Field Crop News

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

August 24, 2005    Vol. 05:11

IN THIS ISSUE:

Mark Your Calendar

Weather Outlook

Production

Agents Corner

WEATHER OUTLOOK

The dry weather continues to nag most of the state. Only a few spots in the northern Poconos have had normal rainfall so far in August. Most sections are experiencing monthly deficits of 1 to 2 inches. Still for the period from late May through now, the lower Susquehanna and Delaware river valleys are averaging near normal rainfall. The driest region is a swath from the Lehigh Valley across the upper Susquehanna Valley then fanning out across the central and western mountains. All of this area is showing between 3 and 5 inches of rainfall below average (about a month shy of rain). Add to this, the persistently high temperatures (though very few records have been set) and an abundance of sunshine, this has led to very high rate of evaporation adding to the crop stress.

Expect very warm weather to return by the weekend with a steady increase in the moisture in the air. No widespread or appreciable rain is expected until perhaps Sunday when scattered thundershowers should develop in western and northern sections. The outlook for the last week of August and first few days of September point to the possibility of near record heat between August 30 and September 2. Little rain is anticipated statewide before Labor Day weekend. The wild-card after then is the potential role of the Tropics in bringing rain during September. Odds are against much impact before mid-September.

Paul Knight, pgk2@psu.edu
Pennsylvania State Climatologist

PRODUCTION

HOW DID YOUR N PROGRAM DO THIS YEAR? THE LATE SEASON CORNSTALK NITRATE TEST CAN TELL YOU

Nitrogen (N) management is one of the most difficult decisions in corn production because of the many factors that influence N behavior including: materials, timing, weather, etc. This is especially true when manure is part of the system. Standard recommendations try to account for many of these variables and early in-season tests such as the Pre-sidedress Soil Nitrate Test (PSNT) and Chlorophyll Meter test are very helpful in reducing the uncertainty in N recommendations. While we can never totally eliminate this uncertainty, with experience we can minimize it. A key to improving N management over time is having reliable feedback on how well your N management is working. Good yields and dark green plants are certainly good indicators of adequate N but they to not tell us if we have too much N, which can be a problem especially with manure. Also, some visual symptoms of N deficiency late in the season may not always indicate a yield loss.

The Late Season Corn Stalk Nitrate Test has been shown in research at a number of locations, including across PA, to be a reliable end of season indicator of crop N status. It provides a good assessment of whether the crop had the right amount of N or too much N or whether it ran out of gas. This information combined with records of N management can be very useful for making future management decisions.

To do this test, 8-inch long sections of corn stalk (subsequently cut into two inch long segments) are taken starting 6 inches above the ground. Pruning shears usually work well for taking these samples. Stalk sampling can be done anytime between about the 1/4 milkline stage of the grain, which is just before silage harvest and up to 3 weeks after the grain forms a blacklayer. If possible, dry the samples immediately or send them to the lab as soon as possible after collection. If there is more than a day between sampling and sending, refrigerate (don't freeze) the samples until you can send them. Keep the samples in paper (not plastic) bags. While you could test all fields, testing a few representative fields will probably be adequate to provide a good assessment of your N program.

This test is available through the Penn State Agricultural Analytical Services Laboratory (AASL). The cost of this test is $10. Information about the test including sample submission forms and detailed sampling instructions are available on the AASL web site at: http://www.aasl.psu.edu. Results of this test provide a good assessment of the adequacy of the nitrogen management in a field and can be very helpful in adjusting management in the future.

Douglas Beegle, dbb@psu.edu
Soil Fertility and Nutrient Management, Crop and Soil Sciences

GRAIN CROP UPDATES

If you or your clients have great looking soybeans, there is still time to enter the PA Soybean Contest. Review the rules and procedures for obtaining an application on our website: http://cornandsoybeans.psu.edu/soybean/yieldcontest.cfm

Silage harvest is in full swing in some areas. If you haven't checked silage moistures in your area, I would start now as the crop may dry down fast with the dry conditions. It's tough to catch up if you start too late. We have added a report on a two year corn silage bunker sampling study in the Capital Region to our website. In this study we found that often bunker densities are less than ideal, but with careful attention, producers can improve packing practices and the densities in their bunk. The report is located at: http://cornandsoybeans.psu.edu/pdfs/bunker_silo_study.pdf

Some areas are harvesting drought stressed corn with forage quality, yield, nitrate, and silo gas issues possible. Nitrates may be more prevalent if these areas get a drought ending rain prior to harvest. Review our Managing Drought Stressed Corn Factsheet for more on these issues on our site at: http://cornandsoybeans.psu.edu/droughtstressmanagement.cfm

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

GET READY TO PLANT COVER CROPS

After corn silage harvest, it is strongly recommended to plant cover crops to protect the soil from erosion and to take up excess nitrate that might otherwise leach from the soil. It is also possible to establish leguminous cover crops that can fix a substantial amount of nitrogen for next year's crop. The cover crops should go in as soon as possible after harvest, so it is high time to get cover crop seed. Seeding rates listed here are for drilled cover crops. Add 25-50% for broadcast rates.

Oats will still put on substantial growth this fall, but will winterkill sometime in December or early January. Oats are easy to manage because you don't have to worry about a burn-down treatment. They are therefore an excellent cover crop prior to alfalfa establishment in the spring. Some oat mulch will be present if you no-till plant next year's crop, but the mulch will not last very long. You need about 3-4 bu/A to establish it.

Rye is the most vigorous of our cover crops that puts on a lot of growth over the winter. Established mid-September, it produces 2-3 tons/A of dry matter by the first of May in southern PA. It is important to kill it in a timely fashion (glyphosate is an excellent burndown product on all winter cereals). Rye produces a very vigorous root system in the spring that can help to alleviate compaction. The mulch will last long if the rye is killed after boot stage (when the head can be felt in the stem). Seeding rates are 1-2 bu/A. Wheat is less aggressive than rye as a cover crop. It will produce about 1.5 tons/A of drymatter by May 1st if established by mid-September. Seeding rate is 2 bu/A. Barley is less winter hardy than wheat. You need also 2 bu/A.

The legumes hairy vetch and crimson clover have been doing quite well in our tests in southeastern Pennsylvania if established before mid-September. Vetch grows slowly during the fall, but really puts on a lot of growth starting in April. Tests in Maryland have shown that it accumulates 2 lbs N/A/day from early April onwards. If you want nitrogen benefits, it is wise to wait until mid-May before killing it. By that time, hairy vetch will have accumulated about 1.5 tons/A of dry matter and 100 lbs N per acre. Seeding rate for hairy vetch is about 20 lbs/A. Crimson clover grows much faster in the fall and can be killed a little earlier than vetch. It will produce a similar amount of biomass as hairy vetch. Seeding rate for crimson clover is 15-18 lbs/A. The residue is much more stemmy than that of hairy vetch, and the crimson clover mulch will last longer in the season. I checked seed prices with some different suppliers which are listed below. The wide price range suggests it may be worth placing a few phone calls.

Cover crop prices listed by some suppliers 8/25/05
Ernst Conservation Seeds Seedway Rohrer Seeds
Rye ($/bu)$8.45$8.00$9.75
Wheat ($/bu)$6.00 $10.00 $15.00
Barley ($/bu) $15.00 $8.00 $8.50
Oats ($/bu) $4.00 $6.50 $8.12
Crimson Clover ($/lb) NA $1.60 $1.43
Hairy Vetch ($/lb) $1.20 $1.65 $2.50

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

Agents Corner

Capital

There are greatly varying crop and soil conditions across the Capital Region at this time. Although many areas have received timely rains there are still many areas where soil moisture levels are extremely low and crops are suffering. This week of forecasted cooler weather will somewhat moderate the severity of droughty soils but many fields are showing drought stress even with temperatures in the mid 80's.

The corn crop is rapidly maturing. There are reports from the southern area of the Capital Region of the start of silage harvest during the week of Ag Progress Days. This week (8-22) silage harvest will pick up more rapidly and next week (8-29) harvest will be in full swing. There is concern of the rapid maturing of the later plantings of corn silage that will result in a narrow harvest window.

Reports of aphids in the soybeans appear to be decreasing. In Upper Dauphin County the winged aphids appear to have disappeared from most fields. All that remain are the small, whitish forms of the aphids but these do not appear to be causing significant injury, at least the presence of the "honey dew" is not evident. The soybean crop is entering the pod filling stage. In areas the beans are nearly chest high. Areas of beans near Hershey were showing curling from droughty soils today, Monday.

Fourth cutting of alfalfa is close by. Many producers are trying to decide which to harvest first, silage or haylage at this time. Potato leafhopper numbers have also dropped significantly. Many growers note that leafhopper levels were not very high this year. Forage supplies will be tight this year as first and second cuttings were short. Grass stands responded nicely to the early summer hurricane but since then the high temperatures and low moisture levels have greatly reduced grass hays and pasture stands. Many fall seedings of alfalfa have been delayed due to limited moisture conditions.

Paul Craig, phc8@psu.edu
Dauphin County

CENTRAL

From what I can gather, I believe most all of the Central Region has been suffering from drought. We finally received some moisture thanks to the start of Ag Progress Days and Grange Fair. According to folklore it always rains during those two events. We hope it continues pretty consistently until harvest. The month of August has brought on many calls and field visits for both us and the crop insurance folks. We have been very busy doing field assessments on corn, soybeans, and grass and legume hay. All three crops including pasture have really suffered this growing season up to now. We have been out doing yield estimates to help farmers decide whether they should chop corn and soybeans for silage or leave it for grain. We have also been looking at what appears to be many failed seedings and in established grass and legume hay we are seeing some very stressed stands that are loosing population and are very weedy. Many of these will have to be rotated or renovated. Some of our farmers that are on a twenty eight day cutting schedule have taken their fourth harvest in the hopes that with moisture they can get a fifth harvest with some tonnage.

Most all the corn I have seen is drying down awful fast and the majority of the ears are either in half milk now or at least dented. Some fields are showing very poor pollination with as low as thirty three percent of the ears developing kernels. Many of the leaves have fired on the stalk. The grain estimates have ranged from forty bushel per acre to one hundred and ten bushel per acre. With the mean falling at around seventy five bushel per acre. As a result many that were planning to harvest grain are harvesting for silage. As far as crop insurance goes for those that crop insurance doesn't kick in until a sixty five percent loss many are telling me that they will receive something but it wonÕt be much to offset the dollars lost this year.

Many of the soybean fields are at R4 maturity stage or beyond and up until the rain received August 17 through the 20th yield estimates ranged from twenty to at most forty bushel per acre. Many of the farmers are considering harvesting some of the fields for silage. But with this last rain and the fact the beans are still in midst of pod fill, I suspect they will hold off to see if we continue to get consistent moisture. If that happens many of the fields could put on another ten bushel per acre for grain. The other thing that came up in the process was working with crop insurance and estimating grain losses due to the size of the bean being much smaller. From what I gathered from farmers, that is not done by the agent. Therefore it makes it difficult to establish a loss in grain yield and then being able to take the soybeans off for silage.

We have been seeing heavy pressure from insects during August. Namely: Western Corn Rootworm Beetles in corn, grasshoppers in drought stressed corn and hay fields, and soybean aphids. I have been reluctant to recommend a spray on the aphids because of the low yields to begin with and we have found quite a few lady beetles in those fields.

That's it for now. I just wonder how the majority of our farms will handle this growing season and the rising fuel cost financially.

Craig Altemose, cea10@psu.edu
Centre County

Southeast

Field moisture levels continue to vary significantly within the region. In Schuylkill County, shale soils are really showing their weaknesses with the lack of timely rainfall. Corn on the shale ridges looks terrible, and in the deeper soils looks quite nice, with most corn in dent. Beans are doing better, with most in pod fill, and height ranging from knee to chest height.

Regrowth on grass hay is not very good. I was in some timothy stands on Friday, both new seeding (with wheat stubble) and established seedings. All had timothy mites visible with the lens. Most 3rd cutting has been made. It's been very short, as well.

Everyone is invited to Paul Reidenhour, Jr.'s farm in Hamburg on September 8th at 6:00 pm for a forage equipment twilight meeting. We'll be demonstrating and evaluating mowing and drying equipment: haybines, discbines, different types of tedders, and different types of rakes. To register, call (610) 489-4315 by September 1st.

Dwane Miller, dmiller@psu.edu
Schuylkill County