, and produce softer cooked pasta. To learn more about the falling number wheat quality test go to http://www.northern-crops.com/technical/fallingnumber.htm. Locally, different mills are said to have different standards for the falling number test that they are requiring. Currently some mills are not requiring the test, while others are rejecting wheat that does not meet their criteria.


Market Strategy

Since the report, commodity prices have fallen. Providing that the August yield estimates hold, then corn and soybean prices are expected to erode further into the harvest season. We are likely to see an LDP on corn and it is possible that an LDP will come into play this harvest season for soybeans. Grain storage is likely to pay big dividends for unpriced grain this fall. Where storage is not available sales should be made early and consideration given to reowning the grain and/or soybeans on paper.


For the remainder of the summer and into harvest, commodity traders will be zeroed in on large production numbers for the '06 corn and soybean crops plus large carry ins. Things should begin to look up again once we turn the calendar year and begin to consider, among other things, a reduced Southern Hemisphere soybean crop. The U.S. is going to need to produce a 3 billion bushel soybean crop and a 12 billion bushel corn crop next year just to stay even with projected use. LDP payments may be projected for corn and soybeans this fall, however, do not expect them to be large. 



Weather Summary


Week of August 10 to August 16, 2006

Readings Taken from Midnight to Midnight



no rainfall recorded


Air Temperature:

Highs ranged from 86°F on August 15 to 78°F on August 11.

Lows ranged from 73°F on August 15 to 54°F on August 13.


Soil Temperature:

77°F average.

(Soil temperature taken at a 2" depth, under sod)


The Weekly Crop Update is available online at



Weekly Crop Update is compiled and edited by Emmalea Ernest, Extension Associate – Vegetable Crops



Cooperative Extension Education in Agriculture and Home Economics, University of Delaware, Delaware State University and the United States Department of Agriculture cooperating. Distributed in furtherance of the Acts of Congress of May 8 and June 30, 1914. Delaware Cooperative Extension, University of Delaware. It is the policy of the Delaware Cooperative Extension System that no person shall be subjected to discrimination on the grounds of race, color, sex, disability, age or national origin.