FCN Logo College of Agricultural Sciences Penn State

June 26, 1998 Vol. 98.8

IN THIS ISSUE:

Production:

SUBSURFACE TILLAGE

In 1996, there were two subsurface tillage plots established, one in Fayette County and one in Washington County. The objective was to validate the benefit of subsurface tillage to crop production in SW Pennsylvania.

The 1996 results were positive in the Fayette plot, but not so in the Washington plot. (One theory was that the subsurface tillage benefit may have been erased by mechanical ground preparation when the fields were too wet.)

In 1997 the Washington county plot was abandoned, but the Fayette plot was continued.

The Fayette plot was at the Uniontown campus of Penn State and the fields have been under no-till management for many years. Corn was the crop in the monitored plot both years. The following table summarizes the yield results for 1996 and 1997.

Subsurface Tillage Plots (Fayette County)
TREATMENT 96 Corn
Yield/Acre		 97 Corn
Yield/Acre
Subsoil 149.26 Bu. 132.9 Bu.
Untreated 116.28 Bu. 122.6 Bu.
% Difference +28.3% +8.4%

The 1997 crop year was dryer at the campus site than at other locations in the county, but the yield benefit from the subsurface tillage the second year after completing the practice was still significantly positive

What might this mean to crop production or pasture management practices in SW PA? Since we are blessed with a rolling topography, what I usually call "topographically challenged," the adaptation of alternative tillage or no-tillage practices that can support additional crop yields, row crop or forage, without causing soil loss, is important to investigate. This demonstration certainly suggests that subsurface tillage practices should be investigated further in SW PA as well as in other "topographically challenged" areas.

Don Fretts
Fayette County

Pest Management:

INSECT ALERT

The following insects can be active during this time period. This does not mean they have been seen in the State, but it is the period of time when they can injure crops. Insects that have been reported are shown in bold type and specifics about their management are presented in individual articles. Pictures of each corn insect species, economic thresholds, and scouting guidelines can be seen on the world wide webpage, http://www.fra.cas.psu.edu/.

Corn
black cutworm
European corn borer adults and larvae
flea beetle
slugs
thrips
wireworm		 corn root aphid
garden symphylan
stalk borer
True armyworm		 corn rootworm larvae
grape colaspis
sod webworm
white grub
Soybeans
bean leaf beetle
thrips		 green cloverworm potato leafhopper
Alfalfa
alfalfa blotch leafminer
Potato leafhopper 		Meadow spittlebug
Spotted alfalfa aphid		 pea aphid
Small Grains
cereal leaf beetle
True armyworm 		corn leaf aphid English grain aphid

Corn Rootworm Larvae - Most areas of the state are in or past the egg hatch period. In southern warmer areas some larvae should be reaching the third instar and causing significant feeding injury to corn when populations are high and the field is untreated. See Tables 1 and 3 for degree day information for your area. By early July, some lodging should become evident, particularly following a rainstorm with high winds.

European corn borer - The first generation flight should be nearing completion in warmer areas of the State and about 75% complete in low areas of central Pennsylvania. Northern areas should be at or slightly beyond 50% completion of the flight. Injury symptoms should be evident in fields with high populations (typically those fields that were planted early in the area). The degree of injury to the field will depend on how many of these small larvae survive to tunnel into the stem. If the economic threshold is exceeded, an insecticide treatment should be applied before the plants are too large to get a sprayer through and before larvae have tunneled into the stem. A granular insecticide formulation will provide the best protection against first generation injury. Fields planted to Bt-corn hybrids should not show any evidence of injury by the pest, although 1 to 7% of plants in a Bt-corn hybrid field may not have the Bt gene. If more than 7% of the plants show injury symptoms in a field planted to a Bt-corn hybrid, consult your seed dealer and have them check the plants for the presence of the gene. The EPA registration requires that all Bt-corn hybrid fields be monitored if resistance is suspected. Failure of the company with the Bt-corn event registration to check these fields can result in a loss of their registration of the product.

Economic Thresholds Values - See the "Field Crop IPM Training and Reference Manual" for methods to calculate specific thresholds which vary based on plant growth stage, yield potential, percentage control, and market value of the crop.

Potato leafhopper - Numbers of adults have increased significantly with the recent storm systems moving across the state. These adults will lay eggs in the stems of alfalfa plants. The nymphs will hatch in a few days and by early July should begin to reach economic levels in some fields. The warm weather will accelerate their rate of development and lead to higher population levels. Watch alfalfa fields closely from 4 to 12 inches of growth. Once the plants have reached 12 inches it is usually better to cut a few days early rather than drive over the field to apply an insecticide. See the Agronomy Guide for Insecticide Options.

Economic Threshold Values - See the Publication, "A Pest Management Program for Alfalfa in Pennsylvania", for specific thresholds.

Threshold Ranges:
For 0 to 4 inch high alfalfa - 0.2 to 1.0 leafhoppers per sweep
For 5 to 8 inch high alfalfa - 0.3 to 1.7 leafhoppers per sweep
For 9 to 12 inch high alfalfa - 0.8 to 5.0 leafhoppers per sweep

Slugs - Both mature and immature stages of slugs can be found in corn and soybean fields in the state. The warm weather should help most fields keep ahead of their feeding injury; however, a few late planted soybean and corn fields may be susceptible to injury. Watch late planted soybeans and corn fields, particularly those planted no-till, for slug feeding. If slug feeding is significant as the plants begin to emerge, a broadcast treatment of Deadline MP at 10 lb per acre should be considered. Remember soybeans are particularly susceptible to slug injury because the growing point is above the cotyledons. Plants consumed below this level will die. Once plants are emerged, follow the listed economic thresholds in making treatment decisions.

Economic Threshold Values: 50% of leaf area removed per plant and plants are less than V6 (6 leaves with the collar showing outside whorl).

Stalk Borer - Movement of stalk borer larvae from grasses in adjacent fence rows and waterways should be underway in southern and central Pennsylvania. Farmers applying a post-emergence treatment on orchardgrass in young corn fields may want to consider mixing an insecticide with the herbicide to protect against stalk borer injury, if they have had a history or suspect stalk borer larvae are in the field. If stalk borer larvae are present, they will move from the orchardgrass host to young corn seedlings as the grass begins to dry down. See the Agronomy Guide for insecticide options and the "Field Crop IPM Training and Reference Manual", for economic thresholds (This manual is available from Dennis Calvin, Dept. of Entomology, 501 ASI, Penn State University, University Park, Pa. for $75.00).

Economic Thresholds Values - See the "Field Crop IPM Training and Reference Manual" for specific thresholds which vary based on plant growth stage and market value of the crop.

V1 - 4 to 10% of plants showing injury symptoms
V2 - 5 to 12% of plants showing injury symptoms
V3 - 6 to 15% of plants showing injury symptoms
V4 - 6 to 16% of plants showing injury symptoms
V5 - 7 to 17% of plants showing injury symptoms
V6 - 14 to 34% of plants showing injury symptoms
V7 - Plants are usually safe by this time

Dennis Calvin,
Entomology


Precision Vision:

DOES A GIS HAVE A PLACE IN MY FARMING OPERATIONS?

In the June 12 Field Crop News, I wrote an article called Farm Mapping - Who Needs It? I talked about data - spatial data and attribute data. And I talked about the need to have a common coordinate system so that all this "data" could be stored in a geographic information system, a "GIS", so that a person could identify a specific location in a field and "look" down through the various maps of spatial data. This looking down through these various data layers is sometimes called "piercing" the data. A person using this GIS technique can pull up all the data in the data bases that relates to that one specific location, and make some informed decisions about a management operation. This management decision can be made based on having all of the information in the data bases available in addition to a set of coordinates that a Global Positioning System (GPS) can use to take the planter/sprayer/manure spreader/crop scout/ or nutrient applicator to that location in the field. Do this for every point in the field and you have the ability to vary the crop inputs to the field depending on the variability of all the data describing the crop and the soil conditions. I'm making a big leap now. What I have been leading up to in the last four or five articles in the Field Crop News is to lead you to understanding the concepts of precision application or precision farming. In order to do this you need a GIS. So let's talk about GIS computer software and using these "GIS"-like programs that use maps and data.

If you remember from my last column, I said that a GPS is a pretty simple instrument - it only tells you where you are. Sure, there is a complex technical background to the hardware and software but it still essentially tells you where you are (or what direction to take to get to your destination). It does some operations with the data tables and maps stored in memory: Well, a GIS really only outputs two things: It prints out data tables and it prints out maps. There are four sections to a GIS.

  1. A section that takes in data and allows all the maps to be geographically coordinated.
  2. A section that manages the maps and data tables.
  3. A section that allows analysis of the data (maps and associated attribute data)
  4. A section that provides output of printed or digital maps and tables.

Three of the sections just do housekeeping and maintenance. The third section is what is interesting. This is the analysis part of the GIS. The GIS does what Joe Berry, a professor at Colorado State University, calls "map-a-matics" or "map algebra". Consider the GIS to do with maps, what you did with your calculator with numbers, you can multiply, divide, add and subtract, and maybe do exponentials. A GIS can add, subtract, multiply, and divide maps of data, and generate a new map as an answer, just like you got an answer to your numerical math. Now a GIS can do this map-a-matics several different ways:

  1. Query or ask questions of the data bases
  2. You can ask questions of the data bases with reference to certain locations in maps.
  3. You can ask questions about location characteristics of the various maps.
  4. You can ask the GIS to make a certain map of specific information you in which you are interested.

For example, if you are a farmer or crop consultant: You can take a single map stored in the GIS, and if you have a point or area around which you want to establish a zone of a certain width, such as a fence or irrigation pond, you could make a map of the zone. That is what we call buffering. Where a farmer could use GIS buffering is when you are spraying herbicides and have wind drift. You want to have a 500 foot buffer downwind of the last row of apple trees or the edge of a corn field. You could set a 500 foot buffer and the GIS would map the protection buffer around the field or orchard and show you the potential impact of the spray on anything in the buffer zone map.

A GIS can do another operation, it can overlay one map on another, and create a third map that combines the characteristics of the two. You could ask it to only show you the areas where the pest map showing leaf hoppers are in corn fields. The resulting maps would only show the pests in the corn fields. You could have a map of pH levels and you could multiply that pH map by another map of values, such as a soils productivity index to get a third map of value of addition of lime to the field in relation to crop market value. That is "map algebra" using overlay operations.

A GIS can do neighborhood or proximity functions. For example, you might have a map of grain elevators and you have a series of rented farm fields around the county. (You are a rich farmer). You could ask the GIS to show each field that you farm, and also the closest grain elevator to each corn field. The resulting map would combine only your corn fields and the closest grain elevator.

A GIS can do another really interesting function. Consider that you have a large field and you want to establish contours to decrease soil erosion. If you had a map of elevation points from a GPS survey or a government survey of digital elevations, you could generate a map that would show the path of each contour strip that had an elevation difference of 10 feet of drop between contour strips, or you could say to the GIS to generate a contour map so that the minimum width of a contour strip would be 40 feet, so you could combine the wheat with a 40 foot header. The resulting map would show the positions of the contour strips so you could always harvest with a 40 foot header. Or you could say that you don't want the distance between two contour strips to be more than 20 feet to minimize soil erosion if the field slope is more than 8 percent. The GIS can do all those calculations and generate the contour plot for you.

A variety of GIS software packages are available for the farmer. Specialized packages that can make simple maps of a farm, keep farm financial and crop records, pesticide records, and can print tables and simple maps, can be purchased for as little as $400 to $500. The more generic GIS type viewers that can do more complex operations like I have described above cost from $1,000 to $2,500. The ultra-complex GIS packages that are used for research cost from $3,000 to $10,000.

You don't need a Global Positioning System (GPS) to operate a GIS. The GPS only give the farmer a way to locate certain data that can be put into a GIS, and if you are going to do your own crop scouting or storing yield maps from the combine yield monitor, then you will need a GPS in addition to the GIS. The GPS can be used with the GPS to make maps of your own farm and to bring the maps into conformance with the proper latitude and longitude and to make sure all the maps will overlay each other.

There are a variety of suppliers of farm oriented GIS software packages. Most of the popular farming magazines and precision agriculture magazines will provide advertisements for GPS and GIS vendors. Here are some suppliers of farm GIS mapping packages.


Insert for Field Crop News for Precision Vision, by David Wagner
Listing of Farm GIS Software Packages

Reprinted with permission from @gInnovator newsletter "for early adopters of agricultural information technologies" published by Successful Farming magazine. For monthly subscription information call 800-564-4005 and for daily online version see http://www.agriculture.com/technology

1. Ag-Chem Equipment Co. Inc., 5720 Smetana Drive, Minnetonka MN 55343 phone 612-933-9006 fax 7432 web http://www.agchem.com SGIS - SOILECTION software suite develops recommendations and makes applicator maps and "as-applied" maps. FieldSurvey and FarmHMS modules add field sampling, navigation, and yield mapping. Contact Ag-Chem for pricing.
2. Ag Leader Technology, 1203A Airport Road, PO Box 2348 Ames, IA 50010; phone 515-232-5363 fax 3595 web http://www.agleader.com Precision Map 2000 v3.2 ($300): makes Ag Leader yield, moisture, and elevation maps (also imports other data formats), as well as site-verification maps and application maps (using Ag Leader monitor and GPS products). Sampler CD available.
3. Agrem, RR 1 Box 13, Anchor IL 61720 phone 309-723-3231 fax 6089 web http://www.ice.net/~agrem/ Agrem Map32 ($1,000): does yield mapping, field sampling, boundaries, navigation, etc. and imports related data. Does not control variable rate applicators.
4. Agri-Logic, Case Corporation, 7100 South County Line Road, Burr Ridge IL 60521 phone 800-444-8214 fax 630-789-7174 web http://www.agrilogic.com Instant Yield Map v3.2 ($195): yield data viewing, archiving, mapping. Instant Survey v5.0 ($395): adds GPS data interface, multi-layering, and integrates with Instant Crops. Pocket Survey v2.0 ($295): sampling/scouting with Handheld PC
5. AGRIS Corporation, 300 Grimes Bridge Road, Roswell, GA 30075 phone 800-795-7995 or 770-587-3324 fax 770-643-2239 web http://www.agris.com AgLink Basic, ($495) Advanced, ($995) Professional v5.1 ($3,000): various levels of yield mapping, GPS field data collection, and data analysis for farm-level and ag retailer use. DOS FieldLink ($2,000): controls variable rate applicators. AgBrowser (free download or $25): for Ag Leader and Case yield monitor data.
6. Agronomy Service Bureau, 768 State Hwy CC, Oran, MO 63771 phone 800-791-8662 fax 573-262-2290 web http://www.asb1.com AgInfo v2.0 - software directed mainly to ag suppliers and consultants. Functions include yield maps, field sampling, making recommendations, and application maps. Can import related data. Pricing varies with software level.
7. CenTrak LLC, 210 E. Kiowa Ave., Ft. Morgan, CO 80701 phone 800-678-2567 or 970-542-0200 fax 1850 web http://www.agritrak.com Agritrak Pro, ( for map registration), Agri-Trak (variable rate application maps) and Scout (zone sampling, navigation) modules require MapInfo (runtime or Professional) and other software (Vertical Mapper, Adobe PhotoShop). Call for function-specific pricing information.
8. Farm Works Software, 6795 South State Road 1, Hamilton, IN 46742-0250 phone 800-225-2848 fax 219-488-3737 web http://www.farmworks.com Farm Site Combo v5.20 ($500): field record keeping and GPS-based mapping with layering capabilities. Includes FarmSite Mobile for GPS data collection and variable rate control. Also: Site Pro (for ag advisors) and Quick Yields (free) yield mapping.
9. Farmers Software, 800 South Stockton, Suite 2, Ft Collins CO 80524 phone 800-237-4182 or 970-493-1722 fax 3938 web http://www.farmsoft.com Red Hen Systems FarmHMS v1.0 ($1,495): field mapping software (requires MapInfo Pro $1,095). FarmGPS v1.55 ($895): runtime or FarmGPS Pro ($595): sampling, boundaries, and navigation software. Imports related data (requires MapInfo).
10. GeoFocus, Inc., 1155 NW 13th Street, Gainesville FL 32601 phone 800-388-4724 fax 352-336-6822 web http://www.gfocus.com AgTrac ($2,500): ag interface to ESRI ArcView: "menu-driven tools for database update; wide range of analytical tool; full integration of GPS data collection; weatherproof vehicle-mounted GPS Yield Data Collectors (Goat and Chameleon) for citrus etc crops. Demo available.
11. GIS Solutions Inc., 2612 Farragut Drive, Springfield IL 62704 phone 217-546-3635 fax 3839 web http://www.gis-solutions.com AgView v1.7 ($2,495): does yield mapping and provides field-based variable rate application using input prescription and GPS data. Options are AgView VRA ($1,995): variable rate only, and AgView Mapping ($1,495): mapping only.
12. ProMap Corporation, 1531 Airport Road, Suite 2, Ames IA 50010 phone 515-233-3311 fax 4575 web http://www.promap.com PMCmap v2.40 ($1,100): desktop GIS for mapping yield, soils, and related field data. PMCpro v2.4 ($1,800): offers comprehensive field analysis and data automation. PMCnav v1.2 ($800): integrates GPS data and variable rate control.
13. RDI Technologies, Inc., 300 Highway 23, Suite 1, Spicer MN 56288 phone 800-221-7348 or 320-796-0019 fax 0048 web http://www.rditech.com AgMAPP Farm Edition ($295): yield mapping, AgMAPP 4.0 ($3,500): adds GPS capabilities; AgMAPP GIS v2.01 ($4,095): adds analysis and application maps; includes full MapInfo Pro and runtime Access '97. Modules ($995) include variable rat e application, sampling/scouting with GPS; and TestPlots ($2,500).
14. Rockwell Ag Systems, Dept 120-130, 350 Collins Road NE, Cedar Rapids, IA 52498 phone 800-321-2223 fax 319-295-5420 web http://www.cacd.rockwell.com/bus_area/ag_sys/index Vision Viewer ($395): basic GIS software for on farm use including yield mapping and field data collection and navigation. Vision Professional v4.0 ($4,950): for advanced farmers, ag retailers, and consultants. Does yield mapping, GPS data collection, and advanced GIS capabilities including spatial analysis and layering.
15. Software Solutions Integrated (SSI), PO Box 380, Shelbyville IL 62565 phone 800-752-7912 fax 217-774-2204 web http://www.ssinews.com Agvance v2.01 ($2,990): maps yield and other imported field data, and prepares prescriptions (does not collect GPS data or control variable rate equipment). Targeted for ag retailers, it integrates with Agvance Planning and Blending software.
16. SST Development Group, Inc., 824 North Country Club Road, Stillwater, OK 74075-0918 phone 405-377-5334 fax 5746 web http://www.sstdevgroup.com SSToolbox v3.0 ($5,995): comprehensive mapping and analysis software. Functions include yield mapping, GPS data collection (sampling, boundaries), developing prescription maps, and importing ancillary data. SSToolkit v3.0 ($1,995): basic and intermediate level software (does not make prescription maps).

David Wagner,
Ag & Bio Engineering, Precision Ag


Agents Corner:


ADAMS COUNTY

As I write this report for the week of June 22, it is not easy to quantify growth and development in this county! Moisture conditions, combined with soil types, causes variability in crop conditions. There is a pocket in the west part of the county without abundant rainfall. Powerful fronts brought cloudbursts and tornado damage in the last month to the central and northern part of the county. Growers reported hail four times so far this year. Heavy rains caused soil erosion and some fields required replanting.

Corn growth ranges from 5-6 leaves and under 12 inches to early planted corn that is over 2 feet tall. Earlier this month, I had a complaint on the unevenness of corn growth. I also have observed this at on-farm plots. Soybeans have not been developing rapidly due to dry soil conditions, followed by moist periods that have cool weather. Wheat harvest for grain has not started, but oats have been cut for straw. Second cutting of grass hay is now occurring.

Concerning pests, there are no major complaints of potato leafhopper in alfalfa. Some growers had difficulty getting early post treatments on due to the wet spring. Because of heavy rains earlier this spring, there may be some interest in sidedressing nitrogen, with some corn looking chlorotic.

We experienced a nice shower last night. Looks like the outlook for the week is increasing temperatures, a benefit for the warm season crops.

Mena Hautau
Berks County

CRAWFORD/ERIE COUNTIES

We're doing fairly well in Northwestern Pennsylvania. We generally have not had an over abundance of rain, but most crops have received enough that they are looking pretty good.

Forage crops came off in good shape and a little earlier than normal. Obviously, hay crops taken off in the later half of May were still fairly high quality, although they were maturing rapidly. Hay crops harvested in June were not only poorer quality due to relative maturity, but also typically got rained on a little after mowing due to scattered showers. Leafhoppers apparently arrived towards the middle of June but have yet to reach threshold levels. Second crop alfalfa is coming along fine. Some second crop grass just came off and a considerable amount of other second crop will involve a June cutting date in many cases.

Some limited but welcomed moisture (and heat!) made a big difference in the corn and soybean crops. Many stands were struggling with uneven germination and emergence, but the showers helped considerably. The annual weed flush was certainly late and seemingly less intense than usual. Herbicide failure due to delayed incorporating/ activating rains was not too significant. Some significant cutworm damage was observed. The limited acreage of early planted (late April) corn looks great and has progressed past the sidedress stage. Most of the corn acreage however is just getting to the sidedress stage. Soybean stands are generally just reaching the two trifoliate stage as the battle to make first crop hay and get corn planted delayed the soybean planting progress. All in all, the corn and soybean crops are looking pretty good. However, some prolonged and steady rains to replenish soil moisture reserves would certainly be welcomed.

Harvesting of winter grains is just getting underway and yields are generally looking very good. Again, timing is a bit ahead of normal. Oats that were planted early (on time) are progressing very nicely too. However, with the heat wave of the last week or so, prospects for some of the later planted oats are not so great.

Joel Hunter
Crawford County

DAUPHIN COUNTY

The unique weather patterns this spring seem destined to continue. An extended dry spell was followed by much needed rain. Currently we are in the period of overcast weather with frequent spotty showers. This is making hay cutting difficult.

Overall, crops continue to be about a week ahead of normal. Most of the early corn and the majority of the soybeans have been planted. Some farmers held off planting beans during the dry period because of emergence concerns. The emergence of corn and soybeans has been very good overall. Weed control in some no-till fields has been a challenge.

For the most part, the weather permitted the harvesting of an excellent first cutting of both alfalfa and grass hay. Most hay was harvested during the "no-rain" window.

Second cutting of alfalfa is progressing real well and some hay will be cut this week. There has been minimal evidence of potato leafhopper in alfalfa fields, with only one field that I visited showing some damage.

Barley harvest started during the second week of June in lower Dauphin County and this past week in the upper part of the county. The wheat crop is ripening rapidly and harvest most likely will begin by the end of the month

Jerry Martin
Dauphin County

FAYETTE COUNTY

Producing crops in the southwest is really a challenge this year. For the past two weeks of this writing (6/22/98), very little field work has been done due to the weather. About 50% of first cutting hay is still to be harvested, growers who are trying to cut barley, in between the rains, are having a really difficult time, and weed outbreaks in corn fields are getting ahead of post emergence herbicide applications.

The positive side is the oats crop looks good and the wheat that is still standing is maturing nicely. Also, hay crop producers that harvested in that May window of opportunity, have a really good second cutting ready for harvest.

Don Fretts
Fayette County

LYCOMING COUNTY

Central PA is experiencing generally good growing conditions at the moment. Currently we have ample moisture for a crop but the almost daily thunderstorms are playing havoc with forage harvesting. A few brave producers are attempting to harvest 2nd cut alfalfa especially in those fields where the economic threshold for leafhopper is being reached. Yields for the second cutting will be average or higher (compared to last year when we couldn't find something to mow!). Scouting for leafhopper is in full swing with the thunderstorm activity. The last of the first cutting grass/clover hay is coming off hill farms and is poor quality now. Soybeans are looking good in most fields and have grown out of the soil crusting problems we experienced in mid-May. Average bean height is in the area of 4 to 8 inches. Annual weeds are growing rapidly in many fields with growers still playing catch-up with their post- emergence. spray program.

Corn growth in the area ranges from chest high to 3" with most in the 15" range. Most of the yellow corn seen two weeks ago has since recovered due to more sunlight, fewer wet spots, and side-dressed nitrogen applications that have recently been applied. Some yellow corn seen recently was due to early corn rootworm larvae feeding. One continuous corn field observed with a no-insecticide check strip, showed a 3" size difference compared to that on either side. Earlier accumulation of DD has brought earlier emergence of this pest and when fields were late planted (or replanted in some cases), the pruning is having a more severe impact on growth and potential yield. Furadan applications are being made on some farms as a rescue treatment. There are also more fields then usual in this region that are spotty and thin. I suspect some are due to cutworm and wireworm damage combined with poor germination in fields that were droughty in late May.

Hopefully reasonably good growing conditions will make up for the grain prices that seem to be on a downward slide.

Tom Murphy
Lycoming County

MIFFLIN/JUNIATA/PERRY COUNTIES

Our long dry spell ended as dry spells usually do, with some rain, from 3 to 6 inches depending on your location. The biggest problem associated with the dry soil conditions seems to have been with uneven crop emergence. Corn and soybeans fields have plants up to five inches tall with other plants a few feet away just beginning to emerge. Many of these late emerging plants are showing herbicide damage.

There are more fields than normal being treated with post-emergence herbicides this year in our area. Some fields that did not get enough rain to activate pre-emergence herbicides need broadleaf weed control. Also fields that had corn and weeds emerged before any herbicides could be applied are now being treated with Accent and Banvel or some other mixture. Growers with Roundup Ready soybeans are beginning to make their postemergent Roundup applications. Soybean populations are acceptable, but many fields still show the wide range of plant heights mentioned earlier.

Alfalfa fields that were harvested early are starting to push out buds but plant heights are much shorter than normal. Some growers tell me they plan to harvest on schedule in order to have high quality forage from this second cutting. Potato leafhoppers are present but seem to be well below threshold levels in the established stands. Pastures that had been turning brown are rebounding quickly since the past weeks' rain.

The wheat fields are beginning to show some serious disease problems. Septoria and sooty mold seem to be the two most serious diseases, while lodging from recent thunderstorms will add to harvest difficulties. The oats fields are headed and seem to be doing fairly well.

Greg Hostetter
Juniata County

YORK COUNTY

As of June 22, due to unfavorable weather, there is still some barley to be harvested. Early yield reports, probably because of the Barsoy variety, were low. Yields as high as 90 bushels/ac were reported. I've noticed a little bit of head scab on some wheat. Second cutting alfalfa is now in progress. Corn stands and heights are variable. Some fields look picture perfect. Others field have a lot of variability. Planting date seems to be an important factor. I have observed many fields with faint yellow streaking on the leaves. One explanation suggested was triazine injury; the corn plants not being able to metabolize the chemical fast enough, especially under week long cloudiness. I'm sure other reasons may also be proposed. Soybeans are beginning to get some size now. Weed control? Hard to tell now in this day and age, isn't it. You drive-by now and you wonder if you're seeing a weed control failure or if they're Roundup Ready awaiting application!

John Rowehl
York County

Degree Day Accumulations:

1998 DEGREE DAY ACCUMULATIONS

To track corn and insect development, compare the 1998 cumulative degree-days shown in Table 1 to the required values in Tables 2 and 3. Choose a location that is closest to your site when making a comparison.

Table 1. Cumulative Degree Days for Corn and Insects for the Period Ending June 22, 1998
  Corn Insects
County Location 1998 30-year ave. SCM/SB AW BCW CRW ECB
  50F 50F Diff 40F 48F 50F 53F 55F
Erie Waterford 675 592 84 1619 950 805 614 503
Crawford Meadville 720 635 85 1714 1016 867 668 552
Mercer Mercer 724 636 88 1733 1026 876 676 559
Bradford Towanda 714 634 80 1723 1016 866 666 548
Lycoming Montoursville 763 680 84 1839 1093 938 728 605
Tioga Mansfield 669 589 80 1628 951 805 612 501
Susquehanna Montrose 612 534 78 1532 878 736 552 446
Butler Butler 766 676 91 1833 1094 938 730 607
Indiana Indiana 759 669 90 1832 1090 934 725 603
Lawrence Lawrence Jct 726 642 84 1715 1019 871 672 555
Blair Martinsburg 730 640 91 1791 1058 903 697 577
Centre State College 727 640 87 1770 1045 891 688 569
Columbia Bloomsburg 774 689 85 1875 1114 957 745 619
Clearfield Curwensville 721 634 87 1747 1031 880 678 560
Dauphin Elizabethville 802 712 90 1946 1162 1001 782 653
Bedford Bedford 785 691 93 1913 1143 981 764 638
Mifflin Belleville 776 687 89 1881 1120 961 748 623
Northumberland Sunbury 805 716 88 1941 1159 999 781 652
Lehigh Trexlertown 818 728 90 1995 1191 1028 805 673
Schuylkill Hegins 772 685 87 1884 1118 960 747 621
Westmoreland Greensburg 760 668 92 1842 1097 939 729 606
Somerset Somerset 665 568 96 1664 968 817 621 509
Washington Washington 809 712 97 1942 1169 1006 787 659
Franklin Chambersburg 843 747 96 2052 1234 1067 838 704
York York 869 773 96 2122 1279 1107 874 735
Lancaster Ephrata 817 725 92 2002 1196 1031 807 675
Berks Hamburg 829 738 91 2014 1205 1040 817 683
Corn degree-days based on a May 1 starting date. Insect degree-days based on a January 1 starting date.


Table 2. Cumulative Degree-Days Required for Insects to Reach key Periods for Scouting or Management
  Maturity rating (days)
80 90 100 110 120
50% Silking 1100 1150 1250 1300 1400
Black Layer Formation 1900 2100 2300 2500 2800


Table 3. Cumulative Degree-Days Required for Insects to Reach key Periods for Scouting or Management
  Stalk Borer Alfalfa Weevil Black Cutworm* Corn Rootworm European Corn Borer Seed Corn Maggot
Adlt Emrg 5% Hatch 1st Gen 2nd Gen
SB AW BCW CRW ECB1 ECB2  
Initiation 1400 300 91 1283 380 WCRW** 558 1550 450***
Termination 1700 500 430 2253 478 NCRW** 1228 2045  

*Degree-day accumulation should begin at first moth capture in a black light or pheromone trap.
**These values represent degree day accumulations for optimal timing of Furadan 4F post emergence applications. WCRW-Western Corn Rootworm, NCRW-Northern Corn Rootworm
***This number of degree days represents the number of degree days required from plowdown of green vegetation until it is safe to plant corn or soybeans and avoid seed corn maggot injury.

Dennis Calvin, Entomology

William S. Curran
Associate Professor Weed Science
email: wsc2@psu.edu

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