Lebanon Crop Management Video


19 May 2011

Wheat Scab Alert - Conditions ripe for infection

The following is an alert from Dr. Alyssa Collins.  Be sure you scout for other anomolies aphids etc before to determine if any other treatment might be necessary. I have seen some aphids and some late Cereal leaf beetles but I would be more concerned if the aphids spike.

All counties in the south central and south west regions of PA are now at “High” to “Medium” risk for the development of scab in wheat and barley that is currently flowering. Our current weather forecast includes a few more days of wet, mild weather that is conducive to the production and spread of spores, and possibly more next week.  Be prepared to spray a fungicide on fields that are at medium to high risk at flowering. Remember, sprays applied PRIOR to flowering will NOT provide significant suppression of scab or toxin production.  Caramba, Proline or Prosaro are effective on scab and give control of most leaf diseases and glume blotch. They do not need to be tank mixed with another product to control these diseases.  Spray nozzles should be angled at 30° down from horizontal, toward the grain heads, using forward- and backward mounted nozzles or nozzles with a two directional spray, such as Twinjet nozzles.

Wheat that is about 5 days or more past initial flowering cannot be treated. The labels state the last stage of application is mid-flower and there is a 30-day to harvest restriction.  Do not use any of the strobilurins (Quadris, Headline), or strobilurin/triazole (Twinline, Quilt, Stratego) combination products at flowering or later. There is evidence that they may cause an increase in mycotoxin production. Here is a chart to help tease out the best fungicide depending on what other diseases may be present in a given field: http://ces.ca.uky.edu/daviess-files/agriculture/NCERA_184_Wheat_fungicide_table_2011.pdf

At this point in the season, the only way to reduce the scab problem is to spray. But in general, do not rely solely on fungicides, as they will provide at most a 50–60% reduction in scab severity and vomitoxin. A combination of choosing resistant wheat varieties, avoiding planting into corn or small grain stubble and residue management are also required to combat this problem long-term.

Keeping an eye on the FHB Risk Assessment Tool will become critical for those farmers who have wheat beginning to flower late this week and into the next two weeks. This forecasting site, at http://www.wheatscab.psu.edu/riskTool_2011.html, is an online model that helps us predict infection risk levels everywhere in the state. Visit it at your convenience, or sign up to have updates e-mailed or texted directly to you. The maps on this site update at approximately 10:15am daily, so check back if you receive a “No Data” message.

The full extent of symptom expression is usually evident 21 days following infection, which will occur sometime next month for most fields in the state. The extent of FHB in fields that begin to flower this week will not be evident until early to mid June. Since fungicides do not completely protect the plant, and fields that are past flowering can get some infection, it is recommended that areas that are designated as medium to high risk be harvested with a high fan speed on the combine. This will clean out some of the infected seed that tends to be lighter and will reduce the toxin level in the final product.

05 May 2011

micronutrient deficiency « Weekly Crop Update

I had more calls on wheat and barley that are turning up a little yellow despite some N applications. Richard Taylor has related similar issues on the soil. Keep in mind their soils contain low CEC's however the symptoms are similar. I have sent growers away with recommendations to get a side by side soil test good and bad area to compare and see if the soil can speak to the issue. The cases I recieved are from non manured areas and I suspect in an effort to cut costs proper soil nutrition might have been taken a back seat. Bad choice with the market the way it is.

Check out Dr. Taylors weekly update.
micronutrient deficiency « Weekly Crop Update

Late Spring Early Summer Corn and Soybean Decisions

Del Voight - Senior Extension Agent - Penn State Extension

5 May  2011
We are experiencing probably the most difficult spring and early summer in years. As we move into June growers, will be staggering after the alfalfa harvest and rush to get crops in the ground.  Today one  might find themselves still having to plant some corn and soybeans. Here are some considerations. 
Research suggests corn will begin decrease in yield after May 10 somewhere between 2-2.5 bu/day as the planting window narrows there will be some economic considerations that may be required to make rational decisions. These charts from the Agronomy Guide might come in handy.

Table 1.4-8. Estimated grain yields for various planting dates and population rates. Figures shown are most applicable to fields with less than 125 bushels per acre

Table 1.4-8. Estimated grain yields for various planting dates and population rates. Figures shown are most applicable to fields with less than 125 bushels per acre.
Planting datePlants/A at harvest
Optimum yield (percent)
April 2072788387909395
April 2575818690939698
May 1778388929598100
May 6788388929598100
May 1177838892959899
May 1675818690939698
May 2173788387919495
May 2669758084879092
May 3164707579828587
June 559646973778081
June 1052586367707375

Table 1.4-8B. Estimated grain yields for various planting dates and population rates

Table 1.4-8B. Estimated grain yields for various planting dates and population rates. Figures shown are most applicable to corn fields with yields greater than 175 bushels per acre.
Planting datePlants/A at harvest
Optimum yield (percent)
Source: University of Illinois
April 154687888959999
April 105770819197100100
April 20587181919710099
April 3058708089959796
May 955687786919391
May 1950637280858684
May 2944566573777875
June 835475663676764
This spread sheet will allow one to compare corn to soybean incomes. farmdocdaily: Planting Delays and Switching to Soybeans: A New FAST Spreadsheet

Corn which is heat dependent, growing degree days are important to determine if the crop has enough time to develop before a frost.  This chart details the latest planting dates based on a hybrid requiring 2600 heat units (110 days)to develop. As the season progresses short season hybrids may need to be reviewed and used as necessary. Follow this link for the full factsheet detailing this relationship of heat and growth.  http://cornandsoybeans.psu.edu/pdfs/latest_planting_dates_for_corn_hybrids_in_pennsylvania.pdf
 As the crop progresses it will be critical to assess the need for addition N using the Chlorophyll meter.  Be sure you do not sample fields with more than 15lbs of commercial N up front and that the corn is at least V6 to gain accurate measurements.  Any other applications would be strictly a pencil estimate of additional N needs.  With late planting one might find that there are few weeds to compete with the crop.  Our weed research indicates the need to control weeds by the time they are the size of a dollar bill or 6 inches in height.
Finally as he soil is much warmer the need for starter fertilizer dimishes and probably can be avoided this time of year. There still is a need to treat seed if pest history of the field requires.

Illinois Extension
Soybeans do not lose yield at such a dramatic rate as corn however there are issues with switching from corn to beans and also considerations in planting late soybeans.  . First off if any residual herbicides have been used the carryover can be an issue. Particularly for atrazine based products. ALS materials are another concern, however, there are STS varieties of soybeans that could work in that scenario.
Row Width is critical as planting date moves into summer.  Switch from wide rows of 15 inch or more to narrow rows 15 inch or less as the planting season progresses.  Our research would suggest narrow rows late planted will outyeild wide rows.  Increasing plant population is also a good management tactic particularly as we approach double crop plant timeing in late June. The beans are going to rapidly grow and move toward R1 as nights become shorter and the populations approaching 200,000 will ensure adequate pod numbers later. This is particularly true of mid to late June plantings. 
Iowa Extension Regional differences in response to planting date
When deciding to switch from corn to beans in June it appears that in our area mid May returns to Corn mimic Soybeans however, by the first week of June returns favor Soybeans. Other pest aspects will also change this summers activity. Many pests are based on heat as well and judging by the heat units many are behind so expect them to rise about 2 weeks or more later than normal.
Since this spring and early summer are so different than what we have experiences before it is difficult to generalize any recommendations. Growers will need to take in as many facts as possible and coupled with the forage supply requirements begin to make cropping decisions to maximize profits this year.

02 May 2011

N Uptake in Wheat

Del Voight - Senior Extension Agent- Penn State Extension - Crop Management Team.

The question right now is how late  is too late to put additional N on wheat? How Much?
Wheat takes much of its N up after GS 6.   Most N is then assimilated somewhere shortly after heading or GS 10.  As long as the N that goes on is available immediately such as in the nitrate form or a form that quickly changes in the soil it will assist in maintaining yields.

How much depends on alot of factors.  The growers I talked to  had put 100 lbs on at planting. If we assume a 25% loss of the N due to leaching then perhaps an additional 25 units of N would need to be applied prior to GS 10. 
Talking to another grower who has not applied any N to date then perhaps a full shot of the N is required.  To lower the yield expectation might be prudent particularly if the wheat is yellow in appearance.  There fore if one expects 80 bu/acre an additional 80 lbs of N should be considered.  As far as form since there is sensitive tissue on the plants now I would recommend a dry formulation that would avoid any hindering of the plant leaves ability to absorb sunshine.  This is of great importance with the flag leaf showing.