Field Crop News

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

April 29, 2005    Vol. 05:03

IN THIS ISSUE:

Mark Your Calendar

Weather Outlook

Production

Pest Management

Agents Corner

MARK YOUR CALENDAR

PENN STATE/PASA ECOLOGICAL WEED MANAGEMENT FIELD DAY

Monday, June 13, 1:30-5pm, Rock Springs Agronomy Farm Pavilion, Centre County
Cost: Free
Refreshments will be provided.

For those trying to get ahead of their weeds, June is a critical month. We'll start this afternoon field day with an introduction to Ecological Weed Management, which will include a lesson on weed identification and life cycles. We'll move to the cover cropping trials where no-till, rolling, herbicides, shallow till and other methods of management are under trial. A team of Penn State researchers will discuss using cover crops to manage weeds and improve soil quality, as well as present information on the role of ground beetles in weed seed predation.

This field day will also afford us an opportunity to get an update on the "transition experiment" where Penn State researchers are transitioning corn and soybean crops from conventional to organic production. Presenters from Pennsylvania Certified Organic will be on hand to explain alternative methods of weed and cover crop management that comply with USDA certification standards. We'll learn what farmers can do to manage crops during the transition period and hear about current marketing opportunities for organic grain.

To register, please call Pennsylvania Association for Sustainable Agriculture (PASA) at 814-349-9856 ext. 7 or register online at www.pasafarming.org.

Bill Curran, wcurran@psu.edu
Weed Science, Crop and Soil Sciences

PASTURE, WHEAT, AND IPM FIELD DAY

June 21 from 5:00 to 9:00 p.m. at the Don and Jeff Byerly Farm and the Elvin Stoltzfus Farm in Lewisburg, PA, Union County.

Get information on pasture improvement with no-till renovation, sweet corn IPM, novel crop biostimulants, and prospects for alternative winter wheats.

Neighboring farmers Don and Jeff Byerly and Elvin Stoltzfus have teamed up with Penn State county and state extension personnel and several agri-businesses for four on-farm research or demonstration projects. The overall objective of the field day is to identify and highlight some opportunities for improving farm productivity and profitability. The event will begin with an evening cookout featuring meats processed and sold through the Byerly brothers' retail market. Discussions of the four field projects will follow.

Pasture renovation studies on the Byerly farm are documenting the yield and quality of two dozen grasses and legumes when no-till drilled into existing pasture. Of interest to some farmers is the novel approach of banding herbicide at the time of no-till drilling. Plots were seeded in August 2004 and are presently being evaluated. The Byerly farm is one of six farms in the north central and northern areas of Pennsylvania participating in this pasture study. Dave Hartman and Ron Hoover will lead the discussion. The project is supported by a grant from the Northeast USDA-SARE program and by donations of forage seed from Kings Agriseeds, P.L. Rohrer Seeds, The Keystone Group, and Seedway.

Many Pennsylvania flour mills and bakeries are interested in specialty and locally-grown flours. This interest coupled with farmers' desire to find a crop with greater market value prompted a field comparison of several alternatives to our standard soft red winter wheat. Included in the agronomic and food quality evaluations are hard red winter wheat, soft white winter wheat, soft red winter wheat with strong gluten, and spelt. The many plots in the large replicated experiment on the Stoltzfus farm should be headed-out at the time of the field day. Research and extension participants include Greg Roth, Erick DeWolf, Shaun Heinbaugh, and Tom Murphy.

Offering worm-free ears of sweet corn to customers while minimizing the amount of pesticide used to control these pests continues to challenge farmers. Extension agent Norm Conrad will lead a demonstration and discussion in a Byerly sweet corn field that will focus on the use of pheromone lures, insect traps, and economic thresholds to help farmers best determine when control measures are necessary.

Also being evaluated on sweet corn is a novel plant biostimulant from China. The product is a blend of three soil microbes that have been found to enhance root uptake of nutrients. The implications of this type of technology could include reduced fertilizer inputs while maintaining crop yields and quality. Reduced rates of commercial fertilizer not only reduce input costs but can reduce the opportunity for these nutrients move into ground or surface water. Norm Conrad and Rick Paulsen will lead the discussion of this technology.

Questions about the event can be directed to Ron Hoover via email at rjh7@psu.edu or by calling 814-865-6672. A $10 fee will be collected at the field day to offset meal and planning costs. Participants are asked to pre-register for the field day electronically with the Pennsylvania Association for Sustainable Agriculture (PASA) at www.pasafarming.org and clicking on the "Farm-Based Education" page, or by calling the office directly at 814-349-9856.

Ron Hoover, rjh7@psu.edu
On-Farm Research Coordinator, Crop and Soil Sciences

July 18 - New Date For Certified Crop Advisor Workshop

The Certified Crop Advisor workshop, planned for May 13, has been rescheduled to July 18. Schedules in July are normally less hectic for agronomic industry personnel, and the study session will be closer to the examination date. The workshop will take place at Penn State in Room 504 ASI Building.

Although there is no charge for attending, participants are asked to register by calling or e-mailing Lisa Crytser at 814-865-2543 or lac8@psu.edu. The tentative schedule follows.

Review of Study Materials Related to Pennsylvania Performance Objectives

Jan Pruss, jap5@psu.edu
Crop Management, Crop and Soil Sciences

WEATHER OUTLOOK

April will end up as a very wet month in the eastern third of the state, but the south-central sections, especially the southern mountains, will conclude with below average precipitation. Temperatures will tally above seasonal levels due to the persistent warm spell during the mid-month.

Other than the southeast, most sections have yet to notice a significant thunderstorm. As the new month begins, it will do so rather wet. Saturday and Sunday will bring showers and a few thunderstorms to the region, though most of the rain will fall on Saturday. Drier, cooler and brisk winds will return on Monday. A few mainly dry days are expected from May 1-3, but a new round of showers and some thunderstorms will arrive later on May 4 or more likely May 5-6. While warmer air will attempt to spread into the region from May 7-9, some showers will likely accompany it. No prolonged warm spells are expected before mid-May. The first half of the summer still favors cooler than average and wet conditions. There are signs that August will turn very warm and much drier.

Paul Knight, pgk2@psu.edu
Pennsylvania State Climatologist

PRODUCTION

EARLY PLANTED CORN UPDATE

Many producers took advantage of our summer like conditions and planted significant acres of corn. The response to mid April plantings in the past several seasons has been good to excellent resulting in high yields and early crop maturity. In general, this should have a positive impact on corn production and yields throughout the state.

This early planted corn could warrant some additional monitoring in the next few weeks. Corn we planted here last week has been in the soil for 7 days and shows some swelling but little sign of development at this point. Soil temperature in the seed zone on Monday was about 41°F and the seed zone is moist but not saturated. Given the 15 day forecast (accumulating about 5 to 6 GDDs per day) and the need to accumulate 125 to 150 growing degree days for emergence, it will likely be three weeks after planting before this corn emerges. Corn planted earlier, and in our southern counties should emerge a bit faster.

At our PAES (Pa. Agronomic Education Society) meeting last winter, Dr. Imad Saab from Pioneer/DuPont reviewed risks associated with seed emergence under cool conditions. The most stressful condition for corn seeds is exposure to cold (<50° F) wet conditions immediately following planting when the seed imbibes cold water that reduces the elasticity of the cellular membranes of the developing seedling. This can cause cell rupture and leakage, which can release sugars and promote fungal and insect damage to the seed. This chilling injury can result reduced vigor of the seedlings and in lasting effects on the growth of the plants. Once the shoot emerges from the soil, considerable cold tolerance develops in the seedling.

When scouting these early planted fields, be on the lookout for some of the typical problems observed under these conditions in the past. Most problems will occur in wetter areas of fields. Chilling injury can resulting in cork screwed seedlings in some cases. In other cases, rotten seeds, some with a developed and yellowed coleoptile can be observed. Some insect feeding on seeds can be observed and contribute seed death- this will likely be reduced with the widespread use of the new insecticide seed treatments. Deep planting on this early planted corn (over 2 inches) can also contribute to reduced emergence. Emergence rates can drop below 90%. When possible, compare performance of varieties or seedlots in problem situations. In some cases, extended exposure to herbicides during germination can increase the potential for herbicide injury. Early detection of stand problems can lead to an early replant decision with minimal yield loss. Once plants emerge, they can take on a yellowish appearance for a few weeks until warm weather resumes. Usually this has no ill effects.

I expect most of our early planted fields will emerge fine and do well. But some may encounter problems, which can be addressed with early scouting, careful diagnosis, and a timely resolution of the problem.

Greg Roth, gwr@psu.edu
Grain Crops Management, Crop and Soil Sciences

EARLY HARVEST IS ESSENTIAL IN MAKING DAIRY-QUALITY GRASS HAY

The use of perennial grasses for high-quality dairy feed throughout much of Pennsylvania is common. Unfortunately, the quality of the harvested forage is less than dairy-quality. The key factor in harvesting dairy-quality forage is harvest management. Research conducted by Dr. Jerry Cherney at Cornell University showed that plant development varies with grass species, but forage quality decline was consistent across all species. In other words, the forage species is not as important as timely harvest in obtaining high quality forage.

Reed canarygrass, bromegrass, tall fescue, and timothy were harvested at various stages of development and tested for quality. According to Dr. Cherney, the research showed that fiber digestion and other quality parameters decline with increased maturity. The magnitude and rate of quality decline with maturity are much more important than quality differences between individual species. Cherney also suggested that producers should consider harvesting their pure grass stands in the spring for dairy feed before they harvest alfalfa, in order to produce acceptable grass quality.

In other research, results indicate that spring harvest of later maturing varieties of cool-season grass species are lower in quality than early maturing varieties. When an early and late maturing variety of orchard grass were harvested at the same stage of maturity, the early maturing variety had greater quality than the late maturing variety. The research suggested that the lower quality was the result of higher temperatures during the growth of the late maturing variety relative to the temperatures in which the earlier maturing variety grew. However, the difference in quality between late and earlier maturing grasses was minor compared to the drop in quality associated with delaying the first harvest of either variety.

In summary, the use of cool-season grasses for dairy-quality feed requires harvesting the grasses earlier than normal. Delay in grass harvest and not grass species is the major factor in producing low quality grass hay or silage. Consider harvesting grasses before you would normally harvest alfalfa to obtain high quality forage that is suitable for dairy animals.

Marvin Hall, mhh2@psu.edu
Forage Management, Crop and Soil Sciences

YOU PLANTED A SEED....

The goal of planting corn is to achieve adequate emergence with uniform spacing and emergence time. Thus plant spacing variability and differences in emergence should be limited as much as possible. Attention to detail is especially critical in no-till conditions.

Plant spacing variability is usually expressed as a standard deviation. Research from Purdue University in Indiana has shown that every inch increase in standard deviation comes with a 2.5 bu/A yield loss. A standard deviation of 2 inches or less is considered to be adequate because typically only 90-95% of seeds are viable (check warm emergence % on the seed bag). A survey done a couple of years ago on farmer fields in Indiana and Ohio recorded standard deviations equal or less than 3 inches on only 16% of the fields, whereas 60% had standard deviations of 4-5 inches. About 24% of the fields had standard deviations equal to or greater than 6 inches. This means that yield improvements of 5-8 bu/A could easily be achieved by doing a better planting job. If the planter works well, plant spacing variability should be small. By now the corn planter is hopefully in good shape (see FCN05#1). You can check planter performance by measuring plant spacing in different spots of the field, calculate the mean, and then the standard deviation (use the formula at the end of this article, or use a computer program such as Excel to do it for you). If the standard deviation of plant spacing is greater than 2, you need to check your planter.

Plant emergence variability happens when some plants emerge before others. Research has indicated that emergence delays of 10 days scattered throughout the field reduce yields 6-9%. Extreme delays in emergence of 21 days can reduce yields 10-22%. Corn plants that lag 2 leaf growth stages or more behind their neighbors are likely to be barren by the end of the season. Reasons for uneven emergence are differences in soil moisture conditions surrounding the seed; differences in soil temperature, and inadequate seed-to-soil contact. To guarantee uniform emergence, you need to have uniform moisture and temperature conditions in the field. Unevenly distributed residue in no-till introduces large differences in these soil properties that lead to uneven emergence. If residue distribution is uneven, it is recommended to wait until average soil temperatures (measured at 2" depth at 7 am) are 55-60 F. Although residue distribution should be taken care of at harvest, you can also use one or more fluted coulters or row cleaners to help you partially correct uneven distribution. Row cleaners should move residue, not soil. Rotary harrows are not suited to redistribute residue. However, most primary plus secondary tillage operations take care of uneven residue distribution. Seeding depth is the next important factor to guarantee even emergence. Seeding depth should be determined based on current soil moisture conditions and the 5-10 day weather forecast. If soil is cold and wet, plant 1.5 inches deep, but if soil is dry to 1.5 inches depth, and the forecast calls for continued dry weather, it is best to plant 2-2.5 inches deep. Seed firmers help to maintain uniform seeding depth. Seeding depth should be checked various times during the day. Finally, it is important to close the seed slot. The pressure on the seed firmer wheels should be set so that the slot closes but that the soil is not compacted excessively on top of the seed, or that the seed is pushed upwards.

Formula to calculate standard deviation

Formula to calculate standard deviation (N= number of observations, xi=each individual measurement, and x with line above it is the average of all observations):

Sjoerd Duiker, swd10@psu.edu
Soil Management, Crop and Soil Sciences

SOIL COMPACTION UPDATE

Truck driving in field

Dry weather conditions in the first half of April have been very helpful to guarantee optimum soil moisture conditions for field work. According to USDA, 87% of fields had soil moisture conditions at or below the adequate level for field work, and only 13% had surplus moisture. This means that manure could be hauled, tillage could be done and planting got started. It is clear that soil moisture conditions can be respected much better this year to avoid compaction than in previous years. Remember that soil is too wet for field work if it is above the "plastic limit", when you can make a ball out of soil that sticks together.

Over the past three years we have learned much about soil compaction in no-till in an experiment near State College on a well-drained limestone soil. These are some of the lessons we have learned: 1) In long-term no-till, compaction of 100% of the soil surface with 10 ton axle load and road tires caused from 10-20% yield loss. We did compaction when soil was really too wet for field work. Yield loss was very often closely associated with a loss of plant population in compacted soil, but was also caused by restricted crop growth during the growing season. Greatest yield losses were observed in a dry year, whereas in wet years the yield losses were smaller. 2) We did not observe subsoil compaction below 10 inches. 2) Flotation tires helped to roughly cut the yield loss in half. The tires avoided rutting the fields up and improved plant stands and plant growth. 3) Zone-tillage with the Rawson three coulter system did not help to significantly alleviate compaction. 4) Strip-tillage with an Unverferth Zone-Builder to 16 inch depth after severe compaction helped alleviate much of the effect of the compaction caused by road tires and high axle load. However, when we set the depth to only 9 inches, we got the same yield improvement (but we only did this in the last year of our trial).

The findings suggest to us that in long-term no-till the soil is indeed more forgiving to compaction than tilled soils due to increased soil organic matter contents and a firm soil profile that is punctured at many places by continuous macropores. Yield losses were not as high as we had feared. When farmers limit field traffic to periods when soil moisture is optimal for field traffic, they have to fear little from compaction. When they use flotation tires and respect traffic patterns so that they compact less than 50% of the field, no deep tillage operations are generally justified. In addition, we observed no subsoil compaction below 10 inches, suggesting that no tillage to deeper depths was justified. One other thing we noticed was that any tillage operation decreases the residue cover. To meet the standard for conservation tillage, more than 30% residue cover needs to be present after planting. We often barely met this with tillage, even if it was limited to in-row tillage only. This is another reason to limit the amount of tillage to the absolute minimum.

Sjoerd Duiker, swd10@psu.edu
Soil Management, Crop and Soil Sciences

PEST MANAGEMENT

BURNDOWN CONTROL OF HORSEWEED AND FLEABANE

Images of horseweed and fleabane

Horseweed and various fleabane species can be difficult to identify when they are in the seedling or early immature stages. Not only have we noticed this while walking fields but others have called inquiring about the appropriate identification of these various species.

Both horseweed and fleabane are part of the aster family and once mature have numerous, small daisy-like flowers and other features to distinguish them. However, in the rosette and early bolting stages, those differences are not so apparent. Despite the fact that there are numerous images of weeds in books and on the web, there are very few that show the differences between the immature fleabane species common to our area namely daisy fleabane (Erigeron annuus), rough fleabane (E. strigosus), and common or Philadelphia fleabane (E. philadelphicus). (For some images of horseweed and fleabane see the following websites: http://weeds.cropsci.uiuc.edu/extension/factsheets/Horseweed.pdf and http://www.wssa.net/photos.html)

As weed scientists, we generally lump these annual fleabanes together and provide a herbicide control rating as a group. In most cases this is adequate, when they are small. However, once they are more mature (i.e., 4 to 6 inches or taller), higher herbicide rates are generally necessary to control them. Glyphosate product labels have a table that lists some fleabane species along with height and rate information. Other labels such as, 2,4-D and Clarity, are not as specific. But if the confusion occurs between horseweed and fleabane how will this impact burndown herbicide selection? The following table lists selected burndown herbicides for control of horseweed and annual fleabane species. With the concern for glyphosate resistant horseweed, the need for tank mixtures becomes more critical. However, annual fleabanes can also be difficult to control and may also require the use of tank mixtures to improve control. Keep in mind that these herbicides will provide better control when the weeds are small (i.e., 2-3 inches tall) and applied in combination with a crop oil concentrate and/or N-fertilizer solution. However, the inclusion of 2,4-D to a soybean burndown program does provide some planting challenges; so remember to wait at least 7 days before planting, when using 1 pt/A or less.

Table 1. Effectiveness of selected corn and soybean burndown herbicides on horseweed and annual fleabanes.
9=85-95%; 8=75-85%; 7=65=75%; 6=55-65%
1 C=labeled for use in corn and S=labeled for use in soybean
2 Not effective on resistant horseweed
Herbicide Crop1 Horseweed Annual fleabanes
2,4-D LV4 ester C&S 8 6
2,4-D + Clarity or Banvel C 9 8
2,4-D + glyphosate C&S 9 7
Atrazine C 8 7
Balance Pro + glyphosate C 9 7
Basis C 6 ?
Canopy XL S 8 6
Extreme S 7+ 8
Glyphosate (0.75 lb ae) 2 C&S 8 7
Gramoxone Max C&S 7 6
Sencor C&S 6 6
Valor S 6 N

Dwight Lingenfelter, dxl18@psu.edu and
Bill Curran, wcurran@psu.edu
Weed Science, Crop and Soil Sciences

Agents Corner

Capital

Crop Conditions

Winter Barley and wheat are at Stage 7 and 8. Much of the corn was placed in the soil in Mid April in ideal seedbeds and to date none is presently out of the soil. Alfalfa is on target for second week of May harvest unless heat units build. Rye is due to be harvested on 4-26. In addition pastures rebounded nicely with adequate N. Many growers released animals far too early for ideal growth in pastures.

Pest Activity

Weevils were reported in Dauphin in the 2nd instar at low levels. Timothy mites spiked in mid April many applications occurred at a proper time. Winter annual weeds were widespread and growers treated accordingly. European Corn borers are still dormant but should be pupating with the next two weeks to seek out egg laying sites. Weather favors leaf diseases currently in winter wheat and should be scouted accordingly.

Weather

Rainy conditions followed by dry conditions crusted most conventional tillage systems. New seedings of alfalfa suffered from the crusting. Recent rains should alleviate most conditions. Prolonged rains hampered manure applications and other field activities this spring.

Del Voight, dgv1@psu.edu
Lebanon County

Northeast

Several weeks of warm, dry weather ended this week with rains and colder temperatures. Many producers took advantage of the dry conditions to do April tillage, which is unusual in our typically wet soils.

Quite a few new seedings were planted in mid April, however emergence has been slow with our return to colder weather. Corn planting should begin in earnest around the second week of May, weather permitting.

Alfalfa growth is in the 4" to 6" range. Fields in the Northeast were covered with a good snow pack over winter so most alfalfa stands seem to have little winter injury. No alfalfa weevil activity has been observed to date.

Dave Messersmith, dtm101@psu.edu
Wayne County

Northwest

The weather in the Northwest region turned for the worse on Saturday and Sunday (23 & 24), but clearing on cool for awhile. Producers were able to accomplish many projects before the snow storms of the weekend, plantings of alfalfa, oats, spring barley, and some corn were reported in the region. Tillage and burndown spraying is evident in many fields across the area.

Planting intentions seem to be pretty much the same as last year despite the rising fuel and fertilizer costs. Many producers are going to reduce the number of trips over the field to reduced energy costs. I think producers did more soil testing this year to figure out ways to reduce fertilizer costs and use fertilizer more prudently. Maybe be a good year for producers to finally try reduced tillage programs we keep trying to promote.

Nelson Smith, nes2@psu.edu
Clarion County

Southeast

After two weeks of unseasonably warm and dry weather we are back to more typical weather for late April. Depending on your location in SEPA you received 1-3Ó of rain 4/23. A good deal of the primary tillage is completed with some areas of the region having a fair amount of corn in the ground. Most of the corn planted is in worked ground, the notillers have been spraying and fertilizing. Rye is in boot stage with some heads visible. Straw prices are quite high reports $150-$200 per ton at auctions. Mites in timothy fields are a problem again this year with the majority of the acres affected and most have been treated. The warm and dry period provided an excellent opportunity to empty manure storages, spread lime and fertilizer, seed oats and grass, do tillage and burn down no-till ground.

Andrew Frankenfield, adf13@psu.edu
Montgomery County

Southwest

Following the April 3rd snowfall of about 4 inches in SW Pennsylvania, and as soon as the fields dried out, field work really picked up. With almost three weeks of dry weather, tillage, spring oats planting concluded and even some corn was planted beginning on April 18.

The early planted oats finally emerged following the rain on April 20 and it looks good.

Soybean growers are concerned about rust this summer, but none have indicated a change in plans to not grow soybeans.

Hay meadow growth was slowed a bit by the dry weather and pastures that were too heavily stocked also were exhibiting symptoms of slow growth.

Cool wet temperatures since April 23 have stopped field work, but farmers are anxious to get on with it.

Don Fretts, dcf3@psu.edu
Fayette County