CMEG Crop Management Extension Group

Field Crop News

Website Address: http://fcn.agronomy.psu.edu/

July 10, 2007    Vol. 07:19

IN THIS ISSUE:

Weather Outlook — Paul Knight, Pennsylvania State Climatologist

The heat and humidity will recede as more seasonable, less humid air arrives later in the week. A series of disturbances (probably one on Friday and another Saturday) should trigger a few thundershowers. The latest computer guidance suggests that the cooling will be short-lived and a return to warm, humid conditions is in store for much of next week. A fundamental, though small, shift in the weather pattern is occurring which should lead to more regular opportunities for rain (during the latter half of July), though it is likely that portions of some counties — particularly in the central third of the state will miss the beneficial rain.

Week One (July 11–17): It will stay very warm and sticky in the eastern half of the state on Wednesday, but thunderstorms (some with damaging winds) developing in the west will affect most areas by sundown. The Southeast will see the spottiest rainfall. Noticeably less humid air will arrive on Thursday, though it will still be a bit humid in the eastern counties. A couple of pushes of cooler air on Friday into Saturday should lead to scattered thundershowers during the afternoon, but less than half the state will see rain on either day. A return of warm, humid air is likely early next week with a few afternoon thundershowers, mainly in the southern counties.

Week One (May 23–29): Increasingly warm afternoons and milder nights will be the rule until Friday. A weakening cool front should produce scattered thunderstorms in the west and northern sections later Friday. Don’t expect much cooling during the weekend as warm, humid air stays nearby. A fresh push of cooler air will trigger more widespread thundershowers later Sunday or Monday (southeast) and this will be followed by more seasonal and dry conditions early next week.

Week Two (July 18–July 24): Warm and humid conditions will dominate this period with at least one rather hot day expected. A surge of cool air from Canada should arrive late next week with widespread thunderstorms (between late Wednesday and Thursday). The front may stall nearby leading to a chance of dull, damp conditions in parts of the state on the weekend of July 21–22.

Check out the predicted Growing Degree Days (base 55) for Pennsylvania for the next two weeks at: http://climate.met.psu.edu/data/regional_gdd.php

Market Outlook — Tom Murphy, Lycoming County Extension Educator

The corn market for the last two weeks has been pretty tough on the bulls looking for more of the upward trend they had been enjoying until June 25th when the recent market high was reached. Since then there has been a number of moves down including some at limit followed by some small positive bounces. But as we said several times recently, it is now all about the weather at this point with particular focus on the pollination of the mid-western corn crop.

In that regard about a third of the crop nationally is silking which is about 15% ahead of the normal average. Weather patterns across much of the big corn states showing a cooler window for the next week which should be positive for the crop. There are some dry areas but rain forecast for many of them. But crops don’t grow on forecasts, so we will have to wait and see where and when it rains.

Predictions for the size of the crop and the carryout are pretty wide ranging. I have seen and heard from 1.25 billion bushels to 3 billion depending on sources in the industry. Internationally, China got some much needed rain in the past week which will potentially bring them back into the export picture again. They had been discussing limits to both exports and ethanol production due to concerns about their domestic grain needs. U.S. exports are still strong overall for corn and looking to meet USDA targets.

Soybeans are still showing bullish signs with recent positive moves even yesterday on the Board. Same story, different crop, weather is a key although not the only one. The world market is in beans is becoming more and more driven by South American production and there is increasing demand for Brazil in particular to grow more beans to cover what the U.S. can’t. Basis numbers for beans are strong in the Midwest at the moment, but weakening in PA and at the Gulf. More to be written on that story later.

In PA, many are reporting continued dryness issues spread throughout the state and consequently, much of the corn and bean crop is hurting in many areas. Early planted corn seems to have the advantage again this year, as it was able to develop a more intensive root system prior to the dryness. PA grain prices:

PA grain prices found at www.agriculture.state.pa.us

Drought And Heat Stress Starting To Take Its Toll — Greg Roth, Grain Production Specialist

Moisture and temperature stress is beginning to affect many of our corn crops. The combination of high temperatures and drought is particularly stressful on the crop, especially during the critical pollination period. Precipitation during the next three weeks will be critical for maintaining reasonable yields. In some areas soil moisture reserves are exhausted and the crops will be depending on precipitation during the remainder of the year.

On the positive side, crops that have been planted early and managed well to this point have remarkable levels of drought tolerance. Weed pressure, compaction and insect injury increase the impact of the drought. Many of us have seen crops that been under extended periods of moderate stress and still yield over 100 bushels per acre. Also, the cooler weather and showers? forecast later in the week should mitigate some of the effects of the dry weather.

Drought and heat stress prior to the pollination period can affect internode elongation and result in shorter corn crops and lower silage yields. During the pollination period, drought stress can delay silk emergence and reduce the pollination of the ear resulting in lower kernel numbers. To assess pollination, use the “shake test” and peel back the husk gently from an ear and then shake it to determine if any silks remain attached to the ear. Those that remain attached are not pollinated. For more on this test, see a recent Purdue website: http://www.agry.purdue.edu/ext/corn/news/timeless/EarShake.html

For fields that have pollinated, continued drought stress will result in kernel abortion on the tips of the ear, further reducing kernel numbers. Stress that continues in August will affect grain fill and grain size. The combination of lower kernel numbers and reduced fill leads to lower yields.

Mid—Season Checkup On Corn Nutrient Status — Douglas Beegle, Extension Fertility Specialist

As the corn crop begins to tassel and silk we have a good opportunity to use plant leaf analysis to give the crop a checkup so see if it is getting the nutrients needed for optimal production. Plant analysis is commonly looked at as a tool for diagnosing problems and it is very useful for that purpose. However, it is also a great monitoring tool to assess the nutrient status of the crop. It is especially useful for fine—tuning top management by making sure nutrients are not limiting the response to all of the other management inputs. With this in—season checkup you can determine if the crop is actually getting the nutrients that were applied or that you thought the soil would supply. Marginal levels of a nutrient in the plant when adequate amounts were applied or when the soil test levels were optimum for the nutrient can indicate that some other factor is limiting the ability of the plant to access that nutrient. Possibilities to look for include: compaction, root injury, low pH, poor drainage, droughty soils, etc.

Remember that even though the plants may look fine, plants can experience what is called hidden hunger. This is when the plant does not have adequate nutrition for optimum production but the deficiency is not severe enough to show up as clear deficiency symptoms on the crop. If you are pushing for top management, this is critical information which plant analysis can provide. There have been several reports this year of corn showing potassium deficiency which probably means that there are also many situations where K maybe limiting production but not showing symptoms. Another area where plant analysis is especially useful is for assessing micronutrient status of the crop. We don’t currently have good soil tests calibrated for sulfur and micronutrients in our area, but plant analysis is a good way to assess micronutrient status of the crop.

To use plant analysis for monitoring nutrient status there are several very important rules that must be followed for the results to be valid. The three big ones are:

Follow the instructions from your ag testing lab for submitting the samples for analysis. Details from the Ag Analytical Services Lab (AASL) at Penn State can be found at: http://www.aasl.psu.edu/plant_tissue_prog.html. For other crops see the instructions from the lab for details on sampling. The Penn State AASL plant sampling instructions can be found at: http://www.aasl.psu.edu/Taking%20Plant%20Samples%20Web_7_1_04.pdf. Most famers who use plant analysis do not sample all fields but select a few representative fields to sample for this in—season checkup. The lab will most likely provide interpretations of your results or you can consult sufficiency level tables such as Table 1.2-10 in the Penn State Agronomy Guide (http://agguide.agronomy.psu.edu/cm/sec2/table1-2-10.cfm) or the AASL web site (http://www.aasl.psu.edu/Plt_nutrients.htm) to interpret the results. Look at the results in light of the whole management program on the fields tested. This includes nutrient application records, soil test levels, yield and yield variability, etc. It is obvious that using plant analysis in corn production will not usually allow corrections for the current year but will be useful for making management adjustments in the future. As a side note, for perennial crops like forages plant analysis can be used to make management changes for the current crop.

Countdown To Corn Silage Harvesting — Greg Roth, Grain Production Specialist

This year’s corn silage harvest is approaching quickly. Now is the time to make plans to be prepared and capitalize on the potential of this crop. With the high feed prices, it will be more critical than ever to take steps to minimize losses and preserve the quality of this years crop. Consider some of the following issues as harvest approaches.

  1. Anticipate harvest. Corn will reach 70% moisture approximately 35 to 45 days following silking, which is happening now in some fields, depending on maturity and the weather. Short season hybrids planted early often are ready in mid August in southern counties. Plan to do some moisture testing prior to harvest.
  2. Repair silos. Now is the time to repair cracks in silos, upgrade walls and floors based on last years experiences.
  3. Invest in extra packing if necessary. Make plans now to invest in extra packing tractors or equipment to achieve desired densities.
  4. Consider inoculants. Research proven inoculants can help to speed up fermentation or alter fermentation to minimize spoilage at feedout. Visit with your feed dealer to determine which might be best.
  5. Consider increasing inventory levels. With volatility in crop markets and weather it may be time to think about increasing your corn silage inventory to avoid spikes in feed prices and reducing issues related to transitioning to fresh corn silage in the fall.
  6. Prepare to manage chop length and kernel processing. Is the chop length and kernel processing of the silage harvested this year adequate? Review these issues with your feed consultant and be prepared to make adjustments when harvesting this years crop.
  7. Consider the chop height. Increasing the chop height is one way to increase the energy density of the silage. This negatively impacts yield, however. The best case for higher chopping seems to be when haycrop silage inventories are higher in fiber.
  8. Be prepared to push the pencil silage prices. Several methods are available to estimate this, but they generally hinge on feed value, the alternative value of the crop harvested for grain, local markets and negotiations between buyer and seller. Some indications are prices could be much higher this fall.

Herbicides and Hot Weather — Andrew Frankenfield, Montgomery County Extension and Dwight Lingenfelter, PSU Weed Science

Since we are dealing with weather and weed control issues similar to past years and those experienced in other parts of the country, we figured it is not necessary to reinvent the wheel regarding discussion on this topic. Therefore, below are some highlights from us and other weed scientists from the Midwest that are very applicable to our situation here in Pennsylvania. The below article contains information from our weed counterparts in the Midwest regarding postemergence herbicides, weather, and corn injury potential.

  1. Contact herbicides are more phytotoxic on weeds and crop under hot temperatures.
  2. Systemic herbicides may be less effective on weeds stressed from drought or other factors.
  3. Crops and weeds are more prone to herbicide injury when actively growing and free from stress. Crops under stress from hot and dry conditions may be less prone to injury from most herbicide.
  4. Weeds may be stressed for moisture before the crop because of the shallow root system of weeds compared to the crop. Poor weed control may result under these conditions.
  5. In determining cause of crop injury, remember that oil concentrates (COC’s) can be phytotoxic with post emergence herbicides and oil concentrates are excellent tank cleaners for sulfonylurea (SU) herbicides. The oil can cause SU herbicides from previous applications. that have been absorbed onto the plastic matrix of spray tends to go into solution and cause serious crop injury when applying POST to a susceptible crop. Even herbicides applied many tank loads before can be solubilized with oil concentrates.
  6. Liquid nitrogen fertilizer may contribute to slight leaf burn in hot temperatures.

Below are some additional information about hot and droughty weather and herbicide application:

http://www.smallgrains.org/techfile/HRBCD.HTM
http://www.ag.ndsu.edu/drought/ds-21-97.htm
http://www.ipm.uiuc.edu/bulletin/article.php?issueNumber=11&issueYear=2005&articleNumber=8

Upcoming Events

2007 Penn State Agronomic Field Diagnostic Clinic — July 24 and 25
July 24 and 25
Penn State Rock Springs Agronomy Farm, Centre Co.

The dates and topics for our annual Diagnostic Clinic have been set. As in the past, the Clinic is a one-day event conducted at the Penn State Agronomy Research Farm near Rock Springs, PA. This year’s Clinic will be held on Tuesday, July 24 and then repeated on Wednesday, July 25, 2007. The topics include cover crop selection and management, no-till planter adjustments and attachments for use in cover crops, an overview of biomass crops for alternative energy use, nitrogen management issues, and pest management topics. As always, various credits will be offered.

Registration forms will be mailed and posted on our CMEG Web site (http://cmeg.psu.edu/) as time gets closer, so you can register and get additional information on each of the topics.

For additional information or comments about the Diagnostic Clinic contact Dwight Lingenfelter at (814) 865-2242 or by email, DwightL@psu.edu.

Ag Progress Days — August 14–16

Contributors: State Specialists: Dr. William Curran, Extension Weed Specialist, Dr. Doug Beegle, Extension Fertility Specialist, Dr. Greg Roth, Extension Grain Crops Specialist, Dr. Marvin Hall, Extension Forage Specialist

Extension Educators: Andrew Frankenfield (Montgomery), Kevin Fry (Armstrong), Joel Hunter (Crawford), Dave Messersmith (Wayne), Mena Hautau, (Berks), John Rowehl (York), Mark Madden (Susquehanna), Tom Murphy (Lycoming), Don Fretts (Fayette)

Editor: Don Fretts, Senior Extension Educator, Fayette County

Upcoming Events

Real time pest and heat unit activity: http://agsci.psu.edu/news/spotlight/pa-pipe

Calendar of Events: http://www.events.psu.edu/cgi-bin/cal/webevent.cgi?cmd=opencal&cal=cal209&

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