CMEG Crop Management Extension Group

Field Crop News

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

June 12, 2007    Vol. 07:15

IN THIS ISSUE:

Weather Outlook — Paul Knight, Pennsylvania State Climatologist

Another dry week was notched for Pennsylvania with most sections receiving less than half the average weekly rainfall and a few spots getting no rain at all. Add to this, above average temperatures and relatively sunny days and the evaporation rates have been very high, adding stress to young plants. The next week not afford many opportunities for widespread showers, though it should not be quite as dry, perhaps closer to 50% of average rainfall. A cold front promises to bring more numerous showers and thunderstorms from June 20–22 and be followed by more seasonable conditions for a few days.

Week One (June 13–20): A steady cooling trend is expected until Friday as ocean air pushes south and west across the state. Along the leading edge of the maritime air, there will be scattered thunderstorms each afternoon and evening on Wednesday and Thursday. The eastern counties should be the coolest on Friday morning. A marked warming trend will begin during the weekend and continue into Tuesday. Early next week will turn hazy and quite humid with temperatures well above seasonal levels and only popcorn thundershowers in some places during the late afternoon.

Week Two (June 20–27): The best opportunity for widespread rain this month is likely from next Wednesday into Friday as a cold front moves slowly across the region. A push of cooler air is expected for the final full weekend of June and this will be followed by a spell of rather hot and humid conditions during the first half of the final week of the month.

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

Herbicide Drift Management — Dwight Lingenfelter, PSU Weed Science

As usual, chances are it will be windy when you plan to apply herbicides. However, herbicide application must be completed and along with that comes the potential for drift. Now that many post herbicides will be applied during the next couple weeks, it is critical to take measures to reduce spray drift. Herbicide drift is spray material that misses the target during application or moves off the target after application. There are two kinds of drift—droplet and vapor. Droplet drift is the movement of liquid spray droplets through the air. Vapor drift is the movement of spray material as a gas or vapor during or after application.

The applicator can control a large portion of potential drift. Research has shown that a large portion of potential drift can be controlled by adjusting spraying equipment and spraying during periods of low wind conditions. The following are some tips to help reduce the potential of herbicide drift.

Drift management is even more critical, with the ubiquitous use of herbicide resistant crops. Although glyphosate is an effective herbicide in Roundup Ready soybeans, it is also an effective herbicide on nearby normal corn or other sensitive crops. Also, products that contain dicamba (Clarity, Banvel, Northstar, Status, etc.) and 2,4–D can cause problems when they drift to nearby soybeans. Spray drift not only wastes your herbicide and money, but it may cost you more if legal action is taken by your neighbor.

Emergency Forage Planning — Paul Craig, PSU Dauphin County Educator

Short first cutting yields due to limited moisture this spring have set the stage for the potential for long term forage inventory issues. Early June seedings of sorghum sudangrass hybrids can serve as a forage stretcher in case these dry conditions continue. Establishment up to July 4 is possible.

These crops will perform well in dry conditions but have the potential to really produce high quality forage under optimum growing conditions too. Early June is an ideal time to establish these forage crops for both dry and normal growing conditions.

A brief review of agronomic production issues related to sorghum sudangrass production for forage follows. Select for high forage quality characteristics. Digestibility is key for highest forage quality levels and will vary by variety. Seed at 65 to 70 pounds of seed per acre and plant at a depth of ½ to ¾ inch. Do not plant too deep!

Weeds rarely out—compete the development of sorghum sudangrass hybrids. Because of multiple harvesting, weeds are rarely a problem so no herbicides are needed after establishment. High fertility levels are necessary for optimum yields. Phosphorous and potassium requirements are similar to those of forages used for corn silage. Sorghum—sudangrass hybrids are also significant users of nitrogen. One hundred pounds of nitrogen is recommended at planting and a second application of 100 pounds of nitrogen following first cutting is recommended for high yield potential. Base the second application on moisture levels and yield potential.

It is critical to harvest stands when they reach 30 to 36 inches in height. Forage quality of taller stands will be greatly reduced. These plants will grow rapidly and if not managed on time, can quickly attain 5 feet or more. Do not let these stands get ahead of your planned cutting height. Under optimum growing conditions, second cutting may be ready for harvest in as little as 25 days. Mow at a cutting height of 3 to 4 inches to encourage rapid regrowth. Do not harvest stands less than 2 feet in height.

This crop contains high levels of moisture and will require wide windrow management to ensure rapid dry down. The shorter the period from mowing to harvest the better the quality of the forage. This crop is an excellent choice for haylage or baleage production.

Grain Marketing Outlook — Tom Murphy, PSU Lycoming County Educator

Since this time last week we have seen prices for corn move mostly sideways as the market tried to determine what the weather impact was going to be in the near term. Monday that changed with a strong move up due to predictions of continued dryness in the Eastern Corn Belt, favorable export demand, and strong domestic usage. December corn closed up Monday 13 ¾ at 406. U.S. and world stocks are both now predicted to be higher as cited in the recent USDA report released Monday. Even with that news, the market moved upward. Now more then ever the market seems to be about weather. Still lots of discussion and predictions from both industry and USDA as to where yields will come in, whether China will be more of a buyer then seller this year, at what corn price ethanol production could slow, and how much more land in South America could come into production. In the last week, soybeans have showed no retreat in their trend to new contract highs with a close on Monday of 830 for November. Why? Weather for one reason, the same concern for the dryness the corn crop is experiencing. There was however an increase in USDA’s projected harvest from South America which will give a small boost to the world stock numbers. That was tempered with a predicted decline in Chinese bean production and an increase in their import demand from the market place. There is also some discussion in the industry that China may be shifting some of its veg. oil production needs from palm oil to soy oil which could further support price.

Bottom line: if you are or will be in the market this year to buy grain, you may want to give some additional thought to a forward contract to lock in a price. And if you will be storing or selling at harvest, don’t lose sight of selling a portion of your grain at a profit through a forward contract as well. And a thought for next year, a local mill owner reminds me he is paying $10.25 for new crop organic corn, $13.00 for nearby.

Southeastern Pennsylvania
Grain Range Avg Contract for Harvest
Corn No. 2 4.19-4.55 4.36 3.84-4.02
Wheat No. 2 4.88-5.43 5.18 4.73-5.27
Barley No. 3 2.70-2.80 2.76 2.45-2.70
Oats No. 2 2.00-2.80 2.35 ---
Soybeans No. 2 7.82-8.00 7.87 7.94-8.14
*Gr. Sorghum --- --- ---
Ear Corn 110.00-128.00 121.83 ---
Western Pennsylvania
Grain Range Avg
Corn No. 2 3.62-3.75*4.16 3.74
Wheat No. 2 4.18-4.25 4.23
Barley No. 3 2.00 2.00
Oats No. 2 2.00-2.25 2.17
Soybeans No. 2 7.52-7.60 7.56
Ear Corn 103.00-107.00 104.67
South Central Pennsylvania
Grain Range Avg
Corn No. 2 4.10-4.32 4.23
Wheat No. 2 4.50-5.00 4.80
Barley No. 3 2.50-2.80 2.66
Oats No. 2 2.15-2.50 2.28
Soybeans No. 2 7.40-7.72 7.58
*Gr. Sorghum --- ---
Ear Corn 117.00-125.00 118.93
Central Pennsylvania
Grain Range Avg
Corn No. 2 4.10-4.40 4.18
Wheat No. 2 4.25-4.78 4.52
Barley No. 3 2.70-2.80 2.75
Oats No. 2 2.25-2.45 2.32
Soybeans No. 2 7.70-7.87 7.78
Ear Corn 114.00-125.00 117.56

Timely Post Control of Weeds Works and Saves Crop Yield — Bill Curran, PSU Weed Specialist

Much of the corn in the southern half of the state should have been already sprayed with a POST treatment if necessary and POST control of weeds in soybeans is just now coming in to full swing. Remember that annual weeds are most susceptible to herbicides in the seedling and early stages of development and missing this window can present several challenges including lack of successful control, nutrient and moisture deficiencies, crop injury, and greater potential for herbicide resistance. In full—season soybeans, we generally recommend spraying glyphosate or other herbicides at the V3 to V4 soybean stage (about 4 to 6 weeks after planting) because common annual weeds that emerge with the crop won’t reduce yield if removed by this time. This assumes weeds were controlled with a burndown treatment or with preplant tillage. Weeds that have a week, or two, or more head start on soybeans will need to be controlled earlier.

Common lambsquarters has become a particular problem in soybean. Control with glyphosate seems to be a particular problem because of later applications and large less susceptible weeds. Glyphosate resistance is suspected in a number of fields in soybean, so making timely application is even more important to help rule out other causes of failure. The standard rate of 0.75 lb ae/acre glyphosate (22 oz Roundup Weathermax/Original Max or 24 oz Touchdown Total, Glyphomax XRT/Durango, or 32 oz Credit, Gly–4, Glyfos, Gly Star, Honcho, etc.) is intended to kill lambsquarters up to 6 inches tall, not 24 inches tall. In addition, if the spray boom height is 18 to 24 inches tall and the weeds are 24 inches tall, the upper and most active portion of the plant does not receive the herbicide spray. These two factors result in poor herbicide performance. Remember that larger more mature weeds generally have thicker leaf cuticle, are better established, and are much more difficult to kill. Control of larger weeds may require a higher herbicide rate and/or a different herbicide program. Weeds that survive the herbicide application and produce seeds, could lead more quickly to herbicide tolerance/resistance. Timely post applications to small more susceptible weeds allow lower herbicide rates and generally results in satisfied customers.

PA Five Acre Corn Club — Andrew Frankenfield, PSU Montgomery County Educator

Now is the time to get signed up for the Pennsylvania Five Acre Corn Club if you haven’t already. The purpose of the program is two—fold. First to increase management skills of corn producers in the state by looking at the details of what it costs to grow an acre of corn at maximum production. And second, to recognize top PA growers in the state and highlight the methods they used to achieve the yields they harvested. If you want to participate in the program this season, you need to complete the application form and return it prior to the July 1 deadline. Enrollment forms can be found online at http://cornandsoybeans.psu.edu The entry fee of $20.00 needs to be submitted with the registration form by the deadline. If you plan to enter, you might want to ask your seed company representative to sponsor the fee since many of them will.

Also, if you plan to enter the similar contest sponsored by the National Corn Growers Association, you can use the same field that you use for the State test as long as the National harvest method is used. And while we are talking about contests, don’t overlook the PA Soybean Contest. The top winner in PA receives a trip to the commodity classic, all expenses paid! All three of these programs give you the chance to see the management techniques and crop inputs used for maximum production. They don’t involve a lot of your time and the outcome is very interesting when you're shooting for top yields.

Scouting for Potato Leafhopper — Del Voight, PSU Lebanon County Educator - (Adapted from Dr. Marlin Rice Iowa State University)

Scouting for potato leafhoppers is an easy and reliable way to prevent serious yield loss. Scouting involves two components: estimating the density of potato leafhoppers and comparing this estimate to an economic threshold. Scouting should begin now and continue until populations decline in late summer. We recommend using a sweep net to estimate the density of leafhoppers in a field. Swing the net like a clock pendulum in front of you as you walk through the alfalfa. Be sure the net goes as deep in the alfalfa canopy as possible, and stop after 10 sweeps through the canopy. Count all of the adults in the net; most will be collected in the bottom of the net. This number is an estimate of leafhoppers per 10 sweeps. Confidence in your estimate will increase if you repeat this procedure in different places in the field and average the 10—sweep estimates. Also, while sweeping estimate the height in inches of the alfalfa canopy. The next step is to compare the estimate of the leafhoppers to the economic threshold.

An economic threshold is a pest density that, if the alfalfa is left unsprayed, will cause yield loss greater than the cost of an insecticide treatment. Thus, the gain in yield from spraying an insecticide is greater than the cost of the insecticide treatment. There are three factors to consider when determining the correct economic threshold. First, know whether you are scouting leafhopper—tolerant alfalfa or traditional alfalfa. It takes about 10 times more leafhoppers in an established stand of tolerant alfalfa to cause the same amount of loss in traditional alfalfa. Therefore, these alfalfa types have different economic thresholds. Second, estimate the height of the alfalfa when scouting for potato leafhoppers. Taller alfalfa is damaged less by the leafhopper than shorter alfalfa. Third, estimate the cost per acre of an insecticide treatment. Using these three variables and the tables provided herein you can calculate the correct economic threshold.

Tables 1 and 2 show the economic thresholds for traditional— and potato—leafhopper—tolerant alfalfa, respectively. The numbers represent the average catch of potato leafhoppers per 10 sweeps.

Table 1. Economic thresholds (potato leafhoppers per 10 sweeps) for potato leafhopper on traditional alfalfa.
Cost of Insecticide treatment ($)
Alfalfa height 10 12 14 16 18
(inches)
4 2 3 4 5 6
6 3 5 6 8 9
8 4 6 8 10 12
10 5 8 10 13 15
>10 10 16 20 26 30
Table 2. Economic thresholds (potato leafhoppers per 10 sweeps) for potato leafhopper on tolerant alfalfa.
Cost of Insecticide treatment ($)
Alfalfa height 10 12 14 16 18
(inches)
4 21 30 41 50 60
6 32 46 62 76 90
8 42 61 82 101 120
10 53 76 103 126 150
>10 106 152 206 252 300

VERY IMPORTANT: Use the threshold for traditional alfalfa when scouting tolerant alfalfa during the initial growth interval of the seeding year.

Management of potato leafhoppers

Harvesting alfalfa can eliminate leafhopper eggs already laid in stems, suppress the nymphal population by killing or removing them from the field, and displace adult leafhoppers to adjacent sources of food. Combined, these effects slow the growth of leafhopper populations. However, adjusting the harvest schedule to suppress leafhopper populations below the economic threshold usually is not justifiable. Using this tactic alone can increase the harvest frequency and can compromise forage quantity and stand persistence.

Another preventive tactic that suppresses potato leafhopper populations is planting alfalfa and grass mixtures. Grass is a poor food source for this leafhopper and research has shown that its populations are smaller in these mixed forage systems. In this instance, suppressing the leafhopper population comes with a cost——the grass component will lower the overall forage quality. Producers should consider forage use and desired forage quality before using this tactic alone to suppress leafhopper populations.

Applying an insecticide is the most reliable way to suppress a potato leafhopper population that has exceeded the economic threshold. The use of an insecticide is justified only if the field has been scouted and the leafhopper density exceeds its economic threshold. Labeled insecticides and the minimum manufacturer rates are listed in Table 3.

Pokeweed Management — Bill Curran, PSU Weed Specialist

(The following article was adapted from an article written by Glenn Nice, Bill Johnson, and Tom Bauman at Purdue University).

Pokeweed again is a problem in many of our corn and soybean fields, especially in the southeastern part of the state. Here are a few reminders about this prevalent problematic weed.

Control of this weed is fairly difficult with single postemergence herbicide treatments and multiple tactics are often necessary. Regardless of the crop or herbicide treatment, make sure the spray boom height is up above the pokeweed and use spray tips and a carrier volume (i.e. > 10 GPA) to maximize coverage.

Control of pokeweed in emerged corn.
Field studies by researchers at Southern Illinois University (SIU) reported common pokeweed control in corn was 90% or better with Lightning, dicamba (Banvel, Clarity, Sterling), Celebrity Plus, or Callisto (3 oz/A). Other effective treatments for non-transgenic corn include Northstar, Yukon, Distinct (4 to 6 oz/A) or Status (5 oz/A), and dicamba + Spirit. Apply when plants are less than 12 inches tall if possible. In Roundup Ready corn, use glyphosate (0.75 lb ae/A) when plants are at least 8 inches tall and make a second application if necessary.

Control of pokeweed in emerged soybeans
In the same SIU report, glyphosate controlled pokeweed 88% or higher. Control was increased when glyphosate was tank mixed with FirstRate or Synchrony STS in soybean. FirstRate and Synchrony STS alone provided 68 and 38% control. In contrast, I observed some positive results last year in a PA soybean field sprayed with Synchrony STS, so other factors (application timing, boom height, etc.) may also play a role in successful control. In Roundup Ready soybeans use at least 0.75 lb ae/A applied when pokeweed plants are at least 8 inches tall. Make a second application if necessary. In soybeans that are not Roundup Ready, use Synchrony STS (0.5 oz/A) or Classic + Harmony GT tank mixes. FirstRate may also be a potential choice, but additional evaluation results are necessary to better understand its potential for pokeweed control.

Register Now for the Rock Springs Weed Control Tour, July 10, 2007 — Bill Curran, PSU Weed Specialist

Attend the Annual Weed Control Research Tour at Penn State — July 10, 2007 at the PSU Agronomy Research Farm, Rock Springs, PA (Meet at the Agronomy Farm, Rock Springs, Rt. 45 west of State College). A number of experiments will be showcased and available for viewing including weed control in corn, soybean, oats, sweet corn, and snap bean plus the latest information on herbicide resistance, and cover cropping and weed management. This field day will focus on the latest herbicide technology. Pest Management CCA CEU's will be available.

Agenda:
9:00 am – Registration
9:15 am –12:00 noon – Tour
12:00 noon – 1:00 pm – Catered lunch

Registration for this event will be $15.00 and includes lunch and a tour book. You must pre register with Lisa Crytser at Penn State to ensure you have a spot at lunch and on the wagons. Registration Deadline — July 6, 2007 by phone (814–865–2543) or email (lac8@psu.edu).

Upcoming Events:

Small Grains Field Day
June 20, 2007
Wednesday, 9:30–2:00
Penn State Rock Springs Agronomy Farm, Centre Co.
Cost: $10
Lunch and handouts will be provided.

This field day will showcase our winter wheat and winter barley variety trials, weed control issues and no—till small grain management efforts on the research farm. We will also be addressing crop insurance issues related to quality in small grains and will be reviewing some of the work with winter and spring canola on the farm this year. Certified Crop Advisor CEU’s will be available at this event.

You must pre register with Lisa Crytser at Penn State to ensure you have a spot at lunch and on the wagons. Please pre—register by phone (814–865–2543) or download a brochure at http://smallgrains.psu.edu/ Credit card registrations will be accepted.

American Forage and Grassland Conference
June 24–26 — in State College
For more information check out http://www.afgc.org/mc/page.do?sitePageId=42837&orgId=afgc

Combined Agronomy Industry / Manure, Crops, Pests & No—till Field Day
Penn State Landisville Research Farm
Friday July 6th, 9:00 AM–3:30 PM
Topics will include: Weed Management in No—till; Composting: Mortality and Nutrient Recycling; Nutrient Balance Sheet and Act 38; Farm Bill and Bio—Fuels Updates;
Herbicide Trials and Chemical Industry Updates; and Cover Crop Management. Featured equipment: No—till equipment of all types: Planters, Drills, Residue Managers.
Manure handling and spreading equipment with demonstrations (water only.)
Registrations: Lancaster Extension, 717–394–6851 $3.00 in advance, $5.00 at the door
Questions? Jeff Graybill 717–394–6851. Landisville Research Farm, Dr. Dave Johnson 653-4728

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

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

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

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

Ag Progress Days — August 14–16

Contributors: Dept. Crop & Soil Sciences: Marvin Hall, Dwight Lingenfelter, Paul Knight County Extension: Paul Craig (Dauphin), Andrew Frankenfield (Montgomery), Mena Hautau (Berks), Kevin Fry (Armstrong), Dave Messersmith (Wayne), Lee Miller (Beaver County), Thomas Murphy (Lycoming) Susan Alexander (Jefferson), Del Voight (Lebanon) and Mark Madden (Sullivan/Bradford)

Editor: Andrew Frankenfield, Montgomery County Extension

Upcoming Events

Real time pest and heat unit activity: http://psu.zedxinc.com/cgi-bin/site.cgi?location=2&user=psu#

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

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If you have problems subscribing or wish to cancel your subscription, please contact Lisa Crytser by e-mail at lac8@psu.edu or by phone at 814-865-2543.

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