September 5, 1997 Vol. 97.11
IN THIS ISSUE:
Production:
Most of PA had limited rainfall for most of the growing season. This fall would be an excellent time to do some deep tillage on fields where compaction is suspected. This years small grain fields should be tilled now. Dry soil shatters and more of the compaction zone will be destroyed. Deep tillage tools on 30 inch centers leave too much compaction unresolved when the soil is wet. Silage corn fields could be done right after silage harvest. Watch out for soil erosion on these fields. Spin on a fall grain - wheat, barley or rye for cover. A light discing will provide sufficient soil to seed contact to permit satisfactory cover crop establishment. Farms located south of State College could benefit by adding 20 lbs. of hairy vetch to the small grain seed. This will provide some nitrogen for next years corn crop or extra protein if you chose to chop the mixture next spring for additional feed. Our experience would indicate most years little contribution from the hairy vetch can be expected when seeding from State College north after September 10.
If your crops looked uniform throughout the drought stress periods of 1997, you will probably not benefit much from deep tillage. If compaction problems are suspected or were observed during the growing season this would be an excellent fall to address these with deep tillage.
Remember! If you are going to spread manure or apply lime - do it before you deep till. Heavy loads after deep tillage will cause recompaction deeper and worse than when you started.
Lynn D. Hoffman
The main benefit of planting cover crops is generally assumed to be soil conservation. However, cover crops also can play a major role in conserving nitrogen. Nitrogen is extremely mobile in the soil, it can be lost by leaching in well drained soils, by denitrification in poorly drained soils or in runoff in any type soil. These losses are a double concern because they can mean a significant economic loss of valuable nitrogen and they can result in pollution of ground and surface water. The greatest potential for loss of nitrogen is in the fall and early spring when rainfall is usually higher and our soils do not normally have a crop growing on them to take up nitrogen.
This loss of nitrogen is of particular concern on fields where manure is spread. Only part of the nitrogen in manure is inorganic and thus immediately available like fertilizer nitrogen. The rest of the nitrogen in manure is organic nitrogen and becomes available slowly over a period of time. This slow release of nitrogen is good while the crop is growing on the field, however, release continues even after the crop is no longer taking up nitrogen. For example corn takes up very little nitrogen after pollination.
Release of nitrogen begins again in the spring before the crop begins to take up nitrogen. Thus, there is a high probability of nitrogen loss in the fall and spring when rainfall is typically higher and there is no crop growing to utilize the nitrogen. Also, unlike nitrogen fertilizer, which we apply very near to corn planting or better yet as a sidedressing, manure is usually applied in the fall and/or early spring or all through the fall, winter, and spring. With manure applied other than right before planting there is an additional risk of nitrogen loss. In this case we can lose both the inorganic and organic nitrogen from the manure.
The best way to reduce these loses of nitrogen is to avoid fall and early spring manure applications as much as possible and to have a crop growing on the soil as much of the time as possible. While avoiding fall and early spring manure applications may be a good idea, it has some serious practical limitations on most farms. Therefore, growing cover crops to utilize this manure nitrogen in the fall and spring when we would not normally have a crop growing is especially important.
The following information from the Penn State Agronomy Guide illustrates the effect of time of manure application and cover crops on recovery of manure nitrogen.
| % available N | ||
| Time of manure application and incorporation, | Poultry Manure | Other Manure |
| Applied in the spring near to planting and incorporated the same day | ||
| Applied previous fall or winter with no cover crop | ||
| Applied previous fall or winter with a cover crop as a green manure | ||
| Applied the previous fall or winter with cover crop harvested for silage | ||
In this table, the first line for manure applied in the spring and incorporated immediately provides a reference. This is the maximum nitrogen availability we can expect from manure. With manure applied in the fall or winter with no cover crop, the recovery of nitrogen is only 20% of that potentially available from poultry manure (15 vs 75%) and only 40% of what is potentially available from other manure (20 vs 50%). With a cover crop the recovery is over 3 times higher than with no cover crop for poultry manure (50 vs 15%) and twice as high for other manure (40 vs 20%). The last line in this table is the nitrogen recovery from fall or winter applied manure where the cover crop is harvested for silage. The recovery by the current crop is the same as if there were no cover crop, however this nitrogen is not lost, it is in the silage and will become available when the silage is fed and the resulting manure is spread. Thus, in addition to conserving soil and adding to soil organic matter, cover crops can significantly improve the recovery of nitrogen from manure and reduce nitrogen loss to the environment.
Douglas B. Beegle
Harvesting corn that has fallen down can be a real frustration, especially when you're trying to make time during the busy harvest season. Like one farmer recently told me, when there are two tractor trailers waiting to be filled at the edge of the field and the weather is uncertain, you don't want to have to be running the combine at one mile an hour because the corn is down. So its not surprising that standability is an important consideration for many farmers in assessing their hybrids and other management practices.
Early fall is an excellent time to assess lodging problems in corn for two reasons. First, you can make harvest plans that take into consideration fields that might have down corn problems and secondly you can learn what caused the problem to avoid it in the future.
If you identify fields that have a potential lodging problem early in the fall they should be harvested as early as possible to avoid more serious problems and increased harvest losses. Down corn is more subject to animal damage and ear molds.
Corn lodges for four basic reasons: root lodging, stalk rots, European corn borer damage, or corn rootworm damage. Each of these could be a factor in fields this fall, but the management to avoid these problems in the future is different so it pays to identify the problems before harvest.
Root lodging occurs when a poor root system develops, the soil gets wet in the fall and windy conditions uproot the crop. The poor root development can be associated with some hybrids and is also associated with dry conditions in July, as many areas experienced this year. Generally the root system is not injured but is small. This problem can also be present in wet years when corn root systems are relatively shallow. Most seed companies provide a root rating for their hybrids. If the root lodging is more than an isolated case, consider switching to a hybrid with stronger roots.
Corn rootworm damage appears similar to root lodging in that the plants are sometimes uprooted, but often this is accompanied by the "goosenecked" plants that lodged earlier in the season. Roots will also shown signs of corn rootworm injury; chewed off roots or root tips. Often, you may have to wash the root system to find these symptoms late in the season. Corn rootworm damage has been common this year but usually only in corn following corn. If this problem is common, consider more crop rotations or reevaluate your soil insecticide program.
Stalk rot also can be a common cause of down corn, especially following a stressful late season with cloudy weather, leaf diseases, or nutrient deficiencies. Stalk rot usually causes the stalk to bend and break below the ear and is caused by one or more fungi weakening the tissues in the lower portion of the stalk. Often the pith in the lower stalk will be nearly gone and discolored- either pink or gray. Sometimes the stalk will appear black as well. Stalk rot is often associated with gray leaf spot, so selecting hybrids with good tolerance to gray leaf spot may be necessary. Stalk rot can also be related to low soil potassium levels or excessive plant populations. Stalk rot can also be managed through hybrid selection, since hybrids also vary in their resistance to various stalk rots.
European corn borer damage is another cause of down corn. Often plants will break over at or below the ear. There will usually be signs of corn borer waste or "frass" near the break and splitting a few stalks will usually reveal signs of the corn borer tunneling. All fields will have some corn borers, but when you find more than 1-2 borers per plant, this is often associated with a significant lodging or a yield loss problem. Damage is often most severe on late planted fields. Management of this pest is best accomplished using Bt hybrids on high risk fields.
If you encounter some down corn this fall, take some time to evaluate the problem or at a minimum take a few plant samples to share with your crop advisor. Careful identification can help to get the problem corrected and avoid blaming the wrong cause.
Greg Roth
Pest Management:
Corn Rootworm Adults - Keep an Eye on late planted corn fields that are just silking. Since most corn fields are beyond silking, these fields will attract large numbers of beetles which may do enough silk clipping to interfere with pollination. Although, these fields will probably not reach physiological maturity by the first hard frost, the more grain that can be made the better the silage quality. Besides their effect on yield potential, corn rootworms attracted to these fields may lay high numbers of eggs that will hatch into larvae next year and cause economic damage. Therefore, a beetle count during the silking period can provide information on the need to use a soil insecticide next year or rotate to a crop other than corn.
European corn borer - Second generation eggs are only now being laid in corn fields in central Pennsylvania. Larvae resulting from these eggs will require three to four week before they reach the fourth instar and tunnel into the stem or ear shank. Because egg laying is late this year, the impact of this pest on grain weight will be minimal. However, larvae may tunnel into the stem and ear shank where they can contribute to ear droppage and stalk lodging. Early harvest of grain or harvesting the plant as silage is the best way to minimize losses from ear droppage and stalk lodging. Late planted fields that were silking at the end of August and beginning of September in central Pennsylvania will have the highest ECB infestations and the highest risk of ear droppage and stalk lodging. For warmer areas of the state (southeast east, southwest and south central counties), egg laying was about 10 days earlier. In cooler northern counties and counties with high elevations, a second generation probably will not occur this year.
Stored Grain Insects - About 100 insect species are known to attack grain in storage. About six to ten are common in Pennsylvania stored grains. Although harvest is still a ways off this year, it is time to begin preparing grain bins for new grain. How well you prepare your grain bins can determine whether you will develop insect problems. See the article on Preparing for On-farm Grain Storage.
The Pennsylvania Agricultural Statistics Service estimates that 39 million bushels of corn grain are stored on Pennsylvania farms. No statistics are available for soybeans and small grains. They also estimate that there is 6.57 million bushels of corn, 850,000 bushels of soybeans, and 2.285 million bushels of wheat stored in off-farm grain elevators. The value of grains stored in off farm elevator is estimated at $24.3 million, $5.2 million, and $9.5 million for corn, soybeans, and wheat, respectively. Corn stored on the farm has an estimated value of $144.3 million dollars. Statistics from the USDA suggested that 5 to 10% of this grain's value is lost while in storage because of insect feeding and contamination. If true, Pennsylvania on an annual basis looses between $9.2 and $18.3 million to insects that attack grain while in storage facilities.
To prevent losses from insect feeding and contamination, farmers need to use good bin and harvest equipment, sanitation methods, and manage temperature and moisture in the bin. If good sanitation and temperature/moisture management techniques are used, a farmer should seldom have to use an insecticide protectant or fumigant on or in the grain. To understand why these are important management tools, you must first understand insect biology. All organisms including insects require:
If any of these requirements are not met, then an insect cannot survive and/or thrive in the environment. Understanding these basic needs can help us develop methods of managing the pest. For instance, if water is eliminated from an area, then an insect will die within a short time. Now lets think in terms of a grain storage facility. In the facility we place 1,000 of bushels of grain. This is an excellent food resource for insects, particularly if many of the kernels are broken. Also, the moisture content of grain at harvest is usually high enough to provide all the moisture needs of stored-grain insects, and the grain is typically within an acceptable temperature range. Because the grain is sheltered in an enclosed area, it offers protection to the insects as well. Finally, if old grain if left in the bin or in surrounding areas a local insect population is ready to invade, feed, and reproduce. Since most grain bins are not sealed, oxygen is not limiting. Therefore, by harvesting the grain and consolidating it in a storage facility, we have provided insects with an ideal environment to survive and multiply.
What can we do to interfere with this ideal environment? Good grain storage begins with a sound sanitation program. The goal of sanitation is to eliminate sources of food and shelter for insects. Sanitation should be focused on three areas: the bin interior, the bin exterior and surrounding grounds, and harvest equipment. Before storing this year's grain in a bin, remove all of last year's grain. Old grain is an excellent source of insects that can quickly infest new grain placed in the bin. After removing the old grain, remove any sources of grain that may remain on the walls, sweep and wash the walls, floor, and ceiling to remove dust and small grain particles, and if possible remove the false floor and clean up any dust and grain (this can be done on a three year rotation). If the false floor cannot be removed, either fumigate under the floor using chloropicron or drench the area with a registered bin treatment (Reldan, Tempo, Methoxychlor, and synergized pyrethrins, always check the label before applying to make sure all requirements are met). If the grain will be left in the bin for a period longer than nine months, you may want to apply a bin treatment to the walls and a grain surface treatment (methoprene, synergized pyrethrins, Dipel) after the bin is filled (remember, it is important to level the grain surface after filling the bin). After preparing the bin interior, make sure the exterior and surrounding grounds are free of old grain and weedy areas which can harbor insects and other pests. Finally, don't forget to clean the combine. Old trash and grain from last year that collected at the base of augers can harbor insects. Forgetting to clean your harvest equipment can negate all your other sanitation efforts. The first load of grain into the bin may inoculate the remaining grain mass with an insect population and by-pass the insecticide barrier.
Another component of sanitation is good harvesting procedures. Harvest speed and misadjusted equipment can increase the number of broken kernels. Insects can feed more easily on broken kernel, especially immature stages. Also, mold can gain a foothold on broken kernel more easily. Several stored grain insects are attracted to these molds and feed on them, resulting in insect contaminated grain. Through proper harvesting, grain quality is improved and the ability of insects to establish in the grain is reduced. After harvesting, dirty and/or poor quality grain should be screened to remove small pieces of grain and dust that insects use as food. If proper sanitation methods are used, grain placed in the bin should be almost insect free.
However, it will not stay insect free unless other management techniques are implemented over the grain storage period. Stored grain insects can smell grain and will begin arriving at the bin within a short period of time. If an insecticide barrier was established immediately after harvest it will protect the grain into the winter months. However, by spring most of this protection will have been lost. For grain that did not have an insecticide barrier applied at harvest, your fan is your most important management tool.
Most insects grow and develop between temperatures from 40 to 95 F and at grain moistures above 13%. At temperatures below 40 F, insect development, reproduction and feeding stop. At temperatures above 95 F, an insect's rate of development is slowed down, and if the temperature exceeds 120 F for an extended period, insects will die. Insects do not survive and thrive if the grain moisture percentage is below 13%. Therefore, if we can keep the grain temperature below 35 F and grain moisture near 13%, we can prevent insect feeding and reproduction. It is important not to keep grain moisture too much below 13%, because you are loosing grain weight and money. See your fan and bin technical manual for information on drying and cooling requirements. In the fall, the fan should be run once temperatures fall below 40 F to drawn the grain temperature down and to decrease moisture content. To maintain this temperature and grain moisture content, it is important to monitor your grain about once every two months in the winter and once a month during spring and summer.
Another important principle of grain storage is the concept of moisture migration. Moisture migration is a phenomenon that takes place in steel grain bins because of the difference in inside and outside temperatures. When the interior grain mass temperature is low relative to the temperature on the outside bin surface, convection currents are established in the grain mass. This is similar to how rain clouds form. Cool air is heavier and drops in the middle of the grain. As the air is warmed along the bin wall, it rises and picks up water (warm air holds greater amounts of moisture). At the top of the bin along the wall, this moisture condense in the grain. This condensation allows fungi and bacteria to begin feeding on the grain and the grain to begin to germinate. Both processes give off heat, which then increases the grain mass temperature at these sights to a point that insects can develop, feed, and breed. Their metabolism gives off more heat that continues to cause a temperature increase. In the winter when outside temperatures are greater than inside temperature, the convection currents cycle in the opposite direction, dropping moisture in the center of the bin. To avoid the effects of moisture migration, monitoring the grain mass for hot spots and moisture is critical. When hot spots and moisture pockets are found, the fans should be run to reduce temperature and moisture in the bin. By running the fans on nights below 60 F in the summer, insect development can be slowed considerably.
Uniform air movement through the grain mass during aeration is very important. To assure uniform movement, the grain mass should be leveled after the bin is full and a spreader should be used to prevent a column of fine material developing down the center of the bin. Screening the grain will also help. When moving air through a grain mass, the air moves along the path of least resistance. Therefore, a more dense area in the bin will cause air to move around it through the less dense areas. When a column of fine material occurs in the bin, you will not be able to effectively draw the temperature and moisture level down. Thus, this management technique will be ineffective at slowing insect population buildup. Fumigation or grain movement and treatment will be become your only alternatives to deal with an insect infestation. In the next newsletter, I will discuss the future of grain fumigants and protectants.
Dennis Calvin
Soybean and corn harvest are right around the corner and there may still be the need to desiccate weeds prior to harvest. In addition, some opportunities for control of weeds in alfalfa or for control of an old alfalfa sod also exist. One or two changes have occurred within the last year that may help some producers harvest more grain or forage or do a better job in managing their weed problems.
Corn. Certain formulations of 2,4-D are registered for pre-harvest use in corn. Check the 2,4-D label for specific use. Corn must be in the hard dough to dent stage and weeds must still be alive. Application may be made by high clearance equipment, by aerial application, or by hand. The rate range is 1 to 2.5 pints per acre depending on formulation and manufacturer. Do not forage or feed fodder for 7 days after treatment.
Sodium chlorate, a quick acting desiccant used widely in cotton, has a federal label as a harvest aid in both corn and soybeans. Riverside/Terra Corporation as well as several other companies sells at least two different formulations of sodium chlorate. Last season, sodium chlorate was not registered in Pennsylvania or in neighboring northeastern states for use in corn and soybeans. However, Terra Corporation applied for this registration last year. Check with your local dealer/distributor for more information about sodium chlorate use and availability.
Roundup Ultra may be applied up to 3 quarts per acre 7 days or more prior to harvest. Application is made at 35% grain moisture or less and after the maximum kernel fill is complete and black layer has occurred. Application prior to this stage may reduce yield. It should not be applied to corn grown for seed. Although the harvest aid application may reduce corn grain moisture and improve drydown, results may vary. Roundup may be applied as a harvest aid in corn using either aerial or ground spray equipment.
Soybeans. Gramoxone Extra may be used for drying weeds just before harvest in soybeans. Gramoxone will not desiccate black nightshade berries, but Penn State research showed that it will quicken berry drop. For indeterminate soybean varieties, plants must be mature (65% of the seed pods have reached a mature brown color or seed moisture is 30 percent or less). The rate is 12.8 ounces of Gramoxone Extra per acre and 1 quart of nonionic surfactant per 100 gallons of spray should be added. Do not pasture livestock within 15 days of treatment and remove livestock from treated fields at least 30 days before slaughter.
Roundup Ultra may be used up to 6 quarts per acre prior to soybean harvest. This may be a good opportunity to attempt control of perennials such as quackgrass or Canada thistle. For perennial control, be sure that the plants have healthy green leaves at application time. Apply Roundup to soybeans after pods have set and lost all green color (80-90% drop of leaves has occurred). Allow a minimum of 7 days between application and harvest. Do not graze or harvest the treated crop for livestock feed within 25 days of application. The application rate is similar to other Roundup uses ranging from 1 to 3 quarts per acre. Do not use on soybeans grown for seed.
Alfalfa. Roundup Ultra preharvest application in alfalfa is aimed at the control of certain perennials such as quackgrass prior to rotation away from alfalfa. Apply Roundup at 1 quart per acre (maximum rate allowed). Treated alfalfa may be harvested 36 hours to 7 days after application (5 to 7 days will provide better weed control). The alfalfa stand should be actively growing (8-12 inches or more and as close to early bud to bloom stage as possible). Late summer or fall applications are more effective on perennial weeds as well as on alfalfa or perennial forage grasses. Follow-up tillage improves the control of some weeds such as dandelion as well as alfalfa. Plowing the treated forage following harvest or an additional herbicide application may be necessary for complete control of the alfalfa. In addition, adequate spray coverage of the target species within the alfalfa forage may be a concern.
Where this label may have some utility for Pennsylvania forage producers is in the control of certain cool-season perennial grasses such as quackgrass and orchardgrass prior to rotation. Application in the fall is most effective on these grasses. Although application in late spring has traditionally been less effective in controlling most perennial species including alfalfa, this strategy could help those producers that frequently try to capture both that first cutting hay and timely no-till corn planting.
Bill Curran
AGENT'S CORNER
Corn silage harvest began around August 15 for the fields most affected from the drought. Early silage tonnage has been 5-6 ton/acre. Due to the low silage yields and the delayed maturity, most corn will be harvested for silage. With the most recent rains, the stalks have remained green however the whole plant moisture has been decreasing. For corn that is to be harvested for grain, we expect a 50-60% reduction in yield.
Fourth cutting alfalfa has begun. Some fields were showing as much as 15 inches of growth with blossoms and only 25 days since the previous cutting. Third cutting consisted mostly of just clipping the stunted plants.
Haylage supplies are about 50% of normal this year. With some warm days, it may be possible to take a fifth cutting on some fields. Although risky, the extra forage may be worth the possible winter damage.
Soybeans have begun to pod fill. The recent moisture has helped increase bean size. Most fields have experienced spider mite damage this year. We have estimated our county harvest at approximately half of a normal yield.
We also had several small plantings of Bt potatoes, those providing protection from the Colorado potato beetle. Initial observations indicate there was no feeding damage as compared to the non-resistant variety planted as a comparison.
Larry A. Swartz
Adams County
Crop development across the county is variable. Soil moisture conditions as of September 3 are very good in the lower portion of the county, while in the northern area soil moisture levels remain low. To date, limited corn silage harvest has begun with most of the crop still in the pre-dent stage. Silage yields will be reduced dramatically, but overall quality of corn silage will be high due to anticipated grain yields. Grain yields should range from 60% to 90% of expected. Later planted corn (mid June) is extremely slow in development with some fields only pollinating in the last weeks of August. The recent cold snap has producers concerned of early season frost in October.
Our soybean fields continue to fill pods. Wide opinions exist on soybean yield potential with many growers taking a wait and see attitude. I have not seen very many tall bean fields and mites remain a problem across the region.
Forages responded to timely rains in August with good 4th cutting development. Harvesting of alfalfa is widely varied at this time as many growers managed their stands quite differently during the drought. Leafhoppers are gone following what has been described by many as the worst season for damage.
Time will be the final judge on the growing season of 1997; however, based on discussion with sweet corn, vegetable and fruit producers, this is one of the worst growing seasons they can remember.
Paul Craig
Dauphin County
Lebanon producers are busy trying to get fourth cutting alfalfa off to allow enough time for the plants to recover for winter. Applications of potassium should follow to aid in carbohydrate movement to the roots system. New seedings of alfalfa have yet to germinate but should at any time.
Corn is behind for the normal for GDD. According to my figures, Lebanon has had 2350 heat units since April 1 and normally the county would receive 2600 units on the same date. Silage has not begun as of today (9/2/97). Pollination is adequate but not excellent. There was a lot of feeding by rootworm beetles and I have found many females ready to lay eggs. Some silk clipping was within 1/4inch of the ear tip. The staygreen quality is also being affected by spider mites and nitrogen deficiency. Some fields showed a yellowing symptom characteristic of magnesium and after a pH check showed acidic soil. This is common when acidity dips down around 5.
Another possible reason for many nutrient deficiencies is compaction and this year compaction was fairly easy to determine. In any soil management system one should be sure pH is corrected; there is no reason pH should not be maintained even on rented ground. Also, producers need to be keenly aware of nitrogen management and not short change the crop. Corn needs 1.1 lb of actual N per bushel of expected harvest no more and no less!
Soybeans have podded and are filling rapidly. A timely rain during pod fill should help yields. In-determinate varieties are hip high in some cases. Determinate varieties are knee high, but podded well.
Soybean populations are not as high as they should be which has caused more branching. I am anxious to get the results of a population study on two farms. Populations in the plot are 117,000-170,000 and 230,000 and may shed some light on population recommendations.
Producers are also gearing up to spray fall weed control products and kill sod for next spring. In addition, wheat and barley planting decisions are being made with the 1997 Winter Wheat and Barley Performance tests in strong demand.
Del Voight
Lebanon County
Crops in this part of the State are turning out to be a mixed bag this year. Wheat and barley were both good to excellent with some reporting higher than average yields. Oats was not bad but some fields showed light test weights in the most drought stressed areas. Hay yields are down considerably with second crop alfalfa none existent on most farms and third cutting not much better. Alfalfa coming off now is looking good but the almost daily showers are preventing good drying conditions. Lycoming County led the state this year in rainfall deficit since January 1st and it is trying hard to make it all up in the last two weeks of August!
Soybeans are looking fair to good, depending on the site, with a yield prediction in the 75% range. One benefit to the very dry weather is that we haven't been able to find any white mold in soybeans which has been a increasing issue the past five years in low riverbottom fields. Corn is the hardest hit crop. I estimate that 10% of the crop is a total loss, 40% is at half a normal crop, and the balance is half to three quarters of a crop. Many fields are under 7' tall and as can be expected, silage yields will be greatly reduced. As with beans, disease pressure in corn is very light so far, quite a contrast to last year when it was widespread.
On the bright side, the Central Susquehanna Grain Marketing Club has been meeting throughout the year and has put their increased commodity marketing skills to work with the purchase of a number of Corn Option contracts in an attempt to achieve a higher return for their farming efforts. Lately the contracts have paid off handsomely. As a producer, doing well with Options normally means that the Fall cash prices are weak and a win in one area should balance out a loss in the other. The group looks at it as a type of "crop insurance" that they have some control over. Although the group members don't see themselves as "experts" in the marketing field, they will tell you there are opportunities for those who are tuned in to the market and study the forces that affect futures prices. If you want to know more about how the club works or about starting one in your area, feel free to give me a call.
Tom Murphy
Lycoming County
William S. Curran
Assoc. Prof. Weed Science
1997 DEGREE DAY ACCUMULATIONS:
To track corn and insect development, compare the 1997 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 comparison.
| Table 1. Cumulative Degree Days for Corn and Insects for the Period Ending August 31, 1997 | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| > | Corn | Insects | |||||||
| County | Location | 1997 | 30-year ave. | CSB | AW | BCW | CRW | ECB | |
| 50F | 50F | Diff | 40F | 48F | 50F | 53F | 55F | ||
| Erie | Waterford | 1861 | 1843 | 17 | 3354 | 2177 | 1906 | 1535 | 1307 |
| Crawford | Meadville | 1956 | 1973 | -16 | 3497 | 2291 | 2015 | 1636 | 1403 |
| Mercer | Mercer | 1964 | 1968 | -4 | 3519 | 2303 | 2026 | 1646 | 1411 |
| Bradford | Towanda | 1963 | 2012 | -49 | 3501 | 2298 | 2023 | 1645 | 1414 |
| Lycoming | Montoursville | 2063 | 2139 | -76 | 3659 | 2422 | 2141 | 1753 | 1516 |
| Tioga | Mansfield | 1866 | 1865 | 1 | 3363 | 2185 | 1914 | 1543 | 1316 |
| Susquehanna | Montrose | 1751 | 1696 | 55 | 3203 | 2053 | 1786 | 1423 | 1205 |
| Butler | Butler | 2054 | 2089 | -35 | 3660 | 2414 | 2132 | 1743 | 1504 |
| Indiana | Indiana | 2045 | 2070 | -25 | 3653 | 2405 | 2123 | 1734 | 1496 |
| Lawrence | Lawrence Jct | 1965 | 1998 | -33 | 3504 | 2299 | 2024 | 1645 | 1411 |
| Blair | Martinsburg | 1992 | 1983 | 9 | 3580 | 2344 | 2063 | 1679 | 1443 |
| Centre | State College | 1986 | 1998 | -12 | 3557 | 2332 | 2054 | 1671 | 1436 |
| Columbia | Bloomsburg | 2086 | 2165 | -79 | 3700 | 2452 | 2169 | 1779 | 1540 |
| Clearfield | Curwensville | 1970 | 1977 | -7 | 3531 | 2312 | 2035 | 1653 | 1419 |
| Dauphin | Elizabethville | 2138 | 2225 | -87 | 3792 | 2521 | 2234 | 1837 | 1595 |
| Bedford | Bedford | 2101 | 2134 | -33 | 3753 | 2480 | 2193 | 1798 | 1555 |
| Mifflin | Belleville | 2086 | 2141 | -55 | 3712 | 2456 | 2171 | 1780 | 1539 |
| Northumberland | Sunbury | 2141 | 2243 | -101 | 3789 | 2522 | 2236 | 1840 | 1598 |
| Lehigh | Trexlertown | 2171 | 2282 | -112 | 3842 | 2563 | 2274 | 1875 | 1631 |
| Schuylkill | Hegins | 2084 | 2149 | -65 | 3706 | 2454 | 2170 | 1779 | 1539 |
| Westmoreland | Greensburg | 2046 | 2057 | -11 | 3663 | 2410 | 2126 | 1736 | 1497 |
| Somerset | Somerset | 1840 | 1738 | 102 | 3367 | 2166 | 1892 | 1518 | 1290 |
| Washington | Washington | 2136 | 2182 | -46 | 3807 | 2523 | 2233 | 1835 | 1590 |
| Franklin | Chambersburg | 2212 | 2306 | -93 | 3930 | 2623 | 2329 | 1923 | 1674 |
| York | York | 2262 | 2388 | -126 | 4009 | 2688 | 2391 | 1981 | 1728 |
| Lancaster | Ephrata | 2169 | 2261 | -92 | 3851 | 2565 | 2275 | 1874 | 1629 |
| Berks | Hamburg | 2188 | 2307 | -119 | 3870 | 2585 | 2295 | 1894 | 1649 |
| 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 Corn Hybrids to reach 50% Silking and Black Layer. | |||||
| 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. Initiation and Termination Dates for Scouting Activities for Key Field Crop Pest | ||||||||
| ECB1 | ECB2 | ECB(a) | CRW | BCW | SB | SCM | AW | |
| Initiation | 648 | 1350 | 1098 | 1,645 | 300 | 1,400 | 450 | 300 |
| Termination | 734 | 1459 | 1272 | 2,336 | 600 | 1,700 | NA | 500 |
The cumulative degree day value given is for the number of degree days needed after tillage of manure or green surface vegetation before it is recommended to plant corn in a field to avoid injury from seed corn maggot.
Dennis Calvin
William S. Curran
Associate Professor Weed Science
email: wsc2@psu.edu
Website Address: http://fcn.agronomy.psu.edu/